Validation of the novel Martin method for LDL cholesterol estimation.

INTRODUCTION: Accurate determination of low-density lipoprotein cholesterol (LDL) is important for coronary heart disease (CHD) risk assessment among others. A low-cost method used is the Friedewald equation, calculating LDL from total cholesterol after subtracting high-density lipoprotein cholesterol (HDL) and triglycerides divided by 5. A new calculation method has been proposed where the value of 5 is not fixed but depends on the values of the other parameters. RESULTS: We validated this method in a Greek population sample, by comparing direct LDL, the Friedewald equation and the novel method. Some clinical laboratories use the direct determination when TG > 200 mg/dl (2.26 mmol/lt). We performed segmented linear regression to check if this value makes sense. Bayesian linear regression was performed to compare the direct determination to the Friedewald and novel one. CONCLUSIONS: We found that TG > 200 mg/dl is a sensible threshold value since it is a saddle point for the standard error of the regression. For Bayesian linear regression, the results were inconclusive. When the LDL values were used for classification of CHD, it turned out that the novel method was better than the Friedewald equation at correctly classifying LDL levels for CHD risk assessment.

Overall survival and clinicopathological characteristics of patients with breast cancer in relation to the expression pattern of HER-2, IL-6, TNF-α and TGF-ß1.

The present study was conducted to investigate the prognostic significance of co-expression patterna of HER-2, IL-6, TNF-a and TGF-ß1 in breast cancer, by correlating the number of markers with positive expression with clinicopathological characteristics indicative of tumor progression and overall survival. One hundred thirty consecutive patients with primary breast cancer were prospectively included and evaluated. Serum concentrations of the above markers were measured by ELISA. Median split was used to subdivide patients with marker positive or negative expression. The presence of ≥ 3 positive markers was independently associated with extended lymph node (>3) involvement (aOR, 11.94, p=0.001) and lymphovascular invasion (aOR, 12.04, p=0.018), increasing the prognostic significance of each marker considered separately. Additional prognostic information regarding survival was also provided; as the number of positive markers increased, a gradually reduction of survival time was observed. In addition, patients with 4 positive markers had significantly shorter survival (25 vs 39 months, p=0.006) and a more than 4 fold increased risk of death (aHR, 4.35, p=0.003) compared to patients with 3 positive markers. Our findings suggest that the coexpression pattern of these four markers could be used clinically as a useful marker for tumor extension and outcome of breast cancer.

Phenotype and genotype frequency of ß-thalassemia and sickle cell disease carriers in Halkidiki, Northern Greece.

A decade of screening (years 2000 to 2010) for hemoglobinopathies in 3,931 patients was performed at the General Hospital of Poligiros, Halkidiki, Northern Greece. Among the patients examined, 10.8% heterozygotes for ß-thalassemia (ß-thal) were found, as well as 4.1% with sickle cell disease and 1.2% with double ß-thal/Hb S [ß6(A3)Glu→Val] heterozygosity. Iron deficiency was observed in 23.4%. The geographical distribution in the region revealed a substantial incidence of hemoglobinopathies even in mountainous areas. This pattern did not follow the typical distribution according to the malaria hypothesis, as incidence did not dovetail with swamp locations recorded in the past. The HBB gene mutations for 85 patients were also analyzed. Most prevalent in Halkidiki, Northern Greece, was the codon 39 (C>T) mutation (27.1%) followed by the IVS-I-110 (G>A) mutation (22.4%); this was in direct contrast to the current distribution of the same mutations seen in the rest of Greece (Greek National Genetic Database, GNGD). This frequency inversion was statistically significant, with the difference from the GNGD being 20.6% for the IVS-I-110 mutation (p <0.0005) and 7.6% for the codon 39 mutation (p = 0.0238). The history of Halkidiki, denoting a clear example of geographical isolation from the rest of the country, may possibly account for a potentially diverse genetical identity of the disease in this region.

Effect of HbS in the determination of HbA2 with the Biorad Variant II analyzer.

OBJECTIVES: The effect of the presence of HbS in the determination of HbA2 using the Biorad Variant II analyzer. DESIGN AND METHODS: The effect of HbS presence in the samples was quantified using the HELENA SAS-MX alkaline gel electrophoresis kit as the reference method. RESULTS: The %HbA2 values from the Variant II analyzer and the HELENA SAS-MX alkaline gel electrophoresis kit show a good linear correlation in the absence of HbS. A strong positive bias in the %HbA2 values from the Variant II is apparent in the presence of HbS in the samples, when compared to the alkaline electrophoresis gel. CONCLUSION: The Variant II analyzer gives reliable results for %HbA2 determination when no HbS is detectable in the samples. When HbS is present, the gel electrophoresis method gives more accurate results.

Effect of HbS in the determination of HbA(2) with the TOSOH HLC-723G7 analyzer and the HELENA Beta-Thal Quik column kit.

OBJECTIVES: The analytical performance of the TOSOH HLC-723G7 hemoglobin HPLC analyzer and the effect of the presence of HbS in the determination of HbA(2) using HPLC and manual column methods. DESIGN AND METHODS: The performance characteristics of the TOSOH HLC-723G7 analyzer in the determination of HbA(2) were compared to those of the HELENA Beta-Thal Quik column. The effect of HbS presence in the samples was quantified using the HELENA SAS-MX alkaline gel electrophoresis kit as the reference method. RESULTS: Within-run and between-run CVs for HbA(2) were better for the TOSOH HPLC analyzer than for the HELENA manual column method. The presence of HbS in the samples produces a strong positive bias in the %HbA(2) values when using both the HPLC and manual column methods, compared to the alkaline electrophoresis gel. CONCLUSION: Both the TOSOH HPLC and the manual column are reliable methods for %HbA(2) determination when no HbS is detectable in the samples. When HbS is present, the gel electrophoresis method gives more accurate results.