Flow cytometry crossmatch in women undergoing paternal lymphocyte immunization: correlation between fluorescence intensity and pregnancy outcome

Abstract

Introduction: The success of a pregnancy depends on alloimmune mechanisms, with the allogeneic fetus being considered a successful allograft. Immunizationwith paternal lymphocytes has been shown to be an effective therapeutic option for cases of recurrent pregnancy loss (RPL). Currently, flow cytometry cross-match (FCXM) is used to evaluate patients with RPL. Objectives: To evaluate the results of FCXM in women with a history of RPL who conceived following paternal lymphocyte immunization (PLI), and correlate them with pregnancy outcome. Materials and methods: Eighty-five patients were selected for the study based on the following inclusion criteria: ≥2 RPL, initial FCXM negative against the father, and women with primary RPL. The women were divided into two groups: successful pregnancy outcome and pregnancy loss. After an initial negative FCXM (baseline), the patients were immunized with doses of PLI and 30 days after the final PLI a second FCXM was performed. Median fluorescence intensity (MFI) was calculated at both time points and the two groups were compared. Results: Evaluation ofMFI ratio (following PLI/baseline) for T and B lymphocytes showed no statistically significant differences between the two groups (p=0.119 for T lymphocytes and p=0.109 for B lymphocytes). Conclusion: There was no difference between the two groups regarding median fluorescence intensity ratio (following PLI/baseline) for T and B lymphocytes. Therefore, themedianfluorescence intensity ratio for T andB lymphocytes cannot be used as a laboratory parameter to evaluate the success of PLI with respect to pregnancy outcome following immunotherapy.