Abdellah Benslimane

Different cytokine profiles of peripheral blood mononuclear cells from patients with persistent and self-limited hepatitis C virus infection

An imbalance between T helper cell Th1 and Th2 like cytokines has been described in several chronic infectious diseases. In an attempt to characterise the mechanism responsible for viral persistence in hepatitis C virus (HCV)-related chronic infection, we analyzed Th1 cytokines (IL-2, IL-12, IFN-gamma) and Th2 cytokines (IL-4, IL-10) production by phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) derived from ten patients with viremic chronic hepatitis C, five healthy HCV seropositive individuals and four HCV seronegative individuals. Cytokine production was determined by enzyme-linked immunosorbent assay (ELISA) after 72 h of stimulation. The results showed that the production of IFN-gamma by PHA-stimulated PBMC was decreased in patients with hepatitis C infection (P=0.05). IL-4 production was not detected in both patients and controls, while no difference was observed for IL-2, IL-10 and IL-12 production between patients and controls. Furthermore, IL-12 and IFN-gamma production was weaker in patients with viremic chronic hepatitis C than in subjects who were able to clear the virus (P=0.01; P=0.03, respectively). These results clearly indicate that a defect both in IL-12 and IFN-gamma production may contribute to the persistence of HCV infection.

Beneficial effect on serum apo AI, apo B and Lp AI levels of Ramadan fasting

In order to investigate for the first time in Morocco the effect of fasting in Ramadan, the ninth lunar month of the muslim year, on lipoprotein metabolism, we determined the levels of serum apolipoproteins; apolipoprotein AI (apo AI), apo B, apo AIV and those of lipoprotein particles; apo AI-containing lipoprotein particles (Lp AI) and also apo AI and apo AII containing lipoprotein particles (Lp AI:AII) in a group of 32 healthy, volunteer adult males. Determination of all these parameters was carried out on each week of the month of Ramadan and the results are compared with the pre-fasting and the post-fasting values. Ramadan fasting reduces significantly serum apo B (P < 0.05), while serum apo AI is significantly increased (P < 0.05) compared with the pre-fasting period. The increase of apo AI occurred on day 29 of Ramadan by 11.8%. Serum apo AIV was unchanged during the fasting period indicating that food intake during Ramadan is not based on lipid diet. The observed diet pattern during Ramadan showed an increase of total energy intake based on carbohydrates (+1.4% of total energy), proteins (+0.4% of total energy) but not on fat (-0.7% of total energy), compared with a usual diet used in the rest of the year. The fat diet is high in monounsaturated (P < 0.05) and polyunsaturated fatty acid in contrast to saturated fatty acid which decreased (P < 0.05) during Ramadan. On the other hand, analysis of serum Lp AI and Lp AI:AII showed that the levels of Lp AI:AII were unchanged but those of Lp AI were significantly increased (P < 0.01) at the end of Ramadan. These findings show that feeding behaviour that occurs during Ramadan beneficially affects serum apolipoprotein metabolism and may contribute to prevention of cardiovascular diseases.

Antibodies to the Epstein-Barr virus transactivator protein (ZEBRA) as a valuable biomarker in young patients with nasopharyngeal carcinoma.

Epstein‐Barr virus (EBV)–associated nasopharyngeal carcinoma (NPC) generally occurs in adults, especially in high‐prevalence populations such as the Chinese and Eskimos. In Maghrebian populations, young patients affected with this malignancy represent 25% of the total NPC cases. In adults with NPC, relatively high titers of IgA antibodies to the EBV viral capsid antigen (VCA) and early antigen (EA) represent important markers. However, nearly 50% of young NPC patients are negative for IgA‐anti‐VCA and ‐EA or exhibit very low titers of these antibodies. We report here that 92% of sera from young NPC patients negative for IgA‐EA and 89% of those negative for IgA‐VCA were positive for IgG antibodies to the EBV transactivator protein (ZEBRA) at very high titers. Our results show that in young patients with NPC these antibodies represent the most reliable marker for diagnosis and prognosis, particularly when compared with conventional NPC markers, i.e., IgA‐VCA (58%) and anti‐EA (25%). The titers of IgG‐ZEBRA antibodies increased along with lymph node involvement only in the young patient group, suggesting a prognostic value of this marker in this patient group. Int. J. Cancer 86:71–75, 2000.

Seroepidemiological study of an acute hepatitis E outbreak in Morocco

This study clearly shows that hepatitis E virus (HEV) was the major aetiological virus in an outbreak in the south of Morocco, in 1994. Acute hepatitis E was diagnosed using recombinant antigen-based enzyme immunoassays and reverse transcription polymerase chain reaction in 77.3% of patients. In the west of Morocco, 6.1% of controls were positive for anti-HEV IgG. The anti-HEV prevalence in patients was significantly higher than that of controls (84.0% vs. 6.1%) (P < 0.001). In healthy contacts residing in southern Morocco, 10.4% had anti-HEV IgG, indicating past HEV infection. Furthermore, HEV-specific IgM was associated with subclinical HEV infection in 9 contacts and was noted in 10 others who were convalescent. Faecal contamination of drinking water samples collected from the epidemic city was observed. It also appeared that primary infection with HEV accounted for more than 86% of the cases. A longitudinal study showed waning of anti-HEV antibodies in patients and healthy contacts six months after the initial testing. Subclinical HEV infection was significantly prevalent in a paediatric population younger than 10 years (P < 0.05). Our results also showed that anti-HEV IgG in healthy contacts decreased significantly after 30 years of age (P < 0.01), whereas the clinical acute HEV infection incidence increased significantly with age (P < 0.01). From this study, it appears that HEV is present in both the west and the south of Morocco.

Study of human leukocyte antigen class I phenotypes in Moroccan patients with nasopharyngeal carcinoma.

Previous reports demonstrated an association between the human leukocyte antigen (HLA) and risk for nasopharyngeal carcinoma (NPC) among the Chinese in Singapore, a population with a high incidence of this malignancy. In our study, we assess the association between HLA and NPC in Morocco, a median‐prevalence area for this cancer, where NPC presents the particularity of also affecting young individuals. Using the standard microlympho‐cytotoxicity test, we typed a total of 154 Moroccan NPC patients and 257 unrelated healthy controls for their HLA‐A and B antigens. The results of these analyses show that the frequencies of HLA‐A10, HLA‐B13 and HLA‐B18 were found to be higher in the NPC group than in the control group, whereas HLA‐A9 was associated with a decreased risk. After correction for the number of specificities tested, these differences were statistically significant only for HLA‐B18 (corrected p value [pc] < 0.023, relative risk [RR] = 4.14) and HLA‐A9 (pc < 0.023, RR = 0.45). The comparison of the distribution of the HLA antigens in younger and older cohorts of patients shows that the incidence of HLA‐A10 and HLA‐ B18 was higher in the older group, whereas the frequencies of HLA‐A19 and HLA‐B13 were significantly higher in younger patients compared with controls. The presence of both HLA‐A19 and HLA‐B13 phenotypes correlated with an increased risk of developing NPC among overall patients compared with controls. According to the sex distribution, increased frequency of HLA‐B18 was found in male and female NPC patients compared with controls, whereas the frequency of HLA‐A10 was higher only in male NPC patients compared with controls.

Antibody Responses to Recombinant Epstein-Barr Virus Antigens in Nasopharyngeal Carcinoma Patients: Complementary Test of ZEBRA Protein and Early Antigens p54 and p138

ABSTRACT Serological tests based on the antibodies directed against the Epstein-Barr virus early antigen (EA) and viral capsid antigen (VCA), which have been recognized as tumor markers for nasopharyngeal carcinoma (NPC), are routinely used to help in the diagnosis of this malignancy. The detection of these antibodies reveals very low titers, found only in a small proportion of young compared with older NPC patients. This is a problem for the diagnosis of NPC, especially among Maghrebians, among whom young people are also affected, and emphasizes the necessity to search for more reliable markers. The present study reports results of immunoglobulin G (IgG) and IgA responses of NPC patients to recombinant EA antigens p54 (BMRF1) and p138 (BALF2), VCA complex antigens p18 (BFRF3) and p23 (BLRF2), and EBNA antigen p72 (BKRF1). Our results show that IgA-EA-p54 and -p138 (IgA-EA-p54+138) antibodies have a diagnostic value for detection of NPC (70%), compared with IgA-VCA-p18+23 and IgA-EBNA-p72, which have limited diagnostic value, especially in young patients. It is also noteworthy that IgA-EA-p54+138 can detect a high percentage (64%) of NPC cases negative by immunofluorescence. These results, however, clearly show that a single test cannot achieve the objective of detecting all NPC patients, and it seems advisable to combine different tests for the diagnosis of NPC. The combination of IgG-ZEBRA with IgA-EA-p54+138 improved the sensitivity of detection of NPC to 95% in the overall NPC population. The use of IgA-EA-p54+138 in combination with IgG-ZEBRA will facilitate detailed studies on the pattern of antibody response, which may result in the development of useful serological markers to guide the treatment of NPC.

HCV genotypes in Morocco

To determine the hepatitis C virus (HCV) genotypes circulating in Morocco, virus isolates from 105 chronically infected and 19 hemodialysis patients were examined using the line probe assay. Genotypes 1 and 2 only were found among Moroccan patients. Subtypes 1b (47.6%) and 2a/2c (37.1%) were the most common, whereas subtype 1a (2.8%) was less common. Among the hemodialysis patients, only genotype 1 was found with a prevalence of 68.4% for subtype 1b and 15.8% for the subtype 1a. It was also shown that the HCV genotypes distribution varies with age in both studied populations. Subtype 1b was most prevalent among older patients, whereas subtype 2a/2c was mainly found among younger ones. Although Morocco belongs to the African continent, the circulating HCV strains are similar to those observed in some American and European 1997 countries. J. Med. Virol. 52:396–398, 1997.

The prevalence of sexually transmitted pathogens in patients presenting to a Casablanca STD clinic

The objective of this study conducted at the sexually transmitted diseases (STD) clinic of the Pasteur Institute of Morocco (SCPIM) is to describe clinical complaints and biological findings in patients attending this facility. Two thousand two hundred sixty-four patients had visited the STD clinic from 1992 to 1996. The main reported symptom was genital discharge for men (44.5%) and women (68.6%). Genital eruption and ulcer were more frequent in men. The principal biological result shows a seroprevalence of 0.62% for human immunodeficiency virus (HIV), 3.05% for hepatitis B virus (HBV), 51.5% for chlamydiae and 13.2% for syphilis. Factors associated with clinical findings were age and Gonococcus for men (odds ratio (OR): 1.94 and 5.96, respectively) and Trichomonas and positive TPHA for women (OR: 9.49 and 0.25, respectively). This work describes for the first time the distribution of various germs involved in sexually transmitted diseases in Moroccan population and underlines the importance of studying its sexual behavior as well as determinants of STD incidence.

Direct genotyping and nucleotide sequence analysis of VS1 and VS2 of the Omp1 gene of Chlamydia trachomatis from Moroccan trachomatous specimens

To determine the range of ocular strains of Chlamydia trachomatis circulating in southern Morocco, where trachoma is endemic, and to compare the value of the molecular methods for genotyping C. trachomatis, ocular specimens were subjected to a direct Omp1 PCR-restriction fragment length polymorphism (RFLP)-based analysis and direct sequencing. PCR-RFLP analysis shows that the Ba genotype represents the most frequent one (63%), followed by genotype A (45%), whereas no B or C genotypes were identified among the 53 out of 108 specimens that were strongly positive in the Omp1 CT1-CT5 PCR. Our results further show that the notion of interfamily and intrafamily transmission is very likely. To confirm the genotype identity of C. trachomatis as determined by PCR-RFLP, 16 selected specimens were sequenced across variable sequence 1 (VS1) and 2 (VS2). No discrepancies were found between PCR-RFLP typing and the genotype identity confirmed by nucleotide sequencing of the PCR product. Our results clearly indicate that both molecular methods of typing chlamydiae (i.e., PCR-RFLP and sequencing) are important and have specific applications for clinical epidemiological purposes. This is the case for individuals infected with more than one clonal population of C. trachomatis. The unambiguous nucleotide sequencing therefore defines an important epidemiologic descriptor for the infected patient whether the source is from a clonal population of organisms or whether it represents a more dynamic process of strain dominance or genetic change. Furthermore, Omp1 genotyping affords the necessary approach to epidemiologic investigations in areas of the world endemic for trachoma, where only one or two serovars are known to predominate.

Analysis of apoptosis and a Th1/Th2 phenotype in HIV-infected patients

Lymphocytes from HIV patients, unlike those from normal HIV-negative subjects, underwent apoptosis upon in vitro culture. We found that the percentage of lymphocytes undergoing apoptosis was significantly higher (P = 0.005) in patients with low CD4 cell counts (< 200 CD4 cells/microliter) (60%) than in patients at earlier stage (> 500 CD4 cells/microliter) (35%). Serum IgE levels increased in two of six patients at last stage and in two of five patients at earlier stage. Spontaneous production of both IL-2 and IL-10, by peripheral blood mononuclear cells (PBMC) after 48 h in culture, was greater in HIV-infected subjects and increased with disease progression. IFN-gamma production was greater in HIV-infected subjects but there was no evident change with disease progression. IL-4 production was barely detectable or not detected in both HIV-infected and HIV-negative individuals. These results indicate that spontaneous apoptosis is associated with advanced disease. However, there was no evidence of in vivo switch from the Th1 to Th2 phenotype in HIV-infected patients.