Download Renal abnormalities in sickle cell disease Patients

RENAL COMPLICATIONS OF SICKLE
CELL DISEASE
Presenter
:
Unit V
Moderators
:
Prof Chintu
Dr Chunda
INTRODUCTION
Many structural and functional abnormalities of
the kidney are observed in patients with sickle
cell anaemia and the related hemoglobinopathies
 The environment of the renal medulla is
characterized by acidosis, hypertonicity and
hypoxia
 These factors tend to promote HB S
polymerisation and red cell sickling, thereby
making this part of the kidney susceptible to
changes in oxygen delivery

lower-back-pain-toolkit.com
FIG SHOWING A NEPHRON

Paediar Drugs 2002;4(1)
HAEMATURIA
Painless, symptomless, benign and self limited
 May also be haemorrhagic in nature and
difficulty to control
 Challenges concerning haematuria in pts with
SCD

To determine whether the condition is related to the
presence of sickling or of a tumour
 How to stop the massive blood loses

CONT….
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
Pathogenesis of haematuria is due to vascular
obstruction in the renal medulla by sickled red
blood cells, with consequent extravasation blood
cells
There is destruction of the vasa recta, small
successive infarctions occur eventually causing
renal papillary necrosis
CONT…

Objective of treatment of haematuria
should be to prevent or reverse sickling,
 to prevent clot retention in urinary tract,
 increase tissue oxygenation
 Reduce acidosis and hypertonicity in the medulla
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
Drugs such as hydroxyurea and recombinant
human erythropoetin increase the percentage of
fetal haemoglobin in pts with SCD and may
reduce sickling
CONT…

Haematuria of a renal sickling crisis
Bedrest
 Increased fluid intake
 Urine alkalanisation
 Oxygen therapy

Blood transfusion
 Noninvasive procedures
 Invasive procedures

GLOMERULAR ABNORMALITIES
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
Exact pathogenesis of glomerular lesions still
remains to be defined
A number of potential etiologic factors exist
Mesangial phagocytosis of sickled cells
 Immune complex glomerulonephritis
 Glomerular injury caused by hyperfiltration and glomerular
hypertrophy

CONT…
Treatment considerations
 Control hypertension and proteinuria with ACE
inhibitors
 Symptomatic treatment of nephrotic syndrome
 Avoid nephrotoxic drugs(NSAIDs,
aminoglycosides)
 Attention to dehydration, thrombosis and
infection

TUBULAR DYSFUNCTION
Renal tubules are more affected in SCA as
compared to the SCT
 Progressive loss of ability to concentrate urine is
the most common renal manifestation in sickle
cell disease
 During childhood this defect maybe reversible
with blood transfusion

CONT…


Aetiology of the concentration defect is probably
difficulty in maintaining a urea gradient in the
medulla necessary to reabsorb water, due to
destruction of the vasa recta by sickled red cells
Bicarbonate reabsorption which occurs in
juxtamedullary nephrons is also impaired
CONT…
Treatment considerations
 Blood transfusion can reverse this defect until
the age of 15yrs
 Instruct patient to increase fluid intake during
physical exercise or in increased
temperature(fever or summer)
 Treat diarrhoea and dehydration promptly

RENAL FAILURE
Acute renal failure may occur as part of the
multiorgan failure syndrome in pts with SS
 Manifest by sudden onset of severe dysfunction of
atleast two major organ systems(i.e. lung, liver
and kidney) in a setting of an acute sickle cell
pain episode
 Pathophysiology of MOFS maybe due to diffuse,
microvascular occlusion and tissue ischaemia
with subsequent organ dysfunction

CONT…
Chronic renal failure is not a frequent condition
in pts with SCA but the most feared renal
complication because of its severity and
consequences for affected individuals
 Renal dialysis and renal transplant should be
considered in patients with ESRD

CONCLUSION

Despite the various treatment modalities, the
true prevention for sickle cell nephropathy as
well as all other complications of sickle cell
disease ultimately depends upon the
development of an early cure for this genetic
disorder.
Thank you