Niveles bajos de fosfatasa alcalina en niños, revisión retrospectiva / Low levels of alkaline phosphatase in children, retrospective review

Introducción: Los niveles elevados de fosfatasa alcalina (FAL) son utilizados en la evaluación de enfermedades hepatobiliares y óseas, pero los niveles disminuidos en general, no son tenidos en cuenta a pesar de ser indicadores de enfermedad como la Hipofosfatasia. Es importante contar con valores de referencia ajustados para edad y sexo. Objetivo: Determinar en los niños que consultan al endocrinólogo pediatra, la proporción de pacientes que presentan una FAL disminuida. Material y Métodos: Se realizó una revisión de corte transversal, retrospectiva, de todas las FAL que se determinaron a pacientes en consulta en la División de Endocrinología Infantil. Resultados: se obtuvieron 5.110 determinaciones de FAL, 938 (18%) presentaban una FAL menor a 100 U/L, los cuales correspondían a 634 pacientes. Los pacientes menores de 18 años fueron categorizados de acuerdo con los valores de referencia de D'Isa y col. y de Colantonio y col. La distribución etaria fue dispersa, con un rango de 2,94 años a 16,13 años, una mediana de 11,88 años; 93% pertenecía al sexo femenino y se describieron los datos clínicos relevantes de los pacientes. Si bien en sus historias clínicas se encontraba registrado, dicho valor no fue jerarquizado. Conclusión: La proporción de pacientes con niveles de FAL menores a 100 U/L es de un 18% que disminuye notablemente si se consideran algunos métodos de referencia propuestos. Es indispensable contar con valores de referencia de FAL ajustados a sexo y edad adecuados para alertar al médico de valores bajos y altos de FAL

Introduction: High levels of Alkaline Phosphatase (ALP) are used in the evaluation of hepatobiliary and bone diseases, but generally decreased levels are not considered despite being indicators of disease such as hypophosphatasia. It is important to have reference values adjusted for age and sex. Objective: to determine in the children who consult the pediatric endocrinologist, the proportion of patients who have a decreased ALP. Material and Methods: A cross-sectional, retrospective review was made of all the ALP´s that were determined to patients in consultation at the Division of Pediatric Endocrinology. Results: 5110 ALP determinations were obtained, 938 (18%) had an ALP less than 100 U/L, which corresponded to 634 patients. Patients younger than 18 years were categorized according to the reference values of D'Isa et al., and Colantonio et al. The age of distribution was scattered, with a range of 2.94 years to 16.13 years, a median of 11.88 years and 93% belonged to the female sex, and the relevant clinical data of the patients were described. Although it was registered in medical records, this value was not considered relevant. Conclusion: The proportion of patients with FAL levels lower than 100 U / L is 18%, which decreases considerably if some proposed reference methods are considered. It is essencial to have FAL reference values adjusted to sex and age to alert the physician of low and high FAL values

Characterization of four Latin American families confirms previous findings and reveals novel features of acid-labile subunit deficiency.

OBJECTIVE: Acid-labile subunit deficiency (ACLSD), caused by inactivating mutations in both IGFALS gene alleles, is characterized by marked reduction in IGF-I and IGFBP-3 levels associated with mild growth retardation. The aim of this study was to expand the known phenotype and genetic characteristics of ACLSD by reporting data from four index cases and their families. DESIGN: Auxological data, biochemical and genetic studies were performed in four children diagnosed with ACLSD and all available relatives. METHODS: Serum levels of IGF-I, IGFBP-3, acid-labile subunit (ALS), and in vitro ternary complex formation (ivTCF) were determined. After sequencing the IGFALS gene, pathogenicity of novel identified variants was evaluated by in vitro expression in transfected Chinese hamster ovarian (CHO) cells. ALS protein was detected in patients' sera and CHO cells conditioned media and lysates by Western immunoblot (WIB). RESULTS: Four index cases and four relatives were diagnosed with ACLSD. The following variants were found: p.Glu35Glyfs*17, p.Glu35Lysfs*87, p.Leu213Phe, p.Asn276Ser, p.Leu409Phe, p.Ala475Val and p.Ser490Trp. ACLSD patients presented low IGF-I and low or undetectable levels of IGFBP-3 and ALS. Seven out of 8 patients did not form ivTCF. CONCLUSIONS: This study confirms previous findings in ACLSD, such as the low IGF-I and a more severe reduction in IGFBP-3 levels, and a gene dosage effect observed in heterozygous carriers (HC). In addition, father-to-son transmission (father compound heterozygous and mother HC), preservation of male fertility, and marginal ALS expression with potential involvement in preserved responsiveness to rhGH treatment, are all novel aspects, not previously reported in this condition.