Clinical implication of renal dysfunction during the clinical course in patients with paroxysmal nocturnal hemoglobinuria: a longitudinal analysis

Although renal dysfunction at the time of diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) is a risk factor for mortality, subsequent renal events can occur. The objective of this study was to identify clinical implication of renal dysfunction occurring during the disease course in PNH patients. One hundred one patients with a granulocyte clone size of > 10% were enrolled. Renal events were observed in 55 (54.5%) patients during a median follow-up of 94.2 months. Median time to first renal event from diagnosis of PNH was 79.3 months. Thromboembolism (TE) event and recurrent TE events were observed in 25 (24.8%) and 8 (7.9%) patients, respectively. The rate of recurrent TE was significantly higher in patients with renal events ≥ 2 compared with that in patients with renal event ≤ 1 (18.8% vs. 2.9%; P = 0.012). The rate of recurrent TE was significantly higher in patients with chronic kidney disease (CKD) + acute kidney disease (AKD) compared with the rest of the patients (27.3% vs. 5.6%; P = 0.040). CKD+AKD was the only independent risk factor for OS in multivariate analysis (hazard ratio 7.95, 95% CI 1.24–51.15, P = 0.029). Therefore, close monitoring of renal events in PNH patients during the entire clinical course is essential.