AIM:To determine the prevalence and significance of primary biliary cirrhosis (PBC)-specific autoantibodies in firstdegree relatives (FDRs) of Greek PBC patients. METHODS:The presence of antimitochondrial antibodies (AMA) and PBCspecific antinuclear antibodies (ANA) were determined using indirect immunofluores-cence assays, dot-blot assays, and molecularly based enzyme-linked immunosorbent assays in 101 asymp-tomatic for liver-related symptoms FDRs of 44 PBCpatients. In order to specify our results, the same investigation was performed in 40 healthy controls and in a disease control group consisting of 40 asymptomatic for liver-related symptoms FDRs of patients with other autoimmune liver diseases namely, autoimmune hepati-tis-1 or primary sclerosing cholangitis (AIH-1/PSC). RESULTS: AMA positivity was observed in 19 (only 4 with abnormal liver function tests) FDRs of PBC patients and none of the healthy controls. The preva-lence of AMA was significantly higher in FDRs of PBC patients than in AIH-1/PSC FDRs and healthy controls [18.8%, 95% confidence interval (CI):12%-28.1% vs 2.5%, 95% CI:0.1%-14.7%, P = 0.01; 18.8%, 95% CI:12%-28.1% vs 0%, 95% CI: 0%-10.9%, P = 0.003, respectively]. PBC-specific ANA positivity was observed in only one FDR from a PSC patient. Multivariate analysis showed that having a proband with PBC independently associated with AMA positivity (odds ratio: 11.24, 95% CI:1.27-25.34, P = 0.03) whereas among the investigated comorbidities and risk factors, a positive past history for urinary tract infections (UTI) was also independently associated with AMA detection in FDRs of PBC patients (odds ratio:3.92, 95% CI:1.25-12.35,P = 0.02). CONCLUSION:In FDRs of Greek PBC patients, AMA prevalence is significantly increased and independently associated with past UTI. PBC-specific ANA were not detected in anyone of PBC FDRs. METHODS: The presence of antimitochondrial antibodies (AMA) and PBCs specific antinuclear antibodies (ANA) were determined using indirect indirect immunofluorescence (FDRs) of Greek PBC patients. AIM: To determine the prevalence and significance of primary biliary cirrhosis (PBC) -specific autoantibodies in firstdegree relatives Immunofluoresce-cence assays, dot-blot assays, and molecularly based enzyme-linked immunosorbent assays in 101 asymp-tomatic for liver-related symptoms FDRs of 44 PBCpatients. In order to specify our results, the same investigation was performed in 40 healthy controls and in a disease control group consisting of 40 asymptomatic for liver-related symptoms FDRs of patients with other autoimmune liver diseases namely, autoimmune hepati-tis-1 or primary sclerosing cholangitis (AIH-1 / PSC). RESULTS: AMA positivity was observed in 19 (only 4 with abnormal liver function tests) FDRs of PBC patients and none of the healthy controls. The prevalence of AMA was significantly higher in FDRs of PBC patients than in AIH-1 / PSC FDRs and healthy controls [18.8%, 95% confidence interval (CI): 12% -28.1% vs 2.5%, 95% CI: 0.1% -14.7%, P = 0.01; % CI: 12% -28.1% vs 0%, 95% CI: 0% -10.9%, P = 0.003, respectively]. PBC-specific ANA positivity was observed in only one FDR from a PSC patient. Multivariate analysis showed that having a proband with PBC independently associated with AMA positivity (odds ratio: 11.24, 95% CI: 1.27-25.34, P = 0.03) was among the investigators comorbidities and risk factors, a positive past history for urinary tract infections (UTI) was also independently associated with AMA detection in FDRs of PBC patients (odds ratio: 3.92, 95% CI: 1.25-12.35, P = 0.02) CONCLUSION: In FDRs of Greek PBC patients, AMA prevalence is significantly increased and independently associated with past UTI. PBC -specific ANA were not detected in anyone of PBC FDRs.