Clinical presentation, outcomes and risk of relapses of lupus podocytopathy in a multicentre Italian cohort.

Abstract

Background: In an Italian cohort of lupus podocytopathy patients, we aimed to characterize the presenting features, therapy, and outcomes, and explore differences between relapsing and non-relapsing patients.

Methods: We identified 29 patients with lupus podocytopathy from 1994 to 2023 in 11 Italian Nephrology/Rheumatology Units, and divided them into two groups: relapsing and non-relapsing. Given the limited sample size, a p-value ≤ 0.2 was considered as significant.

Results: The median age of the patients was 43 (25-52) years, 89.7% were females, 89.6% presented with nephrotic syndrome, 34.4% with acute kidney dysfunction, and 44% with arterial hypertension. After corticosteroids and/or immunosuppressive therapy, complete (25 patients) or partial remission (4 patients) occurred within a median of 4 (1-9) months. Nine patients (31%) relapsed. After a further course of therapy, remission was achieved within 5 (2-11) months. Relapsing patients had higher serum creatinine (0.94 [0.73-2.65] vs 0.8 [0.6-1.1] mg/dl; p = 0.12), lower estimated glomerular filtration rate (76 [32.5-107.5] vs 93 [59.3-109.7] ml/min/1.73m²; p = 0.23) and higher proteinuria (7.7 [5.9-11.7] vs 6.5 g/day [3.2-10.1]; p = 0.14) at lupus podocytopathy diagnosis than non-relapsing subjects. Activity indexes at biopsy were higher [(1 (0-2) vs 0 (0-1); p = 0.08] and cutaneous systemic lupus erythematosus manifestations were more prevalent (44.4% vs 10.5%; p = 0.06) in relapsing patients. After an observation of 49 (18-23) months, 86.2% of patients were in complete remission while 13.8% remained in partial remission. One patient developed mild chronic kidney function impairment.

Conclusions: Lupus podocytopathy typically presents with nephrotic syndrome and kidney dysfunction, it responds favourably to treatment, and generally results in a favourable renal outcome. We observed that more active renal and extrarenal lupus manifestations at the onset of lupus podocytopathy were indicative of higher susceptiblity to disease recurrence.