Aplasia medular carencial por anemia perniciosa hereditaria

Resumen

ANTECEDENTES: La vitamina B12 y sus formas activas (cianocobalamina e hidroxicobalamina) son micronutrientes esenciales para la división y metabolismo celular y se obtiene de la digestión de proteínas animales. La deficiencia de vitamina B12 genera un daño sistémico, generalmente manifestado en alteraciones hematológicas y neurológicas.

CASO CLÍNICO: Paciente masculino de 47 años, con antecedentes familiares de primer grado de anemia perniciosa y otras enfermedades autoinmunitarias, que inició con aplasia medular por deficiencia de vitamina B12. Los estudios etiológicos documentaron anemia perniciosa por biopsia y anticuerpos contra células parietales, con adecuada respuesta a la suplencia.

CONCLUSIONES: Se sugiere practicar estudios genéticos de mutaciones puntuales en los genes AMN, CUBN, GIF y holocortina (vías metabólicas de vitamina B12) y haplotipos HLA-DRB1*03 y DRB1*04 del complejo mayor de histocompatibilidad en pacientes en edades tempranas en los que se sospeche anemia perniciosa hereditaria.

PALABRAS CLAVE: Deficiencia de vitamina B12; anemia perniciosa; factor intrínseco; gastritis atrófica.

Abstract

BACKGROUND: Vitamin B12 and both of its active forms, cyanocobalamin and hydroxycobalamin are essential micronutrients for cellular metabolism and division. Vitamin B12 is mostly obtained from animal-derived proteins, and its deficiency generates a systemic compromise with mainly neurologic and hematologic signs and symptoms.

CLINICAL CASE: A 47-year-old male patient with positive family history for pernicious anemia and several other autoimmune affections presented to the Emergency department with medullary aplasia due to vitamin B12 deficiency. Diagnostic studies showed low levels of vitamin B12, a conclusive biopsy and positive anti-parietal cell antibodies confirmed pernicious anemia. Patient’s symptoms were relieved with vitamin B12 supplementation.

CONCLUSIONS: A genetic panel testing for AMN, CUBN, GIF, and holocortine mutations –all related to the vitamin B12 metabolic pathway–, as well as for the HLA-DRB1*03 and DRB1*04 haplotypes is suggested in young patients presenting with pernicious anemia and positive family history.

KEYWORDS: Vitamin B12 deficiency; Pernicious anemia; Intrinsic factor; Atrophic gastritis.