Accuracy of serum transferrin receptor levels in the diagnosis of iron deficiency among hospital patients in a population with a high prevalence of thalassaemia trait.

The diagnosis of iron deficiency in hospital patients can be difficult in the presence of inflammation. A raised serum transferrin receptor (sTfR) level is useful as a marker of iron deficiency as it is unaffected by inflammation. However, diseases that cause an increase in erythropoietic activity can also result in a raised sTfR level. In South-East Asia, the prevalence of thalassaemia trait is high. As thalassaemia trait is associated with ineffective erythropoiesis and therefore an increase in the sTfR level, we studied the influence of thalassaemia trait on the diagnosis of iron deficiency in hospital patients. Among 431 patients with different combinations of iron deficiency, alpha- and beta-thalassaemia trait, we found that the sTfR level is an excellent diagnostic test for iron deficiency only in patients without thalassaemia trait. alpha-Thalassaemia trait worsened its diagnostic accuracy and beta-thalassaemia trait rendered it a non-diagnostic test. We conclude that in populations with a high prevalence of thalassaemia trait, the sTfR level is not useful in diagnosing iron deficiency unless the patient's thalassaemia status is known.

Should high sensitive C-reactive protein measurement be included in health screening packages?

INTRODUCTION: The Centers for Disease Control and Prevention (CDC) and the American Heart Association (AHA) have endorsed the optional use of high sensitive C-reactive protein (hsCRP) to identify patients without known coronary heart disease but who may be at higher absolute risk than estimated by major risk factors. This study assessed the potential value of hsCRP measurement in addition to routine lipid and risk factor assessment on patient management for individuals undergoing multiphasic health screening. METHODS: hsCRP was measured on fasting lipid samples on patients attending the Health Enrichment Clinic at Tan Tock Seng Hospital between January and April 2004. These results were then compared with the outcome of individual patient risk assessment (using the 2001 Singapore Ministry of Heath Clinical Practice Guidelines on Lipids), the patient's lipid results and whether the patient was already on anti-lipid treatment. RESULTS: 212 samples were analysed for hsCRP. Seven patients were already on anti-lipid drugs. Using the AHA/CDC guidelines, hsCRP measurement would be of value in deciding management in 12.7 percent of all patients. Of this group, 11 percent had hsCRP concentrations in the high risk category. Restricting hsCRP measurement to only those patients with two or more cardiac risk factors and not on anti-lipid drugs would increase the proportion of patients where hsCRP could be useful in deciding management, to 81.8 percent. CONCLUSION: For clinicians prepared to consider treatment in patients with elevated hsCRP levels, hsCRP measurement should be included as part of health screening packages to selected patients based on individual cardiac risk assessment.

Comparison of four point-of-care HbA1c analytical systems against central laboratory analysis.

OBJECTIVE: To assess four commercially available point-of-care HbA1c analytical systems with respect to (1) inaccuracy against the central laboratory HbA1c method and (2) imprecision against the HbA1c analytical goal of coefficient of variation < 3%. METHODS: Analytical inaccuracy was assessed by analysis of 110 patient samples on all five analytical platforms (Biorad Diastat, Drew DS5, Bayer DCA 2000, Nycomed Nycocard and Roche Tinaquant (used in central lab)). Analytical imprecision was assessed by analysis of two levels of patient sample four times daily for six days, as well as analysis of two levels of commercial control. RESULTS: Deming linear regression for agreement: Diastat=0.98 x Tinaquant + 0.36; DS5=1.23 x Tinaquant - 0.65; DCA2000=0.95 x Tinaquant + 0.63; Nycocard=0.94 x Tinaquant + 0.92. Analytical coefficients of variation (CVs) at Tinaquant HbA1c levels of 6.2-10.8% were: Tinaquant 0.8-1.1%, Diastat 1.6-6.6%, DCA2000 2.6-7.2%, DS5 5.1-11.7%, Nycocard 8.5-15.3%. Two HbE samples gave elevated HbA1c results with the DS5 method. CONCLUSIONS: The Diastat and DCA2000 systems gave the best performance with acceptable imprecision and good agreement with both the central lab and each other. The DS5 was less precise with a significant positive bias compared to the other methods and interference from HbE, while the Nycocard system showed the poorest precision in the evaluation. The Diastat and DCA2000 systems appear to be satisfactory analytical alternatives to both central laboratory (Tinaquant) testing and each other.

A preliminary study of the utility of combined cardiac markers in the evaluation of patients presenting early with suspected acute coronary syndrome.

OBJECTIVE: The aim of the study was to investigate and compare the usefulness and accuracy of various cardiac markers [troponin I, creatine kinase MB (CKMB) mass, creatine kinase (CK), CKMB activity] to aid early diagnosis of myocardial infarction. We also examined the ability of the various cardiac markers to prognosticate future adverse cardiac events. MATERIALS AND METHODS: Patients admitted within 8 hours of maximal chest pain suggestive of acute coronary syndrome with non-diagnostic electrocardiograms were recruited. Blood samples were obtained on admission to the wards and repeated 4 hours later. These results were later correlated to the final hospital discharge diagnosis. RESULTS: The 37 patients in the study were a high-risk population with over 50% presenting with a Thrombolysis in Myocardial Infarction (TIMI) risk score of greater or equal to 3. Myoglobin was the most sensitive marker (100% sensitivity) in early prediction of patients who were subsequently diagnosed to have a myocardial infarction. Patients with an elevated troponin I level but normal CK and myoglobin levels had a significantly higher risk of developing a major adverse clinical event (MACE) within 3 months of the initial presentation. CONCLUSION: Myoglobin is the most sensitive marker when compared to CK, CKMB and troponin I for diagnosing patients presenting early with chest pain and a non-diagnostic electrocardiogram and who subsequently develop either a ST-elevation myocardial infarction or non-ST elevation myocardial infarction. Patients with an elevated troponin I level but normal CK and myoglobin levels are at higher risk of an adverse clinical event.

A randomized trial of tacrolimus (FK506) versus total lymphoid irradiation for the control of repetitive rejection after cardiac transplantation.

Recurrent cardiac rejection is a major cause of morbidity during the initial 6 months following transplantation. We compared treatment with tacrolimus versus total lymphoid irradiation in 13 heart transplant recipients on a cyclosporine, azathioprine, and prednisolone regimen, who experienced repetitive rejection. The mean number of episodes of rejection significantly decreased in both groups, with no deaths and no increase in the incidence of infection, hypertension, diabetes, or renal impairment following either treatment at 12-month follow-up. Conversion to tacrolimus or a course of lymphoid irradiation are equipotent strategies, of comparable cost, for the prevention of further rejection in patients with recurrent rejection.

Comparison of the diagnostic utility of CK, CK-MB (activity and mass), troponin T and troponin I in patients with suspected acute myocardial infarction.

OBJECTIVE: The aim of the study was to investigate the clinical performance of serum creatine kinase (CK), CKMB (mass and activity), Troponin T (TnT) and Troponin I (TnI) in the diagnosis of acute myocardial infarction (AMI) in patients admitted to the Coronary Care Unit at Tan Tock Seng Hospital between June and July 1998. METHODS: Routine blood samples sent to the laboratory for cardiac enzyme determination (CK, CKMB activity) were stored at -20 degrees C for later determination of CKMB mass (Abbott Axsym, Ortho Clinical Diagnostics (OCD) ECi and Roche Elecsys), Troponin I (Abbott Axsym) and Troponin T (Roche Elecsys). For CKMB mass measurements, the relative index (RI = CKMB mass/CK) was calculated. The diagnosis of acute myocardial infarction was obtained from inspection of clinical notes and/or discharge diagnosis for each patient. RESULTS: Forty-four of fifty-nine specimens were from AMI patients. Area under Receiver Operating Curve values were: CK 0.56, CKMB activity 0.72, percentage of CKMB activity 0.73, CKMB mass (Abbott) 0.76, CKMB mass (Roche) 0.77, CKMB mass (OCD) 0.78, RI (Roche) 0.83, RI (Abbott) 0.86, RI (OCD) 0.87, TnT 0.94, TnI 0.95. Sensitivity: TnI 88%, TnT 93%; specificity TnI 100%, TnT 92%. There was no significant difference in performance between Troponin T and Troponin I assays or between any of the CKMB mass measurements. CONCLUSION: Troponin T and I are superior to CKMB (mass or activity) and CK in the identification of patients with AMI. Combining multiple sampling of the percentage of CKMB with single confirmatory troponin testing may provide a cost-effective testing protocol for suspected AMI patients.

Polycythemia vera and water-induced pruritus: evidence against mast cell involvement.

The mechanism of water-induced pruritus in patients with polycythemia vera is unknown. Evidence has been presented previously that bathing or showering may trigger mast cell degranulation and that release of a mediator by mast cells may be responsible for the pruritus. Tryptase is a specific marker of human mast cell secretory granules and its presence in body fluids indicates mast cell degranulation. In this study, serum tryptase levels were measured both before and one hour after showering in 11 patients suffering from polycythemia vera and water-induced pruritus. Tryptase was not found in the serum of any of the subjects one hour after showering, when levels would be expected to be near peak had significant mast cell degranulation occurred. These results argue against mass cell degranulation with systemic release of a mast cell product as the mechanism for water-induced pruritus in patients with polycythemia vera.

Pseudohyperphosphataemia in multiple myeloma.

Two cases of spurious hyperphosphataemia in patients with multiple myeloma are presented. An unreduced phosphomolybdate method without dialysis was used and the falsely raised values are shown to be due to the formation of a proteinaceous suspension in the reaction mixture. Such interference may be more prevalent than is generally recognized, and care should be taken to identify the problem in patients with myeloma.

The attributional model of depression: a path analysis test in a naturalistic setting.

A path analysis test of the attributional model of depression was conducted in a naturalistic achievement setting (N = 77). Relatively depressed and nondepressed students reported their attributions on an academic test, and then their subsequent test performance were measured. In support of the attributional model of depression, the results indicated that for successful outcomes the attribution dimension of stability (i.e., stable vs. unstable across different situational contexts) served to buffer the influence of depression on later test performances. The results thus show that stability attributions for a successful behavior, defined in terms of consistency across different situational contexts, play a mediating role in the behavioral consequences of depression.

Pleasures and pounds: an exploratory study.

This study investigated the hypothesis that overweight college students and normal weight "restrained" students, particularly those susceptible to stress related overeating and binge episodes, have a restricted range of pleasurable activities available for positive reinforcement of behaviors other than eating. The major finding was that overweight students in a behavioral weight control program reported less enjoyment of pleasant activities than did normal weight classroom control subjects. The relationship of the amount and variety of pleasurable activities to subsequent body weight fluctuations, however, was ambiguous.

Anxiety reduction in hospitalized schizophrenics through thermal biofeedback and relaxation training.

Biofeedback training and muscular relaxation have therapeutic value for general reduction of tension in non-patient and patient populations. The present study investigated the efficacy of thermal biofeedback and relaxation as adjunctive treatments to antipsychotic medication for reduction of anxiety in 40 hospitalized schizophrenics who were randomly assigned assigned to four groups: biofeedback, relaxation, biofeedback and relaxation, and minimal treatment control. Significant reduction in anxiety followed treatment, but there were no between-group differences. One-year follow-up and post boc analyses indicated a subgroup of "anxious" schizophrenics who showed substantial reduction in anxiety following treatment with biofeedback and relaxation.