Download Laboratory Diagnosis of Specific Antibody

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Neonatal infection wikipedia , lookup

Acute lymphoblastic leukemia wikipedia , lookup

Vaccine wikipedia , lookup

Herd immunity wikipedia , lookup

Vaccination wikipedia , lookup

Childhood immunizations in the United States wikipedia , lookup

DNA vaccination wikipedia , lookup

Transcript
Clinical Chemistry 53:3
505–510 (2007)
Clinical Immunology
Laboratory Diagnosis of Specific Antibody
Deficiency to Pneumococcal Capsular
Polysaccharide Antigens
Axel Jeurissen,1† Leen Moens,1† Marc Raes,2 Greet Wuyts,1 Luc Willebrords,1
Kate Sauer,2 Marijke Proesmans,2 Jan L. Ceuppens,3 Kris De Boeck,2 and
Xavier Bossuyt1*
Background: Measurement of postimmunization antibody response to pneumococcal capsular polysaccharide
(caps-PS) is the standard method to identify deficiency
of antipolysaccharide antibody production. However, no
standardized criteria have been defined for classification
of patients into responders or nonresponders to caps-PS.
Methods: We vaccinated 37 healthy children and 39
healthy adults with Pneumovax® and measured the
anti– caps-PS antibody response to 5 serotypes. We also
measured antipneumococcal antibody titers in 82 patients with increased susceptibility to airway infection.
The ELISA was performed according to the 3rd-generation assay format.
Results: The lower 5th percentile (cutoff) concentrations
for the postimmunization antibody titer in healthy individuals were 0.67 mg/L, 0.45 mg/L, 0.46 mg/L, 0.31
mg/L, and 1.04 mg/L for serotypes 3, 4, 9N, 18C, and 19F,
respectively. In 96% of healthy individuals, antibody
responses higher than the cutoff concentration were
seen for at least 3 of the 5 serotypes. Nine of 82 patients
(11%) failed to mount an adequate antibody response
for at least 4 of the 5 serotypes tested, whereas only 1
control (1.3%) failed to do so.
Conclusion: The cutoffs for antibody responses to
caps-PS identified in this study appear useful for identi-
fying individuals with an inadequate response to vaccine.
© 2007 American Association for Clinical Chemistry
Infections caused by Streptococcus pneumoniae are an important cause of mortality and morbidity, particularly
among children and older adults and immunocompromised patients (1 ). Also of major concern is emerging
resistance of S. pneumoniae to antibiotic drugs (2 ). Phagocytes, complement, and specific antibodies to the capsular
polysaccharides (caps-PS) are important in the host defense against S. pneumoniae (3 ).
Pneumococcal caps-PS are polymers composed of repeating units of 2 to 5 different saccharide moieties. It has
long been known that anti– caps-PS antibodies provide
protection against invasive pneumococcal infection (3 ).
Reports have appeared of patients suffering from recurrent infections with encapsulated microorganisms with
normal antibody concentrations, but also with a specific
deficiency in the production of anti– caps-PS antibodies
(4, 5 ). Wasserman et al. estimated that 5%–10% of children referred for evaluation of recurrent infection suffer
from this syndrome (6 ). Javier et al. found this disorder in
23% of patients who underwent immunologic evaluation
for recurrent infection (7 ).
The deficient antibody response to caps-PS is determined by measurement of the anti– caps-PS antibody
concentrations after immunization with the 23-valent vaccine (Pneumovax®) (6 ). Assays in which the total antibody response is measured are commercially available,
but these assays have some disadvantages. These ELISAs
do not use all the absorption steps to remove nonfunctional antibodies. Antibodies to the cell wall polysaccharides (C-PS) are not functional, and they interfere with the
determination of serotype-specific antibodies. Absorption
of sera with C-PS reduces the mean concentrations of
anti– caps-PS antibodies by 15%– 84% and is incorporated
in most assays (8, 9 ). Absorption with 22F, which is
1
Laboratory Medicine, Immunology, University Hospital Leuven, Belgium.
2
Department of Pediatrics, University Hospital Leuven, Belgium.
3
Department of Internal Medicine, Allergy, University Hospital Leuven,
Belgium.
† These authors contributed equally to this study.
* Address correspondence to this author at: Laboratory Medicine, Immunology, GHB-Herestraat 49, B-3000 Leuven, Belgium. Fax 32-16-34-79-31;
e-mail [email protected].
Received September 15, 2006; accepted December 28, 2006.
Previously published online at DOI: 10.1373/clinchem.2006.080051
505
506
Jeurissen et al.: Specific Antipolysaccharide Antibody Deficiency
thought to remove cross-reactive antibodies (10 ), is not
used in current commercially available assays. In addition, the diversity in immunogenicity between the different serotypes may lead to domination of the overall
antibody response by high antibodies to a single serotype,
despite a possible deficiency in the antibody response to
serotypes that are less immunogenic (11 ). Reference intervals for an assay that is based on the detection of antibodies
to a mixture of 23 serotypes have recently been published
(12 ). For children ⬍4 years of age, the lower reference limit
was less than the detection limit of the assay.
Several investigators have evaluated the immune response to individual pneumococcal polysaccharide serotypes (13–21 ), but some issues remain unsolved. Because
the polysaccharide pneumococcal vaccine contains 23
serotypes, defining the serotype antibody responses to be
measured is a major concern, and no reliable data are
available on cutoff values. Most studies use the same cutoff
concentration for all serotypes despite differences in immunogenicity. Finally, guidelines for interpreting the global
antibody response to caps-PS have not been validated.
The present study was undertaken to determine reference (cutoff) values for the serotype-specific antibody
response to caps-PS and to validate criteria for defining
patients with a defect in the antibody response to caps-PS.
Materials and Methods
materials
Pneumovax® was obtained from Aventis Pasteur MSD.
Pneumococcal caps-PS of serotypes 3, 4, 9N, 14, 18C, 19F,
and 22F were obtained from ATCC. C-PS was from
Statens Serum Institute. NaCl 9 g/L was from Braun
Medical NV./SA. Peroxidase-conjugated goat-antihuman
IgG was from Nordic Immunological Laboratories. Goat
serum and phosphate-buffered saline (PBS; 2.67 mmol/L
KCl, 1.47 mmol/L KH2PO4, 137.93 mmol/L NaCl, 8.06
mmol/L Na2HPO4 –7H2O) were from Gibco BRL, Life
Technologies Ltd. Polyoxyethylenesorbitanmonolaurate
(Tween 20) and TMB (3,3⬘-5,5⬘-tetramethylbenzidine)
were from Sigma-Aldrich NV/SA. H2SO4 solution was
from Merck KgaA. Covalink NH and Maxisorp 96-well
ELISA plates were obtained from NUNC Brand Products,
Nalge Nunc International.
determination of type-specific
antipolysaccharide antibodies
Serum antibody concentrations to 5 pneumococcal serotypes (3, 4, 9N, 18C, and 19F) were measured by ELISA 3
weeks after immunization with Pneumovax. Covalink
NH ELISA (for serotype 3) and Maxisorp 96-well ELISA
plates (Nunc) (for serotypes 4, 9N, 18C, and 19F) were
coated overnight at 37 °C with 100 ␮L pneumococcal
polysaccharide (final concentration 3.3 mg/L in NaCl, 9
g/L). After coating, the plates were washed 4 times with
200 ␮L of 0.5 mL/L Tween 20 in PBS. Thereafter, the
plates were blocked for 1 h at 37 °C with 100 ␮L 100 mL/L
goat serum in PBS per well. Serum was diluted 200-fold in
absorption solution containing PBS with 20 mL/L goat
serum, C-PS (5 mg/L), and caps-PS 22-F (5 mg/L).
Thereafter, five 2-fold serial dilutions were prepared in
absorption solution. The diluted samples were incubated
for 30 min at room temperature. We added 50 ␮L of the
diluted serum samples to each well and incubated for 2 h
at 37 °C. After 4 washes with 200␮L of 0.5 mL/L Tween 20
in PBS, peroxidase-conjugated goat antihuman IgG in a
1/5000 dilution was added to the wells. The plates were
incubated for 1.5 h at 37 °C. After 4 washes with 200␮L of
0.5 mL/L Tween 20 in PBS, 100 ␮L TMB was added for
color development. After 30-min, the reaction was
stopped by adding 100 ␮L of 0.5 mol/L H2SO4 to each
well. Thereafter, plates were read at 450 nm. Absorbance
data were converted to antibody concentrations with the
computer program CDC ELISA (Plikaytis BD, Holder PF,
Carlone GM, Program ELISA for Windows, version 09/
27/2004, US Department for Health & Human Services),
which uses a 4-parameter logistic-log method to perform
a curve-fitting procedure. As a reference (standard), the
US Pneumococcal Reference Serum Lot 89-SF was used.
The ELISA described above is based on the 3rdgeneration assay format (22 ) (absorption with C-PS and
caps-PS 22-F) with some modifications. We initially performed the assay described by Wernette et al. (22 ) using
conventional polystyrene microtiter plates (Maxisorp) for
all serotypes. This method displayed a bad linearity for
measurement of antibodies to serotype 3, as shown in Fig.
1 in the Data Supplement that accompanies the online
version of this manuscript at http://www.clinchem.org/
content/vol53/issue3. Linearity for serotype 3 was appreciably improved by using the assay described above, in
which the method of Sanders et al. (16 ) was applied using
Covalink NH 96-well plates. A linearity analysis for this
assay is shown in Fig. 2 in the online Data Supplement. In
the assay described by Sanders et al. (16 ), coating was
performed overnight in NaCl 9 g/L at 37 °C, whereas in
the protocol of the 3rd generation assay format (22 )
(described in http://www.vaccine.uab.edu), coating was
performed in PBS for 5 h at 37 °C, and the plates were
stored at 4 °C. The assay of Sanders et al. (16 ) used a
peroxidase-labeled antihuman antibody, whereas the
method of Wernette (22 ) used an alkaline-phosphataseconjugated antibody. Fig. 3 in the online Data Supplement
shows the correlation between the assay of Wernette and
the assay described in this protocol.
The ELISA was performed in 2005–2006 by 2 experienced (⬎10 years) technologists who were not blinded to
the results of the other test. Outliers were not excluded.
The sera were frozen before analysis.
control and patient populations
We examined the antibody response of 37 child and 39
adult controls (recruited between 2000 and 2005) and 82
consecutive patients (recruited between 2000 and 2003)
who were referred to our institution because of recurrent
infections of the upper and lower airways. Recurrent
507
Clinical Chemistry 53, No. 3, 2007
Table 1. Median values, 5th and 25th to 75th percentile for the antibody responses to caps-PS in control individuals
Caps-PS3
Caps-PS4
Caps-PS9N
Caps-PS18C
Caps-PS19F
All
Childrena
Adults
All
Childrena
Adults
All
Children
Adults
All
Children
Adults
All
Children
adults
5th percentile, mg/L
Median, mg/L
25th–75th percentile, mg/L
0.67
0.99
0.58
0.45
0.73
0.37
0.46
0.78
0.23
0.31
0.55
0.31
1.04
1.66
0.91
4.5
5.4
2.9
3.8
5.7
2.9
4.8
5.4
4.4
4.3
3.8
4.9
5.7
6.4
4.4
2.1–8.5
3.6–9.5
1.6–6.0
2.1–8.4
2.9–10
1.2–5.0
2.5–10
2.7–9.6
1.9–11
1.6–8.6
1.3–5.8
1.9–9.3
2.6–15.6
3.8–15.9
2.0–15.4
a
Statistically significantly different from adults (Mann-Whitney U-test).
Thirty-seven child and 39 adult controls were immunized with Pneumovax, and antibody titers were measured against serotypes 3, 4, 9N, 18C, and 19F.
infections of the upper respiratory tract were defined as at
least 5 episodes (in a 1-year period) of upper respiratory
tract infections complicated by otitis media or chronic
(longer than 3 weeks duration) draining ears. Recurrent
infection of the lower respiratory tract was defined as at
least 3 lower respiratory tract infections in a 1-year period
with radiographic evidence of pneumonia in at least 2 of
these periods. The age distribution of the child controls
was 1, 8, 12, and 16 for the age groups, 3– 4, 5– 6, 7–9, and
10 –15 years. No children aged ⱕ2 years were included in
the control group. The adults were healthy students 19 –30
years of age (median 21 years of age). The age distribution
of the patient group was 46, 17, 11, and 8 for the age
groups 3– 4, 5– 6, 7–9, and 10 –23 years. No individuals
were excluded from the tests.
Approval of the study was granted by the local ethical
committee of the Catholic University Leuven.
statistical methods
Differences in antibody responses between the adult and
the child controls and between the different age groups
were evaluated by use of Kruskall-Wallis ANOVA with
posthoc Mann–Whitney tests (and Bonferoni adjustment).
A ␹2 test was performed when indicated. Passing and
Bablok analysis was performed to evaluate linearity.
Statistical analysis was performed with Analyze It for
Excel (version Windows 2003).
Results
imprecision of the assay for quantification of
serotype-specific antibodies
Estimates of interrun imprecision (as CV, n ⫽ 17–20 runs
per serotype) were 9%, 6%, 18%, 8%, and 8%, for, respectively, serotypes 3, 4, 9N, 18C, and 19F at concentrations
of 1.6, 9.9, 1.1, 1.2, and 7.7 mg/L.
postvaccination antibody titers in controls.
cutoff concentrations for antibodies to
serotypes 3, 4, 9n, 18c, and 19f
Table 1 shows anti– caps-PS antibody concentrations to
serotypes 3, 4, 9N, 18C, and 19F in 39 adult controls and
37 healthy children immunized with Pneumovax®. Table
1 of the on-line Data Supplement shows reference values
(n ⫽ 72) for serotype 14. For serotype 3 and serotype 4,
antibody concentrations in children were higher than in
adults (P ⫽ 0.008 Mann–Whitney U-test).
We evaluated age-dependent differences in the ability
to develop antibodies against different polysaccharides
(14 ). In children ⬍16 years of age, no statistically significant difference was observed among age groups (Table 2).
A serotype-specific response below the 5th percentile
(Table 1) was defined as an inadequate response.
With a cutoff concentration for the total group (adults
and children), 67 (88%) of the 76 controls responded
adequately to all 5 serotypes. One (1%) adult did respond
adequately to only 1 serotype. Two (3%) individuals (1
child and 1 adult) did not respond adequately to 3 of the
5 serotypes, 4 (5%) (all adults) did not respond adequately
to 2 of the 5 serotypes, and 2 (3%) (1 child and 1 adult) did
not respond adequately to 1 serotype. The results of the
controls who did not respond to 1 or more of the 5 tested
serotypes are shown in Table 3. In the total control group,
all individuals responded adequately to 5 serotypes.
evaluation of the anti– caps-ps antibody
response in individuals referred to our
institution for measurement of caps-ps
antibodies
The antipolysaccharide antibody concentrations after vaccination with Pneumovax in 82 patients referred to our
institution for measurement of anti– caps-PS antibodies in
508
Jeurissen et al.: Specific Antipolysaccharide Antibody Deficiency
Table 2. Age-dependent anti– caps-PS antibody concentrations
Antibody concentration: median (25-75th percentile), mg/ L
Age (years)
Serotype
Caps-PS3
Caps-PS4
Caps-PS9N
Caps-PS18C
Caps-PS19F
5–6 (n ⫽ 8)
8.9 (4.3–18.2)
4.6 (3–8.8)
4.3 (1.6–8.4)
1.6 (0.8–4.3)
4.5 (2.4–7.8)
7–9 (n ⫽ 12)
5.1 (4.4–8.7)
7.6 (4.4–10.1)
7.7 (4.1–10)
4.7 (2.2–7.5)
6.2 (4.0–18.2)
10–15 (n ⫽ 16)
4.1 (1.8–9.6)
3.9 (2.2–10.2)
4.8 (2.3–7.0)
3.5 (1.3–8.6)
9.7 (5.2–31)
⬎18 (n ⫽ 39)
2.9 (1.6–6)
2.9 (1.2–5.1)
4.4 (1.9–10.9)
4.7 (1.9–9.3)
4.4 (2.0–15.4)
Thirtyseven child and 39 adult controls were immunized with Pneumovax, and antibody titers were measured against serotypes 3, 4, 9N, 18C, and 19F. The
anti– caps-PS antibody concentrations were classified according to age. The values found in 1 child 3 years of age were 10.4 mg/L, 45.1 mg/L , 19.1 mg/L, 12 mg/L,
and 6.4 mg/L for serotype and 3, 4, 9N, 18C, and 19F, respectively.
the context of evaluation of the humoral immune function
are shown in Table 3. The response to all 5 tested
serotypes tested was adequate in 48 (58%) of the 82
patients, whereas 34 (41%) had an inadequate response to
at least 1 serotype. Inadequate responses were seen in 16,
5, 4, 5, and 4 patients to 1, 2, 3, 4, and 5 serotypes,
respectively. This distribution was statistically different
from the distribution found in the control population (P ⫽
0.0007, ␹2). Nine patients (11%; 95% CI: 17.7%– 4.2%) had
a defective response to 4 or 5 serotypes, a condition
observed in only 1 (1.3%; 95% CI: 0%–3.8%) control
individual (P ⫽ 0.03, ␹2). The ages of these children were
3 years (n ⫽ 3), 4 years (n ⫽ 2), 5 years (n ⫽ 3), and 14
years (n ⫽ 1).
Table 2 in the on-line Data Supplement shows detailed
results for the patients and controls who did not react to
at least 1 of the 5 serotypes tested. For each serotype, 4
(5%) of 76 control individuals had an inadequate response, a rate that corresponded with the cutoff, which
was set at the 5th percentile. In the patient group, 8 (10%),
11 (13%), 17 (21%), 13 (16%), and 29 (35%) of individuals
did not react to serotype 3, 4, 9N, 18C, and 19F, respectively. These data suggest that the immune response to
serotype 19F is more sensitive than the immune response
to serotype 3 to detect an impaired antipolysaccharide
response. On the other hand, a defective immune response
to serotype 3 is more predictive for a general failure to react
Table 3. Controls and patients were vaccinated with
Pneumovax.
Number of serotypes
to which an inadequate
response was generated
Controls (n ⴝ 76)
Patients (n ⴝ 82)
0
1
2
3
4
5
67
2
4
2
1
0
48
16
5
4
5
4
Antipolysaccharide antibodies to 5 serotypes were measured 3 weeks after
vaccination. The table shows the number of patients and controls with an
inadequate response to 0, 1, 2, 3, 4, and 5 serotypes. The differences between
controls and patients were significant (P ⫽ 0.0007, ␹2).
to polysaccharide antigens. In many patients, an impaired
immune response to serotype 3 is accompanied by an
impaired immune response to other serotypes.
The patient group comprised a substantial number of
3-year-old children, which was not the case in the control
group. Therefore, we confirmed that the antibody concentrations found in the patient group of 3 and 4 years of age
were comparable to the antibody concentrations in the
patient group of ⬎4 years of age. The evidence is given in
the on-line Data Supplement, (Text 1).
Discussion
The main problem in the evaluation of the antibody
response to caps-PS is the lack of standardized criteria for
interpretation of the functional test. There is no consensus
about which serotypes of the 23-valent pneumococcal
vaccine should be tested. Different studies select different
serotypes and often it is not mentioned why particular
serotypes are tested (Table 4). We selected serotypes 3, 4,
9N, 18C, and 19F because they are among the most
frequently isolated serotypes in Belgium (23 ), and thus
analysis of the immune response to these serotypes is
relevant in Belgium.
Table 4. Serotypes tested in different studies.
Reference
Serotypes Measured
Ambrosino et al. (4 )
Epstein et al. (5 )
3, 6, 14, 23
1, 3, 4, 6A, 7F, 8, 9N, 12F, 14, 18C
19F, 23F
1, 3, 4, 6B, 9V, 14, 18C, 19F, 23F
3, 7F, 9N, 14
1, 3, 4, 6B, 9V, 14, 18C, 19F, 23F
3, 4, 6A, 9N, 14, 19F, 23F
3, 4, 6A, 9N, 14, 19F, 23F
3, 4, 5, 7F, 9V, 14, 18C, 6B, 19F, 23F,
1, 3, 4, 6A, 7F, 8, 9N, 12F, 14, 18C
19F, 23F
1, 3, 4, 6A, 7F, 8, 9N, 12F, 14, 18C
19F, 23F
3, 6A, 19F, 23F
1, 4, 5,6B, 9V, 14, 18C, 19F, 23F
3, 4, 9N, 18C, 19F
Javier et al. (4 )
Sorensen et al. (12 )
Sorensen et al. (13 )
Sanders et al. (15 )
Rijkers et al. (16 )
Esposito et al. (17 )
Zora et al. (18 )
Gigliotti et al. (19 )
Ekhdal et al. (20 )
Uddin et al. (25 )
This study
Clinical Chemistry 53, No. 3, 2007
Furthermore, there is no consensus about the cutoff
that should be used for each serotype and about the
number of serotypes to which a patient has to respond to
be classified as a responder or a nonresponder. Javier et al.
defined an abnormal response as a postimmunization
antibody concentration not reaching either 1.3 mg/L or a
4-fold increase above the preimmunization concentration
for at least 5 of the 9 serotypes (7 ). Epstein et al. considered a normal response a 2-fold or more increase in
antibody titer, or an absolute increase to ⬎0.3 mg/L in 8
or more of the 12 serotypes tested (5 ). Zora et al. used the
same criteria per serotype as Epstein et al., but considered
acceptable an antibody response to at least 6 of 12
measured serotypes (19 ). Sanders et al. defined a normal
response to caps-PS as a 2-fold or greater increase in
serum antibody titer and a postimmunization antibody
concentration of at least 20% (20 U/L) of a hyperimmune
plasma pool of healthy volunteers immunized with Pneumovax® (16 ). Nonresponsiveness was defined as nonresponsiveness to 5 or more of the 7 serotypes tested (16 ).
Gigliotti et al. and Ambrosino et al. described a patient
with a selective absence of IgG antibody response to all
the serotypes tested (4, 20 ). Ekhdal et al. expressed the
anti– caps-PS concentrations as geometric means. Patients
with geometric mean postvaccination antibody concentrations ⬍10% of the reference standard of the Statens
Seruminstitut (Copenhagen, Denmark) were designated
nonresponders (21 ). All patients tested did not respond to
any of the 4 serotypes tested (21 ). Finally, Wasserman et
al. stated that an adequate response to an individual
serotype should be defined as a 4-fold or higher increase in
serum antibody titer or a postimmunization antibody concentration of 1.3 mg/L or greater (6 ). Failure to respond
normally to ⬎50% of the serotypes tested should be considered abnormal (6 ). Taken together, several criteria are being
used to evaluate the anti– caps-PS antibody response. A
standardized evidence-based protocol is obviously lacking.
In our study, postimmunization antibody concentrations were compared with a hyperimmune plasma pool
standard (FDA US Pneumococcal Reference Serum Lot
89-SF), as was done in several previous studies (14, 16 )
and recommended by the guidance protocol for the
3rd-generation pneumococcal antibody ELISA (22 ).
The cutoff concentrations (5th percentile) determined in
our study varied between 0.31 and 1 mg/L. Esposito et al.
(18 ) suggested that IgG anticapsular antibody concentrations ⬎ 1 mg/L are required for protection for the
majority of the serotypes (particularly serotype 1 and 19),
whereas for serotype 4, an IgG antibody concentration of
ⱖ0.15 mg/L seems to be protective. Sorensen et al.
(13, 14 ) and Wasserman et al. (6 ) estimated a protective
concentration to be 1.3 mg/L, whereas Epstein (5 ) and
Zora et al. (19 ) suggested a protective concentration of 0.3
mg/L. Protective concentrations of anticapsular antibodies against bacteremia are serotype dependent. An antibody concentration of 0.35– 0.4 mg/L is generally considered to be sufficient for protection (24 ).
509
All individuals of our control population responded
well to at least 2 of the 5 tested serotypes except 1 adult
who responded to only 1 serotype. More of the patients
with a defect in the anti– caps-PS antibody response did
not respond to 4 or 5 of the 5 tested serotypes (n ⫽ 9). An
inadequate response to 4 or 5 of the 5 tested serotypes
indicates a specific antipolysaccharide antibody deficiency.
Our results also indicate that an inadequate response to
serotype 3 predicts unresponsiveness to other serotypes.
This finding has also been reported by Sorensen et al. (14 ),
who found that patients who failed to respond to serotype 3
at any age also failed to develop protective concentrations of
antibodies against the other serotypes.
Our reference values were obtained in a relatively
small number of control persons. Moreover, our reference
values in adults have been obtained with young adults,
and cannot be applied to old adults.
Bacterial capsular polysaccharides induce antibodies
primarily by T cell–independent mechanisms. Therefore,
antibody response to most pneumococcal capsular types
is generally poor or inconsistent in children aged ⬍2 years
whose immune systems are immature. This is the reason
why no children aged 2 years or less were included in the
control group. The cutoff concentrations proposed in this
manuscript are valid for children ⬎4 years of age. To
overcome the problem of nonresponsiveness in children
younger than 2 years, a conjugated vaccine (Prevnar®)
was developed. This contains 2 ␮g of serotype 4, 9V, 14,
18C, 19F, and 23F and 4 ␮g of serotype 6B. Use of the
conjugated vaccine will have an influence on the choice of
serotypes to diagnose specific anti– caps-PS antibody deficiency. Once a patient has been vaccinated with Prevnar,
the serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F can no
longer be used for antibody measurement, because the
evaluation would assess the response to protein antigens
rather than to polysaccharide antigens. For patients who
have previously been vaccinated with the conjugated
vaccine, other serotypes must be chosen. Uddin et al.
compared the total pneumococcal IgG antibody, IgG
subclass antibody titers, and serotype-specific antibody
concentrations (4, 6B, 9V, 14, 18C, 19F, 23F, 1, and 5) in
children who had received 2 doses Prevnar followed by a
dose of Pneumovax to evaluate the most useful assays in
clinical practice (25 ). They determined that children after
Prevnar vaccination produced mostly IgG1 antibodies in
contrast to the IgG2 antibody response to natural infection
with S. pneumoniae or pneumococcal polysaccharide vaccines. Uddin et al. concluded that serotype-specific IgGs
were useful in determining protection against specific
pneumococcal strains, and showed that Pneumovax did
not broaden protection against non-Prevnar serotypes
(25 ). The increased clinical use of Prevnar and possible
use of the next generation conjugated vaccines, such as
9-valent (26 –28 ) and 11-valent (29 ), will make it necessary
to determine the response to additional serotypes in the
future. On the other hand, potential new antigens for
vaccine formulations, such as the surface proteins PspA,
510
Jeurissen et al.: Specific Antipolysaccharide Antibody Deficiency
PspC, PsaA, pneumolysin, BVH-3, and BVH-11, will also
need the establishment of reference values.
In conclusion, we established reference intervals for the
specific antipolysaccharide immune response to 5 serotypes. Among 76 healthy controls (3–30 years of age), 75
adequately responded to at least 2 of these 5 serotypes,
and 73 (96%), of the controls responded to at least 3 of
these 5 serotypes. Patients who did not respond to at least
4 of the 5 serotypes were diagnosed as nonresponders.
X. Bossuyt is a senior clinical investigator of the Fund for
Scientific Research – Flanders (FWO-Vlaanderen).
References
1. Musher DM. Infections caused by Streptococcus pneumoniae:
clinical spectrum, pathogenesis, immunity, and treatment. Clin
Infect Dis 1992;14:801–9.
2. Davidson R, Cavalcanti R, Brunton JL, Bast DJ, De Azevedo JCS,
Kibsey P, et al. Resistance to levofloxacin and failure of treatment
of pneumococcal pneumoniae. N Engl J Med 2002;346:747–50.
3. Bruyn GAW, Zegers BJM, Van Furth R. Mechanisms of host
defense against infection with Streptococcus pneumoniae. Clin
Infect Dis 1992;14:251– 62.
4. Ambrosino DM, Siber GR, Chilmonczyk BA, Jernberg JB, Finberg
RW. An immunodeficiency characterized by impaired antibody
responses to polysaccharides. N Engl J Med 1987;316:790 –3.
5. Epstein MM, Gruskay F. Selective deficiency in pneumococcal
antibody response in children with recurrent infections. Ann Allergy
Asthma Immunol 1995;75:125–31.
6. Wasserman RL, Sorensen RU. Evaluating children with respiratory
tract infections: the role of immunization with bacterial polysaccharide vaccine. Pediatr Infect Dis J 1999;18:157– 63.
7. Javier JC, Moore CM, Sorensen RU. Distribution of primary immunodeficiency diseases diagnosed in a pediatric tertiary hospital.
Ann Allergy Asthma Immunol 2000;84:25–30.
8. Musher DM, Watson DA, Baughin RE. Does naturally acquired IgG
antibody to cell wall polysaccharide protect human subjects
against pneumococcal infection? J Infect Dis 1990;161:736 – 40.
9. Musher DM, Luchi MJ, Watson DA, Hamilton R, Baughn RE.
Pneumococcal polysaccharide vaccine in young adults and older
bronchitics: determination of IgG responses by ELISA and the
effect of absorption of serum with non-type specific cell wall
polysaccharide. J Infect Dis 1990;161:728 –35.
10. Concepsion NF, Frasch CE. Pneumococcal type 22F polysaccharide absorption improves the specificity of a pneumococcalpolysaccharide enzyme-linked immunosorbent assay. Clin Diagn
Lab Immunol 2001;8:266 –72.
11. Balmer P, North J, Baxter D, Stanford E, Melegaro A, Kacsmarski
EB, et al. Measurement and interpretation of pneumococcal IgG
levels for clinical management. Clin Exp Immunol 2003;133:
364 –9.
12. Schauer U, Stemberg F, Rieger CH, Büttner W, Borte M, Schubert
S, et al. Levels of antibodies specific to tetanus toxoid, Hemophilus influenzae type b, and pneumococcal capsular polysaccharide
in healthy children and adults. Clin Diagn Lab Immunol 2003;10:
202–7.
13. Sorensen RU, Hidalgo H, Moore C, Leiva LE. Post-immunization
pneumococcal antibody titers and IgG subclasses. Pediatric Pulmonology 1996;22:167–73.
14. Sorensen RU, Leiva LE, Javier FC, Sacerdote DM, Bradford N,
Butler B, et al. Influence of age on the response to Streptococcus
penumoniae vaccine in patients with recurrent infections and
normal immunoglobulin concentrations. J Allergy Clin Immunol
1998;102:215–21.
15. Hidalgo H, Moore C, Leiva LE, Sorensen RU. Preimmunization and
postimmunization pneumococcal antibody titers in children with
recurrent infections. Ann Allergy Asthma Immunol 1996;76:
341– 6.
16. Sanders LAM, Rijkers GT, Kuis W, Tenbergen-Meekes AJ, de
Graeff-Meeder BR, Hiemstra I, et al. Defective antipneumococcal
polysaccharide antibody response in children with recurrent respiratory tract infections. J Allergy Clin Immunol 1993;91:110 –9.
17. Rijkers GT, Sanders LA, Zegers BJ. Anti-capsular polysaccharide
antibody deficiency states. Immunodeficiency 1993;5:1–21.
18. Esposito S, Droghetti R, Faeli N, Lastrico A, Taglabue C, Cesati L,
et al. Serum concentrations of pneumococcal anticapsular antibodies in children with pneumonia associated with Streptococcus
pneumonia infection. Clin Infect Dis 2003;37:1261– 4.
19. Zora JA, Silk HJ, Tinkleman DG. Evaluation of postimmunization
pneumococcal titers in children with recurrent infections and
normal levels of immunoglobulin. Ann Allergy 1993;70:283– 8.
20. Gigliotti F, Herrod HG, Kalwinsky DK, Insel RA. Immunodeficiency
associated with recurrent infections and an isolated in vivo
inability to respond to bacterial polysaccharides. Pediatr Infect Dis
J 1988;7:417–20.
21. Ekhdal K, Braconier JH, Svanborg C. Impaired antibody response
to pneumococcal capsular polysaccharides and phosphorylcholine in adult patients with a history of bacteriemic pneumococcal
infection. Clin Infect Dis 1997;25:654 – 60.
22. Wernette CM, Frasch CE, Madore D, Carlone G, Goldblatt D,
Plikaytis B, et al. Enzyme-linked immunosorbent assay for quantitation of human antibodies to pneumococcal polysaccharides.
Clin Diagn Lab Immunol 2003;10:514 –9.
23. Verhaegen J, Van de Ven J, Van Eldere J, Verbist L. Evolution of
Streptococcus pneumoniae serotypes and antibiotic resistance in
Belgium – update (1994 –98). Clin Microbiol Infect 2000;6:308 –15.
24. Johnson SE, Rubin L, Romero-Steiner S, Dykes JK, Pais LB, Rizvi
A, et al. Correlation of opsonophagocytosis and passive protection assays using human anticapsular antibodies in an infant
mouse model of bacteremia for Streptococcus pneumoniae.
J Infect Dis 1999;180:133– 40.
25. Uddin S, Borrow R, Haeney MR, Moran A, Warrington R, Balmer P,
et al. Total and serotype-specific pneumococcal antibody titres in
children with normal and abnormal humoral immunity. Vaccine
2006;24:5637– 44.
26. Klugman KP, Madhi SA, Huebner RE, Kohberger R, Mbelle N,
Pierce N, et al. . A trial of a 9-valent pneumococcal conjugate
vaccine in children with and those without HIV infection. N Engl
J Med 2003;349:1341– 8.
27. Huebner RE, Mbelle N, Forrest B, Madore DV, Klugman KP.
Long-term antibody levels and booster responses in South African
children immunized with nonavalent pneumococcal conjugate
vaccine. Vaccine 2004;22:2696 –700.
28. Goldblatt D, Southern J, Ashton L, Richmond P, Burbidge P,
Tasevska J, et al. Immunogenicity and boosting after a reduced
number of doses of a pneumococcal conjugate vaccine in infants
and toddlers. Pediatr Infect Dis J 2006;25:312–9.
29. Capeding MZ, Puumalainen T, Gepanayao CP, Kayhty H, Lucero
MG, Nohynek H. Safety and immunogenicity of 3 doses of an
eleven-valent diphtheria toxoid and tetanus protein– conjugated
pneumococcal vaccine in Filipino infants. BMC Infect Dis 2003;3:17.