Renal Involvement in Primary Sjogren's Syndrome: A Case Series of Three Cases with Various Clinicopathological Presentations.

Sjogren's syndrome is a prevalent and underdiagnosed systemic disease that primarily affects epithelial tissue. It may affect renal function, either as an epithelial disease causing tubulointerstitial nephritis (TIN) or as an immune complex-mediated glomerulopathy. These lesions may cause a variety of clinical features, both overt and occult. The epithelial disease is mediated by B and T cells. The prevalence of renal involvement in primary Sjogren's syndrome has been reported to range approximately from 10% to 30%. Patients with renal involvement in primary Sjogren's syndrome may have renal manifestations, such as renal tubular acidosis (RTA) Type I, TIN, diabetes insipidus, nephrolithiasis, and Fanconi syndrome. Distal RTA was reported more commonly than proximal RTA, which can present as acute hypokalemic paralysis. We present three cases of primary Sjogren's syndrome with significant renal involvement and various clinicopathological presentations.