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Since 2017, the clinical value of podocyte injury in IgA nephropathy(IgAN) has been studied, the presence of podocyte hypertrophy and tip- lesions are markers of podocyte damage. It has been observed that these histological findings tend to be treated with immunosuppression, so they have a better kidney prognosis, but those who do not receive inmunsuppression have a worse prognosis. In Latin America there are no cohorts that evaluate the clinical course of these lesions.
Cases and controls.
A total of 37 patients with a diagnosis of IgAN were evaluated, of these 27% presented podocytopathy(IgAN-P) and 72.9% presented IgAN without histological data in the optical microscopy of podocytopathy(IgAN-NP), with an average follow-up of 41±32months. Clinically, the proteinuria in IgAN-P patients was higher with a mean of 3.9±3.0gr/gr vs 1.6±1.5gr/gr in the group with IgAN-NP, without being statistically significant p=0.54. Kidney function in the group with podocytopathy was slightly lower with an average eGFR of 65.9±45ml/min/1.73m2 vs 80.2±36.4 ml/min/1.73m2 p=0.23, associated with a greater presence of 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 2% of tip-type FSGS. The findings in the 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 score was not statistically significant between the groups p=0.59. Patients with podocytopathy tended to be treated with immunosuppression prior to the biopsy 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, long-term results reported no differences in the requirement for kidney replacement therapy. When evaluating MAKE outcomes, there were no differences between groups with respect to ESKD; 40% decrease in eGFR and need for kidney
replacement therapy.
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.