Clinical and Experimental Medicine

The function of B cells in the immune response against Mycobacterium tuberculosis (Mtb) is still regarded as secondary, although major findings in mouse models of tuberculosis (TB) support their participation as regulators and antibody producers. However, studies in cohorts of TB or multidrug-resistant TB (MDR-TB) patients have failed to clearly identify changes in the circulating B cell pool. Therefore, in the present study we aimed at identifying alterations in the different B cell subpopulations in peripheral blood samples of HIV-negative pulmonary MDR-TB patients when compared to healthy donors. The data show, for the first time, that MDR-TB patients, similarly to what has been observed in other chronic inflammatory diseases, have a much lower frequency of peripheral blood unswitched IgD+CD27+ memory B cells. Equally novel are the findings that in MDR-TB patients there is a reduction in the circulating plasma cell pool and that in MDR-TB there is an increased frequency of circulating type 1 transitional IgD+CD38++, CD69+ and TLR9+ B cells. These results document disease-related shifts in peripheral blood B cell subsets in MDR-TB and suggest that such changes should be taken into account when designing new strategies to boost the cellular and humoral immune response against Mtb.

Apelin, a peptide of 77 amino acids, and its endogenous ligand, angiotensin-like-receptor 1 (APJ), play a key role in the development of tumors by enhancing angiogenesis, metastasis, cell proliferation, development of cancer stem cells and drug resistance and inhibiting apoptosis of cancer cells. However, little is known about Apelin/APJ system involvement in hepatocellular carcinoma (HCC). The aim of this study was to evaluate Apelin and APJ expression in liver specimens, obtained from subjects with HCV-positive HCC who underwent liver transplantation, according to liver disease severity (liver recipients, LR, n = 14, age 59.4 ± 1.8) and in donors (liver donors, LD, n = 14, age 62.1 ± 17.3). Apelin/APJ axis, apoptotic and inflammatory markers were evaluated by Real-Time PCR analysis. The Apelin/APJ system expression resulted significantly higher in LR in comparison with LD (p < 0.05), in particular in those with more severe liver disease. The apoptotic (Bcl-2, BAX, NOTCH-1, Casp-3) and inflammatory (IL-6, TNF-α) markers were increased as a function of disease severity (p < 0.05). Multiple significant positive correlations were found between Apelin/APJ axis and the other markers. Although further investigations are needed to better understand the role of Apelin/APJ axis in HCC, our result indicated a potential role of this axis in its development and progression as well as in recognizing novel therapeutic targets opening a new avenue for treatment.

During the last few decades a substantial amount of evidence has accumulated proving that the abrogation of the normal p53 pathway is a critical step in the initiation and progression of tumors. Decoding the genetic mechanisms involved in carcinogenesis requires screening for consistent genetic tumor alterations, including those concerning the p53 gene. Thus, practical, efficient, and inexpensive techniques for accurate determination of p53 mutational status are needed. Polymerase chain reaction/single-strand conformation polymorphism (PCR-SSCP) analysis is considered to be a useful tool to investigate the role of the p53 gene in the development and progression of human cancers. The sensitivity of the method can be increased considerably by varying the experimental conditions. Here we demonstrate a scheme of PCR-SSCP optimization for detection of p53 gene mutations of patients with various cancers. Optimal conditions for PCRSSCP of p53 exons 4–9 are reported. Such PCR-SSCP optimization could allow an increase in the sensitivity and reproducibility of the technique and facilitates screening of large series of patients to assess the clinical significance of p53 mutations in human cancers. Using the optimized PCR-SSCP analysis we screened Bulgarian patients with invasive breast cancer for p53 gene mutations and registered a 33.33% frequency of mutations. To date, there are no data concerning the p53 status of Bulgarian breast cancer patients. Screening for p53 gene mutations enables an accurate and routine determination of the p53 status of patients with cancer and may be applied in clinical oncology to cancer diagnosis, prediction of prognosis and response to treatment.

5, 10-Methylenetetrahydrofolate reductase (MTHFR) is a crucial enzyme in homocysteine/methionine metabolism. The most-studied C677T polymorphism in the MTHFR gene results in a thermolabile variant with reduced activity, and is associated with increased levels of total plasma homocysteine, a risk factor for coronary artery disease. A new mutation in the MTHFR gene (A1298C) has also been reported to lower enzyme activity. Whether A1298C is a risk factor for coronary artery disease, separately or in combination with C677T, and/or relative to total plasma homocysteine and folate status, is unclear to date. We evaluated this hypothesis in 470 angiographically characterized subjects, 302 with coronary artery disease, and 168 with normal coronary arteries. The frequency of the 1298C allele was 0.33 and that of combined heterozygosity 0.315. No difference was found in the frequency of the genotypes or when analyzed for combined heterozygosity between patients with coronary artery disease and normals. Independent of folate status, the 1298C allele was not associated with increased total plasma homocysteine. No additional effect of A1298C on total plasma homocysteine was observed in 148 combined heterozygotes compared with 98 heterozygotes for the C677T alone. These findings do not support a major role for the A1298C mutation in homocysteine metabolism and emphasize the hypothesis that MTHFR genotypes may interfere with coronary artery disease risk only when an unbalanced nutritional status leads to raised total plasma homocysteine levels.

Kawasaki disease (KD) is an acute systemic vasculitis and suspected to be triggered by several potential infections in which procalcitonin (PCT) experiences an increase to some extent. However, whether PCT can serve as a useful candidate for differentiating KD from sepsis, and even for predicting incomplete KD, intravenous immunoglobulin (IVIG) nonresponsiveness and coronary artery abnormalities (CAAs) remains unclear. A total of 254 Chinese KD children were enrolled and divided into 6 subgroups, including complete KD, incomplete KD, IVIG-responsive KD, IVIG-nonresponsive KD, KD with CAAs and KD without CAAs. Blood samples were collected from all subjects within 24-h pre- and 48-h post-IVIG infusion, respectively. PCT, C-reactive protein, erythrocyte sedimentation rate and blood cell counts were detected. In addition, both 261 children with sepsis and 251 healthy children sex- and age-matched with KD children were enrolled in the same period. (1) PCT experienced the highest increase in sepsis patients before antibiotic therapy, followed by acute KD patients and the healthy controls. (2) The proportion of KD patients with a PCT concentration below 0.25 ng/ml was 11 folds higher than that of sepsis patients. (3) PCT had a sensitivity of 91.7% and a specificity of 30.3% at a cutoff value of > 0.15 ng/ml to predict IVIG nonresponsiveness, and the proportion of IVIG-nonresponders with a PCT concentration of 0.25–0.50 ng/ml was 2 folds higher than that of IVIG-responders. The PCT concentrations below 0.25 ng/ml may be useful for discriminating KD from sepsis, and moreover, the PCT concentrations of 0.25–0.50 ng/ml may be helpful in predicting IVIG nonresponsiveness.