Idiopathic refractory ascites after allogeneic stem cell transplantation: a previously unrecognized entity.

At our center, we observed a series of patients who developed transudative refractory ascites secondary to noncirrhotic, non-veno-occlusive disease (VOD)-related portal hypertension after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients were considered to have idiopathic portal hypertension-related refractory ascites (IRA) if they developed ascites secondary to intrahepatic portal hypertension (serum ascites albumin gradient >/=1.1 g/dL or hepatic venous pressure gradient [HVPG] >5 mm Hg), but did not meet the clinical criteria for classical VOD/sinusoidal obstructive syndrome (SOS) and did not have any alternate etiology of portal hypertension. From our institutional database, we identified 40 patients who developed IRA after allo-HSCT between 2004 and 2018. The patients' median age at the time of allo-HSCT was 54 years (range, 21-73 years). The median time to development of IRA after allo-HSCT was 80 days (range, 16-576 days). The median number of paracentesis was 3 (range, 1-11), and 15 (38%) patients had an intraperitoneal catheter placed for continued drainage of the rapidly accumulating ascites. Portal pressures were measured in 19 patients; 6 (15%) had moderate portal hypertension (HVPG 6-9 mm Hg), and 13 (33%) had severe portal hypertension (HVPG >/= 10 mm Hg). Liver biopsy was performed in 24 patients. None of the patients met the criteria for classical VOD/SOS (clinical/histological) or cirrhosis (histological). The cumulative incidence of nonrelapse mortality was 63%, and the median survival duration after the development of the IRA was 7 months (range, 0.8-125.6 months). IRA is a poorly understood and often fatal complication of allo-HSCT.