Evaluation of bone mineral density in patients with severe congenital neutropenia: experience of six centers in Turkey.

Severe congenital neutropenia (SCN) is a rare hematological disorder characterized by a marked reduction in circulating neutrophils and recurrent infections. This study aimed to evaluate bone metabolism in patients with SCN via biochemical and bone mineral density (BMD) measurements. This study included 76 patients who were diagnosed with SCN at six tertiary immunology centers. Demographic, clinical, laboratory, and BMD findings were retrospectively analyzed and measured via dual-energy X-ray absorptiometry (DXA). The study included 76 patients, 39 (51.3%) females and 37 (48.7%) males. The mean age was 206.9 ± 105.1 months, with a median age at diagnosis of 18.5 months (range: 1-264) and a follow-up period of 120 months (range: 2-324). Parental consanguinity was present in 57 patients (75%). Among patients evaluated by DXA, 30 (39.5%) had low BMD, with a mean BMD score of 0.63 ± 0.20 and a Z-score of -2.88 ± 0.90. Osteoporosis was detected in 11 adult patients (29.7%). The most common genetic mutations were HAX1 in 46 patients (60.5%) and ELANE in 15 patients (19.7%). No significant difference in BMD was observed between patients with HAX1 and ELANE mutations (p = 0.60). Granulocyte colony-stimulating factor (G-CSF) was administered to 73 patients. The median G-CSF dose was 5 (2-12) µg/kg/day in the normal BMD group and 5 (2-10) µg/kg/day in the low BMD group. No significant relationship was found between the duration or dose of G-CSF and BMD (p = 0.76, p = 0.38). Additionally, 13 patients received vitamin D, four received calcium, and one was treated with calcitonin and alendronate. Our findings indicate that patients with SCN have a high prevalence of bone mineral loss. The underlying pathophysiology and potential effects of recombinant G-CSF treatment on increased bone mineral loss remain controversial and warrant further investigation.