IGHA1 and rheumatoid arthritis: showed three cases with glomerular Gd-IgA1 positive complicated with rheumatoid arthritis, systemic lupus erythematosus, and Crohn’s disease achieved clinical renal remission treated with tonsillectomy and steroid pulse therapy, while another case with hepatitis C showed negative for Gd-IgA1 and successfully treated by antivial agents [36].