Apheresis principles in a patient with chronic myeloid leukemia during pregnancy: challenges in cell separation and assessing transcript levels.

<bold>Background: </bold>Chronic myeloid leukemia (CML) is rarely diagnosed in pregnant women.<bold>Case Report: </bold>We report a case of a pregnant woman who presented with a leukocyte count of 250 × 109 cells/L at gestational age (GA) 26 weeks and was diagnosed with CML in the chronic phase. Because the patient deliberately opted out of interferon α and tyrosine kinase inhibitor treatment, the main goal was to reduce the leukocyte count to postpone delivery beyond the number of weeks considered severely premature and avoid thromboembolic complications while continuously evaluating the clinical safety of the mother and fetus. Hence therapeutic leukapheresis was initiated, and we report the first application of an apheresis approach for this procedure using the Spectra Optia instrument without sedimentation agents. Leukapheresis was conducted 2 to 4 times per week for 9 weeks.<bold>Results: </bold>During treatment the leukocyte count decreased remarkably, and the patient developed lymphopenia together with a paradoxical increase in her blood platelet count. Premature labor was induced at GA 35 weeks, and a healthy boy was delivered. Thereafter, the patient initiated imatinib treatment and was in major molecular and complete cytogenetic remission after 1 year. Despite the remarkable reduction of the leukocyte count, we observed a pronounced increase in expression of BCR-ABL1 transcripts, implying the need for close monitoring of patients with CML during pregnancy.<bold>Conclusions: </bold>We report a pregnant woman who was diagnosed with CML and treated solely with apheresis procedures using the Spectra Optia instrument for 9 weeks, ensuring the safe delivery of her child. [ABSTRACT FROM AUTHOR]