Podocyte number and glomerulosclerosis indices are associated with the response to therapy for primary focal segmental glomerulosclerosis

• Published in: Frontiers in medicine Vol. 11; p. 1343161
• Main Authors: de Zoysa, Natasha, Haruhara, Kotaro, Nikolic-Paterson, David J, Kerr, Peter G, Ling, Jonathan, Gazzard, Sarah E, Puelles, Victor G, Bertram, John F, Cullen-McEwen, Luise A
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 06.03.2024
• Subjects: FSGS; kidney; Medicine; podocyte; podometrics; therapy; FSGS; kidney; podometrics; therapy; podocyte
• ISSN: 2296-858X; 2296-858X
• DOI: 10.3389/fmed.2024.1343161

Corticosteroid therapy, often in combination with inhibition of the renin-angiotensin system, is first-line therapy for primary focal and segmental glomerulosclerosis (FSGS) with nephrotic-range proteinuria. However, the response to treatment is variable, and therefore new approaches to indicate the response to therapy are required. Podocyte depletion is a hallmark of early FSGS, and here we investigated whether podocyte number, density and/or size in diagnostic biopsies and/or the degree of glomerulosclerosis could indicate the clinical response to first-line therapy. In this retrospective single center cohort study, 19 participants (13 responders, 6 non-responders) were included. Biopsies obtained at diagnosis were prepared for analysis of podocyte number, density and size using design-based stereology. Renal function and proteinuria were assessed 6 months after therapy commenced. Responders and non-responders had similar levels of proteinuria at the time of biopsy and similar kidney function. Patients who did not respond to treatment at 6 months had a significantly higher percentage of glomeruli with global sclerosis than responders (  < 0.05) and glomerulosclerotic index (  < 0.05). Podocyte number per glomerulus in responders was 279 (203-507; median, IQR), 50% greater than that of non-responders (186, 118-310; 0.05). These findings suggest that primary FSGS patients with higher podocyte number per glomerulus and less advanced glomerulosclerosis are more likely to respond to first-line therapy at 6 months. A podocyte number less than approximately 216 per glomerulus, a GSI greater than 1 and percentage global sclerosis greater than approximately 20% are associated with a lack of response to therapy. Larger, prospective studies are warranted to confirm whether these parameters may help inform therapeutic decision making at the time of diagnosis of primary FSGS.