Renal Complications Of Sickle C ell D isease

1. Renal Complications Of Sickle Cell Disease Presenter : Unit V Moderators : Prof Chintu Dr Chunda

2. 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

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4. Fig showing a Nephron

5. Paediar Drugs 2002;4(1)

6. 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

7. Cont…. • 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

8. 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 • Drugs such as hydroxyurea and recombinant human erythropoetin increase the percentage of fetal haemoglobin in pts with SCD and may reduce sickling

9. Cont… • Haematuria of a renal sickling crisis • Bedrest • Increased fluid intake • Urine alkalanisation • Oxygen therapy • Blood transfusion • Noninvasive procedures • Invasive procedures

10. Glomerular abnormalities • Exact pathogenesis of glomerular lesions still remains to be defined • A number of potential etiologic factors exist • Mesangialphagocytosis of sickled cells • Immune complex glomerulonephritis • Glomerular injury caused by hyperfiltration and glomerular hypertrophy

11. 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

12. 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

13. 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 juxtamedullarynephrons is also impaired

14. 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

15. 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 atleasttwo 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

16. 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

17. 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.

18. Thank you