No abstract

Rationale:Renal tubular acidosis (RTA) represents a class of metabolic disorders characterized by metabolic acidosis with a normal plasma anion gap. As a rare complication of primary biliary cirrhosis (PBC), RTA is easily overlooked, likely leading to misdiagnosis.Patient concerns:A 32-year-old woman who had been diagnosed with PBC at our hospital was found to have hypokalemia due to repeated fatigue for 2 years, and the etiology was unknown.Diagnoses:Due to the laboratory test results, radiographic findings, and pathologic results, she was diagnosed with PBC associated with RTA.Interventions:She was then treated with ursodeoxycholic acid, potassium citrate, and calcium supplements together with activated vitamin D.Outcomes:Thus far, the patient showed a good response to ursodeoxycholic acid, and the clinical symptoms and liver function were significantly improved.Lessons:Physicians that encounter refractory hypokalemia in a patient with PBC should be aware of the presence of RTA. The early diagnosis and treatment of such patients are of paramount importance to alleviate clinical symptoms and delay disease progression.

Background and objective The relationship between antimitochondrial antibody (AMA) levels and the severity or prognosis of primary biliary cholangitis (PBC) is unclear. This study explored the clinical significance of serum IgG antimitochondrial M2 antibody (IgG-M2) levels. Methods From 2008 to 2017, a retrospective analysis was conducted with PBC patients who had available quantitative values of serum IgG-M2 levels obtained with ELISA based on triple expression hybrid clones. The patients were divided into two groups based on high and low concentrations of IgG-M2. Baseline parameters, the incidence of adverse events, and prognosis were compared. Results Among the 530 PBC patients, the levels of albumin, cholinesterase, hemoglobin, fibrinogen and triglycerides and the red blood cell count were significantly lower in the high-concentration group than in the low-concentration group (n = 263, 49.6%). The red cell distribution width (RDW) and levels of serum immunoglobulin (Ig) G, IgM and IgA were significantly higher in the high-concentration group than in the low-concentration group. Spearman’s correlation analysis suggested that the correlation between the above baseline indicators and IgG-M2 levels was statistically significant but weak (r < 0.2, P < 0.05). In total, 203 patients were followed up, of whom 87 (42.9%) were in the high-concentration group. During the median follow-up period of 52 months (range: 28–75), 121 (59.6%) experienced hepatic decompensation, and 37 (18.2%) died or underwent liver transplantation. There was no significant difference in the incidence of complications or survival (log-rank test: P = 0.079) between the two groups. One year after ursodeoxycholic acid (UDCA) treatment, the two groups had similar responses. In addition, the levels of IgG-M2 did not fluctuate significantly during treatment. Conclusion IgG-M2 levels were not related to the disease severity, prognosis or efficacy of UDCA. The levels of IgG-M2 did not change significantly during treatment.