Anti-factor H autoantibodies assay.

Area of Science:

• Immunology
• Nephrology
• Hematology

Background:

• Non-Shiga-toxin-associated hemolytic uremic syndrome (atypical HUS) is a rare thrombotic microangiopathy characterized by hemolytic anemia, thrombocytopenia, and acute kidney injury.
• Approximately 10% of atypical HUS cases are caused by autoantibodies against Factor H (FH), a key regulator of the alternative complement pathway, leading to acquired functional FH deficiency.

Purpose of the Study:

• To emphasize the importance of early anti-Factor H (FH) autoantibody screening in all HUS cases for accurate diagnosis and appropriate therapy.
• To highlight the utility of anti-FH IgG titer determination as a diagnostic marker for assessing disease progression and monitoring treatment effectiveness.
• To introduce an ELISA assay for detecting anti-FH autoantibodies and associated analyses to enhance diagnosis.

Main Methods:

• Development and description of an ELISA assay for detecting autoantibodies against Factor H (FH).
• Analysis of concomitant diagnostic tests to improve the accuracy of anti-FH autoantibody detection.
• Review of clinical implications of anti-FH IgG in atypical HUS and potential associations with C3 glomerulopathies.

Main Results:

• Anti-FH autoantibodies are a significant cause of atypical HUS, leading to acquired FH deficiency.
• Anti-FH IgG titers correlate with disease evolution and can precede clinical symptom manifestation.
• The described ELISA assay facilitates the detection of these autoantibodies, aiding in diagnosis and management.

Conclusions:

• Early screening for anti-FH autoantibodies is essential for the prompt diagnosis and management of atypical HUS.
• Anti-FH IgG serves as a valuable diagnostic and monitoring biomarker in atypical HUS.
• The developed ELISA assay and associated analyses improve diagnostic capabilities for conditions involving anti-FH autoantibodies.