IgA vasculitis nephritis: insights from kidney biopsies

Area of Science:

• Nephrology
• Immunology
• Pathology

Background:

• IgA vasculitis nephritis (IgAVN) diagnosis and prognosis traditionally rely on the ISKDC classification.
• The ISKDC classification has demonstrated limited prognostic capability for IgAVN patients.
• The Oxford (MEST-C) classification, proven effective for IgA nephropathy, has been less explored in IgAVN.

Approach:

• Review of current literature and recent international studies on IgAVN biopsy assessment.
• Analysis of the prognostic value of the Oxford (MEST-C) classification in IgAVN.
• Comparison of ISKDC and Oxford classifications for predicting kidney outcomes in IgAVN.

Key Points:

• A recent study on 361 IgAVN patients revealed that endocapillary hypercellularity (Oxford E1) identifies patients with initial kidney function improvement post-immunosuppression, followed by decline.
• Kidney outcomes in IgAVN are influenced by clinical factors and the presence of endocapillary hypercellularity.
• The ISKDC classification does not include endocapillary hypercellularity, highlighting the need for MEST-C scoring in IgAVN biopsy reports.

Conclusions:

• The Oxford (MEST-C) classification provides crucial prognostic information for IgAVN, aiding in clinical decision-making.
• Incorporating MEST-C scores into IgAVN biopsy reports is recommended for enhanced prognostic assessment.
• Long-term patient follow-up is essential, even with initial positive responses to immunosuppression, due to the risk of future kidney function deterioration.