SH2D1A mutation analysis for diagnosis of XLP in typical and atypical patients.

X-linked lymphoproliferative disease (XLP) is a rare inherited immunodeficiency to Epstein-Barr virus (EBV). The gene responsible for XLP has recently been identified as the four-exon SH2D1A gene encoding a 128-amino-acid protein that contains an SH2-domain. Functional studies indicate the SH2D1A protein acts as a regulator of at least two signal transduction pathways initiated by the cell surface molecules SLAM and 2B4, respectively, and possibly related to the host immune response to EBV infection. We have carried out a systematic mutation study of the SH2D1A gene in our series of 19 typical and 8 atypical XLP patients by polymerase chain reaction (PCR), reverse transcription/PCR, and sequencing, and have reconstructed the haplotypes of the patients. Four out of the 13 mutations detected are previously unreported. The identification of SH2D1A mutations in carriers from all three XLP families screened and the detection of mutations in two out of eight atypical patients indicates the usefulness of a DNA-based diagnosis for XLP disease.

Genetic analysis of 24 French families with multiple endocrine neoplasia type 2A.

The gene for multiple endocrine neoplasia type 2A (MEN2A) has been mapped to the pericentromeric region of chromosome 10 by linkage analysis. Thirty-four families with multiple cases of medullary carcinoma of the thyroid (MTC), including 24 families with origins in France, have been typed with nine polymorphic markers spanning the centromere of chromosome 10. No recombination was observed between the MEN2A locus and either of the four loci D10Z1 (lod score 12.79), D10S102 (lod score 6.38), D10S94 (lod score 7.76), and D10S34 (lod score 5.94). There was no evidence for genetic linkage heterogeneity in the panel of 34 families. Haplotypes were constructed for a total of 11 polymorphisms in the MEN2A region, for mutation-bearing chromosomes in 24 French families and for 100 spouse controls. One haplotype was present in four MEN2A families but was not observed in any control (P less than .01). Two additional families share a core segment of this haplotype near the MEN2A gene. It is likely that these six families have a common affected ancestor. Because the incidence of pheochromocytoma among carriers varies from 0% to 74% within these six families, it is probable that additional factors modify the expression of the MEN2A gene.

The gene for MEN 2A is tightly linked to the centromere of chromosome 10.

We have examined 30 families with multiple endocrine neoplasia type 2a (MEN2A). Linkage studies indicate that the gene for MEN2A is located on chromosome 10, tightly linked to the D10Z1 locus.

Antibody response against the Epstein-Barr virus-coded nuclear antigen2 (EBNA2) in different groups of individuals.

Specific antibody responses against the 2 major subcomponents of EBNA, EBNA1 and EBNA2 were evaluated, in order to study whether this serological study was beneficial compared to classical EBV serology. During this investigation, 491 sera, obtained from blood donors and patients with Burkitt's lymphoma (BL), nasopharyngeal carcinoma (NPC), infectious mononucleosis (IM), Hodgkin's disease, renal transplantation, rheumatoid arthritis and Human Immunodeficiency Virus (HIV) infection, were tested. While the anti-EBNA1 response followed the classical anti-EBNA/Raji response (99% of anti-EBNA/Raji-positive sera also recognize EBNA1), the anti-EBNA2 response was much less frequent and did not correlate with either anti-EBNA/Raji or anti-EA antibodies. In a control population, 8% of individuals had antiEBNA2 antibodies at titers greater than or equal to 10. The percentage was 45% in NPC and 38% in EBV-associated BL; thus, although not detected in all patients with EBV-associated tumors, anti-EBNA2 serology might be a useful marker in BL and NPC. No antibody was detected in the early course of IM, but in rheumatoid arthritis and in HIV-infected patients, the percentage of positive individuals reached 54 and 68, respectively. Seroconversion to EBNA2 was noted in a few cases, including renal transplant recipients, AIDS patients, and complicated IM. This suggests that in these situations, EBNA 2 serology might represent a useful marker related to modulation of the immune status or EBV reactivation.

Epstein-Barr viral serology in nasopharyngeal carcinoma patients in the USSR and Cuba, and its value for differential diagnosis of the disease.

Serological responses to Epstein-Barr virus (EBV)-associated antigens were studied in nasopharyngeal carcinoma (NPC) patients in 2 countries non-endemic for the disease: the USSR (77 cases) and Cuba (55 cases). Two age- and sex-matched control groups were available, one consisting of patients with other head-and-neck tumours (OHNT) (171 from the USSR and 56 from Cuba), and the other of normal individuals (blood donors) (83 from the USSR and 80 from Cuba). Unlike the control groups, NPC patients from both countries had high levels of IgG and IgA antibodies, similar to those seen in patients from endemic areas. The only difference between NPC patients in the USSR and those in Cuba was lower (2-2.5 fold) anti-VCA IgG and IgA antibody titres. Using one-factor and multi-factor statistical methods the diagnostic value of different titres of EBV-specific IgG and IgA antibodies and their combinations for NPC patients (in the USSR) was evaluated. It was found that with simple mathematical analysis of EBV-specific antibody titres a differential diagnosis of NPC could be made to a significance level of 90%. The data obtained demonstrated the importance and reliability of EBV serology in the diagnosis of NPC in areas of low incidence of the disease.

[Burkitt's lymphoma-Epstein-Barr virus association in western Algeria. Clinical, cytological and serological aspects apropos of 34 pediatric cases]. / Association lymphome de Burkitt-virus d'Epstein-Barr dans l'ouest Algérien. Aspects cliniques, cytologiques et sérologiques à propos de 34 observations pédiatriques.

Burkitt's lymphoma (BL) and naso-pharyngeal carcinoma (NPC) are tumors generally believed to be associated with Epstein-Barr virus (EBV). Algerian population could be considered at high risk for BL-EBV association. In a series of 34 BL patients observed by us between 1982 and 1984 characteristics were: 70% of children were under 5 years age, abdominal location in 90% of cases (n = 30), 13% only isolated, massive tumor burden (70% stage III after Murphy, 30% stage IV after Murphy and Duque-Hammershaimb), EBV serology titers above or equal to 640 in 60% of cases (anti-EBNA and anti-VCA) and 50% (anti-EA) respectively, presence of EBNA antigen in tumor cells found in 63% of cases, no complete correlation between serology positivity and EBNA presence.

Induction of Epstein-Barr virus early antigen by phytohaemagglutinin in the presence of 5-iodo-2'-deoxyuridine: application to EBV serology.

Induction of EBV early antigens in the non-producer lymphoid cell line RAJI by treatment with PHA in the presence of IUdR has been shown to be a convenient and efficient procedure for the preparation of cells for EBV serology. This induction procedure results in significant levels of EA-D and EA-R positive cells. The serological titres obtained on cell preparations induced with PHA and IUdR were comparable to those obtained on smears prepared by the classical procedure requiring infectious EBV. This convenient method of induction can replace more cumbersome techniques for routine EBV serology.

In vitro transforming activity of Epstein-Barr virus (EBV). II. Differences between M81 and B95-8 EBV strains.

Lymphocytes from 38 human cord blood and 9 adult circulating blood were aliquoted and infected in parallel either with the B95-8 EBV strain (produced by cotton-top marmoset lymphocytes transformed by EBV originating from an infectious mononucleosis line) or with the M81 EB virus (produced by callithrix jacchus marmoset lymphocytes transformed by EBV originating from a nasopharyngeal carcinoma (NPC) derived line). Significant differences were observed in the lymphoblastoid lines obtained and involved cell morphology, cell growth and synthesis of viral antigen. Cord blood lymphocytes infected with M81 virus resulted in lymphoblastoid lines where EA and VCA synthesis and production of virions took place, whereas this was not observed in B95-8 induced lines.

A comparison of the prognostic value of antibody-dependent lymphocyte cytotoxicity and other EBV antibody assays in Chinese patients with nasopharyngeal carcinoma.

Antibody titres to EBV-associated antigens in Chinese NPC patients were analysed according to length of survival after diagnosis and to disease stage. Geometric mean titres of ADLC antibody were highest in the long-term survivors, whereas VCA, EA and EBNA antibody titres showed an inverse relationship to survival. High VCA, EA and EBNA titres were less frequent, and high ADLC titres were more frequent in long-term survivors than in intermediate or short-term survivors. The association of geometric mean titres of EBV antibodies with prognosis could not be entirely explained by stage of disease. A functional role for the ADLC antibody is suggested by the association of a high ADLC antibody titre with a good prognosis regardless of stage of disease.

[Epstein-Barr virus and infectious mononucleosis. A clinical study of Epstein-Barr antibodies (author's transl)]. / Mononucléose infectieuse: intérêt de la recherche des différents anticorps anti-virus Epstein-Barr.

Thirty-seven patients--aged 2 to 58--with clinical and hematological signs of infectious mononucleosis were studied. Thirty patients gave serologic evidence of Epstein-Barr virus infections; antibodies to viral capsid antigen (VCA) appeared very early (only two seroconversions and 4 cases of increased titer were detected); antibodies to early antigen (EA) occured in 25 patients, but only 9 had high titers; antibodies to nuclear antigen (EBNA) appeared late in the course of the disease. VCA-specific IgM antibodies occurred in 25 cases (they usually disappeared during the 2nd month). The transforming EB virus was found in the saliva of the 2 patients where we looked for it. Heterophile antibody responses occured in only 17 patients; among children about half of them had a positive Paul-Bunnell-Davidsohn test. After the age of 40 (3 cases) heterophile antibodies were no longer found. Three patients had another recent viral infection at the same time as the primary EBV infection (two cases of rubella, one case of adenovirus infection). Of the remaining 7 patients (having either no antibodies to EBV or antibodies of past infection), 2 had cytomegalovirus infections and one rubella.

Differences in EBV antibody titres of patients with nasopharyngeal carcinoma originating from high, intermediate and low incidence areas.

In order to assess the differences in serological reactivities of NPC patients from high, intermediate and low incidence areas, 288 NPC sera from Hong Kong, Singapore, Tunis, East Africa, Paris and Los Angeles, together with sera from patients with ear, nose and throat tumours other than NPC and with those from normal individuals from the same areas, were tested 'blind' with the same batches of antigen. Important differences (up to 3-fold) in the GMTs of antibodies directed against VCA, EA and EBNA were observed between different ethnic groups. Although the stages of the disease varied somewhat between groups, the main cause of the variations appeared to lie in the socio-economic environment of the patients. Apart from these variations, and regardless of geographical or ethnic origins, NPC was consistently found to be associated with an active infection (or reactivation) by Epstein-Barr virus, which was not the case for patients with other tumours or for normal individuals from the same areas or of the same ethnic groups.

Herpes simplex-RAJI(A44), a new cell line for serologic testing by immunofluorescence.

An IF technique for the detection of HSV antibodies by using a lymphoblastoid cell line, Raji(A44), which continuously produce a constant amount of HSV antigen, is described. IF and IH tests were found to be similar with respect to sensitivity and reproducibility. Sero-conversions detected by the CF test were detected with this cell line. The Raji(A44) line (cells in suspension) can be routinely used for the diagnosis of HSV infection.

Sero-epidemiology of the Epstein-Barr virus: preliminary analysis of an international study - a review.

Samples of Chinese, Indian, African and Caucasian populations, randomly selected in Hong Kong, Singapore, the West Nile District of Uganda, and Nancy, France, were titrated for antibodies to EBV, viral capsid (VCA) and complement-fixing soluble (CF/S) antigens. The age-specific prevalence of infection (as reflected by the proportion of VCA-positive individuals) varied greatly up to the age of 10 years in the four populations studied, the West Nile District of Uganda being outstanding in having an early and massive infection rate. Differences were also observed between ethnic groups in Singapore, where the Chinese appeared to have a delayed infection rate compared to the Indians. Immune response, as measured by the prevalence of CF/S antibodies and by the geometric mean titres (GMT) of VCA and CF/S antibodies, differed significantly between ethnic groups, Ugandan infants (1-3-year age-groups) having a humoral response to VCA and CF/S antigens as high as or higher than that of Burkitt's lymphoma patients, decreasing thereafter to levels lower than those of any other ethnic group observed. Indians in Singapore, known to be at no risk for NPC and BL, exhibited a higher and steadier immune response to VCA in going from young to old age-groups than did the Chinese.

The variability in immunofluorescent viral capsid antigen antibody tests in population surveys of Epstein-Barr virus infections.

A comparative study of the extent of Epstein-Barr virus (EBV) infections in populations that differ with respect to the incidence of tumours associated with this virus is now in progress in different countries. In these surveys of antibody titres from the various study populations, it is of critical importance that strict comparability be maintained. Despite standardization of techniques and reagents in the cooperating laboratories, considerable variation in the results has remained. The components of the total variability in the results of the immunofluorescence test for estimating the antibody titres against viral capsid antigens (VCA) of the EBV have been investigated. With repeated tests on the same sera, four sources of variation were measured: the reading of the slides, the performance of the tests, the use of various batches of the same cell line as antigen, and the use of different cell lines. The greatest variations were due to the use of different cell lines and to differences in performing the test; the reading of the slides caused only minor variations. Both the systematic and unsystematic variations were measured. The systematic variation was great in tests between laboratories and when different cell lines were used as antigens. Most of the systematic variation resulting from the use of different cell batches from the same cell line could be accounted for by the differing proportions of brilliant fluorescent cells. Adjustments are possible to correct the systematic variation whenever this has been measured, but not the unsystematic "residual" variability, which presents the real obstacle to the comparison of results obtained in different laboratories or by different observers. To attain full comparability of VCA antibody tests the sera from the different surveys should all be tested in the same laboratory.