X-linked lymphoproliferative disease: prenatal detection of an unaffected histocompatible male

Chorionic Villous Biopsy (CVS) for diagnosis of XLP was undertaken at 10 weeks gestation in an obligate carrier. The fetus was found to be male by cytogenetic analysis. XLP (Xq25-q26) is closely linked to the RFLP markers DXS10, DXS37 and DXS42, but only DXS10 (distal to XLP) was informative for prenatal diagnosis in this family. RFLP analysis using this marker gave a 7% risk that the fetus was affected, based on the known recombination frequency between DXS10 and XLP. Further investigation was then undertaken to obtain a rapid and more accurate diagnosis using the three highly polymorphic PCR based markers. These were the AC repeat markers DXS424 (XL5A) and DXS425 (XL90A3) and the tetramer repeat marker within HPRT. DX425 is approximately 10 cM proximal to DXS10 and HPRT but is not known with certainty to map proximal or distal to XLP. DXS424 is proximal to DXS10 and HPRT and was inferred to be proximal to XLP on the basis of map distance from HPRT estimated by linkage analysis of data from CEPH pedigrees. This was confirmed by a recombinant in the XLP family between DXS424 and DXS425, placing DXS424 proximal to XLP. Diagnosis by linkage using DXS424 and DXS425, at least one of which is proximal to XLP, and distal markers DXS10 and HPRT, increased the accuracy of diagnosis using flanking marker analysis to greater than 99% that the fetus was unaffected. HLA DR typing of the CVS showed that the fetus was DR identical to a male sibling with XLP. HLA compatibility was confirmed at delivery by full HLA typing and MLC.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of three overlapping deletions causing X-linked lymphoproliferative disease

Blot hybridization was used to find DNA sequences missing in a male who lacked two-thirds of Xq25. The probes were used to discover two additional males with deletions resulting in X-linked lymphoproliferative disease (XLP). All three deletions have a region in common, and DXS739 is within this candidate region. The new deletions were also detectable using chromosome banding, and the smallest removes only one-third of Xq25. XLP is the only consequence of the deletions.

Augmentation of natural cytotoxicity by leucine enkephalin in cultured peripheral blood mononuclear cells from patients infected with human immunodeficiency virus

Natural Killer (NK) activity of lymphocytes from acquired immunodeficiency syndrome (AIDS) patients is frequently below normal and declines as disease progresses. We studied the potential of leucine enkephalin (leu-enkephalin) to restore this immune parameter by incubating nylon wool nonadherent mononuclear cells from 14 patients in the presence or absence of leu-enkephalin, and measuring NK cytolysis in a standard 51Cr release assay. The NK activity of human immunodeficiency virus antibody positive (HIV+) individuals with some remaining NK lytic ability was significantly augmented by leu-enkephalin concentrations of 10(-10) and 10(-8) M (n = 7). HIV+ patients with no measurable basal level of NK activity (n = 3) were not responsive to stimulation with leu-enkephalin. Human immunodeficiency virus antibody negative (HIV-) individuals (n = 4) responded in a pattern similar to normals. In addition, naloxone, an antagonist of alkaloid and peptide opiates including leu-enkephalin, displayed the properties of an antagonist/agonist, reflecting the immunoregulatory capacities of the endogenous opiate system.

Genetic and immunopathological findings in a lymphoma family

We have studied a remarkable family with seven cases of malignant lymphoma extending through three generations wherein five sisters and their mother had histopathologically documented non-Hodgkin's lymphoma, while a granddaughter had Hodgkin's disease. An immunological study of three lymphoma survivors, nine of their first degree relatives, and four spouse controls was undertaken. Significant findings consisted of a depressed serum IgG3 level in four of the nine first-degree relatives; in two of these four, lymphocyte stimulation by both pokeweed mitogen and concanavalin A were significantly depressed. The subtle immunological abnormalities present in this kindred may be associated with the pathogenesis of the lymphomas.

Antibody reactivity to a synthetic peptide (P62) of the Epstein-Barr nuclear antigen in sera of patients with X-linked lymphoproliferative syndrome

An enzyme-linked immunosorbent assay (ELISA) was used to measure IgG antibody titers against a synthetic peptide whose sequence was derived from the glycine-alanine repeating region of Epstein-Barr virus nuclear associated antigen 1 (EBNA-1). Antibody titers were determined in sera from 15 normal subjects, sera from 21 normal male siblings of X-linked lymphoproliferative syndrome (XLP) patients, from 20 XLP patients comprising a total of 42 samples, and ten samples before and ten samples after gamma-globulin therapy in ten patients with XLP. Data analysis demonstrated that while there are differences between the ELISA and ACIF, they appear to measure a similar response as demonstrated by their correlation coefficient (0.77) and the GMT to EBNA observed by both methods. No cross-reactivity of cytomegalovirus antibodies to the EBNA-1 peptide was observed by immunoblotting, ELISA or ACIF using adsorption against AD-169 infected MRC-5 cells. However, non-specific binding was observed if samples were not pre-incubated in a 10% goat serum PBS-Tween 20 solution. This pre-treatment removed the non-specific binding that falsely elevated the GMT in approximately 15% of both normal and XLP samples in ELISA. The ELISA system appears to be a sensitive, reproducible and objective test that may be useful for assessing the antibody response of patients to the EBNA-1 protein.

Epstein-Barr virus infections in males with the X-linked lymphoproliferative syndrome

A registry of persons with the X-linked lymphoproliferative syndrome, which is characterized by marked susceptibility to diseases induced by the Epstein-Barr virus, has enrolled 161 patients within 44 kindreds. Fifty-seven percent of the males died of infectious mononucleosis, 29% developed acquired hypogammaglobulinemia, and 24% had malignant lymphoma. The mortality rate was 80%; 70% died by 10 years of age and 100% by 40 years. Thirty-two boys survive, most with malignant lymphoma, acquired hypogammaglobulinemia, or both. We hypothesized that the defective lymphoproliferative control locus on the X chromosome results in unregulated cytotoxic lymphocytic responses to the Epstein-Barr virus; hence, severe hepatitis and virus-associated hemophagocytic syndrome occur with the infectious mononucleosis phenotype. T-cell suppression of immunoglobulin secretion by B cells is responsible for acquired hypogammaglobulinemia. A sustained polyclonal B-cell proliferation probably converts to a monoclonal B-cell malignancy as a result of molecular alterations.