A panel of a mitogenic (PDGF), biochemical (albumin) and demographic (age) parameters for the non-invasive assessment of hepatic fibrosis

Background: Several studies have investigated certain fibrosis markers that incorporate liver function tests, fragments of liver-matrix components and/or degraded products generated by hepatic stellate cells for determining the degree of hepatic fibrosis. However, the role of these molecules in the development of hepatic fibrosis is unclear. This work aimed (a) to determine whether platelet-derived growth factor (PDGF) is linked to different stages of hepatic fibrosis and (b) investigate its diagnostic performance alongside other laboratory and demographic factors in assessing liver fibrosis in chronic hepatitis C infection. Methods: Liver-fibrosis was staged according to Fibroscan, PDGF quantified using ELISA, and liver function tests and other analytes determined by standard techniques in 239 patients with chronic hepatitis C virus infection. Results: Patients with significant (F2-F4), advanced fibrosis (F3-F4) and cirrhotic liver disease (F4) showed significantly (P<0.0001) higher PDGF levels increase respectively compared to stage F0/1. We used this to construct the PARA-Index (PDGF/albumin ratio, age), which performed well in assessing hepatic-fibrosis stages with AUCs of 0.91, 0.87 and 0.86 for identifying F2-F4, F3-F4 and F4, respectively. Additionally, the PARA-Index correlated strongly (r=0.65, P<0.0001) with the severity of the fibrosis. An elevated PARA-index provided odds ratios of 21.0, 20.7 and 10.3 for developing F2-F4, F3-F4 and F4, respectively. Conclusion: A panel of mitogenic (PDGF), biochemical (albumin) and demographical (age) parameters may improve liver-fibrosis staging with a high degree of accuracy in those with a hepatitis C virus infection.

IL-28B rs12979860 polymorphism affect the course of chronic hepatitis and the development of HCC in Egyptian patients with hepatitis C type 4

BACKGROUND

A single nucleotide polymorphism (SNP) in the interleukin 28B (IL28B) gene may alter the trajectory of hepatitis C virus (HCV) chronic infection. Several studies have sought to determine a link between IL28B rs12979860 SNP and the development of HCV-related hepatocellular carcinoma (HCC), but with variable results, and consensus is awaited. We hypothesised that IL28B rs12979860 SNP is linked to HCC in patients with HCV type 4.

METHODS

IL28B genotyping of 300 patients with HCV-related fibrosis (n = 100), cirrhosis (n = 100) and HCC (n = 100) was carried out and the results were analysed to determine the association between the IL28B genotype and clinical outcome.

RESULTS

In IL28B TT genotype carriers, the proportions of moderate/severe fibrosis, advanced cirrhosis (Child B-C) and HCC (50%, 84% and 60.2%, respectively) were higher (p < 0.05) than in CC/CT (4.3%, 46% and 23%, respectively). IL-28B SNP was linked significantly (p < 0.05) with cirrhosis progression and HCC advanced stages. Moreover, HCC advanced Child, Okuda and CLIP stages were associated with T allele carriage (73.9%, 82.6% and 78.3% vs. 44.2%, 50.6% and 46.8% in CC/CT). The percentage of large tumour size (> 3cm) increased (p = 0.028) in TT genotype carriers (81.8% vs.52.6% in CC/CT).

CONCLUSION

IL-28B rs12979860 TT genotype is more prevalent in patients with advanced fibrosis, cirrhosis and HCC stages. Thus, it seems to be associated with poor outcomes in chronic HCV patients and to augment the risk of developing HCC.

Clinical value of a diagnostic score for colon cancer based on serum CEA, CA19-9, cytokeratin-1 and mucin-1

BACKGROUND

Although established markers such as CEA and CA19-9 are important for diagnosing early stages of colon cancer, they are not ideal. Developing promising markers include cytokeratin 1 (CK1) and mucin-1 (MUC1), but the combined value of each of these markers is unclear. We therefore evaluated the value of a combined laboratory-based score of these four markers in the diagnosis of colon cancer.

METHODS

Two hundred patients who had undergone colonoscopic examination (150 colon cancer, 50 benign growths) were recruited. The study was controlled by 35 healthy subjects. CEA, CA19-9, CK1 and MUC1 were measured by ELISA and evaluated for cancer diagnosis using area under the receiver operating characteristic curve (AUC).

RESULTS

Serum levels of all four markers were increased in the order colon cancer > benign disease > healthy controls (p < 0.001). In multivariate analysis, CA19.9 (p = 0.025), CK1 (p < 0.001) and MUC1 (p = 0.009) were significant independent predictors of colon cancer. A score that gave the greatest power of discrimination for colon cancer was defined as 1.06 + [0.001 × CA19.9 result] + [0.003 × CEA result] + [0.03 × CK1 result] + [0.05 × MUC1 result]. The colon score provided superior discrimination, AUC, and sensitivity and specificity for colon cancer versus benign growth than each of the individual markers. Similarly, the colon score provided superior AUC, and sensitivity and specificity that each individual marker for tumour stage, lymph node invasion and distant organ metastases than each individual marker.

CONCLUSION

A colon score derived from serum CEA, CA19-9, CK1 and MUC1 is a potential valuable non-invasive index that could be used for detection and screening early stage colon cancer patients.

Fibro-Mark: a panel of laboratory parameters for predicting significant fibrosis in chronic hepatitis C patients

BACKGROUND

Fibrosis markers are useful for the prediction of cirrhosis but clinical scores such as King's score, AST-Platelet ratio index (APRI), Biotechnology research center (BRC), Fibrosis routine test (FRT), Fibro-α score and Fibro-quotient (FibroQ) have limited accuracy for diagnosing significant fibrosis. We hypothesised that new markers (reflecting the balance between hepatic fibrogenesis and fibrolysis) together with other indirect fibrosis markers would together construct a more sensitive and specific score capable of identifying fibrosis than existing scores.

METHODS

Collagen IV, hyaluronic acid, platelet-derived growth factor (PDGF) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were measured by ELISA, and AST, ALT, platelet count, albumin, total bilirubin, INR and AFP by routine methods in 148 patients with hepatitis C induced liver disease. Stepwise linear discriminant analysis and area under receiver-operating characteristic curves (AUCs) were used to create a predictive score and compare it to others.

RESULTS

Patients with significant fibrosis (n = 100, F2-F4) showed 2.08, 2.14, 1.80 and 1.90-fold increase in collagen IV, hyaluronic acid, PDGF and TIMP-1, respectively, over patients with no or mild fibrosis (n = 48, F0/F1)(all p < 0.01). Significant independent predictors of F2-F4 were AFP (AUC 0.79), age (0.76), PDGF (0.74), collagen IV (0.78) and TIMP (0.75), which together formed a five-marker score 'Fibro-Mark' for predicting F2-F4. In comparison with other scores, AUC for Fibro-Mark was 0.89, BRC was 0.83, followed by FRT and King's score (both 0.82), APRI (0.80), Fibro-α (0.70) and finally Fibro Q (0.63).

CONCLUSIONS

The Fibro-Mark score provides better discrimination in hepatic-fibrosis staging in chronic hepatitis C patients than existing scores.

Combined use of nuclear phosphoprotein c-Myc and cellular phosphoprotein p53 for hepatocellular carcinoma detection in high-risk chronic hepatitis C patients

BACKGROUND

Hepatocellular carcinoma (HCC) is a multistage process resulting from various genetic changes. We aimed to determine nuclear phosphoprotein c-Myc and cellular phosphoprotein p53 expression and to evaluate their importance in HCC diagnosis.

METHODS

One hundred and twenty chronic hepatitis C (CHC) patients (60 non-HCC CHC patients and 60 HCC patients who had a single small (<5 cm) tumour) were recruited. The gene products of c-Myc and p53 were identified in liver tissues and serum samples using immunostaining, western blot and ELISA.

RESULTS

Immunohistochemical detection of c-Myc and p53 with monospecific antibodies revealed intense and diffuse cytoplasmic staining patterns. Accumulated mutant proteins, released from tumour cells into the extracellular serum, were detected at 62 KDa, for c-Myc, and 53 KDa, for p53, using western blotting. In contrast to alpha feto-protein, there was a significant increase (p < 0.0001) in the positivity rate of c-Myc (86.7% vs. 6.7%) and p53 (78.3% vs. 8.3%) in the malignant vs. non-malignant patients. The parallel combination of c-Myc and p53 reach the absolute sensitivity (100%), for more accurate and reliable HCC detection (specificity was 87%).

CONCLUSION

c-Myc and p53 are potential HCC diagnostic biomarkers, and convenient combinations of them could improve diagnostic accuracy of HCC.

Evaluation of serum procollagen aminoterminal propeptide III, laminin, and hydroxyproline as predictors of severe fibrosis in patients with chronic hepatitis C

In an attempt to identify biochemical analytes that could enhance the discrimination between the patients with severe liver fibrosis (F3-F4) and mild fibrosis (F1-F2) based on absolute values of biochemical markers, we measured 12 analytes, including procollagen III aminoterminal propeptide (PIIINP), laminin, proline, hydroxylproline, glycine, AST, ALT, alkaline phosphatase, albumin, total bilirubin, total protein, and prothrombin time in 252 individuals with chronic hepatitis C infection (CHC). PIIINP and laminin were determined by radio-immunoassay; the degraded amino acids were determined using high performance liquid chromatography. Statistical analyses were performed by logistic regression, and receiver operating characteristic (ROC) curves. The best linear combination of blood markers was selected by multivariate discriminant analysis (MDA) for construction of the fibrosis discriminant score (FDS). FDS, an index of five markers (PIIINP, laminin, hydroxyproline, prothrombin activity, and AST/ALT) correctly classified 82% of the patients with severe liver fibrosis at a discriminant cut-off score=-0.5 (i.e., less than -0.5 indicated severe liver fibrosis and greater than -0.5 indicated mild liver fibrosis with sensitivity (76%) and specificity (89%). This result was reproduced in a validation study with no significant difference. In conclusion, FDS is useful for identifying severe liver fibrosis in patients with CHC.

Evaluation of serum procollagen aminoterminal propeptide III, laminin, and hydroxyproline as predictors of severe fibrosis in patients with chronic hepatitis C

In an attempt to identify biochemical analytes that could enhance the discrimination between the patients with severe liver fibrosis (F3-F4) and mild fibrosis (F1-F2) based on absolute values of biochemical markers, we measured 12 analytes, including procollagen III aminoterminal propeptide (PIIINP), laminin, proline, hydroxylproline, glycine, AST, ALT, alkaline phosphatase, albumin, total bilirubin, total protein, and prothrombin time in 252 individuals with chronic hepatitis C infection (CHC). PIIINP and laminin were determined by radio-immunoassay; the degraded amino acids were determined using high performance liquid chromatography. Statistical analyses were performed by logistic regression, and receiver operating characteristic (ROC) curves. The best linear combination of blood markers was selected by multivariate discriminant analysis (MDA) for construction of the fibrosis discriminant score (FDS). FDS, an index of five markers (PIIINP, laminin, hydroxyproline, prothrombin activity, and AST/ALT) correctly classified 82% of the patients with severe liver fibrosis at a discriminant cut-off score=-0.5 (i.e., less than -0.5 indicated severe liver fibrosis and greater than -0.5 indicated mild liver fibrosis with sensitivity (76%) and specificity (89%). This result was reproduced in a validation study with no significant difference. In conclusion, FDS is useful for identifying severe liver fibrosis in patients with CHC.

Vaccination of mice with a 30 kDaSchistosomaantigen with and without human adjuvant induces high protection againstS. mansoniinfection

A 30 kDa antigen was characterized as a hydrophobic polypeptide containing 16 amino acids and evaluated as a potential candidate vaccine against infection bySchistosoma mansoni. CD1 albino mice immunized at 0, 14, and 21 days with 25 or 50 μg of the 30 kDa antigen per mouse with and without alum developed high levels of IgG antibodies (predominantly IgG2a and IgG2b isotypes). When immunized mice were infected with 200S. mansonicercariae, the highest protection levels (61% and 65% reduction in worm burden in two separate experiments) were obtained using the 50-μg antigen without alum adjuvant. The granuloma size decreased to 10%, a non-significant level in mice immunized using alum adjuvant. The results demonstrate the ability of the 30 kDa antigen with and without alum adjuvant to protect mice againstS. mansoniinfection.

Susceptibility of neonate mice born to Schistosoma mansoni-infected and noninfected mothers to subsequent S. mansoni infection

The present study tested the hypothesis that prenatal exposure of neonate Outbred albino mice to Schistosoma mansoni antigens (Ags) or antibodies (Abs) modulates their immunity against postnatal responses to infection. Persistence of maternal S. mansoni Abs and/or Ags in mice born to S. mansoni-infected mothers (IF-IMs) and noninfected mothers (IF-NMs) for up to 8 weeks after delivery was investigated. A higher level of anti-S. mansoni IgG Ab was detected in sera of 1-week-old mice born to IF-IM compared to controls. Then, immunoglobulin (Ig)G gradually decreased to the eight week. No anti-S. mansoni IgM Ab was detected in sera of these offspring at any week after delivery. Schistosoma Ags were detected in liver and kidney tissues of mice born to infected mothers. However, Ags decreased markedly till the sixth week in the liver but increased significantly at the sixth week in the kidney. Eight-week-old mice born to infected and noninfected mothers were infected with 200 S. mansoni ceracriae. Their sera and livers were collected for testing IgG and granuloma formation 6 weeks postinfection. Worms were collected via portal perfusion and counted. Anti-S. mansoni IgG level, size and number of liver granuloma, and worm burden were significantly reduced in the offspring of infected mothers. These data suggest that in utero exposure of Outbred albino mice to S. mansoni may attenuate the pathogenesis of S. mansoni in subsequent challenge.

Immunoreactivity evaluation of mutant p53 gene product with DNA ploidy pattern in colorectal carcinoma

BACKGROUND/AIMS

Studying p53 protein expression in tumor cells is one of the effective methods for detecting p53 gene mutations. This study attempted simultaneous monitoring of p53 overexpression in colon cancer using immunohistochemical and immunoblotting techniques and also to compare abnormalities of p53 with DNA ploidy and clinicopathological variables.

METHODOLOGY

The occurrence of p53 protein expression was analyzed in forty-nine fresh colorectal cancer specimens by immunohistochemical and p53 protein expression also demonstrated by Western immunoblotting technique in 28 colorectal cancer specimens, using an anti-human p53 monoclonal antibody (Do-7), and 25 normal colon mucosa as a negative control. DNA ploidy in 36 specimens of colon cancer tissues was determined by Flow cytometry.

RESULTS

Overexpression of p53 protein was detected immunohistochemically in 53.1% (26 of 49) of the tumor specimens. DNA ploidy was performed in 36 cases, 55.6% (20 of 36) of colon cancer specimens were DNA aneuploidy, p53 immunostaining was positive in 60% of cases with DNA aneuploidy compared to 31.3% in diploid tumors (p<0.001). There was no significant association between p53 immunostaining and clinicopathological variables. Overexpression of p53 protein was demonstrated in nuclear protein extract by immunoblotting in 75% (21 of 28) of colorectal carcinoma. Aneuploidy carcinomas were more frequently p53 positive by immunoblotting than DNA diploidy carcinomas; 76.5% (13 of 17) vs. 72.7% (8 of 11) (p<0.2). P53 expression by immunoblotting was more frequently found in good lymphocytic infiltration than moderate and poor lymphocytic infiltration (p<0.001). Also, p53 expression in right colon was significant with rectum (p<0.009). The incidence of p53 expression in Duke's stage B was significant if compared with Duke's stage C (p<0.005). Immuno-reactivity of p53 expression was detected by immunostaining and immunoblotting in 89.3% (25 of 28) of colorectal cancer. P53 immunoreactivity by immunostaining and immunoblotting were closely related to the clinicopathological variables such as pathological type (p<0.01), lymphocytic infiltration (p<0.0001), tumor grade, and tumor site (p<0.001). DNA aneuploidy was more frequently p53 positive than DNA diploid tumor by immunostaining and immunoblotting (p<0.001).

CONCLUSIONS

Immunohistochemistry confirmed by immunoblotting assay is a sensitive method for detecting the trace amount of p53 protein and provides valuable information for the understanding of colorectal cancer biology.

Dysregulation of blood lymphocyte subsets and natural killer cells in schistosomal liver cirrhosis and hepatocellular carcinoma

Immunological factors are important in the pathogenesis of a wide spectrum of hepatobiliary diseases. Using flow cytometry, we determined the changes in lymphocyte subsets and natural killer cells in 123 individuals (81 patients with liver disease and 42 healthy volunteers). The liver diseases included periportal fibrosis (PPF, 10 patients), liver cirrhosis (LC, 31 patients), and hepatocellular carcinoma (HCC, 40 patients). Schistosomiasis and viral hepatitis B and C were the putative etiological agents of liver diseases. Immunophenotyping by indirect immunofluorescence was conducted using monoclonal antibodies to CD3 (T-lymphocytes), CD4 (helper/inducer T-cells), CD8 (suppressor/cytotoxic T-cells), and CD57 (natural killer cells) cell surface markers. Immunophenotyping of PPF patients showed no significant changes in all markers compared with the healthy controls. However, there was a significant decrease ( P<0.01) in CD3 and CD4 T-cells, and a highly significant increase ( P<0.001) in CD57 T-cells in patients with LC or HCC. In addition, LC and HCC patients showed no significant change in CD8 T-cells compared with controls. In conclusion, the progression of liver diseases is associated with a dysregulation of cellular immune responses. T-lymphocytes and natural killer cells may play a role in the immunopathogenesis of liver cirrhosis and HCC.

Dysregulation of blood lymphocyte subsets and natural killer cells in schistosomal liver cirrhosis and hepatocellular carcinoma

Immunological factors are important in the pathogenesis of a wide spectrum of hepatobiliary diseases. Using flow cytometry, we determined the changes in lymphocyte subsets and natural killer cells in 123 individuals (81 patients with liver disease and 42 healthy volunteers). The liver diseases included periportal fibrosis (PPF, 10 patients), liver cirrhosis (LC, 31 patients), and hepatocellular carcinoma (HCC, 40 patients). Schistosomiasis and viral hepatitis B and C were the putative etiological agents of liver diseases. Immunophenotyping by indirect immunofluorescence was conducted using monoclonal antibodies to CD3 (T-lymphocytes), CD4 (helper/inducer T-cells), CD8 (suppressor/cytotoxic T-cells), and CD57 (natural killer cells) cell surface markers. Immunophenotyping of PPF patients showed no significant changes in all markers compared with the healthy controls. However, there was a significant decrease ( P<0.01) in CD3 and CD4 T-cells, and a highly significant increase ( P<0.001) in CD57 T-cells in patients with LC or HCC. In addition, LC and HCC patients showed no significant change in CD8 T-cells compared with controls. In conclusion, the progression of liver diseases is associated with a dysregulation of cellular immune responses. T-lymphocytes and natural killer cells may play a role in the immunopathogenesis of liver cirrhosis and HCC.

Identification and characterization of a 26- to 28-kDa circulating antigen of Fasciola gigantica

As a disease of domestic ruminants, fascioliasis is of considerable economic importance. Although serological tests are available for the diagnosis of the disease, they are of generally low specificity because of cross-reactivity with antigens from other parasites. There is a need to identify other Fasciola antigens on which more specific tests could be based. In the present study, a specific rabbit anti-serum and western-blot analyses were used to demonstrate the presence of a highly reactive antigen of 26-28 kDa not only in an extract of adult F. gigantica but also in the excretory/secretory products of the worms and in the bile secretions and sera of cattle that were naturally infected with this parasite. The 26- to 28-kDa antigen was isolated from preparative polyacrylamide gels, by electro-elution. The purified antigen showed a single peak at 5.8 min when analysed by capillary zone electrophoresis. It was characterized as protein containing 47.5% hydrophilic and 29.3% hydrophobic amino acids. Immunostaining demonstrated that the target epitope was located in the gut and tegument of adult F. gigantica and within the bile ducts, the portal tracts of the livers and the mucosa and muscularis of the gallbladders of infected cattle. A simple and rapid dot-ELISA technique based on the specific rabbit anti-serum was 100% specific when tested on the sera from nine cattle infected with F. gigantea and 27 uninfected cattle. In conclusion, the 26- to 28-kDa Fasciola antigen may be a promising candidate for the immunodiagnosis of fascioliasis.

Identification and characterization of a 26- to 28-kDa circulating antigen of Fasciola gigantica

As a disease of domestic ruminants, fascioliasis is of considerable economic importance. Although serological tests are available for the diagnosis of the disease, they are of generally low specificity because of cross-reactivity with antigens from other parasites. There is a need to identify other Fasciola antigens on which more specific tests could be based. In the present study, a specific rabbit anti-serum and western-blot analyses were used to demonstrate the presence of a highly reactive antigen of 26-28 kDa not only in an extract of adult F. gigantica but also in the excretory/secretory products of the worms and in the bile secretions and sera of cattle that were naturally infected with this parasite. The 26- to 28-kDa antigen was isolated from preparative polyacrylamide gels, by electro-elution. The purified antigen showed a single peak at 5.8 min when analysed by capillary zone electrophoresis. It was characterized as protein containing 47.5% hydrophilic and 29.3% hydrophobic amino acids. Immunostaining demonstrated that the target epitope was located in the gut and tegument of adult F. gigantica and within the bile ducts, the portal tracts of the livers and the mucosa and muscularis of the gallbladders of infected cattle. A simple and rapid dot-ELISA technique based on the specific rabbit anti-serum was 100% specific when tested on the sera from nine cattle infected with F. gigantea and 27 uninfected cattle. In conclusion, the 26- to 28-kDa Fasciola antigen may be a promising candidate for the immunodiagnosis of fascioliasis.

Immunochemical characterization and diagnostic potential of a 63-kilodalton Schistosoma antigen

Schistosoma circulating antigens were used for the detection of active infection. Anti-S. mansoni IgG2a monoclonal antibody (MAb) designated C5C4 was generated. The target epitope of this MAb was detected in adult worms, eggs, and cercariae antigenic extracts of S. mansoni and S. haematobium, had a molecular size of 63 kD, and was not detected in Fasciola hepatica and Ascaris. In addition, a 50-kD degradation product was identified only in the urine of infected individuals. Analysis by high-performance liquid chromatography of the purified antigen demonstrated only one peak. The 63-kD antigen was characterized as a protein containing 40.4% hydrophobic, 7.5% acidic, and 8.8% basic amino acids. The C5C4 MAb was used in a Fast Dot-ELISA for rapid and simple diagnosis of human schistosomiasis. The 63-kD circulating antigen was detected in 92% of urine samples from 330 S. mansoni-infected individuals, with 16% false-positive results among 130 noninfected individuals.

DNA ploidy of liver biopsies from patients with liver cirrhosis and hepatocellular carcinoma: a flow cytometric analysis

Flow cytometric DNA analysis was used to assess cellular kinetics of needle liver biopsies from patients with liver cirrhosis and hepatocellular carcinoma (HCC). An abnormal DNA content was shown in 44.5% of liver cirrhosis cases and in 78.6% of tumor sites. The number of proliferating cells (S + G2M%) was significantly increased in cirrhotic liver (P < 0.05). Dysplasia was found in 66% of cirrhotic specimens. All negative dysplasia specimens showed a diploid pattern while 69% of positive dysplastic specimens were aneuploid (P < 0.001). In conclusion, cell proliferation, aneuploidy and liver cell dysplasia are important indicators in liver cirrhosis for the development of HCC.

DNA ploidy of liver biopsies from patients with liver cirrhosis and hepatocellular carcinoma: a flow cytometric analysis

Flow cytometric DNA analysis was used to assess cellular kinetics of needle liver biopsies from patients with liver cirrhosis and hepatocellular carcinoma (HCC). An abnormal DNA content was shown in 44.5% of liver cirrhosis cases and in 78.6% of tumor sites. The number of proliferating cells (S + G2M%) was significantly increased in cirrhotic liver (P < 0.05). Dysplasia was found in 66% of cirrhotic specimens. All negative dysplasia specimens showed a diploid pattern while 69% of positive dysplastic specimens were aneuploid (P < 0.001). In conclusion, cell proliferation, aneuploidy and liver cell dysplasia are important indicators in liver cirrhosis for the development of HCC.

Vaccination against Schistosoma mansoni infection using 74 kDa Schistosoma protein antigen

An IgG2a anti-Schistosoma mansoni mouse monoclonal antibody was shown to passively protect Swiss mice. The 74 kDa target antigen was isolated from antigenic extracts of S. mansoni adult worms. Swiss and C57 BL/6J mice were immunized with 30, 50, 100 and 200 microg antigen/mouse doses with and without Freund's adjuvant. Sera of immunized mice showed high reactivity against 74 kDa antigen. The highest protection level (76.6% in Swiss mice and 50.1% in C57 BL/6J mice) was obtained using the 50 microg antigen dose with and without Freund's adjuvant. A marked reduction in granuloma number and intensity of collagen and reticular granuloma fibers was observed. The 74 kDa antigen has the ability to protect mice of different strains and to modulate the host immune system.

Vaccination against Schistosoma mansoni infection using 74 kDa Schistosoma protein antigen

An IgG2a anti-Schistosoma mansoni mouse monoclonal antibody was shown to passively protect Swiss mice. The 74 kDa target antigen was isolated from antigenic extracts of S. mansoni adult worms. Swiss and C57 BL/6J mice were immunized with 30, 50, 100 and 200 microg antigen/mouse doses with and without Freund's adjuvant. Sera of immunized mice showed high reactivity against 74 kDa antigen. The highest protection level (76.6% in Swiss mice and 50.1% in C57 BL/6J mice) was obtained using the 50 microg antigen dose with and without Freund's adjuvant. A marked reduction in granuloma number and intensity of collagen and reticular granuloma fibers was observed. The 74 kDa antigen has the ability to protect mice of different strains and to modulate the host immune system.

Induction of resistance against Schistosoma mansoni infection by passive transfer of an IgG2a monoclonal antibody

Monoclonal antibodies can confer resistance to schistosome infections. This has led to identification of several protective antigens. An IgG2a monoclonal antibody designated BRL4 mAb identified a 74-kDa antigen in antigenic extract of Schistosoma mansoni adult worms. The target antigen was localized in gut and tegument. In 3 passive transfer experiments, the BRL4 mAb conferred 51.6, 41.9 and 53.8% protection levels into female Swiss mice. Histopathological examination revealed a marked decrease in number, size, collagen and reticular fibers of the liver granulomas. Further experiments using purified 74-kDa-target antigen as a candidate vaccine will be performed.

Immunochemical characterization and diagnostic potential of a 63-kilodalton Schistosoma antigen

Schistosoma circulating antigens were used for the detection of active infection. Anti-S. mansoni IgG2a monoclonal antibody (MAb) designated C5C4 was generated. The target epitope of this MAb was detected in adult worms, eggs, and cercariae antigenic extracts of S. mansoni and S. haematobium, had a molecular size of 63 kD, and was not detected in Fasciola hepatica and Ascaris. In addition, a 50-kD degradation product was identified only in the urine of infected individuals. Analysis by high-performance liquid chromatography of the purified antigen demonstrated only one peak. The 63-kD antigen was characterized as a protein containing 40.4% hydrophobic, 7.5% acidic, and 8.8% basic amino acids. The C5C4 MAb was used in a Fast Dot-ELISA for rapid and simple diagnosis of human schistosomiasis. The 63-kD circulating antigen was detected in 92% of urine samples from 330 S. mansoni-infected individuals, with 16% false-positive results among 130 noninfected individuals.

Rapid detection of a Schistosoma mansoni circulating antigen excreted in urine of infected individuals by using a monoclonal antibody

Schistosoma circulating antigens were used to indicate the infection intensity and to assess cure. An immunoglobulin G2a (IgG2a) mouse monoclonal antibody was used in a fast dot-enzyme-linked immunosorbent assay (ELISA; FDA) for rapid and simple diagnosis of schistosomiasis in the field. Seven hundred Egyptians were parasitologically examined for Schistosoma mansoni and other parasitic infections. A rectal biopsy was done as a "gold standard" for individuals showing no S. mansoni eggs in their feces. Egg counts were obtained by the Kato smear method for only 100 of 152 individuals with eggs in their feces. Specific anti-schistosome IgG antibodies were evaluated in sera by ELISA. Urine samples from the 700 individuals were tested by FDA for detection of the circulating antigen. The assay showed a sensitivity of 93% among 433 infected individuals and a specificity of 89% among 267 noninfected individuals. FDA showed the highest efficiency of antigen detection (91%) compared with the efficiency of antibody detection by ELISA (75%) and stool analysis (60%). In addition, FDA detected infected patients with 20 eggs/g of feces. Also, the sensitivity of FDA ranged from 90 to 94% among samples from patients with different clinical stages of schistosomiasis. All the assay steps can be completed within 30 min at room temperature for 96 urine samples. The monoclonal antibody identified a 74-kDa antigen in different antigenic extracts of S. mansoni and Schistosoma haematobium and in the urine of infected individuals. In addition, a 30-kDa degradation product was identified only in the urine samples. On the basis of these results, FDA should be used as a rapid tool for the sensitive and specific diagnosis of Schistosoma infection.

High prevalence of hepatitis B viral DNA in cirrhotic patients without surface antigen

The diagnosis of liver diseases induced by hepatitis B virus (HBV) is supported by the detection of HBV surface antigen (HBsAg) in serum. The present study aimed to investigate the presence of HBV deoxyribonucleic acid (DNA) in patients with liver cirrhosis using a polymerase chain reaction (PCR) based on primers derived from the pre-S1 and pre-core regions. HBsAg was detected in 10 of 48 patients (21%), total anti-hepatitis B core antigen (HBc) antibodies in 54%, anti-hepatitis B e antigen (HBeAg) in 14.6%, anti-HBc immunoglobulin M in 8%, and anti-HBs in 26%; none had detectable HBeAg. HBV DNA was detected in 73% of the cirrhotic patients. All cirrhotic patients with HBsAg also had HBV DNA; HBV DNA was detected in 64.5% of those without HBsAg. We conclude that the clearance of HBsAg does not necessarily indicate termination of viraemia in patients with liver cirrhosis and the detection of HBV DNA using a PCR based on primers from the pre-S1 and pre-core regions should be included in the diagnosis of HBV infection.

Immunochemical purification and characterization of a 74.0-kDa Schistosoma mansoni antigen

A polypeptide antigen of 74.0 kDa molecular weight was detected in the antigenic extracts of the 3 developmental stages of Schistosoma mansoni (eggs, cercariae, and adult worms) by western blotting using BRL4 monoclonal antibody (mAb) that significantly protected mice at the levels of 51.6%, 42%, and 53.8% against challenge S. mansoni infection in 3 separate experiments. This antigen was isolated and purified from crude soluble worm antigen preparation by immunoaffinity chromatography using CNBr-activated sepharose-4B beads coupled with the BRL4 mAb. The purified antigen showed a single peak when analyzed by both high-performance liquid chromatography and high-performance capillary electrophoresis. The 74-kDa antigen was characterized as a protein in nature with 56.9% hydrophilic amino acids and 43.1% hydrophobic amino acids. This antigen was detected in 93% of urine samples from infected cases with specificity of 89% among noninfected cases using an enzyme immunoassay-fast dot-enzyme-linked immunosorbent assay based on BRL4 mAb.

Detection of p53 protein overexpression and DNA ploidy analysis in colon cancer

BACKGROUND/AIMS

This study was designed to demonstrate the accumulation of the mutant p53 protein in human neoplasms. The correlation of flow cytometric DNA ploidy pattern with p53 expression using the immunoblotting technique was also investigated.

METHODOLOGY

In this study, the occurrence of p53 overexpression was analyzed in 34 cases of adenocarcinoma of the colon by western immunoblotting technique, using an anti-human p53 monoclonal antibody (Do-7). The nuclear protein extract from human colon tumor specimens was immunoblotted relative to protein standards of known molecular weight. Flow cytometric analysis was used to study the DNA ploidy pattern of the tumor cells.

RESULTS

Monoclonal antibody p53-Do 7 detected a single band of 53 KDa in 70.5% (24 of 34) of the tumor specimens examined. Whereas, no bands were detected in the normal colon mucosa. The relation between p53 overexpression and the clinicopathological variable (Dukes' staging) was studied and no significant difference in p53 overexpression between Dukes' stages B and C was found. Flow cytometric analysis revealed a higher incidence of DNA aneuploidy in 75% (15 of 20) of p53 positive cases compared with 64.3% (9 of 14) in the diploid tumors.

CONCLUSION

The immunoblotting technique can successfully detect the mutant p53 and is therefore expected to provide valuable information on the role of p53 in the process of carcinogenesis.

Cellular proliferation and ploidy of the gastric mucosa: the role of Helicobacter pylori

BACKGROUND/AIMS

Recently, H. pylori has been recognized as a risk factor for gastric adenocarcinoma. As such, we have analyzed the DNA content of gastric epithelial cells in an attempt to reveal the role of H. pylori in gastric carcinogenesis.

METHODOLOGY

Fifty-three subjects presented with gastric dyspepsia, 39 males and 14 females, with a mean age of 42.15 (+/- 13.16) years. They were referred to the out-patient clinic to undergo endoscopic examination for the first time. Biopsy specimens from the antrum of each subject were subjected to culture for the presence of H. pylori histologic diagnosis, and DNA flow cytometry for the analysis of cellular proliferation and DNA policy.

RESULTS

The endoscopic diagnoses were normal appearance (12), Gastric ulcer (12), duodenal ulcer (29). Thirty-eight (72%) subjects were positive, and 15 (28%) subjects were negative for H. pylori. Abnormal DNA-content (aneuploidy) was found in specimens from the antrums of 3 patients, 2 patients with duodenal ulcers (DU, and one with a gastric ulcer (GU). The cellular proliferation detected by flow cytometry in the form of proliferative index (PI; percentage of cells in the DNA S and G2M phases) was 27.88 (+/- 12.48) and 14.17 (+/-2.94) in the antrums of those positive and negative for H. pylori, respectively. A very significant increase in the PI (p < 0.005) was found between subjects positive and negative for H. pylori. Patients with DU and H pylori infection had the highest PI, and the PI was significantly higher than in patients with DU, but without infection. Regarding histology, there was a significant increase in the PI in the presence of H. pylori infection in either CAG or dysplasia groups as compared to cases without infection in the same groups.

CONCLUSION

These results show that H. pylori infection is associated with changes in the DNA-content and cellular proliferative activity, suggesting that H. pylori may be implicated in gastric carcinogenesis. Also, the significant increase in the PI along the progression of severity of the disease suggests that measuring this parameter might allow more accurate monitoring of patients, so that a targeted therapeutic protocol may be defined.

Fast-Dot ELISA using urine, a rapid and dependable field assay for diagnosis of schistosomiasis

The fast dot-enzyme linked immunosorbent assay (FD-ELISA) was used as a field applicable tool for rapid diagnosis of schistosomiasis. Seven hundreds faecal specimens were parasitologically examined for detection of S. mansoni eggs and other parasitic infection. Egg count was done for 100 infected patients. Rectal biopsies (394) were taken from individuals with no S. mansoni egg in their stool where it was used as a golden standard for diagnosis of schistosomiasis. Cross-reactivity with other parasites was studied. Serum samples were tested by ELISA technique for detection of human IgG anti-schistosomal antibodies. Seven hundreds urine samples (433 S. mansoni infected patients and 267 healthy individuals) were tested by FD-ELISA for detection of a schistosomal antigen excreted in urine using BRLF4 mouse monoclonal antibody. FD-ELISA results were compared with ELISA detecting antischistosomal IgG and stool analysis where, it showed highest efficiency (91%), compared with 81% and 60% for ELISA and stool analysis respectively. The sensitivity of FD-ELISA was high ranging from 90-94% in the four different clinical stages of schistosomiasis (Simple intestinal. Hepatosplenomegaly, Shrunken liver & Splenomegaly, and Shrunken liver-splenomegaly & ascites). FD-ELISA was highly sensitive, detecting infection cases with 20 eggs/gm faeces and its specificity was 89%. The antigen was characterized as a protein with a molecular weight of 74 KDa using western blot technique.

Correlation between endoscopy, histopathology, and DNA flow cytometry in patients with gastric dyspepsia

BACKGROUND/AIMS

Gastric cancer has a poor prognosis, this is partly due to the advanced stage in which the tumor is diagnosed. The objective of this study is to elucidate the clinical significance of DNA flow cytometry and study its impact on monitoring the progression of gastric precancerous lesions in patients with gastric dyspepsia, and to correlate between endoscopic and histopathological findings with results of DNA flow cytometry.

MATERIAL AND METHODS

A total of 92 cases underwent upper gastrointestinal endoscopy, 69 males with mean age 44.0 years and 23 females with mean age 38.7 years. Based on the endoscopic appearance, patients under study were classified into: 15 cases with endoscopic normal mucosa (EN), 26 cases with endoscopic gastritis (EG), 43 cases with duodenal ulcer (DU), and 8 cases with gastric ulcer (GU). Two antral biopsies were taken for histopathology and DNA flow cytometry.

RESULTS

Chronic gastritis (CG) was present in 12 (80%) of EN cases. In DU patients, CG was present in 42 (97.7%) of cases, and it was associated with intestinal metaplasia (IM) in 11 (25.6%), and with dysplasia in 9 (20.9%) of these cases. While in GU patients, CG was present in all cases. Two (13.3%) of endoscopic normal cases revealed DNA aneuploidy in specimens with CG. The incidence of aneuploidy increases as the endoscopic findings changes from EG (15.4%), DU (16.3%) to GU (37.5%), and as the histopathological changes progresses from chronic atrophic gastritis (CAG) (18.2%), IM (21.7%) to dysplasia (33.3%).

CONCLUSION

DNA aneuploidy is a useful marker for recognizing the presence of abnormal cells in epithelial lesions of the stomach, and for monitoring the progression of gastric lesions. Patients with gastric dyspepsia should not only be subjected to endoscopy but also to biopsy and DNA flow cytometry to allow the early detection of malignant transformations in gastric precancerous lesions.

Apoptosis in chronic gastritis: evaluation of the gastric mucosa by DNA flow cytometry and the expression of the high molecular weight cytokeratin

BACKGROUND/AIMS

A series of premalignant lesions, including chronic gastritis (CG), intestinal metaplasia (IM) and dysplasia are associated with gastric carcinogenesis. The present study aimed to define these precancerous gastric lesions further by the study of the cellular DNA using flow cytometry, and the expression of the high molecular weight (68 KDa) Cytokeratin "CK1" proposed as a marker for epithelial cells dying by apoptosis.

MATERIAL AND METHODS

Multiple antral biopsies from each of 92 cases with gastric dyspepsia were subjected for DNA content analysis using flow cytometry, and immunostaining using anti-CK1 monoclonal antibody.

RESULTS

Chronic gastritis (CG) was present in 85 (92.4%) of cases, 14/85 (16.5%) cases showed chronic superficial gastritis (CSG), and 71/85 (83.5%) cases were chronic atrophic gastritis (CAG). Sixty two of the 85 (74.7%) cases with CG revealed variable degrees of activities. A hypodiploid "Sub-G1" peak was detected in 35 of 85 cases with CG. This peak was significantly higher in active chronic gastritis (ACG) than in the inactive (ICG) cases (p < 0.005). Proliferative activity of cases with CG was higher than in normal cases (p < 0.05) and in cases with ACG than in ICG (p < 0.05). Abnormal DNA-content (aneuploidy) was present in 16 (18.8%) of the 85 cases with CG. The presence of gastric epithelial cells with morphological changes typical of apoptosis in cases showing hypodiploid "Sub-G1" peak, high proliferation, and DNA-aneuploidy, suggests that these cells may be apoptotic bodies. Mild degree of apoptosis was present in some cases (57%) with histologically normal mucosa, while dense apoptotic bodies occurred in 87% of cases with chronic gastritis. These apoptotic bodies were constantly expressing CK1, except those in normal mucosa, suggesting that CK1 can be used as a marker for dying epithelial cells by apoptosis. CK1 was detected in 16 (100%) aneuploid cases which also showed apoptosis.

CONCLUSION

The presence of apoptotic bodies in cases with chronic gastritis especially in those showing DNA-aneuploidy, may accounts for the deletion of cells with altered DNA.

Comparative study between cytology and dot-ELISA for early detection of bladder cancer

Schistosomiasis remains one of the major public health problems of the tropics. Conservative estimates place the number of infected individuals at about 200 millions. In Egypt, carcinoma of the urinary bladder associated with schistosomiasis is the foremost oncologic problem, because of its high frequency and the late presentation of cases. A newly developed monoclonal antibody CK1K10 to keratinized grade 1 squamous cell carcinoma was used in a dot enzyme-linked immunosorbent assay (Dot ELISA) to test urine samples of 118 patients with bladder carcinoma, 291 patients with genitourinary pathology other than bladder carcinoma, in addition to 550 healthy controls. The overall sensitivity of the dot ELISA was 90% among 118 patients with bladder carcinoma. Twenty-seven of 33 transitional cell carcinoma cases (82%), 68 of the 71 squamous cell carcinoma cases (96%), 7 of 10 undifferentiated tumors cases (70%), and 4 of 4 adenocarcinoma were positive with this assay. The specificity was 90% in our sample population. A comparative study of diagnosis by cytology and dot ELISA was carried out in 57 patients with bladder carcinoma. Dot ELISA was found to be superior as a screening tool for high risk groups (P < .001 using chi-square test). Cytology detected 21% of transitional cell carcinoma, 68% of squamous cell carcinoma, 50% of adenocarcinoma, and 86% of undifferentiated tumors. The dot ELISA assay should be useful for screening high-risk groups because it does not require sophisticated equipment, is noninvasive, does not require highly trained staff, and can be performed in less than 30 minutes.

UNME/K1: an IgG2a monoclonal antibody specific to cytokeratin of human urinary bladder squamous cell carcinoma

The main distinctive feature of carcinoma in schistosomal bladder is keratinized squamous cell carcinoma. Keratins/cytokeratins constitute a multigeneic family of structurally related polypeptide markers for the malignant state of epithelial cells. A monoclonal antibody (UNME/K1) regognizing keratins associated with squamous cell carcinoma of the human urinary bladder was generated at the Urology and Nephrology Center, Mansoura, Egypt (UNME), by fusion of spleenocytes from a BALB/c mouse immunized with a keratin extract (K1) of human squamous cell carcinoma and P3X63Ag8/U1 syngeneic myeloma cells. UNME/K1 was purified by a protein-A affinity column and was of the IgG2a type, as determined by immunoelectrophoresis and gel diffusion techniques. When tested against keratins of different types of urinary bladder tumors using enzym linked immunosorbent assay (ELISA), UNME/K1 reacted only with the high molecular weight keratin of squamous cell carcinoma and showed selectivity towards specific histopathological grades of tumors.

Antibiotics and immunity: effects of antibiotics on mitogen responsiveness of lymphocytes and interleukin-2 production

The immunomodulating properties of antimicrobial drugs may have important implications in prescriptive practice. This is particularly so for patients whose immune system has been compromised. In this study, tetracycline, cephalothin, rifampicin, polymyxin B and nitrofurantoin reduced mitogen responsiveness of both B and T lymphocytes of mouse spleen cells and human peripheral blood lymphocytes in vitro in a dose-dependent fashion. Ampicillin, chloramphenicol, gentamicin, streptomycin and erythromycin had no effect. In the in vivo study none of the antibiotics affected mouse spleen cell transformation in response to mitogen. The addition of interleukin-2 (IL-2) did not prevent the effect of the antibiotics tested on human lymphocytes in vitro. Cephalothin, chloramphenicol and gentamicin decreased IL-2 production by mouse spleen cells in vitro.

Cytokeratin shedding in urine: a biological marker for bladder cancer?

Cytokeratin shedding into the urine was measured using an enzyme-linked immunosorbent assay in 154 individuals. Samples include urines of normal controls, patients with urological conditions other than bladder cancer and bladder cancer patients. The assay results reflect the potential value of cytokeratin shedding in urine as a new urinary marker for bladder cancer. A 94% sensitivity for patients with squamous cell carcinoma of the bladder suggested the importance of using antibodies prepared against cytokeratin extracted from the same cell type of carcinoma as that to be detected. The relatively low sensitivity shown while detecting transitional cell carcinoma patients and the relatively low degree of assay specificity suggested the use of a panel of monoclonal antibodies specific to various types of cytokeratins of bladder carcinoma.

Antibiotics and immunity: effects of antibiotics on natural killer, antibody dependent cell-mediated cytotoxicity and antibody production

We studied the effects of antibiotics on natural killer (NK), antibody dependent cell-mediated cytotoxicity (ADCC) and immunoglobulin production. When human peripheral blood lymphocytes were incubated overnight with the antibiotic before the assay, nitrofurantoin significantly reduced NK but not ADCC activity. Nitrofurantoin also suppressed both spontaneous and interferon-enhanced NK activities in a dose-dependent fashion. Though it did not affect spontaneous ADCC activity, nitrofurantoin suppressed interferon enhancement of ADCC. Chloramphenicol significantly decreased the number of plaque forming cells in mice. In addition to chloramphenicol, tetracycline, rifampicin, cephalothin, polymyxin B and nitrofurantoin reduced mitogen-induced polycloned immunoglobulin synthesis. Results of this study may have clinical relevance, especially in treating immunocompromised patients.

Immunological activities of recombinant interferon-alpha 2 and its A fragment

The immunomodulating effects of the A fragment of recombinant human interferon-alpha 2 (rIFN-alpha 2) generated by thermolysin treatment was compared to that of the intact rIFN-alpha 2 and lymphoblastoid IFN. The A fragment was similar to intact IFN in augmenting natural killer (NK) activity and suppressing the proliferation of certain cell lines, but it failed to inhibit human polyclonal immunoglobulin production; rIFN-alpha 2 and lymphoblastoid IFN were equally effective in suppressing this in vitro system. These data suggest that the A fragment mediates certain, but not all, of the immunomodulating properties of IFN-alpha 2.

Early immunological prediction of renal allograft rejection

Reliable predictors of impending renal allograft rejection would be valuable for better patient management. To date, no available test has been shown to be consistently predictive and results have often been conflicting. We evaluated an effector of cell-mediated immunity, antibody-dependent cell-mediated cytotoxicity (ADCC) as well as the response of these cells to different biological response modifiers (BRM) in patients following renal allograft transplantation. The in vitro test used assayed monocytes as ADCC effector cells against antibody-sensitized chicken red blood cells. The effects of BRM were studied by preincubating the monocytes with lymphoblastoid IFN, recombinant alpha 2-interferon or gamma-interferon. A follow-up study was performed on 47 patients with end-stage renal disease treated with renal allograft transplantation. ADCC activity and its response to BRM were assayed prior to transplantation, 2, 4, and 9 weeks post transplantation. In the case of rejection, ADCC was then studied prior to initiation of antirejection therapy and for 2 months following treatment of rejection episode. We noted that in patients with stable grafts, the ADCC activity as well as its response to BRM declined gradually during the first 2 weeks post grafting and remained decreased up to 3 months after transplantation. In contrast, in recipients who experienced rejection episodes there was a sustained and significant increase in ADCC response to BRM during the first 3 weeks post grafting. By the time the diagnosis of rejection had been established the baseline ADCC activity had also increased. Following treatment and stabilization of the graft, ADCC activity and its response to BRM was decreased, similar to that in patients with stable grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro effect of alpha-interferon on mononuclear cells of normal and autoimmune patients

The effect of lymphoblastoid interferon (IFN-alpha) on cell-mediated and humoral immunity was studied in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). The base-line natural killer (NK) and antibody dependent cytotoxic cell (ADCC) activity was higher than normal in individuals with RA. The NK and ADCC activities were tested after IFN-alpha pretreatment and the augmentation of NK and ADCC activity was less in these patients than in normals. Lymphoblastoid IFN inhibited antigen induced T-cell proliferation in SLE to a lesser extent than in normal individuals. Finally, the addition of lymphoblastoid IFN was also less effective at suppressing in vitro polyclonal antibody formation by mononuclear cells from patients with SLE than from normals, with enhancement observed in some patients at the lower IFN-alpha concentrations tested.

Parasitic modulation of host immune mechanisms in schistosomiasis

Antigen antibody complexes are suspected to play a role in the pathogenesis of some of the lesions that result from schistosomiasis. To examine the effect of immune complexes on the immune system of mice experimentally infected with Schistosoma mansoni, we measured antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-mediated serum hemolysis in normal and infected animals. ADCC activity in infected mice was depressed compared to control mice. However, preincubation of spleen cells for 24 h in medium followed by washing restored ADCC activity. This suggested that a soluble factor(s), presumably immune complexes, was bound to the Fc receptors with resultant block in ADCC activity and this was removed in vitro during the 24-hour preincubation. Furthermore, the complement activity of mouse serum was markedly depressed in mice infected for 3 or 6 weeks. Again, the presence of immune complexes could explain this depression since immune complexes bind complement. We attempted to confirm and extend these findings with an immunoperoxidase-staining technique using antibody to S. mansoni antigen. Most of the granuloma formations identified in portal tracts and intestinal mucosa were composed of macrophages and epithelial cells surrounding a central nidus of schistosome egg. In addition, schistosome antigen was seen diffusely bound to some of the lymphoid elements in the lamina propria and many of these cells appeared plasmacytoid. Furthermore, large amounts of schistosome antigen were sequestered in the medullary cords of the mesenteric lymph nodes and in the Billroth cords of the spleen. This suggests that the antigen is conveyed to the lymph nodes and the spleen through the systemic circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunological monitoring and early prediction of rejection in renal allograft recipients

Graft rejection remains the major problem complicating renal allograft transplantation. A reliable posttransplant predictor of impending rejection will be valuable to help maintain better graft function. We monitored 47 patients with end-stage renal disease treated by renal allograft starting 1 day pretransplantation and continuing for up to 90 days postgrafting. Peripheral blood mononuclear cells (PBMC) from both patients and 71 healthy subjects were compared for: (1) DNA synthesis in T and B lymphocytes in response to mitogens; (2) interleukin-2 (IL-2) production; (3) natural killer (NK) and antibody-dependent cell-mediated cytotoxic (ADCC) activities; (4) induced augmentation of NK and ADCC activities by the biological response modifiers (BRM), lymphoblastoid interferon, recombinant alpha-2-interferon, gamma-interferon and recombinant IL-2. During the 2 weeks preceding rejection we found lower than normal levels of IL-2 production (p less than 0.0005) and DNA synthesis (p less than 0.01) in concanavalin A-stimulated PBMC. IL-2 yield reached its lowest level on the day of rejection and increased sharply the following week after antirejection therapy was started. Mitogen-stimulated DNA synthesis rose in parallel with increasing levels of IL-2 production. Both NK and ADCC activities increased during rejection (p less than 0.05). The ADCC response to BRM activation measured during the first 2 weeks postgrafting was found to correlate with the stability of the graft. Recipients whose graft function remained stable had a minimal ADCC response to BRM.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunopathology of experimental Schistosoma mansoni: immunohistochemical localization of parasite antigens in the host tissue

Schistosoma mansoni antigens play a crucial role in the induction of immunopathological processes and in modulating the host immune system. A polyclonal rabbit antiserum to an antigenic fraction of adult schistosoma worms was used to localize worm and egg antigens in tissue sections of infected mice. Most granuloma formations identified in paraffin sections of portal tracts and intestinal mucosa were vigorous with florid cellular composition, consisting of macrophages and epithelioid cells, surrounding a central nidus of S. mansoni egg. Schistosome pigments were demonstrated at the periphery of the granuloma, within sinusoidal Kupffer's cells and within macrophages of intestinal mucosa. Large amounts of schistosome antigen were found sequestered in the mesenteric lymph nodes and in the spleen. A strong reaction for locally synthesized IgG was found. These findings suggest that the schistosome antigen-antibody complex found in the host lymphoreticular system plays a major role in the immunopathological process.

Cell-mediated immunity and biological response modifiers in insulin-dependent diabetes mellitus complicated by end-stage renal disease

Previous studies have shown several immunoregulatory abnormalities in insulin-dependent diabetes mellitus (IDDM). In this report we compared peripheral blood mononuclear cells (PBMC) from patients with IDDM complicated by end-stage renal disease (ESRD) to those from normal subjects and from patients with ESRD of different etiologies for their: natural killer (NK) and antibody-dependent cell-mediated cytotoxic (ADCC) activities; modulation of NK and ADCC activities by biological response modifiers (BRM) including purified human lymphoblastoid interferon, human recombinant alpha-2 interferon, human gamma interferon and human recombinant interleukin 2; proliferative response of T and B lymphocytes to concanavalin A (Con A), phytohemagglutinin and pokeweed mitogen, and ability to produce T-cell growth factor (interleukin 2; IL-2). PBMC of diabetic patients demonstrated significantly lower NK activity than normal and ESRD subjects. Upon treatment with BRM, NK activity was augmented and achieved normal levels. ADCC activity was not different from that of normal controls and exhibited similar increases when stimulated by BRM. The proliferative responses to Con A, phytohemagglutinin and pokeweed mitogen as well as IL-2 production in response to Con A stimulation were significantly lower in the IDDM group. Our results indicated that NK cells from patients with IDDM can respond to IL-2 with enhanced cytotoxicity, and, because activation of resting T cells by mitogenic stimuli depends on the production of IL-2 as well as the appearance of a receptor for IL-2, our finding of low levels of in vitro IL-2 production by PBMC from patients with IDDM may explain the depressed NK activity and the observed poor response to T-cell mitogens.

Immune abnormalities in the diabetic New Zealand obese (NZO) mouse: insulin treatment partially suppresses splenic hyperactivity measured by flow cytometric analysis

Immune abnormalities in both the humoral and cell-mediated immune systems were found in New Zealand obese (NZO) mice, a model of diabetes associated with autoimmune disease. Both the formation of anti-sheep red blood cell plaques and mitogen stimulation of NZO spleen cells were significantly decreased compared to normal strains of mice. In addition to perturbations of splenic lymphocyte function, the enlarged spleens of NZO mice demonstrated increased cycling cells as measured by flow cytometric analysis of the DNA content of individual cells. These abnormalities are similar but less pronounced than those found in another autoimmune model, the New Zealand black (NZB) strain. The pancreases of diabetic NZO mice contained a higher fraction of nuclei with greater than 2c amount of DNA. Chronic insulin administration decreased the percentages of splenic proliferating cells and polyploid pancreas cells in NZO mice. In addition, insulin treatment of NZO mice decreased spleen weights and serum glucose levels. Chronic insulin treatment did not alter these parameters in either nondiabetic Balb/c or autoimmune NZB mice. Thus, the features of the NZO strain which serve as both an autoimmunity model and a diabetes model can be dissociated. Insulin treatment had a unique effect on NZO traits but not on NZB traits even through many of these traits were present in both strains. In conclusion, although autoimmunity may underlie the diseases of both the NZO and the NZB strains, the amelioration of some of the features of the NZO strain by insulin may represent the beneficial effects of insulin on the metabolic control of cellular function in NZO mice.

Production and partial characterization of interleukin 2 induced by periodic acid oxidation of lymphocyte membranes

Murine splenocytes, when stimulated to undergo blastogenesis by H5IO6 oxidation, produced a lymphokine with a spectrum of properties identical to that generally ascribed to IL-2 released by lectin-stimulated cells. These included the sustained propagation of IL-2-dependent CT6 cells, as well as identical thermal and enzymatic stabilities. Cell membrane carbonyls generated in situ by the oxidation of cell membranes served as triggers for subsequent IL-2 production by the activated cells. Reduction of membrane carbonyls by NaBH4, and their addition reaction with NaHSO3 and NH2OH abrogated cell activation and inhibited, but did not abolish, IL-2 production. None of the specific carbonyl reagents, e.g., NaBH4, NaHSO3, and NH2OH, have by themselves induced blastogenic transformation, although they did elicit IL-2 production. It is therefore concluded that cell membrane carbonyls serve as triggers for IL-2 production by H5IO6-transformed cells, although an increased rate of DNA synthesis per se is not an indispensable precondition for IL-2 synthesis.

Interleukin 2 production induced by chemically defined cell membrane modification

We present evidence that murine spleen cells produce a T-cell growth-stimulating factor following oxidation by periodic acid (H5IO6). The identification of this factor as interleukin 2 (IL-2) is indicated by its ability to support the growth of the IL-2-dependent CT6 cell line. In addition, preliminary analysis shows that H5IO6-stimulated growth factor has biochemical properties similar to IL-2. The time course of H5IO6-induced IL-2-like production by spleen cells was determined. No growth-stimulating activity was detected after 1 h of culture. The peak of periodic acid-induced IL-2-like production was between 18 and 24 h, while the maximum 3H-thymidine incorporation in spleen cells occurred at 72 h. Flow cytometry of CT6 cells was used for cell cycle analysis and to demonstrate their stimulation by IL-2-containing supernatants. These results were in agreement with the 3H-thymidine incorporation data. Electron microscopy of CT6 cells stimulated by supernatants from concanavalin A- or H5IO6-treated spleen cells showed no differences in their morphology. Degradation of spleen cell sialic acid prior to periodic acid oxidation inhibited IL-2-like production by 84% and inhibited 3H-thymidine uptake by 80%.

Tunicamycin treatment inhibits the antiviral activity of interferon in mice

Earlier we reported that tunicamycin (TM) treatment of L cells in vitro significantly enhances the antiviral activity of interferon (IFN) against viruses (such as vesicular stomatitis, Sindbis, and herpes simplex) which bud from membranes. However, no such enhancement of the antiviral activity of IFN by TM was observed against encephalomyocarditis virus (EMCV) (nonbudding). We were interested to know whether TM would similarly enhance the antiviral activity of IFN and IFN inducers in vivo against Semliki Forest virus (SFV) and EMCV infections in mice. It was observed that TM alone (0.001 to 5.0 micrograms per mouse) did not protect mice against infections of SFV and EMCV; instead, TM-treated mice died with virus-specific paralytic symptoms earlier than untreated animals. The enhanced mortality in TM-treated and SFV- or EMCV-infected mice was associated with the concomitant increase in virus titer in brain tissue. IFN significantly protected mice against SFV and EMCV infections. The antiviral protection of mice by IFN against both the viruses was markedly inhibited by TM administration. IFN inducers (polyinosinic acid-polycytidylic acid, 6-MFA [a mixture of proteins, polysaccharides, and double-stranded DNA isolated from Aspergillus ochraceus ATCC 28706]) protected a significant number of mice against SFV infection. However, no such protection was observed in mice injected with a combination of TM and IFN inducer. These results indicate that TM treatment inhibits the antiviral action of IFN or IFN inducers in vivo.

Interferon-mediated inhibition of human polyclonal immunoglobulin synthesis

Human lymphoblastoid IFN suppressed human polyclonal Ig synthesis in a dose-related manner, with 71% mean inhibition of antibody production found when 1000 units of IFN were added to the cultures. This suppression was demonstrated to be mediated by an electrophoretically pure preparation of IFN. Furthermore, IFN inhibition of both the T-dependent and the T-independent polyclonal activators was not the result of direct cellular cytotoxicity. IFN-mediated suppression of human polyclonal Ig production does not result from induction of T suppressor cells, and in a T helper cell-independent system this inhibition appears to result from either a direct action on the B cells or an indirect effect via monocytes.

Interferon-mediated inhibition of human polyclonal immunoglobulin synthesis

Human lymphoblastoid IFN suppressed human polyclonal Ig synthesis in a dose-related manner, with 71% mean inhibition of antibody production found when 1000 units of IFN were added to the cultures. This suppression was demonstrated to be mediated by an electrophoretically pure preparation of IFN. Furthermore, IFN inhibition of both the T-dependent and the T-independent polyclonal activators was not the result of direct cellular cytotoxicity. IFN-mediated suppression of human polyclonal Ig production does not result from induction of T suppressor cells, and in a T helper cell-independent system this inhibition appears to result from either a direct action on the B cells or an indirect effect via monocytes.