P0494UNUSUAL CASE OF ACUTE KIDNEY INJURY (HISTOLOGICAL EVALUATION: COLLAPSING GLOMERULOPATHY) IN HEMOPHAGOCYTIC SYNDROME ASSOCIATED WITH NK/T LYMPHOMA

Abstract Background and Aims Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome induced by aberrantly activated macrophages and cytotoxic T cells. The primary (genetic) form, caused by mutations affecting lymphocyte cytotoxicity and immune regulation, is most common in children, whereas the secondary (acquired) form is most frequent in adults. Secondary HLH is commonly triggered by infections or malignancies but may also be induced by autoinflammatory/autoimmune disorders, in which case it is called macrophage activation syndrome. The diagnosis of HLH in adults should be based on the HLH-2004 diagnostic criteria in conjunction with clinical judgment and the patient’s history. Renal involvement has previously been reported in 24 adult cases, mostly as acute renal failure. Collapsing glomerulopathy is extremely rare with only six previous cases reported in the literature. Case presentation We report the case of an African man, 31 years old, presented with fever, acute kidney injury: serum creatinine 10.3 mg/dl; urine protein 600 mg/dl, macrohematuria, ANA/ANCA were negative, low serum C3, organomegaly, anemia, thrombocytopenia, hypertriglyceridemia, hypofibrinogenemia, hyperferritinemia, direct and indirect antiglobulin (Coombs) tests were negative, low haptoglobin; elevated LDH; normal partial thromboplatin time. Peripheral blood smear examination reveal few schistocytes. ADAMTS13 activity was found to be 25%. HBV-DNA and HIV were negative. Anticardiolipin antibodies were negative. Lab exam suggested the relapse of an EBV infection and primary mycoplasma infection. Because of uremic symptoms and persisting oliguria we started replacement therapy by hemodialysis. Plasmapheresis was started because of suspected thrombotic microangiopathy. Suprisingly the kidney biopsy was consistent with collapsing glomerulopathy with evidence of tubular injury while the bone marrow biopsy diagnosed an EBV NK/T-Cell lymphoma. During the course of his hospitalization, the patient suffered high fever. C-reactive protein, WBC and procalcitonin levels were elevated. Antimicrobial agents were initiated, starting with ceftriaxone then upgraded to piperacillin/tazobactam and then the shifted to teicoplanin and meropenem. Blood, urine and stool cultures were negative.VRE positive, IgM Mycoplasma pneumoniae were positive; EBV PCR on bone marrow blood was positive. Malaria screening was negative. The antibiotic therapy was finally switched to doxycycline as unique agent. Steroid therapy (dexamethasone daily 40 mg) and IVIG (daily 35g) were initiated then these drug were stopped. CHOP-like regimen ( Etoposide 75 mg/m2, twice a week for two weeks then once a week until the seventh week) and Rituximab (375 mg/m2, once a week for 4 weeks) were initiated and continued for two weeks. Later on the patient died because of sepsis and multi-organ failure. Conclusions The multidisciplinary approach is very important. Physicians should be aware of HLH, because early recognition may prevent irreversible organ damage and subsequent death.4,5 In adults, HLH-associated mortality remains high, especially in patients with underlying malignancies. Collapsing glomerulopathy is the most commonly reported finding on renal biopsy. Renal prognosis appears to be poor with most patients remaining dialysis-dependent. The increased awareness of HLH, together with a more rapid diagnostic workup and new therapeutic approaches, will improve the prognosis of HLH in adults.