Renal involvement in paroxysmal nocturnal haemoglobinuria: a brief review of the literature.

Introduction: Paroxysmal Nocturnal Haemoglobinuria (PNH) is an acquired genetic disorder characterized by complement-mediated haemolysis, thrombosis and variable cytopenias. Renal involvement may occur and causes significant morbidity to these patients.

Objective: To review the literature about pathophysiology and provide recommendations on diagnosis and management of renal involvement in PNH.

Methods: Online research in the Medline database with compilation of the most relevant 26 studies found.

Results: PNH may present with acute kidney injury caused by massive haemolysis, which is usually very severe. In the chronic setting, PNH may develop insidious decline in renal function caused by tubular deposits of hemosiderin, renal micro-infarcts and interstitial fibrosis. Although hematopoietic stem cell transplantation remains the only curative treatment for PNH, the drug Eculizumab, a humanized anti-C5 monoclonal antibody is capable of improving renal function, among other outcomes, by inhibiting C5 cleavage with the subsequent inhibition of the terminal complement pathway which would ultimately give rise to the assembly of the membrane attack complex.

Conclusion: There is a lack of information in literature regarding renal involvement in PNH, albeit it is possible to state that the pathophysiological mechanisms of acute and chronic impairment differ. Despite not being a curative therapy, Eculizumab is able to ease kidney lesions in these patients.