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H Erlich

Publications and source records attributed to H Erlich.

At least 37 records · Page 2Linked to original sources
PubMed1992

HLA alleles in the population of Cartagena (Colombia).

It is known from historical records that the population of Cartagena (Colombia) is a mixture of caucasoids (Spaniards) and negroids (Africans) that is named mulattos. The present study was carried out to determine the distribution of HLA antigens in this population. A sample of 370 individuals was HLA serologically typed; 91 of them were typed for Complement alleles and 47 were DNA typed using PCR amplification and oligonucleotide probes for the HLA-DQA1 locus. The analysis of the allele and haplotype frequencies obtained, together with the genetic distances calculated with other populations, showed that most of the HLA genes of mulattos are from negroids and caucasoids. The Asian and Amerindian contribution is small, consistent with the historical and socioanthropological documentation. For example, A23, Aw34, Aw36 and Bw45, as well as DQA1*0101, DQA1*0301 and BfF have frequencies similar to that observed in negroids. In contrast, many significant differences were observed when comparing the antigen and allele frequencies of mulattos with that of Asians and Amerindians. Our results add evidence to the notion that the arrival of Spaniards in America 500 years ago established several racial mixtures. The HLA characterization of one of these, mulattos, will allow a better application of the HLA technology in the fields of basic research, organ transplantation and forensic medicine among this population.

Alleles↗
PubMed1992

Prognostically significant heterogeneity of cytoplasmic islet cell antibodies in relatives of patients with type I diabetes.

A significant proportion of relatives of patients with insulin-dependent (type I) diabetes with high titers of cytoplasmic islet cell autoantibodies (ICAs) do not progress to overt diabetes with up to 8 yr of follow-up. This may reflect that follow-up of such relatives has not been long enough to observe diabetes, that despite expression of identical ICAs, some relatives will not progress to diabetes; or that there is heterogeneity in what is identified as ICA. We identified a subset of ICA that was restricted in its species (not reacting with mouse islets) and cell-type reactivity within islets (beta-cell specific). Only one of eight relatives whose sera had the restricted pattern of reactivity progressed to overt diabetes, and on sequential evaluation, all but the one relative who progressed to diabetes have maintained normal first-phase insulin secretion to intravenous glucose. In contrast, by life-table analysis, 70% of relatives expressing nonrestricted ICA became diabetic within 5 yr of follow-up (1 of 8 vs. 16 of 25 diabetic at last follow-up, P less than 0.02). Moreover, preliminary data suggest a significant association of the human leukocyte antigen DQB1*0602 allele of DR2 haplotypes with the restricted ICA pattern (4 of 5 DQB1*0602 restricted vs. 0 nonrestricted ICA, P = 0.006). We propose that expression of a genetically determined restricted ICA pattern confers a markedly lower risk for progression to diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Polymerase chain reaction (PCR) amplification and human leukocyte antigen (HLA)-DQ alpha oligonucleotide typing on biological evidence samples: casework experience.

The polymerase chain reaction (PCR) method of specific gene amplification was used in casework to synthesize millions of copies of the polymorphic second exon of the human leukocyte antigen (HLA)-DQ alpha (or DQA1) locus from a variety of evidence samples. The HLA-DQ alpha allelic variants in the amplified deoxyribonucleic acid (DNA) were determined in a rapid non-radioactive test by hybridization to sequence-specific oligonucleotide probes in both the dot-blot and reverse dot-blot formats. This genetic typing system has been subjected to blind proficiency testing; the performance of this test in the analysis of experimentally mixed samples was also evaluated. As of August 1990, over 250 cases have been tested and more than 2000 individual evidence (bloodstains, semen stains, individual hairs, bone fragments, and tissue sections) and reference samples have been analyzed. The first 198 of these cases are summarized in this paper; in 65% of the cases with conclusive results a suspect was included, and in 35%, all suspects were excluded. Individual cases as well as some of the general issues relating to forensic science analysis and this genetic typing system are discussed. The high rate of exclusion reported here combined with the ability of PCR to type old evidence samples suggests the relevance of this genetic test for postconviction review; two cases in which the convicted suspect was excluded are discussed.

Adolescent↗
PubMed1991

Specific HLA-DQA and HLA-DRB1 alleles confer susceptibility to Sjögren's syndrome and autoantibody production.

Primary Sjögren's syndrome (1. SS) is a systemic autoimmune disease characterized by lymphocytic infiltration of the salivary glands and autoantibody production. In order to identify genetic factors that play a role in pathogenesis and predict extent of disease, we used Southern blot and polymerase chain reaction (PCR) methods to detect polymorphisms of the HLA-DRB1 (DR), HLA-DRB3 (DRw52), and HLA-DQA1 genes among 75 Caucasoid 1. SS patients and 150 Caucasoid controls living in the same geographic region of Southern California. We found significantly increased frequency of HLA-DR3 (P less than .001), HLA-DW52a (P less than .001), and HLA-DQA4 (P less than .05), in comparison to normal controls. Also, an increased frequency of heterozygosity for HLA-DQA1/DQA4 (P less than .05) was present among 1. SS patients. Autoantibodies to SS-A and to SS-B were significantly associated with DR3 (P less than .001), HLA-DQA4, (P less than .05), and DQA4/DQA1 heterozygotes (P less than .01). Among the 1. SS patients, clinical and laboratory features such as hypergammaglobulinemia, symmetric peripheral neuropathy, and hypothyroidism were significantly associated with HLA-DR3 (P less than .01) but not with HLA-DR2 (P greater than .10). In comparison, 1. SS patients with leukocytoclastic vasculitis were more frequently HLA-DR2 (P less than .05). These results using PCR methods confirm and extend prior studies that have used serologic methods.

Adolescent↗
PubMed1991

MHC class-II molecules and autoimmunity.

Molecular and genetic studies of HLA class-II genes provide new insights into the basis for MHC associations with autoimmunity. Polymorphisms among class-II genes identify specific haplotypes associated with autoimmune diseases such as type-I diabetes, rheumatoid arthritis, celiac disease, and pemphigus vulgaris. In some cases, single genes within those haplotypes are themselves implicated in disease susceptibility. Interactions, both cis and trans, between candidate susceptibility genes suggest a number of possible mechanisms critical for autoimmune triggering events involving class-II molecules. Amino acid sequence comparisons between products of candidate susceptibility genes and other class-II genes pinpoint a limited number of critical sites within HLA molecules which appear to be responsible for pathogenic events.

Amino Acid Sequence↗
PubMed1991

[Relationship between HLA D region gene and primary Sjögren's syndrome].

Primary Sjögren's syndrome is characterized by lymphocytic infiltration of the salivary and lacrimal glands and by autoantibody production. In order to identify the genetic factors that play a role in the pathogenesis and to predict the progress of the disease we used the restriction fragment length polymorphism and polymerase chain reaction method to detect the polymorphism of HLA-DRB1, DRB3, DQA and DQB genes among 75 Caucasoid primary SS patients, and compared the results with normal controls living in the same area. We found (1) significant increased frequency of HLA-DR3 (54%) and DRw8 (13%) (P less than 0.001); (2) increased frequency of the HLA-DRB3 allele DRw52a and of the HLA-DQA allele DQA 4 (P less than 005); (3) increased frequency of heterozygosity for DQA 1/DQA 4 (P less than 005); (4) autoantibody SSA and SSB associated with DR3 (P less than 002 and P less than 0001 respectively).

Adolescent↗
PubMed1991

A dimorphic 4-bp repeat in the cystic fibrosis gene is in absolute linkage disequilibrium with the delta F508 mutation: implications for prenatal diagnosis and mutation origin.

The gene causing cystic fibrosis (CF) has been recently cloned, and the major mutation (delta F508) accounting for approximately 70% of CF chromosomes has been uncovered. We have identified at the 3' end of intron 6 in the CF gene a 4-bp tandem repeat (GATT) that exhibits interesting features. First, PCR screening of 103 normal individuals revealed that the repeat exists only in two polymorphic allelic forms, either as a hexamer or a heptamer. These two alleles are in Hardy-Weinberg equilibrium and predict a heterozygote frequency of 41% (p[seven repeats] = .71; q [six repeats] = .29). Second, the allele with six repeats was found linked to delta F508 on all 76 CF chromosomes investigated, demonstrating strong linkage disequilibrium and suggesting that delta F508 had originated on the gene bearing six repeats. Third, when the repeat alleles are linked to the DNA markers XV2c and KM19, extended haplotypes are generated. These new haplotypes become informative in situations in which prenatal diagnosis cannot be performed solely with XV2c and KM19. Since this repeat marker is located in the CF gene and would be very less likely to recombine with the gene, it can serve as a valuable DNA marker for haplotype analysis. A possible crossover, however, was identified between XV2c and KM19, transferring delta F508 to a different haplotype.

Alleles↗
PubMed1989

Rapid detection and sequencing of alleles in the 3' flanking region of the interleukin-6 gene.

The 3' flanking region of the interleukin 6 gene is polymorphic due to insertions of different size. Within this region lies a sequence of approximately 500 base pairs that is AT rich. Based on flanking sequence information we have constructed oligonucleotides which prime the polymerase chain reaction (PCR) and amplify this AT rich region. The amplification products visualized by agarose gel electrophoresis gave fragment sizes for both homozygous and heterozygous individuals that were concordant with those observed by conventional genomic blotting techniques. Alleles that could not be typed by Southern analysis were resolved with this approach. These results illustrate the value of PCR for the rapid detection of length polymorphisms such as those due to variable numbers of tandem repeats. In contrast to RFLP analysis this procedure takes less than a day to perform, is cheaper, avoids the use of radioactivity and requires far less substrate DNA. Three different human alleles were sequenced, and differences were detected that were due to both large duplications and loss of one or two bases, suggesting that AT rich regions identify highly polymorphic loci. The same primers also amplified non-human primate DNA, allowing a comparison of the human sequence with that of the common chimpanzee and baboon.

Alleles↗
PubMed1989

A beta-thalassemia gene caused by a 290-base pair deletion: analysis by direct sequencing of enzymatically amplified DNA.

The base composition around a recently detected deletion in the human beta-globin gene was determined by direct DNA sequencing of an enzymatically amplified DNA segment. The deletion removes 290 base pairs (bp), including the entire exon 1 and the mRNA cap site. In the vicinity of the deletion endpoints, the normal beta-globin gene contains direct and inverted repeats which may have taken part in generation of this deletion.

Base Sequence↗
PubMed1989

Prenatal diagnosis of beta-thalassaemia in Mediterranean populations by dot blot analysis with DNA amplification and allele specific oligonucleotide probes.

In this study, we describe a simple strategy to detect beta-thalassaemia mutations in prospective parents and to make prenatal diagnosis in pregnancies at risk in the Mediterranean population. Screening of prospective parents is carried out by dot blot analysis on enzymatically amplified DNA with a set of oligonucleotide probes complementary to the most common mutations in this population. Prenatal diagnosis is accomplished by the same procedure on enzymatically amplified amniocyte or trophoblast DNA. The main advantages of this procedure are the simplicity, sensitivity (0.05 micrograms of DNA), and rapidity (12-24 h). Further simplification is obtained by amplification of the DNA from crude amniotic cell lysate. The very low amount of fetal material necessary for this analysis eliminates the need to culture amniotic fluid cells and may decrease the fetal loss rate associated with trophoblast sampling. The number of specific DNA sequences obtained by the amplification procedure allowed us to use non-radioactive labelled oligonucleotide probes, which have several advantages compared to radioactive probes.

Alleles↗
PubMed1989

In utero gene transfer and expression: a sheep transplantation model.

Retroviral-mediated gene transfer was used to insert a Neo R gene into fetal sheep hematopoietic cells obtained by exchange transfusion from lambs in utero. After gene transfer the cells were returned to the donor fetus. The lambs were examined after birth for the presence of a functioning Neo R gene. Of ten analyzable animals, six were positive for G418 resistant progenitor cells (CFU-Mix, CFU-C, BFU-E, CFU-E). Two animals were studied for extended periods of time: 8 and 24 months. Each has demonstrated a pattern wherein positive periods are interspersed with times when there were no detectable G418-resistant cells. We conclude that retroviral-mediated gene transfer can be used to insert genes into early progenitor cells of fetal sheep in utero and that the animals can continue to demonstrate blood cells expressing the gene for more than 2 years after birth. This is a US government work. There are no restrictions on its use.

Adenosine Deaminase↗
PubMed1988

A single amino acid substitution in the human histocompatibility leukocyte antigen DR3 beta chain selectively alters antigen presentation.

Activation of T lymphocytes by immunogenic peptides bound to HLA molecules is a central event in the generation of an immune response. To determine the sites on HLA molecules involved in this process, we isolated mutant EBV-transformed B cell clones that express altered HLA-DR3 molecules. One mutant has lost the ability to stimulate a T cell clone specific for a mycobacterial protein, but retains the ability to stimulate other antigen-specific T cells. The DNA sequence of the complete DR alpha and beta coding regions revealed a single nucleotide change resulting in a glutamic acid to lysine substitution at amino acid 9 in the first hypervariable region of the DR beta chain. These results are discussed in relation to a recently proposed model of class II molecule structure.

Amino Acid Sequence↗
PubMed1987

HLA-DP and HLA-DO genes in presumptive HLA-identical siblings: structural and functional identification of allelic variation.

We analyzed HLA class II genomic polymorphisms in three families in which bone marrow transplantation was performed between individuals presumed to be HLA identical, but in which unexplained mixed lymphocyte culture reactivity was observed. These families were characterized by classical HLA serology, MLC, and DP typing. In each family, a pair of "HLA-identical" siblings demonstrated a small proliferative response in bidirectional MLC. Southern blotting analysis performed with cDNA probes for DQ alpha, DP alpha, and DP beta identified DP genomic differences in each case. Hybridization of Bgl II-digested genomic DNA with a DP alpha cDNA probe revealed three prominent polymorphic fragments (7.7, 5.8, and 3.7 kb), which discriminated between presumptive identical siblings and indicated crossover events within HLA. Similarly, hybridization of SstI-digested genomic DNA with a DP beta cDNA probe, although resulting in a more complex pattern, identified DP genomic disparity between the presumed HLA identical siblings. Hybridization of SstI-digested DNA from two families with evidence of DP recombination was performed by using an oligonucleotide probe specific for the newly described HLA class II gene DO beta. Two major polymorphic fragments, at 6.2 and 3.3 kb, segregated in these families and localized the crossovers flanking the DO beta gene between the DQ and DP loci. The contribution of the antigenic differences marked by these HLA DP and DO DNA polymorphisms to allorecognition in MLR and in graft-vs-host disease are discussed.

Alleles↗
PubMed1986

Molecular analysis of HLA class I and class II antigen loss mutants reveals a homozygous deletion of the DR, DQ, and part of the DP region: implications for class II gene order.

The mutant human B-lymphoblastoid cell lines, 721.174 and 721.180, previously reported to exhibit greatly reduced expression of human HLA class I and II antigens (DeMars et al., Hum Immunol 11:77, 1984), were analyzed by Southern blotting using class II cDNA and genomic clones as hybridization probes. All genomic sequences complementary to DR alpha, DR beta, DQ alpha, and DQ beta probes were absent from these mutants. DZ alpha genomic sequences were deleted as were the DP alpha 1 and DP beta 1 loci but the DP beta 2 and most, if not all, of the DP alpha 2 locus were retained. However, no RNA transcripts for either DP alpha 2 or DP beta 2 could be detected. The mapping of the deletion breakpoint within the DP cluster allows the orientation of the loci in the DP region with respect to the centromere as follows: centromere, DP beta 2, DP beta 1, DP alpha 1, (DQ, DR). In addition, the analysis of a set of DR-, DQ-, DP+ homozygous deletion mutants (721.82, 721.84, and 721.101) reveals a deletion breakpoint between the DQ alpha 1/DQ beta 1 loci and the DQ alpha 2/DQ beta 2 loci. These mutants retain DZ alpha genomic sequences, tentatively mapping the DZ alpha locus between the DQ and the DP region. The residual ability of the DR-, DQ-, DP- mutants (174 and 180)* to stimulate allogeneic and autologous lymphoproliferative responses must be attributed to expression of as yet unidentified class II antigens, or to non-class II antigens.

Cell Line↗