Immune repertorie of IgAN Patients

IgA nephropathy (IgAN) is the most common glomerulonephritis which characterized by the deposition of IgA antibody in the glomerulus. We applied immune repertoire sequencing technology to parallel analyzed CDR3 region of all the B cell receptors, including all five antibody subtypes IgA, IgG, IgM, IgE and IgD in 13 IgAN patients and 7 normal people. The significant decrease of the CDR3 length was observed in IgAN group. In particular, JH6 family is significantly increased in IgAN. The amino acid usage also showed different patterns in IgAN. Shannon, Simpson, Gini and D50 indice also showed significant differences in the diversity of IgG, IgM and IgA antibodies to controls. The proportion of IgA, IgG are increased whereas IgM are decreased in IgAN. Moreover, there are more CDR3 sequences shared in IgAN patients. These findings suggest that the BCR immune repertoire is altered dramatically in IgAN, characterized by the shortened CDR3 length as well as decreased overall diversity of CDR3.