T-cell immunity in human chronic toxoplasmosis.

Toxoplasmosis is a disease affecting 500 million people worldwide. The seroprevalence varies (from 5% to 90%), depending on geographical location, age, habit of eating raw meat or unwashed fruit and vegetables, and general level of hygiene. The incidence of infections is higher in warmer and humid climate and increases with age. The disease can be congenital or acquired. Cell response (TNF-alpha and IFN-gamma secreted by Th1 cells) and humoral response (IL-4, and IL-10 secreted by Th2 cells) were evaluated. This study assessed the effect of T. gondii on chosen indices of the immune response. The study involved 45 women infected with T. gondii (aged 18-42 years) proven have a chronic toxoplasmosis (IgG positive & IgM negative). The control group consisted of 25 healthy women (aged 18-45 years) (IgG and IgM negative). The results showed that patients infected with T. gondii had increased production of theTh-1 cytokines involved TNF-alpha and IFN-gamma that responsible for the cellular response compared to controls. Also, increased production of Th2 cytokines involved IL-4 and IL-10 that responsible for humoral response compared to controls.

Elevated renin levels in patients with liver cirrhosis and hepatocellular carcinoma.

Liver fibrosis is the common consequence of chronic liver injury of any etiology, disrupting the normal architecture,and causing hepatocellular dysfunction and portal hypertension. Since the renin-angiotensin system (RAS) may be involved in chronic liver diseases, in the present study we assayed renin levels using ELISA in groups of Egyptian patients with liver cirrhosis (N=32) and hepatocellular carcinoma (HCC) (N=67), for comparison with twenty five healthy controls. The results showed significant differences between the control and liver cirrhosis patients (P<0.001) and also the controls and HCC patients (P<0.001), without significant variation between the patient groups. Furthermore, in HCC patients, it was found that the renin levels negatively correlated with serum albumin and prothrombin time (P=0.003 for each) and positively with α-fetoprotein (P=0.04). Thus, it is concluded that renin levels are elevated in patients with liver cirrhosis and HCC and suitable medical intervention should be placed for management of such alteration. Moreover, further studies are warranted to explore its prognostic significance.

Mutant p53 protein in the serum of patients with colorectal cancer: Correlation with the level of carcinoembryonic antigen and serum epidermal growth factor receptor.

INTRODUCTION: Enzyme-linked immunosorbent assay (ELISA) was used for analysis of serum mutant p53 protein, carcinoembryonic antigen (CEA), and epidermal growth factor receptor (EGFR). Serum samples were obtained from 48 patients with colorectal cancer (CRC) and a control group of twenty healthy individuals. RESULTS: The results demonstrated a significant increase of serum mutant p53, EGFR, and CEA levels in CRC patients compared to the control group (P<0.001 for each). Mutant p53 protein was significantly different in the different CRC grades (P=0.028). p53, CEA, and EGFR can differentiate successfully between different CRC grades and normal control (P<0.001 for each). Sensitivities of p53, CEA, and EGFR were 39.6, 31, and 71%, respectively. There was no correlation between CEA, EGFR, and p53 indicating that these variables were independent. Positive status of serum CEA and (or) p53 was found in 29 out of 48 (60%) patients. Also, positive status of serum CEA and (or) EGFR was found in 39 out of 48 (81%) patients. CONCLUSION: Thus, the simultaneous determination of p53 or EGFR combined with the CEA may increase the sensitivity to diagnose CRC patients and may aid in disease prognosis.

Rapid and simple detection of a mycobacterium circulating antigen in serum of pulmonary tuberculosis patients by using a monoclonal antibody and Fast-Dot-ELISA.

OBJECTIVES: Several immunoassays have been established for detection of Mycobacterium tuberculosis (MTB) antigens in serum, sputum and cerebrospinal fluid of tuberculous patients using polyclonal or monoclonal antibodies raised against different mycobacterium antigens. Some of these assays display both high sensitivity and specificity for the detection of these antigens. However, these assays require special and highly expensive equipment and the procedures require long periods for their completion. Thus, the rationale of this study was to establish and evaluate Fast-Dot-Enzyme-Linked Immunosorbent Assay (FD-ELISA) as a fast, cheap and field applicable assay for detection of mycobacterium antigen in serum of patients with pulmonary TB. DESIGNS AND METHODS: This study included three groups: group I: 175 tuberculous patients with pulmonary TB proves with sputum Ziehl-Neelsen (ZN) for acid-fast bacilli and sputum culture (all cases were culture positive for MTB); Group II: 65 patients with diseases other than pulmonary TB as bronchial carcinoma (17 patients), bronchial asthma (29 patients) and chronic obstructive pulmonary disease (19 patients); group III: 50 healthy individuals. Groups II and III served as negative control groups. The target mycobacterium antigen was identified in both crude mycobacterium antigens extract and serum of patients with pulmonary TB, using western blotting technique and anti-TB monoclonal antibody (TB20-mAb) and then it was estimated in the serum samples of all studied groups as an index of tuberculosis, using a newly developed FD-ELISA. RESULTS: The target mycobacterium antigen was identified at 20 kDa molecular mass in crude mycobacterium antigens extract as well as in serum of patients with pulmonary TB. The developed FD-ELISA detected the mycobacterium antigen in the sera of 159 out of 175 pulmonary TB patients with a sensitivity of 90.8% and 93.0% positive predictive value (PPV). In addition, it identified 12 false weakly positive cases out of 115 samples of negative control groups (7 out of 65 non-TB patients and 5 out of 50 healthy individuals) with a specificity of 89.6% and 86.6% negative predictive value (NPV). Standardization of the FD-ELISA using a serial dilution of the purified mycobacterium antigen indicated that the assay was able to detect 1.8 microg/ml as a lowest detectable antigen concentration. CONCLUSIONS: The newly developed FD-ELISA is a simple, rapid and highly sensitive assay for detection of mycobacterium antigen in patients with pulmonary TB. Moreover, all steps were performed at room temperature and without the need to use expensive equipment, and this may enhance the application of this assay in tuberculosis screening programs. Further study is needed for confirmation of FD-ELISA reproducibility in light infected pulmonary TB patients and in a large population.

Pro-inflammatory and anti-inflammatory cytokines profile in rheumatoid arthritis patients.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by severe joint deformities due to bony erosions and tendon damage. Cytokines are protein mediators of inflammation and are produced as a result of the activation of various cellular reactions. They are the final mediators and/or regulators of the inflammatory process. Cytokines such as TNF-alpha and IL-6, play key roles in driving the inflammation and synovial cell proliferation that characterize rheumatoid arthritis and joint destruction. Sera from 58 RA patients were analyzed for TNF-alpha, IL-6, IL-10, TGF-beta, sTNF-R 1 and sTNF-R2 using ELISA. The proinflammatory cytokines TNF-alpha and IL-6 were significantly elevated in RA patients, while TGF-beta, an immunomodulatory cytokine, was elevated in control individuals. Assays of TNF receptors, sTNF-R1 and sTNF-R2, were noted to be significantly elevated in RA patients when compared to control. Our data indicate that local production of cytokine inhibitors is capable of diminishing cytokine and disease activity thereby may improve signs, symptoms and quality of life for patients with RA.

Different cytokine patterns in patients coinfected with hepatitis C virus and Schistosoma mansoni.

Schistosoma mansoni (S. mansoni) and hepatitis C virus (HCV) coinfection is common in Egypt and other developing countries. Patients coinfected with HCV and schistosomiasis exhibit a unique clinical, virological and histological pattern manifested by viral persistence with high HCV RNA titers as well as higher necroinflammatory and fibrosis scores in their liver biopsy samples. Dual infections of schistosomiasis and viral infections display significant influences on host immune reactions including cytokine shift pattern alteration, cytotoxic T lymphocyte response and other impaired immunologic functions with diminished capacity to clear the virus. We investigated the cytokine pattern against HCV and S. mansoni antigens in patients coinfected with HCV and S. mansoni and compared them with responses in patients infected with HCV or S. mansoni alone. This study included 4 groups; (Gr I) included 20 patients infected with chronic HCV, their sera were reactive for anti-HCV antibodies, samples were verified for RNA detection to identify those who have viremia. (Gr II) included 15 patients infected with schistosomiasis alone, they were subjected to detection of S. mansoni ova in stool, rectal snip or serological test. (Gr III) included 20 patients with chronic HCV and schistosomiasis coinfection, which were diagnosed by the above-mentioned criteria. (Gr IV) included 15 healthy individuals, who were matched for age and sex and have no evidence of liver diseases served as control subjects. The results showed that a highly significant increase in serum IFN-gamma and IL-18 levels in patients infected with HCV alone compared with the other patient groups and control. On the other hand, a highly significant increase was found in serum IL-4 and IL-10 levels in coinfected patients and patients with schistosomiasis alone compared with the control but a significant increase was found in the two groups compared with HCV patients. A significant increase in serum IL-4 and IL-10 were also found in HCV patients compared with the control. In conclusions, our data showed that coinfected patients have dominant Th2 cytokine profile induced by S. mansoni and this Th2 antagonized and down-regulated the antiviral activities of Th1 cytokine profile in HCV infection that probably acquired after S. mansoni infection resulting in failing to mount significant HCV specific Th1 response and thereby fail to clear the virus in coinfected, compared with patients infected with HCV or schistosomiasis alone.

Assessment of humoral immune response in patients with chronic hepatitis C virus infection.

Hepatitis C infection is a major public health problem worldwide. Hepatitis C virus (HCV) infection has been identified as a major causative agent of post-transfusion hepatitis. The host immune response to HCV infection is composed of both non- specific immune response, including interferon (IFN) production and natural killer (NK) cell activity and a virus-specific immune response, including humoral and cellular components. Susceptibility to infection has been related to immunological disturbances. Several studies have provided experimental evidence of disorders of both cellular and humoral immunity. Humoral Immunity is dependent mainly on immunoglobulins and little data are available about serum immunoglobulin values in chronic hepatitis C. The present study aimed to evaluate humoral immune response by measuring the concentration of serum immunoglobulin isotypes (IgG, IgM, IgA) and IgG-subclasses level (IgG1-4) in chronic hepatitis C patients and healthy controls. This study included 50 patients with chronic hepatitis C. All of them had positive serum anti-HCV antibodies, positive serum HCV-RNA by PCR, and histologically-proven chronic hepatitis. The results were compared with 25 healthy controls. Total IgG, IgA and IgM were assayed by nephelometry. IgG subclasses were assayed using human IgG subclasses enzyme immunoassay. Serum protein electrophoresis was performed in agarose gel. The results showed that no significant difference in serum immunoglobulin levels were found among patients with chronic hepatitis C of minimal liver damage( Knodell index < or =3) and patients with mild liver disease (Knodell index > 3). A significant increase in total serum IgG, IgG1 and IgG2 levels were found in patients with chronic hepatitis than in healthy controls but no difference was found in IgG3 and IgG4 in both patients and controls. Mean serum IgM was increased in patients with HCV infection compared with healthy controls. No significant difference was found in IgA level in both the patients and healthy controls. Our data revealed an increase of humoral immune response in chronic hepatitis C infection. This is evidenced by an elevation in serum immunoglobulin isotypes; IgG and its subclasses IgG1 and IgG2 and IgM. These findings may provide some new insights into the antibody response to HCV.

The effect of endoscopic retrograde cholangiopancreatography on the serum IL-18 and erythrocytes antioxidative capacity in biliary obstructive jaundice.

INTRODUCTION: Obstructive jaundice is an important clinical problem. It may cause transient hemolysis and shortened erythrocyte life span as well as cytokine induction. An increase in lipid peroxidation has been noted as evidence of oxidative damage in red cells due to cholestasis. The influence of endoscopic retrograde cholangiopancreatography (ERCP), mechanical lithotrepsy and stone extraction on the antioxidative capacity of the erythrocyte and immune response is still unclear. METHODS: Superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) content of red blood cells (RBC), and serum interleukin (IL-18) were measured in 20 patients with calcular obstructive jaundice before and 4 weeks after ERCP intervention and compared with 10 matched healthy volunteers. RESULTS: A significant decrease (p<0.05) in SOD and CAT activities and glutathione concentration but a significant increase (p<0.05) in serum IL-18 were observed in cholestatic patients compared with the healthy control and were significantly correlated with variable of hepatic dysfunction (alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT). After ERCP, serum IL-18 and antioxidant capacity of red blood cells were significantly improved and returned to normal concentration (p<0.05). CONCLUSIONS: In biliary obstruction, serum IL-18 is increased and antioxidative capacity is decreased, and have a direct correlation with biochemical markers of liver injury. After ERCP intervention, the altered antioxidative capacity as well as serum IL-18 was completely restored to normal.