C282Y hemochromatosis gene mutation and iron parameters in dialysis patients.

BACKGROUND: Hereditary hemochromatosis is an autosomal recessive condition causing excessive intestinal iron absorption related to C282Y hemochromatosis mutation gene. Dialysis patients receive intravenous iron supplements as treatment for anemia. The gene mutation frequency and its influence on iron deposits and intravenous iron response are unknown in these patients. STUDY DESIGN: Prospective observational. SETTING AND PARTICIPANTS: 290 dialysis patients in Gran Canaria, Spain. OUTCOMES AND MEASUREMENTS: The C282Y hemochromatosis mutation gene was studied. Other active players in iron metabolism have not been included in this study. Red cell parameters, serum iron, transferrin and ferritin concentrations were measured every 2 months for 2 years. RESULTS: No differences in allelic and genotypic frequencies between dialysis patients and the general population were detected. Baseline clinical or analytical parameters were similar in C282Y +/- and C282Y -/- patients. Among those who did not need intravenous iron treatment, C282Y+/- patients maintained constant serum ferritin (302.1 ± 216.7 vs. 319.5 ± 300.5 µg/l after 4 months), whereas C282Y-/- patients showed decreased levels during the same period (306.7 ± 212.2 vs. 221.6 ± 167.8 µg/l, p < 0.001). After 4 months of parenteral iron, serum ferritin increased more intensely in C282Y +/- patients than in C282Y -/- patients (934.2 ± 195.8 vs. 658.7 ± 259.9 µg/l, p < 0.001). A multivariance analysis identified the C282Y allele as the most important factor that explains this difference. CONCLUSIONS: Heterozygosity for the C282Y allele of the hemochromatosis mutation gene could be associated with differences in iron parameters in dialysis patients.

Longitudinal study of serum copper and zinc levels and their distribution in blood proteins after acute myocardial infarction.

The levels and distribution of serum Cu and Zn were studied in patients diagnosed with acute myocardial infarction from the day of admission to the Cardiovascular Intensive Care Unit until the 10th day following the attack. The results obtained show that Cu increases significantly (p < 0.01) after the 5th day after the acute myocardial infarction, while Zn decreases significantly (p < 0.01) with respect to the control group from the first day on, with the lowest values being found on the 3rd day after the attack. Further, total serum Cu showed an excellent correlation with the albumin-bound and globulin-bound Cu (ceruloplasmin), as well as with the concentrations of both serum protein fractions. In contrast, total serum Zn only presents this correlation with Zn bound to albumin, but not with Zn bound to globulin nor with the albumin concentration. These findings suggest the existence of some type of relationship between the two fractions of the element bound to protein. This relationship is probably different for both metals.

Evaluation of canine serum thyrotropin (TSH) concentration: comparison of three analytical procedures.

A comparative study of 3 analytical methods (immunoradiometric assay, enzyme immunometric assay, and chemiluminescent immunometric assay) for canine serum thyrotropin (TSH) was performed. Ninety-six dogs were included in the study. The within- and between-run precision was evaluated for each method, and correlations for the results obtained with each method were examined. The best within- and between-run precision was obtained with the chemiluminescent immunometric assay. Satisfactory correlations for the 3 analytical procedures were obtained but varied in relation to serum TSH concentration.

Inter-alpha-trypsin inhibitor heavy chain 4 as a marker of acute rejection in pancreas allotransplantation in pigs.

BACKGROUND/AIMS: An early, simple, and reliable marker for acute pancreatic allograft rejection is not available. Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) is an interleukin-6-dependent acute-phase positive protein that can act as an anti-inflammatory protein. We studied the response of the ITIH4 in pigs undergoing pancreas allotransplantation (PT) and evaluated this protein as a biomarker for acute graft rejection. METHODS: PT with enteric drainage of the exocrine secretion and systemic venous drainage was performed on 12 Landrace pigs. No immunosuppression was administered. Serum concentrations of glucose, amylase, lipase, insulin, C-peptide, and ITIH4 were determined daily. RESULTS: The response of ITIH4 to PT was early, intense, and prolonged, with 2 peaks in serum concentration. The first peak, which started on day 1 and reached maximum (around 6 mg/dL) on day 3, was attributed to the systemic acute phase response to surgical stress. The second peak, which exceeded the first peak and reached maximum (>8 mg/dL) on day 6, began when the recipients were still normoglycemic, and preceded onset of the diabetic state caused by acute graft rejection by an average of 4 days. CONCLUSION: Serum ITIH4 could help to predict subclinical acute graft rejection after PT in pigs.

Thyroxine in unextracted urine.

The aim of this work was to estimate the daily urinary excretion of free and conjugated thyroxine using a direct radioimmunoassay and enzyme hydrolysis. The renal clearance of free T4 was also determined. The mean urinary values of free and total T4 (mean +/- 1 SD) in 112 euthyroid controls were 1353 +/- 496 and 1855 +/- 651 pmol/24 h, respectively. Urinary excretion of free hormone in 13 hyperthyroid patients was 5552 +/- 4320 pmol/24 h and total T4 was 8122 +/- 7219 pmol/24 h. Urinary free T4 excretion was 223 +/- 223 pmol/24 h in hypothyroid patients and total T4 was 542 +/- 490 pmol/24 h. These results indicate that daily urinary T4 excretion is a good indicator of thyroid function. The mean renal clearance of free T4 was 52 +/- 19 ml/min (mean +/- 1 SD) in euthyroid patients, 53.7 +/- 12.3 ml/min in hyperthyroid patients, and 67.6 +/- 13.1 ml/min in hypothyroid patients. We estimated the endogenous creatinine renal clearance as a control of the renal filtration rate. The data suggest that there is T4 filtration of unbound T4 and partial tubular reabsorption. Further experimental studies will be necessary to clarify the renal handling of thyroxine as well as the fate of reabsorbed T4.

Urinary triiodothyronine excretion.

The purpose of this work was to estimate the 24 h urinary excretion of free and conjugated triiodotironine (T3) using a direct radioimmunoassay and enzyme hydrolysis. Mean urinary values of free and total T3 (mean +/- 1 SD) in euthyroid controls were 2074 +/- 673 and 2819 +/- 809 pmol/24 h respectively. In patients with hyperthyroidism, values of free hormone were about 4.2 times higher than the mean value of the euthyroid controls, and about one-third in patients with hypothyroidism. These results show this measurement to be useful as an indicator of thyroid function. Mean renal clearance of free T3 was 211.6 +/- 62.8 ml/min (mean +/- 1 SD) in euthyroid controls, 260.8 +/- 87.5 ml/ml in hyperthyroid patients and 229 +/- 98.7 ml/min in hypothyroid patients. The data show that T3 renal clearance is, in all cases, greater than glomerular filtration rate, suggesting tubular secretion of T3.