HLA antibody enhancement by double addition of serum: use in platelet donor selection

The identification of HLA class I alloantibodies is important for organ transplantation and platelet transfusion in alloimmunized patients. Because microcytotoxicity testing against frozen trays of lymphocyte panels is rapid and efficient for determining specificities of unknown antibodies, a simple method was devised to increase test sensitivity to weak antibodies. Standard anti-human globulin (AHG)-facilitated microcytotoxicity was modified by the insertion of a double addition-of-serum (DAS) step, and reagent and patient's sera were evaluated by both methods. DAS modification increased antibody titers and, more significantly, made the identification of weak specificities easier because of the twofold to threefold increase in reactivity rates (29-42% for AHG vs. 75-82% for DAS) of panel cells that were expected to be positive, while low (approx. 1%) "extra" reaction rates were maintained for cells that were expected to be negative. DAS was relatively unaffected by variations in serum volumes or target cell preparation, and its use did not significantly increase test time or costs. In a program of platelet donor selection driven by donor antibody rather than donor-recipient antigen matching, DAS greatly facilitated platelet transfusion support for alloimmunized patients.

Genetic linkage of autosomal recessive canine narcolepsy with a mu immunoglobulin heavy-chain switch-like segment

Identification of genes determining narcolepsy susceptibility is important not only for understanding that disorder but also for possible clues to general sleep-control mechanisms. Studies in humans reveal at least one such gene related to the major histocompatibility complex and in dog an as-yet-unmapped single, autosomal recessive gene canarc-1. Gene markers for canarc-1 were therefore sought by DNA restriction fragment length polymorphisms in our colony of narcoleptic dogs. A human mu-switch immunoglobulin probe and the enzyme Hae III identified a gene cosegregating with canarc-1 in backcrossed animals (logarithm of odds scores: m = 24, Z max = 7.2 at theta = 0%). canarc-1 was also shown not to be tightly linked with the dog major histocompatibility complex (m = 40, Z less than -2 at theta less than 4.8%). These results represent the mapping of a non-major histocompatibility complex narcolepsy gene and strongly suggest involvement of the immune system in the pathophysiology of that disease.

Generation of a human hybridoma producing a pure anti-HLA-A2 monoclonal antibody

We report the production and characterization of a human monoclonal IgM hybridoma antibody recognizing antigen HLA-A2. B lymphocytes obtained from the peripheral blood of a multiparous volunteer 1 week postpartum were transformed in vitro by Epstein-Barr virus, screened by a microlymphocytotoxicity assay, and electrofused with the heterohybridoma fusion partner, K6H6/B5. A specifically anti-A2 secreting hybridoma cell line. MBW1, was then identified and cloned. The cytotoxic IgM antibody produced showed complete correlation (r = 1.00) with the A2 antigen on a large panel of unrelated donors' lymphocytes, and no cross-reactivity with A28, Aw68, or Aw69 antigens was observed.

Familial patterns of narcolepsy

Familial patterns of narcolepsy were investigated in a clinic population of 334 unrelated narcoleptic patients. 40% of probands had at least 1 family member with an isolated daytime sleepiness complaint and 6% had a positive family history of narcolepsy. Multicase families were rare; only two families were found with 3 or more affected relatives. Family members often shared the same HLA-DR2 haplotype as the proband but did not have narcolepsy. However, the risk of disease for first-degree relatives was six to eighteen times greater than that for unrelated individuals. Although most patients were HLA-DR2+, 2 new HLA-DR2- individuals were found. The data predict that as many as 9% of unrelated North-American white patients with narcolepsy will be DR2-. Analysis of these and other data indicates that although strongly associated with disease, the HLA-DR2 haplotype is neither sufficient nor necessary for the development of narcolepsy.

Secretion of genetically engineered human/mouse class I antigens

Two soluble, secreted forms of HLA-B7 were engineered by the creation of hybrid human/mouse molecules containing the polymorphic 5' region of the HLA-B7 gene and the secretory 3' region of the mouse Q10d gene. The hybrid, designated F1, is the first construct with only human extracytoplasmic domains, consisting of exons for the leader peptide and the three extracellular domains (alpha 1, alpha 2, alpha 3) of B7 spliced to the exons for the Q10d truncated transmembrane and 3' untranslated (3'UT) sequences. The second construct, designated C2, is similar but has the human alpha 3 replaced by the Q10 alpha 3 domain. Protein product from each construct was best demonstrated after gene transfection into the J27.2 cell line. In particular, secretion of the F1 product proves that the Q10 alpha 3 domain is not necessary for secretion of class I/Q10 hybrids. Moreover, the two soluble B7 forms, which differ only in their alpha 3 domain, are similarly recognized by monoclonal antibodies W6/32 (anti-HLA-ABC), BBM.1 (anti-human beta 2 microglobulin), and allo-B7-antibody, but differentially recognized by monoclonal antibody Q1/28 (anti-HLA class I heavy chain). Production of such soluble hybrid class I molecules in large amounts should allow critical structural and functional studies of these proteins.

Narcolepsy without unique MHC class II antigen association: studies in the canine model

Human narcolepsy is almost exclusively associated with the major histocompatibility complex (MHC) class II antigen HLA-DR2 and is the strongest HLA-disease association described to date. Canine narcolepsy resembles the human disease in its behavioral manifestations and responses to therapeutic drugs. Therefore, mixed leukocyte culture (MLC) was used to study differences in the canine MHC class II (DLA-D) antigens present in narcoleptic dogs to determine whether an analogous, unique DLA-D antigen could be identified in canine narcolepsy. Results show at least five different DLA-D antigens appear in potential narcoleptic haplotypes among the 29 dogs studied. The data demonstrate that, unlike man, in dogs there is no unique D locus antigen associated with narcolepsy and further suggest that linkage disequilibrium with a specific MHC antigen is unlikely to be essential for the manifestation of canine narcolepsy. Because human narcolepsy is thought to be multigenic, the canine narcolepsy-MHC dissociation suggests that the dog model may help elucidate the non-MHC narcolepsy gene(s).

Application of biosafety principles in blood establishments

In light of increasing public and employee concern over potential infectious hazards associated with blood and other body fluids, several government agencies (the Food and Drug Administration, the Centers for Disease Control, the Occupational Safety and Health Administration, the Environmental Protection Agency, the Health Care Financing Administration and the National Heart, Lung and Blood Institute) cosponsored a Biosafety Workshop in April 1988. The objective of the workshop was to identify appropriate biosafety practices and standard control procedures to protect workers involved in the collection, storage, and transportation of human blood donations with the least possible disruption of the nation's blood supply. Speakers focused on human immunodeficiency virus (HIV) and hepatitis B virus (HBV); however, the safety principles discussed were considered equally applicable to other known (e.g., non-A, non-B hepatitis and human T-lymphotropic virus type I (HTLV-1) blood-transmitted infections. The resulting consensus included the need for blood establishments to develop and apply thoughtful biosafety programs to address staff training, accident prevention, HBV vaccination, handling spills, managing contaminated waste and transporting blood specimens. There was lack of agreement, however, on the usefulness of gloves during the phlebotomy of healthy blood donors.

Use of RecA protein to enrich for homologous genes in a genomic library

RecA protein-coated probe has been utilized to enrich genomic digests for desired genes in order to facilitate cloning from genomic libraries. Using a previously cloned HLA-B27 gene as the recA-coated enrichment probe, we obtained a mean 108x increase in the ratio of specific to nonspecific plaques in lambda libraries screened for B27 variant alleles of estimated 99% homology to the probe. Class I genes of lesser homology were less enriched: 6.7x for non-B27 genes of estimated greater than 95% homology and 3.7x for other-Class I genes of greater than 80% homology. Loss of genomic DNA during the enrichment procedure can, however, restrict application of this technique whenever starting genomic DNA is very limited. Nevertheless, the impressive reduction in cloning effort and material makes recA enrichment a useful new tool for cloning homologous genes from genomic DNA.

Enterobacterial involvement in the pathogenesis of secondary ankylosing spondylitis

Ankylosing spondylitis (AS) is closely associated with the histocompatibility antigen HLA-B27. Pathogenesis of AS is thought to involve interactions between B27 and certain enterobacterial antigens. However, this is uncertain and contested by some. The present paper argues that the presence of statistically raised specific serum IgA to a common enterobacterial heat modifiable major outer membrane protein (h-momp; Mr 35,000) in active AS (N = 25; IgA = 1485 +/- 20) in comparison to controls, most notably hospital patients without known arthropathies or gastrointestinal disease (N = 12; IgA = 548 +/- 59), supports an inductive contribution of enterobacterial antigens to the pathogenesis of secondary AS. Serum IgG and IgM did not statistically differ. Raised specific serum IgA to h-momp might indicate enterobacterial antigenic stimulation from the gastrointestinal tract. It does not necessarily imply direct involvement in the pathogenesis of primary AS. H-momp appears to be a convenient tool for serological studies of AS and at present is likely to be more suitable than other bacterial antigens, notably those with B27-like epitopes. Namely, the confirmed presence in AS of enterobacteria with freely accessible B27-like antigenic epitopes on their cell surface might induce unusual tolerance to these organisms in B27 positive hosts, thus causing chronic inflammation, initially sacroiliitis (and spondylitis) due to the proximity of presacral and para-aortic colon draining lymph nodes, later becoming more generalized (for reasons unclear) to include other lesions (e.g. peripheral arthritis, uveitis, enthesopathies). Thus, antibodies to B27-like antigenic epitopes need not be detectable or may be absent. Also, cellular immune responsiveness to these antigens might be involved.

Human monoclonal antibodies to Rh0(D)

B lymphocytes from Rh negative donors with serum anti-D antibodies were isolated and fused with the mouse-human heteromyeloma, SBC-H20, to produce hybridomas secreting IgM or IgG1 human monoclonal antibodies to D antigen. The IgM antibody in hybridoma supernatant agglutinates all normal D positive cells at the immediate spin phase of reactivity. Using concentrated IgM hybridoma supernatant of approximately 50 micrograms/ml, Du cells were also agglutinated. The IgG1 antibody reacts by indirect hemagglutination with all D and Du cells. Against Rh mosaics, different reactivity was noted for each antibody. Furthermore, D positive cells precoated with the IgG1 antibody inhibit the IgM direct hemagglutination, suggesting that the antibodies identify closely associated epitopes. These human monoclonal antibodies will be useful diagnostic reagents and, ultimately, should be useful in the prevention of Rh hemolytic disease of the newborn.

Evans' syndrome as a presenting manifestation of atypical paroxysmal cold hemoglobinuria

Paroxysmal cold hemoglobinuria is a rare and potentially life-threatening acquired hemolytic anemia occurring either as an acute transient anemia following several different viral syndromes, or in a chronic idiopathic form. Episodic hemolysis in paroxysmal cold hemoglobinuria is usually associated with a biphasic (Donath-Landsteiner) IgG cold-reactive complement-fixing autohemolysin with anti-P specificity. Paroxysmal cold hemoglobinuria has not previously been associated with malignancy nor has it been clearly shown to be steroid-responsive. This report describes a patient with steroid-responsive autoimmune hemolytic anemia and immune thrombocytopenia (Evans' syndrome) associated with oat cell carcinoma of the lung and a unique biphasic anti-IgM autohemolysin. This case extends the spectrum of biphasic antibody-mediated immune cytopenias and widens both the clinical and the serologic definition of paroxysmal cold hemoglobinuria.

New polymorphisms of HLA-B27 and other B locus antigens detected by RFLP using a locus-specific probe

Genomic DNA from 46 B27+ ankylosing spondylitis, Reiter's syndrome, or normal individuals was digested with Taq I and probed, in Southern blots, with the HLA-B locus specific probe, EI7. Four restriction fragment length polymorphisms (RFLP), 2.5, 3.4, 3.8 and 4.0 or 8.0 kb, were observed for the B27 gene. In Caucasians, one of the B27 variants (2.5 kb) was more frequent in normals and almost never appeared in patients, suggesting a trend that is not yet statistically significant. In the course of defining the B27 polymorphisms, three and two RFLP, respectively, were also found for the B18 and B44 genes.

Lack of serologically defined arthritogenic Shigella flexneri cell envelope antigens in post-dysenteric arthritis

Post-dysenteric or reactive arthritis (ReA) is closely associated with HLA-B27. This histocompatibility antigen is heterogeneous and consists of 2 serologically defined variants: B27M1+M2+ and B27M1+M2-. This paper gives a qualitative evaluation of the antibodies present in the sera of 62 patients with dysentery due to Shigella flexneri 2a, a known arthritogenic bacterium. The patients were classified in 4 groups: B27M1+M2+ReA+ (n = 5), B27M1+M2+ReA- (n = 7); B27M1+M2-ReA- (n = 1); B27-ReA- (n = 49). The isolated infectant possessed cell envelope antigens with B27M2-like epitopes (Mr 20,000). Analysis of the spectrum of antibodies directed against the separated cell envelope antigens of S. flexneri in the sera of these patients revealed 7 main patterns of reactivity. The detectable immunogens encompassed protein stainable antigens (Mr 98, 78, 68, 54, 50, 44, 41, 35, 14 and 13 kDa), lipopolysaccharides and peptidoglycan. None of the sera possessed detectable antibodies to the B27M2-like antigen. Consequently, this antigen is unlikely to be associated with ReA, and this applies equally to other antigens or patterns of antigens. The arthritogenicity of S. flexneri may therefore not be determined by the presence or absence of detectable antibody titers to certain cell envelope antigens. We hypothesize that other properties of these antigens could be of significance.

Early immune response in healthy and immunocompromised subjects with primary varicella-zoster virus infection

Events in pathogenesis and immunity during primary varicella-zoster virus (VZV) infection were examined in 64 healthy subjects and 21 immunocompromised patients. Activation of the interferon system and activation of circulating T lymphocytes were early immune responses that occurred during the incubation period in some healthy subjects. Elevated levels of 2-5A synthetase in peripheral blood mononuclear cells and detection of serum alpha interferon (IFN-alpha) and gamma interferon (IFN-gamma) were present in the majority of healthy subjects who had acute primary VZV infection. Expression of HLA-DR antigen occurred on circulating T lymphocytes from subjects with acute VZV infection. The early production of VZV-specific IgG or IgM antibodies did not correlate with the severity of the clinical infection, but the detection of T lymphocyte proliferation to VZV antigen within three days after the appearance of the varicella exanthem was associated with milder illness. The mean VZV-specific lymphocyte transformation for subjects with less than 100 lesions/m2 was 7.5 +/- 10.43 SD compared with 1.4 +/- 1.85 SD for those with greater than 400 lesions/m2 (P less than .05). Only one (7.7%) of 13 immunocompromised patients had early VZV-specific lymphocyte transformation compared with 19 (42%) of 45 healthy subjects (P less than .05). The rapid host response to primary VZV infection was associated with rapid termination of viremia in healthy subjects; VZV was isolated from only 11% of peripheral blood mononuclear cell samples cultured within 48 hr after the appearance of the exanthem.

Lack of correlation between HLA-B27 like antigenic epitopes on Shigella flexneri and the occurrence of reactive arthritis

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HLA-B27M1M2 and high immune responsiveness to Shigella flexneri in post-dysenteric arthritis

The heterogeneous HLA-B27 antigen is closely associated with post-infectious or reactive arthritis (ReA) and is comprised of two serologically defined variants: B27M1+M2+ and B27M1+M2-. An outbreak of dysentery (n = 120) caused by a Shigella flexneri 2a strain, which possessed cell envelope antigens with epitopes resembling B27M2, resulted in five B27M1+M2+ patients with ReA. The remaining seven B27M1+M2+, one B27M1+M2- and all but three B27-negative patients remained free of joint symptoms; the latter three displayed arthralgia. IgM, IgG and IgA serum titers were statistically raised in all patient groups, but were exceptionally and persistently high in the B27M1+M2+ patients with ReA, especially IgA, as determined in acute-phase sera and sera sampled 1 year after dysentery. B27M1+M2+ thus appears to be a marker for a subset of disease, characterized by a high immune response. It is concluded that the B27M2 epitope is not unequivocally disease-related to Shigella ReA, that B27M1+M2+ is not likely to be the only immune-response-regulating gene involved in this form of ReA and that cross-reactivity between bacterial antigenic epitopes and B27 can only be part of a multifactorial process leading to ReA and in itself not sufficient to produce ReA. The intensity of the immune response appears to be another important factor.

Anti-IgA antibody associated reactions to intravenous gammaglobulin in a patient who tolerated intramuscular gammaglobulin

A patient with common variable immunodeficiency syndrome tolerated intramuscular IgG (which contains IgA) and an initial infusion with intravenous (IV) IgG, but developed reactions to subsequent IV IgG. High-titre, class-specific anti-IgA antibodies were detected suggesting immunization by the IgA-contaminated IV immunoglobulin. Subsequent IgG replacement was achieved with IgA-deficient plasma infusions. Patients who tolerate intramuscular IgG may not tolerate the IV preparations.

A human monoclonal antibody to rhG

Hybridomas secreting a human monoclonal IgG1 antibody against a variant of the rhG antigen were produced from B lymphocytes of an Rh-negative donor with serum antibodies to D and G [correction of C] antigens. The antibody reacts by indirect hemagglutination with nearly all C- or D-positive cells, confirming the strong association in the expression of G with D or C antigens. The lack of antibody reactivity to C-negative Du cells suggests a particular epitope on the D complex associated with the G antigen.

A monoclonal antibody against HLA-A11 and A24

A monoclonal IgG antibody was produced from a mouse immunized with an A11, A24; B27, B44 Epstein-Barr virus transformed B lymphoblastoid cell line. The antibody, A11.1M, by standard lymphocytotoxicity assay, reacts with all cells expressing HLA-A11 and -A24. Absorption studies with both A11+, A24- and A11-, A24+ platelets removed antibody reactivity against A11 and A24 lymphocytes. The shared antigenic determinant between A11 and A24, as defined by this antibody, A11.1M, represents a new "supertypic" determinant.

HLA-JY328: mapping studies and expression of a polymorphic HLA class I gene

The JY328 clone was identified in a human genomic library using cDNA corresponding to mRNA for HLA-B7 as a probe. The L/328 cell line was established by cotransformation of mouse Ltk- cells with the herpes thymidine kinase gene and clone JY328. On Northern blots, RNA from L/328 strongly hybridized to an HLA class I probe, and an antigen was recognized by an anti-HLA class I framework antibody on the cell surface. A DNA probe corresponding to a segment of intron 7 was developed by comparing the nucleotide sequence of clone JY328 with that of other HLA class I-type genes. Using the radiolabeled probe to screen Southern blots of DNA from families with siblings exhibiting intra-HLA recombinations, a restriction fragment length polymorphism was revealed--a 1.4 kb BstE II band not present in all individuals. A corresponding fragment was apparent in the base sequence of clone JY328. The occurrence of this band on Southern blots established that JY328 maps distinct from and centromeric to the HLA-C locus and near to the HLA-B locus. Antibody absorption studies and cytotoxicity tests indicated that the JY328 gene product was not an HLA-B antigen but that it did specifically absorb CW7-specific antibody. In sum, these results suggest a novel, polymorphic HLA class I gene which expresses a product serologically similar to HLA-Cw7 but which does not map within the corresponding locus.

Genetic interrelationship between insulin-dependent diabetes mellitus, the autoimmune thyroid diseases, and rheumatoid arthritis

To investigate the possible coinheritance of autoimmune diseases that are associated with the same HLA antigen, we studied 70 families in which at least two siblings had either type I diabetes mellitus (IDDM), autoimmune thyroid disease (ATD), rheumatoid arthritis (RA), or a combination of these diseases. HLA-A, B, and C typing was performed on all affected sibs in one generation or more. First, we estimated by sib-pair analysis the disease allele frequency (pD) and the mode of inheritance for each disease. According to the method of ascertainment entered into the analysis, the pD for ATD ranged from .120 to .180, for an additive (dominant) mode of inheritance. For RA, the pD ranged from .254 to .341, also for additive inheritance, although recessive inheritance could not be excluded. For IDDM, the pD ranged from .336 to .337 for recessive inheritance; additive inheritance was rejected. Second, we examined the distribution of shared parental haplotypes in pairs of siblings that were discordant for their autoimmune diseases. The results suggested that the same haplotype may predispose to both IDDM and ATD, or IDDM and RA, but not to both RA and ATD. Analysis of pedigrees supported this hypothesis. In 16 families typed for HLA-DR also, the haplotype predisposing to both IDDM and ATD was assigned from pedigree information to DR3 (44%), DR4 (39%), or DR5, DR6, or DR7 (5.5% each). In some families, these haplotypes segregated over several generations with ATD only (either clinical or subclinical), suggesting that in such families, ATD was a marker for a susceptibility to IDDM. In several families, an IDDM haplotype segregated with RA but not with ATD. This suggests that ATD- and RA-associated susceptibilities to IDDM may be biologically different and thus independently increase the risk of IDDM.

HLA-antigens in the human uvea

With the use of monoclonal antibodies in an indirect immunofluorescence technique we studied the distribution of Class I (HLA-ABC and B27) and Class II (HLA-DR) antigens in the human uvea. W6/32, directed against the core of HLA-ABC antigens, was used to study the distribution of Class I antigens. The anterior border layer of the iris, the non-pigmented and pigmented epithelium and the external basement membrane of the ciliary body and the vascular endothelium in the uvea showed a positive staining for Class I antigens. B27/M1, directed against an epitope of the HLA-B27 antigen, and the control antibody A11/Aw24, which was directed against an epitope of HLA-A11, revealed the same distribution pattern in respectively HLA-B27 and HLA-A11 positive donor eyes. The intensity of their staining was much weaker than the staining with W6/32. Class II antigens were studied with OkIa1, an antibody directed against the core of HLA-DR antigens. HLA-DR antigens were detectable on single cells scattered throughout the entire uvea. These cells did not seem to relate to any anatomical entity. No staining for Class II antigens was seen in the uveal blood vessel endothelium. The expression of HLA-antigens in the uvea is compatible with the distribution in other tissues. These findings suggest that the expression of HLA-B27 in the human uvea does not explain why the eye is one of the target tissues in HLA-B27 associated disease.