RESUMEN
BACKGROUND: Loss of response to anti-TNFα treatment occurs frequently in IBD- patients. We evaluatedthe predictive value of serum albumin and γ-globulin concentrations for treatment failure. METHODS: Prospectively, all patients treated for the first time with either infliximab or adalimumab for IBD between 2007 and 2018 were included. All patients were tested for serum albumin and γ-globulin concentrations and were followed up until June 2018. RESULTS: 128 patients (95 Crohn's disease, 67 females, age 40.1 ± 13.7 years) were included in the study. 81patients (63.3%) received infliximab and 47 (36.7%) adalimumab first line. Eight patients (6.3%) were primary non-responders, 50 patients (39.0%) showed a sustained clinical remission and 70 patients (54.7%) developed a secondary loss of response. Meantime to develop secondary loss of response was 24.5 ± 20.5 months. Albumin serum concentrations in the clinical response group were significantly higher than in the secondary loss of response group (39.8 ± 5.7 g/L vs. 35.0 ± 5.4 g/L). γ-globulin serum concentrations in the sustained response group were significantly lower than in the secondary loss of response group (11.8 ± 2.8 g/L vs. 14.7 ± 4.5 g/L). Hypoalbuminemia and hypergammaglobulinemia were associated with the loss of response. Immunosuppressant co-medication in patients with high γ-globulin serum concentrations reduced the risk of secondary loss of response. CONCLUSION: Low albumin and increased γ-globulin serum concentrations are strongly associated with a higher risk for loss of response to an anti-TNFα treatment. Increased serum γ-globulin concentrations may have a higher risk to produce anti-drug antibodies or a different phenotype of disease less responsive to anti-TNFα treatment.