Interest of Follicular Helper Lymphocytes / Regulatory Follicular Helper Lymphocytes Ratio in IgA Nephropathy

Interest of Follicular Helper Lymphocytes / Regulatory Follicular Helper Lymphocytes Ratio to Characterize and Predict Poor Prognosis Forms in IgA Nephropathy: an Exploratory Proof-of-concept Study

This study aims to investigate the relevance of the Tfh/Tfr (Follicular helper T cells/ Follicular regulatory T cells) ratio in patients with IgA nephropathy:

• To identify a differential expression of the Tfh/Tfr ratio in patients considered stable or progressive
• To predict, at diagnosis, the clinical evolution of the disease (progressive or stable form) in the first year.

Inclusion Criteria:

• IgA nephropathy histologically proven on renal biopsy according to KDIGO criteria, with 8 permeable glomeruli (patients diagnosed from 2009 with a minimum follow-up for their nephropathy of 5 years (arm 1) or patients diagnosed during the study (arm 2))

Control patients: Lupus or ANCA-associated vasculitis or polycystic kidney disease (arm 3)

Exclusion Criteria:

• Legal incapacity or limited legal capacity
• Subjects with no social security coverage.
• Pregnancy / No effective contraceptive method