Hilde van der Staaij

Background and Objectives: Preterm infants are commonly transfused, yet direct cardiorespiratory effects of red blood cell (RBC) transfusions remain poorly understood. We explored the feasibility of using multicentre electronic health data (EHD) to study such cardiorespiratory responses. Methods: Highly granular routine EHD were collected from preterm infants born <32 weeks gestational age at three European centres. Heart rate, oxygen saturation, and respiratory rate were evaluated 12 hours before and after the RBC transfusion. Results: A total of 321 transfusions in 164 infants were analysed. Overall, there was no significant change in the rate of bradycardia and apnoea following transfusion. Cardiorespiratory parameters varied substantially between infants; e.g. 20% of transfusions were associated with an unexpected, significant increase in heart rate. Respiratory rate and oxygen saturation exhibited similarly heterogenous patterns following transfusion. In sub-group analysis, the proportion of transfusions with increased heart rate was significantly higher within the first two weeks than later (32% vs 13%, p=0.0019). Conclusions: Multicentre EHD extraction allows to identify otherwise masked short-term effects of RBC transfusions on cardiorespiratory parameters, possibly indicating cardiac or pulmonary overload. Such effects may vary with adaptation to anaemia. Analysing EHD may ultimately enable personalized transfusion practice.

Objective: To describe the incidence of major bleeds according to different platelet counts in very preterm infants, and to explore whether this association is influenced by other risk factors for bleeding. Design: Observational cohort study. Setting: A Dutch tertiary care neonatal intensive care unit. Patients: All consecutive infants with a gestational age at birth 9/L) during admission (9/L. The incidence of major bleeds was 8% among infants with and without severe thrombocytopenia (platelet count 9/L), 18/231 (95% CI 5 to 12) and 206/2541 (95% CI 7 to 9), respectively. Similarly, after adjustment for measured confounders, there was no notable association between nadir platelet counts below versus above 50×10⁹/L and the occurrence of major bleeds (OR 1.09, 95% CI 0.61 to 1.94). Conclusion: In very preterm infants, the vast majority of major bleeds occur in infants without severe thrombocytopenia.

Pathogenic TMPRSS6 variants impairing matriptase-2 function result in inappropriately high hepcidin levels relative to body iron status, leading to iron refractory iron deficiency anemia (IRIDA). As diagnosing IRIDA can be challenging due to its genotypical and phenotypical heterogeneity, we assessed the transferrin saturation (TSAT)/hepcidin ratio to distinguish IRIDA from multi-causal iron deficiency anemia (IDA). We included 20 IRIDA patients from a registry for rare inherited iron disorders and then enrolled 39 controls with IDA due to other causes. Plasma hepcidin-25 levels were measured by standardized isotope dilution mass spectrometry. IDA controls had not received iron therapy in the last 3 months and C-reactive protein levels were TMPRSS6-unrelated IDA early in the diagnostic work-up of IDA provided that recent iron therapy and moderate-to-severe inflammation are absent. These observations warrant further exploration in a broader IDA population.