The role of transferrin saturation as a screening test for hereditary haemochromatosis in an Irish population seeking medical care.

BACKGROUND: Genetic studies have indicated a high prevalence of mutations for hereditary haemochromatosis (HH) in Irish populations. Given the high cost of genetic screening and the ethical implications thereof, we assessed the role of transferrin saturation (TS) as a primary screening test for HH in an Irish population seeking medical care. METHODS: TS and ferritin were measured on 330 consecutive blood specimens received in the laboratory for routine screening. Patients with TS > 45% were genetically screened for the C282Y and H63D mutations. RESULTS: Twenty-six patients had TS values > 45%. Of these, specimens were available for genetic screening on 20 patients. Three previously undiagnosed patients were found to be C282Y homozygotes and one a compound heterozygote (C282Y/H63D). The prevalence of C282Y homozygotes was 0.93%, which is similar to the reported prevalence found in Irish populations by genetic screening. CONCLUSION: Given the number of positive findings in this study, we conclude that, in the absence of a national programme, TS could be used as part of a health-screening panel in the Irish setting. Patients expressing iron overload would be detected before organ damage occurred, leading to less severe clinical disease and better patient prognosis.

A novel lectin-based enzyme-linked immunosorbent assay for the measurement of IgA1 in serum and secretory IgA1 in secretions.

Jackfruit lectin (Jacalin) specifically binds IgA1 and secretory IgA1 (sIgA1). Jacalin was successfully purified, and used as the immobilized phase in novel noncompetitive enzyme-linked immunosorbent assays (ELISAs) for the measurement of IgA1 in serum and sIgA1 in saliva, using jacalin affinity purified material as standards. A non-competitive ELISA for the measurement of total sIgA was also developed using commercially available reagents.

Immunoglobulin G subclasses and spirometry in patients with chronic obstructive pulmonary disease.

Immunoglobulin G (IgG) subclass levels were measured in 58 patients with chronic obstructive pulmonary disease (COPD) and in 125 healthy controls. Total IgG values were significantly lower in the 27 COPD patients on steroid therapy compared with patients not taking steroids (8.31 (0.14) vs 9.80 (0.14), p less than 0.05), geometric mean (log SD). Total IgG (9.80 (0.14) vs 12.18 (0.16), p less than 0.005), IgG1 (5.87 (0.19) vs 6.68 (0.12), p less than 0.05) and IgG2 levels (2.75 (0.21) vs 3.70 (0.20), p less than 0.005) were significantly reduced in the COPD patients not taking steroids compared with the controls. IgG3 values were significantly elevated in smokers compared with nonsmokers in both the control and COPD groups. Fifteen COPD patients (25.9%) had a low level of one or more subclasses. IgG2 subclass deficiency was the most common, being present in 9 patients. A significant correlation was found between forced expiratory volume in one second (FEV1) and IgG2 subclass levels (r = 0.415; p less than 0.005). IgG subclass deficiencies may contribute to the development and progression of respiratory disease in COPD patients.