Renal involvement in primary Sjögren's syndrome

Area of Science:

• Nephrology
• Rheumatology
• Internal Medicine

Background:

• Primary Sjögren's syndrome (pSS) is an autoimmune disease that can affect various organs, including the kidneys.
• Renal involvement in pSS, particularly distal renal tubular acidosis (dRTA), requires accurate diagnostic methods for timely intervention.

Purpose of the Study:

• To evaluate renal involvement in patients with primary Sjögren's syndrome.
• To assess the prevalence of distal renal tubular acidosis (dRTA) and other renal dysfunctions.
• To investigate the utility of the urine citrate to creatinine ratio as a diagnostic marker for dRTA.

Main Methods:

• Sixty-two patients with primary Sjögren's syndrome were assessed.
• Urine concentration capacity was tested using 1-desamino-8-D-arginine-vasopressin.
• Acidification tests, urinary citrate, albumin, NAG, ALP, beta2-microglobulin measurements, and creatinine clearance calculations were performed.

Main Results:

• Twenty-one percent of patients showed reduced maximum urine concentration capacity and creatinine clearance.
• Only 1.6% of patients had significant albuminuria, indicating minimal glomerular disease.
• Seven patients (11.3%) were diagnosed with complete or incomplete dRTA, with low citrate to creatinine ratios observed in these individuals.

Conclusions:

• The urine citrate to creatinine ratio is a valuable and simple method for identifying patients with dRTA in primary Sjögren's syndrome.
• The prevalence of dRTA in this cohort was lower than previously reported.
• Early identification of renal complications like dRTA is essential for managing patients with primary Sjögren's syndrome.