A research work of Prof. Makoto Hirokawa in Akita University Graduate School of Medicine Department of General Internal Medicine and Clinical Laboratory Medicine has published in "Scientific Reports" titled "High-throughput sequencing of IgG B-cell receptors reveals frequent usage of the rearranged IGHV4-28/IGHJ4 gene in primary immune thrombocytopenia".

This study is related to Primary immune thrombocytopenia(ITP), which aimed to clarify the immune response. Our BCR repertoire analysis was used to measure B cell receptor (BCR) IgG.
As a result of measurement, in the patient group, IGHV4-28 was often used in the V gene region of IgG. Most of this used IGHJ4 segment in the J gene region. There were also multiple related clones with single amino substitution in the CDR3 region suggesting somatic hypermutation.
The increase in B cells that express IgG containing these IGHV4-28 / IGHJ4 may be due to specific antigens. And Our analysis suggests that it may help to elucidate the immune pathophysiology of ITP.