A Case of Insidious Onset of Kimura Disease-associated Immunoglobulin A Nephropathy without Eosinophil Infiltration in the Renal Tissue.

Kimura disease (KD), also known as eosinophilic lymphogranuloma, is a rare chronic inflammatory or allergic disease. It can present with immune-related diseases such as nephrotic syndrome, asthma, and ankylosing spondylitis. In this study, we report a case of KD combined with immunoglobulin A nephropathy that first presented as a mass in the inguinal region, followed by recurrent renal involvement. Previous reports suggested that renal involvement caused by KD was due to direct infiltration of eosinophils; however, in this case, no eosinophil infiltration was found in the renal tissue after renal biopsy. This observation reminds us to approach the case from an immune-related molecular perspective to investigate the exact cause of renal damage due to KD.