Abstract: TH-PO0098
Unmasking Renal Tubular Acidosis in Sjögren Disease
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Clinical Research
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Locastro, Marissa, UW Health, Madison, Wisconsin, United States
- Mccoy, Sara, UW Health, Madison, Wisconsin, United States
- Singh, Tripti, UW Health, Madison, Wisconsin, United States
Background
One-third of patients with Sjögren's Disease (SjD) will have distal renal tubular acidosis (dRTA) increasing their risk for bone disease and chronic kidney disease (CKD). There is little data on clinical characteristics to predict dRTA in SjD. We described clinical characteristics of a cohort of patients with SjD and dRTA.
Methods
We conducted a retrospective study of patients with SjD meeting 2016 ACR/EULAR criteria and dRTA (defined as CO2 <22 plus clinician documentation) treated at a single academic center. All demographic, clinical, and laboratory data were extracted from the electronic medical record. Descriptive statistics were used to analyze data.
Results
There were 23 patients with a mean age of 44 (± 19) years. Most patients were white (83%), non-Hispanic (83%) women (96%). The most common comorbidities were anxiety (48%), asthma (39%), lupus (39%), and thyroid disorders (26%). Majority (62%) of patients were diagnosed with SjD prior to dRTA. Seven patients (30%) were diagnosed with dRTA at the same time as SjD and one patient (4%) was diagnosed with dRTA prior to SjD. First CO2 level <22 mEq/L was at 72 (± 376) months following SjD diagnosis; however, the lag time between first CO2 <22 mEq/L and dRTA diagnosis was 62 (± 91) months. Of note, 35% (8/23) patients had a CO2 <22 mEq/L prior to SjD diagnosis.
At the time of dRTA, mean serum bicarbonate, potassium, and creatinine were 19 (± 3) mEq/L, 3.7 (± 0.8) mEq/L, and 0.94 (± 0.37) mg/dL, respectively. Mean UPCR was 0.73 (± 0.87) gm/gm and urine pH was 6.4 (± 0.6). Proteinuria (UPC >0.3 gm/gm) was present in 39% (9/23) patients. Half of patients were on immunosuppression. 96% of patients had a positive anti-SSA antibody and 61% had a positive SSB. 39% of patients (9/23) had a kidney biopsy. Biopsies were notable for chronic interstitial nephritis (n=3), lupus nephritis (n=4), membranoproliferative glomerulonephritis (n=1), and early diabetic nephropathy (1). Osteoporosis and CKD (eGFR <60ml/min/1.73m2) developed in 13% and 26% of patients, respectively. Less than half (43%) of patients received oral sodium bicarbonate therapy.
Conclusion
SjD diagnoses proceeded dRTA diagnosis, however, a third of patients had a CO2 <22 mEq/L prior to their SjD diagnosis. Furthermore, there was a significant lag time between first CO2 <22 mEq/L and dRTA diagnosis by a clinician.