Wang Bangchen, Singh Harpreet, Ellis Matthew, Barisoni Laura, Howell David N
Department of Pathology, Duke University, Durham, North Carolina.
Division of Nephrology, Department of Internal Medicine, Duke University, Durham, North Carolina.
Lab Invest. 2025 Jul;105(7):104163. doi: 10.1016/j.labinv.2025.104163. Epub 2025 Apr 6.
Selective IgA deficiency (sIgAD) is the most common type of primary immunodeficiency. The diagnosis of sIgAD has occasionally been suggested when a complete absence of background IgA immunofluorescent staining on renal biopsies was observed, but such findings have been described in only 2 patients to date. In this study, the clinical, demographic, and renal biopsy findings of 15 patients with suspected sIgAD, based on a total lack of immunofluorescence for IgA, were collected. In our cohort, most patients presented with acute kidney injury, with or without proteinuria, and had clinical histories consistent with sIgAD, including recurrent infections, autoimmune diseases, allergic disorders, and cancer. However, only 1 patient had a known history of sIgAD. Immunoglobulin testing was available in 10 of 15 patients, 9 of whom showed findings consistent with a diagnosis of sIgAD. Renal biopsies in most patients revealed immune-related glomerular diseases, with lupus nephritis being the most common diagnosis. Recognizing the total absence of IgA staining indicative of sIgAD is important because it can be associated with recurrent infections, autoimmune diseases, allergic disorders, anaphylactic transfusion reactions, and, rarely, malignancies.
选择性IgA缺乏症（sIgAD）是最常见的原发性免疫缺陷类型。当在肾活检中观察到完全没有背景IgA免疫荧光染色时，偶尔会提示sIgAD的诊断，但迄今为止仅在2例患者中描述过此类发现。在本研究中，收集了15例疑似sIgAD患者的临床、人口统计学和肾活检结果，这些患者基于完全缺乏IgA免疫荧光。在我们的队列中，大多数患者表现为急性肾损伤，伴有或不伴有蛋白尿，并且有与sIgAD一致的临床病史，包括反复感染、自身免疫性疾病、过敏性疾病和癌症。然而，只有1例患者有已知的sIgAD病史。15例患者中有10例进行了免疫球蛋白检测，其中9例的检测结果与sIgAD的诊断一致。大多数患者的肾活检显示免疫相关的肾小球疾病，最常见的诊断是狼疮性肾炎。认识到完全没有指示sIgAD的IgA染色很重要，因为它可能与反复感染、自身免疫性疾病、过敏性疾病、过敏性输血反应以及罕见的恶性肿瘤有关。
