Relationship between Bone Mineral Density and Selected Parameters of Calcium-Phosphate Economy with Dietary Management and Metabolic Control in Polish Pediatric Patients with Classical Homocystinuria-A Preliminary Study.

BACKGROUND: Classical homocystinuria (HCU) is an inborn defect of methionine metabolism caused by a deficiency of the enzyme cystathionine ß-synthase (CBS). The main symptoms of classical homocystinuria are lens subluxation, bone lesions, vascular disease and developmental delay/intellectual disability. The treatment method for HCU is a methionine-poor diet supplemented with amino acid preparations. The aim of the study was to examine the relationship of dietary factors, metabolic compensation and selected skeletal parameters in patients with HCU. METHODS: Bone mineral density measurements (DXA) were performed in pediatric patients with HCU, and blood levels of selected amino acids, minerals and vitamins, as well as dietary nutritional value, were analyzed. RESULTS: A total of 11 patients with HCU whose median age was 9.3 years were enrolled in the study. The median DXA total body less head of HCU patients was -0.4 z-score, and the lumbar spine was -1.4 z-score. Despite supplementation, calcium intake was below the age norm. Average vitamin D3 intake was in line with recommendations, but 36% of patients had reduced blood levels. Bone mineral density depended on blood levels of 25-hydroxyvitamin D, homocysteine and methionine, as well as on BMI, age and intake of natural protein (R2 = 98.5%, p = 0.015; R2 = 86.7%, p = 0.0049) and protein from an amino acid preparation (r = 0.69, p = 0.026). CONCLUSION: The results of the study indicate the need for regular densitometry in patients with HCU and also the use of additional calcium and vitamin D3 supplementation. It is also necessary to perform a comprehensive analysis of the diet and metabolic controls.

Long-term outcome of patients with alpha-mannosidosis - A single center study.

INTRODUCTION: Alpha-mannosidosis (AM) is a rare autosomal recessive lysosomal storage disease which the natural history has not been exhaustively described yet. The aim of this study was to present the long-term follow-up of 12 Polish patients with AM, evaluate the clinical, biochemical, and molecular findings and progression of the disease. MATERIAL AND METHODS: The article presents a long-term (over 30 years) observational, retrospective, single-center study of patients with AM. RESULTS: The hearing loss, as one of the first symptoms, was detected in childhood (mean age of 2 years and 6 months) in 10 patients. The other symptoms include: recurrent infections (all patients), inguinal hernias (6 patients), craniosynostosis (1 patient). The mean age at AM diagnosis was 6 years while median was 4 years (age range: 1 year and 8 months - 12 years). The most commonly identified variant in the MAN2B1 gene was c.2245C > T, p.(Arg749Trp). The mean time of follow-up in our study was approximately 14 years (range: 1 year - 26 years). Following birth, children with AM grow slowly, finally reaching the 3rd percentile (or values below the 3rd percentile). Hearing loss was not progressive while a gradual exacerbation of intellectual disability with no developmental regression was observed in all patients. Ataxia was diagnosed in 6 patients in the second decade of life (age range 15-20 years). CONCLUSIONS: Our study revealed the sensorineural hearing loss as one of the first noted symptom in AM which was congenital and non-progressive during the natural course of disease. A detailed anthropometric phenotype of AM patients was provided with observation of the growth decline during the long-term follow-up. Our study confirmed the existence of two distinguished clinical phenotypes of AM (mild and moderate), and also the lack of clear genotype-phenotype correlation.

Progressive macrophage accumulation in lysosomal acid lipase deficiency.

Lysosomal acid lipase (LAL) deficiency (LAL-D) is a lysosomal lipid storage disorder in which the accumulation of cholesteryl esters and triglycerides predominantly in hepatocytes and cells of the macrophage-monocyte system is observed. The disturbance in the synthesis and trafficking of cholesterol and other lipids (triglycerides as well as phospholipids) as well as the systemic lipoprotein dysregulation, reflects the pathophysiology of LAL-D. The aim of this study was to present the occurrence of macrophage derived structures in LAL-D patient, and to provide an overview on underlying mechanisms, as the literature about the presence of such cluster cells in LAL deficiency is sparse. We describe the case of LAL-D patient diagnosed at 3 years of age, in whom the massive macrophage accumulation resulting in the abdominal lymphadenopathy, subcutaneous papules and hepatosplenomegaly, have been observed within 4 years since diagnosis. Histopathological examination of the excised lymph nodes and subcutaneous papules revealed them to be diffusely infiltrated by lipid-overloaded histiocytes. The immunohistochemistry revealed the macrophages to be CD68-positive. This study comprises one of the first reports of accumulation of lipid-laden macrophages throughout the body in the course of LAL-D.