title: Parathyroid hormone resistance and B cell lymphopenia in propionic acidemia.
abstract: The mechanisms of hypocalcemia, recurrent infections and hypogammaglobulinemia associated with metabolic decompensation of propionic acidemia due to propionyl-CoA carboxylase deficiency have not been defined. A 7-week-old infant with this disorder presented with severe hypocalcemia and B cell lymphopenia during an episode of metabolic acidosis and hyperammonemia. Hypocalcemia (1.1 mmol l-1) was associated with elevated serum intact parathyroid hormone (122 ng l-1), hyperphosphatemia, hypophosphaturia and hypercalcuria, indicating parathyroid hormone resistance. B cell lymphopenia (20 cells microliters-1) was associated with transient neutropenia, anemia and subsequent hypogamma-globulinemia (IgG < 294 mg dl-1, IgM < 8 mg dl-1, IgA < 8 mg dl-1), while T cells were normal. Parathyroid hormone resistance and B cell lymphopenia resolved following treatment with hemodialysis, diet and carnitine. These complications may be due to interference with parathyroid hormone renal tubular action and B cell maturation/proliferation by accumulated organic acids.
authors.affiliation: Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Griffin
authors.forename: R W
authors.initials: RW
authors.lastname: Hostoffer
authors.forename: K Y
authors.initials: KY
authors.lastname: Tserng
authors.forename: D J
authors.initials: DJ
authors.lastname: Lebovitz
authors.forename: C L
authors.initials: CL
authors.lastname: Hoppel
authors.forename: J L
authors.initials: JL
authors.lastname: Mosser
authors.forename: D
authors.initials: D
authors.lastname: Kaplan
authors.forename: D S
authors.initials: DS
authors.lastname: Kerr
mesh_terms: D000592:Amino Acid Metabolism, Inborn Errors / Q000150:complications* / Q000628:therapy; D001402:B-Lymphocytes; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000209:etiology; D007136:Immunoglobulins / Q000172:deficiency; D007223:Infant; D008231:Lymphopenia / Q000209:etiology*; D010281:Parathyroid Hormone / Q000502:physiology*; D011422:Propionates / Q000097:blood*
chemical_list: D007136:Immunoglobulins; D010281:Parathyroid Hormone; D011422:Propionates