Carboxyhemoglobin Formation in Preterm Infants Is Related to the Subsequent Development of Bronchopulmonary Dysplasia

Objective. To evaluate the usefulness of carboxyhemoglobin (CO-Hb) levels as a biomarker to predict the development and severity of bronchopulmonary dysplasia (BPD). Methods. Twenty-five infants born at <33 wk of gestational age or with a birth weight of <1,500 g were enrolled. CO-Hb levels were measured between postnatal days 5 and 8, 12 and 15, 19 and 22, and 26 and 29. Urinary levels of 8-hydroxydeoxyguanosine (8-OHdG), advanced oxidation protein products, and Nε-(hexanoyl) lysine were measured between postnatal days 5 and 8 and 26 and 29. Receiver operating characteristic (ROC) analysis was used to compare the biomarkers’ predictive values. Results. Compared with infants in the no-or-mild BPD group, infants with moderate-to-severe BPD exhibited higher CO-Hb levels during the early postnatal period and higher 8-OHdG levels between postnatal days 5 and 8. Using ROC analysis to predict the development of moderate-to-severe BPD, the area under the curve (AUC) for CO-Hb levels between postnatal days 5 and 8 was higher than AUCs for the urinary markers. Conclusions. CO-Hb levels during the early postnatal period may serve as a practical marker for evaluating oxidative stress and the severity of subsequently developing BPD

Postnatal Changes in Humerus Cortical Bone Thickness Reflect the Development of Metabolic Bone Disease in Preterm Infants

Objective. To use cortical bone thickness (CBT) of the humerus to identify risk factors for the development of metabolic bone disease in preterm infants. Methods. Twenty-seven infants born at <32 weeks of gestational age, with a birth weight of <1,500 g, were enrolled. Humeral CBT was measured from chest radiographs at birth and at 27-28, 31-32, and 36–44 weeks of postmenstrual age (PMA). The risk factors for the development of osteomalacia were statistically analyzed. Results. The humeral CBT at 36–44 weeks of PMA was positively correlated with gestational age and birth weight and negatively correlated with the duration of mechanical ventilation. CBT increased with PMA, except in six very early preterm infants in whom it decreased. Based on logistic regression analysis, gestational age and duration of mechanical ventilation were identified as risk factors for cortical bone thinning. Conclusions. Humeral CBT may serve as a radiologic marker of metabolic bone disease at 36–44 weeks of PMA in preterm infants. Cortical bones of extremely preterm infants are fragile, even when age is corrected for term, and require extreme care to lower the risk of fractures

The Usefulness of T1-Weighted Magnetic Resonance Images for Diagnosis of Acute Leukemia Manifesting Musculoskeletal Symptoms prior to Appearance of Peripheral Blood Abnormalities

The patients with acute leukemia occasionally present with musculoskeletal symptoms initially, including bone pain, joint pain, muscular pain, and functional impairment. Without abnormal findings of peripheral blood cell counts or smear, the correct diagnosis tends to be delayed. Magnetic resonance imaging is often performed to examine musculoskeletal abnormalities; it can simultaneously reveal the bone marrow composition with high anatomical resolution and excellent soft tissue contrast. We present 4 pediatric patients who were initially diagnosed with acute pyogenic osteomyelitis or arthritis, based on the elevated white blood cell counts and/or C-reactive protein in addition to the localized high signal intensity on T2-weighted magnetic resonance images. Finally, they were diagnosed with B-cell precursor acute lymphoblastic leukemia by bone marrow examination. The period between the onset of musculoskeletal symptoms and the diagnosis of leukemia ranged from 20 days to 6 months. In all cases, the T1-weighted magnetic resonance images taken prior to detection of peripheral blood abnormality revealed diffuse low signal intensity of the bone marrow in regions adjacent or contralateral to localized musculoskeletal symptoms. These findings should raise the suspicion of leukemia even without abnormalities in peripheral blood