Podocytopathy Associated with IgA Nephropathy: Is It Really a Prognostic Factor?

Background: In IgA nephropathy(IgAN) podocyte hypertrophy and tip- lesions are markers of podocyte damage, which tend to be treated with immunosuppression, so they have a better kidney prognosis. In Latin America there are no cohorts that evaluate the clinical course of these lesions. Methods: Cases and controls. Results: 37 patients with IgAN were evaluated, 27% presented podocytopathy(IgAN-P) and 73% IgAN without histological data in the optical microscopy of podocytopathy(IgAN-NP), with a mean follow-up of 41±32months. Clinically, IgA-P, independent of treatment prior to biopsy, is associated with higher baseline proteinuria, (ß of .044, p=0.01) mean of 3.9±3.0gr/gr vs 1.6±1.5gr/gr in the group with IgAN-NP). Kidney function in IgAP was slightly lower with a mean eGFR of 65.9±45ml/min/1.73m2 vs 80.2±36.4 ml/min/1.73m2 p=0.23, associated granular casts in podocytopathy (92% vs 80% p=0.02) describing probable associated acute tubular injury. Histologically, patients with podocytopathy presented 80% of podocyte hypertrophy and 20% of tip-type FSGS. MEST-C score had no differences between the groups, except for mesangial proliferation that was present in 96.3% of subjects with podocytopathy compared to 70% of subjects without podocytopathy, p=0.02. The prognosis based on the international SCORE was not statistically significant between the groups p=0.59. Association was found between immunosuppressive treatment prior to biopsy and the presence of podocytopathy (OR=8, 95% CI 1.4-44.9, p=0.018), in 50% vs 37% in the group without podocytopathy p=0.01, however once the histological diagnosis was obtained it was more common to decide to continue with immunosuppressants in subjects with podocytopathy with 90% vs 63% (p=0.11). Finally, when evaluating MAKE outcomes, there were no differences between groups. Conclusion: In previous reports the presence of podocytopathy reported as podocyte hypertrophy and tip-lesions was 16%. In our population this finding was more frequent (27%), with podocyte hypertrophy being more prevalent. Greater proteinuria and worse kidney function were observed compared to IgAN-NP, justifying a greater frequency of immunosuppressive therapy, impacting the kidney outcome being the same as that reported in patients without podocytopathy. Similar result to that observed in previous cohorts.