The effects of human interleukin 3 (IL-3), macrophage colony-stimulating factor (M-CSF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) were studied on the functional activity of human peripheral blood monocytes from healthy individuals and from eight patients at 4, 8 and 12 weeks following autologous bone marrow transplantation (ABMT). Functions studied included superoxide production, phagocytosis of Candida albicans and reduction of 3-[4,5-dimethylthiazol-2-yl]-2.5-diphenyl tetrazolium bromide (MTT). IL-3 and GM-CSF significantly enhanced the oxidative metabolism of monocytes from healthy individuals, while the effect of M-CSF was moderate. A considerable variability between healthy individuals was found in both resting and cytokine-stimulated monocytes with regard to superoxide production. All three investigated CSFs, i.e. IL-3, M-CSF and GM-CSF did not affect phagocytosis of C. albicans by the cells or their metabolic activity (reduction of MTT). In ABMT patients no deficit in the functional activity of monocytes was found at any time after transplantation and all three CSFs investigated did not modulate the functional activity of the cells. These results suggest that monocytes do not have a major role in infectious complications post-ABMT.

Adolescent↗

PubMedDate not supplied

Arylsulfatase A pseudodeficiency: altered kinetic and heat-inactivation properties.

Arylsulfatase A (ASA) pseudodeficiency (PD) was described in clinically healthy individuals with ASA-deficient activity. To confirm that the PD individual in the present study is homozygous for the PD allele without any other mutations, direct solid-phase sequencing was done and the two A-to-G transitions--one at the third N-glycosylation site (N350S) and the other at the first polyadenylation signal (ATTAAC to AGTAAC)--were identified. No other mutations were detected in the entire coding region nor in the intron-exon boundary region of the ASA gene in the PD cells. Kinetic studies to compare the partially purified ASA from controls to that from a homozygote (PD allele) were carried out using p-nitrocatechol sulfate (p-NCS) as a substrate. The apparent Km for the control ASA was 0.6 mM and for the PD enzyme 2.0 mM (p < 0.01). The heat inactivation at 60 degrees C revealed 50% inactivation within 90 min for control ASA and 28 min for PD ASA. At 65 degrees C, the 50% inactivation was reached at 18 min for the control and at 8.5 min for the PD. These results document the decreased affinity of ASA toward p-NCS and increased heat inactivation from a PD individual. Western blot analysis following SDS-PAGE and isoelectric focusing revealed differences in both the molecular weight and the isoelectric point between the control ASA and that of the PD allele. To the best of our knowledge, this is the first report showing the altered properties of ASA from a PD homozygote.

Alleles↗

PubMedDate not supplied

Long-term outcome in treated combined methylmalonic acidemia and homocystinemia.

PURPOSE: To describe the clinical and biochemical features and long-term outcome of a cohort of eight patients with methylmalonic acidemia and homocystinuria (cblC). METHODS: Documentation of clinical features at birth and longitudinal follow-up of the biochemical and clinical response to treatment with daily oral carnitine and intramuscular hydroxocobalamin observed during continuous follow-up for an average of 5.7 years. RESULTS: Our patients had an increased incidence of congenital malformations including microcephaly (<5%) at birth (2 of 8), congenital heart disease (2 of 8), dysmorphic facial features (1 of 8), and thyroglossal duct cyst (1 of 8). Postnatal hydrocephalus (2 of 8) and hip dislocation caused by ligament laxity (1 of 8) were also noted. One patient had profound visual impairment before 6 months of age secondary to cblC retinopathy, and two patients had abnormal retinal pigmentation with normal visual function. All patients presented with poor growth, feeding problems, and/or seizures. No patients had acute acidotic crises before or after treatment. All patients had dramatic reduction of plasma free homocystine and urine methylmalonic acid excretion after initiation of therapy with carnitine, intramuscular (IM) hydroxocobalamin (OHcbl) and, in two cases, oral betaine. Growth was significantly improved in most cases after the initiation of therapy, and microcephaly was resolved in one patient. All patients were developmentally delayed regardless of age of treatment onset, although two patients had relatively mild developmental delay. CONCLUSION: cblC patients may have an increased incidence of congenital malformations suggesting prenatal effects of abnormal cbl metabolism. Treatment with IM OHcbl and carnitine successfully corrects the biochemical abnormalities and improves growth. Developmental delay of variable severity is always present regardless of age at diagnosis or treatment onset.

Adolescent↗

PubMedDate not supplied