IGHA1 and kidney disorder: Serum levels of Gd-IgA1 predict disease progression[12] or recurrence after kidney transplantation[25, 26]and multiple studies have attempted to use Gd-IgA1 as a biomarker to discriminate IgAN patients from healthy individuals and patients with other kidney diseases.[17, 27] We found serum Gd-IgA1 levels to be higher in IgAN patients but to have poor discriminative value due to overlap of the data for the disease and healthy controls.