Renal biopsy findings in psoriasis patients with renal involvement: a descriptive clinicopathologic study

Psoriasis is a chronic inflammatory skin disease increasingly recognized for its systemic involvement, particularly renal impairment. However, the pathological spectrum of kidney lesions observed in psoriasis patients remains under-characterized. We conducted a retrospective clinicopathologic study of native kidney biopsies from patients with psoriasis at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine between 2009 and 2025. Clinical characteristics, laboratory data, and renal pathological findings were systematically analyzed. Among 68 patients (55 male [81%], 13 female [19%]; mean age 51 years), clinical presentations included nephrotic syndrome (35%), nephritis (29%), isolated proteinuria (18%), chronic kidney disease (16%), and acute kidney injury (1%). Renal biopsies revealed a broad spectrum of pathological diagnoses, which we organized into four descriptive categories: (1) Immune complex-mediated glomerulonephritis (n = 48, 71%): including IgA nephropathy (IgAN, n = 33, 49%) and membranous nephropathy (MN, n = 15, 22%), both entities exhibit pathologic distinctions from primary glomerular diseases. (2) Podocyte injury (n = 9, 13%): including podocytopathy and focal segmental glomerulosclerosis (FSGS). (3) Comorbidity-related renal disease (n = 6, 9%). (4) Other renal disease (n = 5, 7%). Compared with published primary IgAN cohorts, psoriasis patients with IgAN demonstrated older age, higher proteinuria, and more frequent endocapillary hypercellularity, necrotizing lesions and glomerular basement membrane (GBM) ultrastructural abnormalities. MN cases showed lower rates of PLA2R positivity compared to idiopathic MN. This study describes the clinicopathologic characterization of biopsy-proven renal involvement in patients with psoriasis. The observed associations between psoriasis and various renal pathologies cannot establish causality and likely reflect a complex interplay of systemic inflammation, metabolic comorbidities, and treatment effects. These findings highlight the heterogeneity of renal involvement in psoriasis patients and underscore the importance of renal biopsy for accurate diagnosis.