Fecal calprotectin and α1-antitrypsin dynamics in gastrointestinal GvHD

In a previous study, the fecal biomarkers calprotectin and α1-antitrypsin (α1-AT) at symptom onset were reported to be significantly associated with the response to steroids in gastrointestinal GvHD (GI-GvHD). The purpose of this trial was to evaluate the dynamics of the fecal biomarkers calprotectin and α1-AT throughout the course of GvHD. Patients who were refractory to steroids had initially higher biomarker levels and in the course of GvHD demonstrated a continuous increase in fecal biomarkers. In contrast, the dynamics of calprotectin and α1-AT demonstrated low and decreasing levels in cortico-sensitive GvHD. In steroid-refractory patients who received a second line of treatment, the biomarker levels at the beginning of second-line treatment did not predict the subsequent response. Nevertheless, calprotectin levels progressively decreased in subsequent responders, whereas non-responders demonstrated continuously high levels of calprotectin. α1-AT values correlated to a lesser extent with the response to second-line treatment and remained elevated in both non-responders and responders. In conclusion, calprotectin monitoring can be of use in the management of immunosuppressive treatment in GI-GvHD.