Hypocitraturia has been identified as a highly sensitive biomarker for diagnosing renal tubular acidosis in patients with Sjögren’s disease, according to a new study.

The research, published in Advances in Rheumatology evaluated the predictive value of low urinary citrate levels in diagnosing renal tubular acidosis (RTA) in a cohort of patients with Sjögren’s Disease (SD) at a tertiary hospital in southern Brazil.

The study included 42 patients with SD, predominantly female with a median age of 61 years. Researchers assessed the presence of RTA by analyzing urinary pH, blood pH, and other biochemical markers. Urinary acidification tests using furosemide and fludrocortisone were conducted on patients with persistently high urinary pH to confirm the diagnosis of RTA.

Results showed that 4.8% of the patients had complete distal RTA. Among those who underwent urine acidification testing, five had hypocitraturia, and two of these had complete distal RTA. The association between hypocitraturia and RTA was statistically significant, with a sensitivity of 100%, specificity of 91.2%, and an overall accuracy of 91.7%. The study demonstrated that low urinary citrate levels could serve as a highly sensitive and accurate biomarker for diagnosing RTA in patients with SD.

The findings suggested that hypocitraturia could be a valuable tool for early detection of renal complications in SD, potentially improving patient outcomes through timely intervention. Further research with larger, multicenter cohorts is recommended to validate these results and establish standardized protocols for using urinary citrate as a diagnostic marker for RTA in SD patients.

The authors reported no conflicts of interest.