The aspartate aminotransferase (SGOT) and alanine aminotransferase (SGPT) are sensitive indicators of liver damage. While the TSGOT is also found in other organs, the SGPT is considered an enzyme specific liver. However, some authors state that the TGP can rise also in cases of muscle injury. Furthermore, there are reports in the literature suggesting the association of idiopathic inflammatory myopathies (IIM) with viral hepatitis.
Objective: To determine the frequency of abnormal liver function tests in patients with idiopathic inflammatory myopathies, evaluate possible associationsto liver diseases, determine its relationship with elevation of muscle enzymes and whether these patients have particular clinical and / or serological characteristics.
Material and methods: Consecutive patients older than 16 years diagnosed with DM / PM according to Bohan and Peter criteria during 1999-2000 were included. Patients with other connective tissue disease (CTD) were excluded. Demographic data were recorded, characteristics of the disease, laboratory data and elevated liver enzymes and muscle during the course of the disease. Serologic tests were performed for viral hepatitis B and C and confirmatory tests (HBV-DNA and HCV-RNA by PCR). Autoantibodies were determined: ANA (antinuclear antibody) by Hep II, ASMA (anti smooth muscle antibody), AMA (anti-mitochondrial antibodies) and LKM (Liver Kidney Microsomal) by mouse wound, MSA (myositis-specific antibodies) by ELISA. Patients who had abnormal liver tests underwent hepatic ultrasonography. For statistical analysis, descriptive statistics, categorical variables were compared by Fisher's exact test.
Results: We included 27 patients, of whom 22 had sufficient data for analysis. Mean age 47.95 years ± 16, 18 female (81.8%) and mean disease duration 8.09 ± 5.6 years. With regard to liver enzymes, 14/22 patients (63.3%) had elevated SGPT and 11/22 (50%) elevated SGOT, 10 of these patients also had elevated SGPT concomitantly. In the 10/15 (66.7%) abdominal ultrasonography showed abnormalities, 8 patients had liver hyperechogenicity, 4 cholelithiasis and 1 patient hepatomegaly. No patient bearing of HBV or HCV. The 8 patients with liver hyperechogenicity matched the 8 patients with isolated elevation of SGPT/SGOT. As for the 10 patients who had both elevated liver enzymes (SGPT and SGOT), only one case could be explained by liver disease (patient ASMA +). However in the 15 cases studied, elevations of SGPT and / or SGOT coincided with outbreaks of myositis,findingconcomitant apparent liver disease in only 9 of them.
Conclusions: In this study, elevated transaminases, including the TGP, was observed concomitantly with the activity of myositis. Approximately half of these cases could not be associated with coexisting liver disease, which could be attributed to injury to muscle secondary to inflammatory myopathy.