Teresa Cavero

Hematuria is a cardinal symptom in IgA nephropathy, but its influence on the risk of disease progression has been scarcely investigated. We followed a cohort of 112 patients with IgA nephropathy for a mean±SEM period of 14±10.2 years, during which clinical and analytic risk factors (including urine sediment examination) were regularly recorded. According to the magnitude of time-averaged hematuria, we classified patients as those with persistent hematuria and those with negative or minimal hematuria. We also classified patients according to the magnitude of time-averaged proteinuria (>0.75 or ≤0.75 g/d). The proportion of patients reaching ESRD or a 50% reduction of renal function was significantly greater among patients with persistent hematuria than patients with minimal or negative hematuria (30.4% and 37.0% versus 10.6% and 15.2%, respectively; P =0.01). Multivariable analysis revealed time-averaged hematuria, time-averaged proteinuria, renal function at baseline, and the presence of tubulointerstitial fibrosis on renal biopsy as independent predictors of ESRD. After hematuria disappearance, which occurred in 46% of the patients, the rate of renal function decline changed from −6.45±14.66 to −0.18±2.56 ml/min per 1.73 m 2 per year ( P =0.001). Patients with time-averaged proteinuria >0.75 g/d had significantly poorer renal survival than those with time-averaged proteinuria ≤0.75 g/d. However, on further classification by time-averaged hematuria, only those patients with time-averaged proteinuria >0.75 g/d and persistent hematuria had significantly worse renal survival than those in the other three groups. In conclusion, remission of hematuria may have a significant favorable effect on IgA nephropathy outcomes.

Background: Complement dysregulation occurs in thrombotic microangiopathies (TMAs) other than primary atypical haemolytic uraemic syndrome (aHUS). A few of these patients have been reported previously to be successfully treated with eculizumab. Methods: We identified 29 patients with so-called secondary aHUS who had received eculizumab at 11 Spanish nephrology centres. Primary outcome was TMA resolution, defined by a normalization of platelet count (>150 × 10 9 /L) and haemoglobin, disappearance of all the markers of microangiopathic haemolytic anaemia (MAHA), and improvement of renal function, with a ≥25% reduction of serum creatinine from the onset of eculizumab administration. Results: Twenty-nine patients with secondary aHUS (15 drug-induced, 8 associated with systemic diseases, 2 with postpartum, 2 with cancer-related, 1 associated with acute humoral rejection and 1 with intestinal lymphangiectasia) were included in this study. The reason to initiate eculizumab treatment was worsening of renal function and persistence of TMA despite treatment of the TMA cause and plasmapheresis. All patients showed severe MAHA and renal function impairment (14 requiring dialysis) prior to eculizumab treatment and 11 presented severe extrarenal manifestations. A rapid resolution of the TMA was observed in 20 patients (68%), 15 of them showing a ≥50% serum creatinine reduction at the last follow-up. Comprehensive genetic and molecular studies in 22 patients identified complement pathogenic variants in only 2 patients. With these two exceptions, eculizumab was discontinued, after a median of 8 weeks of treatment, without the occurrence of aHUS relapses. Conclusion: Short treatment with eculizumab can result in a rapid improvement of patients with secondary aHUS in whom TMA has persisted and renal function worsened despite treatment of the TMA-inducing condition.