MVT-1075

The study was conducted to quantify laryngeal cartilage matrix composition and to investigate its relationship with cartilage shape in a mouse model. A sample of 30 mice (CD‐1 mouse, Mus musculus) from five age groups (postnatal Days 2, 21, 90, 365, and 720) were used. Three‐dimensional mouse laryngeal thyroid cartilage reconstructions were generated from contrast‐enhanced micro‐computed tomography (CT) image stacks. Cartilage matrix composition was estimated as Hounsfield units (HU). HU were determined by overlaying 3D reconstructions as masks on micro‐CT image stacks and then measuring the attenuation. Cartilage shape was quantified with landmarks placed on the surface of the thyroid cartilage. Shape differences between the five age groups were analyzed using geometric morphometrics and multiparametric analysis of landmarks. The relationship between HU and shape was investigated with correlational analyses. Among five age groups, HU became higher in older animals. The shape of the thyroid cartilage changes with age throughout the entire life of a mouse. The changes in shape were not synchronized with changes in cartilage matrix composition. The thyroid cartilage of young and old M. musculus larynx showed a homogenous mineralization pattern. High‐resolution contrast‐enhanced micro‐CT imaging makes the mouse larynx accessible for analysis of genetic and environmental factors affecting shape and matrix composition.

Acute splenic sequestration crisis (ASSC) is a potentially life‐threatening complication of sickle cell disease (SCD), typically occurring in young patients under 5 years of age, with a median age at first episode of less than 2 years. Because a beneficial effect of hydroxyurea (HU) on spleen perfusion and splenic function has been suspected, we hypothesized that HU treatment might be associated with later onset of ASSC in patients with SCD. To investigate this hypothesis, we analyzed data from the ESCORT‐HU study on a large cohort of patients with SCD receiving HU, enrolled between January 2009 and June 2017 with a follow‐up of 7309 patient‐years of observation. The median age at ASSC of the 14 patients who experienced a first episode of ASSC during the study period was 8.0 [IQR: 5.0–24.1] years. The median age at HU initiation was significantly lower in these 14 patients (4.8 [IQR: 3.3–18.7] years) compared to the 1664 patients without ASSC (19.9 [8.8–33.4] years, p = .0008). These findings suggest that ASSC may occur at an unusually late age in patients receiving HU, possibly reflecting longer preservation of spleen perfusion and function secondary to early initiation of HU. Further studies are needed to better characterize the effects of HU on spleen perfusion/function and on the occurrence of ASSC in patients with SCD (ClinicalTrials.gov identifier: NCT02516579; European registry ENCEPP/SDPP/10565).