Human leukocyte antigen and leprosy: study in northern Louisiana and review

We examined the relationship of human leukocyte antigen (HLA) phenotype to leprosy in six sporadic cases in northern Louisiana and in the world literature through pooling of the results of several studies. We found that HLA antigens DR2 and DQwl were associated with leprosy in the six cases in northern Louisiana (relative risks, 4.57 for DR2 and 4.53 for DQwl), but the results are not statistically significant. We pooled the Louisiana study and other population studies of HLA and leprosy. The results of the pooling show DR2 and DQwl to be associated with leprosy (relative risks, 2.65 for DR2 and 2.73 for DQwl), and these associations are highly statistically significant (P less than 1 x 10(-8) for DR2 and P = 3.6 x 10(-8) for DQwl). Further, we pooled studies of lepromatous leprosy patients vs. controls and studies of tuberculoid leprosy patients vs. controls and found that DR2 and DQwl are associated with both the lepromatous and the tuberculoid forms of leprosy and that these associations are statistically significant. We consider the associations of DR2 and DQwl in these population studies to be evidence for an HLA-associated genetic influence on susceptibility to leprosy.     

A method for the detection of M. leprae antigens in urine of leprosy patients by gel diffusion and gel electrophoretic techniques and significance in diagnosis.

A simple and novel method has been developed for the first time to detect M. leprae antigens in the urine of leprosy patients by treating the urine samples with sodium dodecyl sulphate (SDS). The antigens thus released can be demonstrated by simpler techniques like gel diffusion. By this method about 86% antigen positivity is observed in the urine of TT/BT and 83% positivity in BB patients. In BL/LL patients the antigen positivity is observed in 87% of the subjects. The high rate of M. leprae antigen positivity by the present method in the urine of patients with early leprosy may prove to be of diagnostic significance.     

Antigenic protein from Mycobacterium leprae released in macrophages in vitro as indicator of viability of bacteria

Peritoneal macrophages from randombred, Swiss white mice, when cultured and infected with Mycobacterium leprae for 24 hours, are able to show the presence of antigen(s) with binding affinity to antibodies present in the sera of bacteriologically positive, lepromatous leprosy patients. Such antibodies are not seen in sera from normal and healthy persons, tuberculoid leprosy patients, or long-term-treated, bacteriologically negative, lepromatous leprosy patients. The production of the antigen(s) is blocked by the anti-M leprae drug rifampin. Other mycobacteria when incubated with macrophages from mice show very little antigens in the lysate but the antigens have an equal affinity for antibodies in sera from both normal individuals and lepromatous patients. Only the lysates from macrophages exposed to live M. leprae could discriminate and could exhibit differential binding to sera from leprosy patients compared to sera from normal individuals. This antigen(s) does not have any binding ability to the monoclonal antibodies available to the antigens of M. leprae identified at present and shown to be specific to M. leprae. This indicates a separate identity of this product which has potential for further exploitation in exploring host-pathogen interactions related specifically to the leprosy infection and the tolerance of M. leprae inside cells.     

T-cell responses of leprosy patients and healthy contacts toward separated protein antigens of Mycobacterium leprae.

Sonicated extracts of Mycobacterium leprae were separated by two-dimensional gel electrophoresis and electroeluted into 400 distinct soluble fractions. These fractions were probed with T lymphocytes from leprosy patients of different disease types, healthy contacts, and unexposed healthy individuals. Proliferative responses were visualized using three-dimensional stimulation profiles. T cells from many patients and contacts responded to a multitude of antigen fractions of different molecular masses and isoelectric points. T cells from unexposed individuals gave significant responses to lysates or whole organisms of M. leprae, but no or only marginal responses to separated antigen fractions. T cells of polar tuberculoid (TT) and the majority of polar lepromatous (LL) leprosy patients responded only to separated antigen fractions but not to lysates or whole organisms of M. leprae. The remaining LL patients were totally unresponsive and even failed to respond to separated M. leprae fractions. Thus, in some leprosy patients unresponsiveness to M. leprae seems to be caused by distinct components and can be broken by using separated antigen fractions; whereas in others, anergy remains. T cells of borderline tuberculoid (BT) patients, who were under chemotherapy, responded to separated antigen fractions as well as to lysates of M. leprae organisms. In contrast, BT patients who were untreated failed to react with any of the M. leprae preparations. Similarly, T cells of the majority of LL patients responding to separated fractions were under chemotherapy; whereas T cells from untreated LL patients gave no or only marginal responses to any of the M. leprae antigen preparations. These findings suggest some linkage between the degree of T-cell responsiveness and antileprosy drug treatment.     

Sero-immunoreactivity of cloned protein antigens of Mycobacterium leprae.

Sera from 173 leprosy patients with various types of disease (tuberculoid = TT, borderline tuberculoid = BT, borderline lepromatous = BL, and lepromatous = LL), 12 intrafamilial contacts, and 40 normal healthy individuals were assayed in an indirect enzyme-linked immunosorbent assay (ELISA) using Mycobacterium leprae antigens. Recombinant clones carrying M. leprae antigens, namely, Y3184 (12 kDa), Y3179 (18 kDa), Y3164 (28 kDa), Y3180 (36 kDa), and Y3178 (65 kDa) and a cell sonicate from armadillo-derived M. leprae were used for the study. A high degree of reactivity with the 65-kDa, 36-kDa, and 28-kDa protein lysates was observed in most of the sera from multibacillary patients, with a low degree of positivity with 18 kDa and 12 kDa. Only a few sera from paucibacillary patients showed positive reactions. The majority of the contacts' sera tested showed no reactivity with these antigens.     

Association of hla–dr4-dw15 (drb1*0405) and dr10 with rheumatoid arthritis in a spanish population

Objective. To analyze the associations of HLA class II antigens with rheumatoid arthritis (RA) in a Spanish population. Methods. We used DNA oligotyping to determine DR types, DQA1 and DQB1 alleles, and DR4 variants in 70 unrelated seropositive RA patients and 189 healthy controls living in Spain. Results. A significantly higher frequency of DR4 was seen in RA patients compared with controls (relative risk [RR] = 2.40). The DR10 specificity correlated most strongly with disease susceptibility (RR = 3.84). A significant decrease in the frequency of DR7 was observed in the RA patients (RR = 0.48). DR4-Dw15 (DRB1*0405) was found to be the unique DR4 allele associated with RA (RR = 4.27, P < 0.05), whereas Dw4 (DRB1*0401) and Dw14 (DRB1*0404/0408) showed no association, and both D10 (DRB1*0402) and Dw13 (DRB1*0403/0407) were negative risk factors for the disease. Approximately one-third of the cases of RA could not be explained by the “shared epitope” hypothesis. Investigation of the DQ alleles associated with DR4 showed that the haplotype Dw15-DQ8 (DRB1*0405-DQB1*0302) was a susceptibility factor for RA (RR = 6.36, P < 0.05). Conclusion. Our results suggest that HLA class II alleles involved in RA susceptibility can vary among different Caucasian populations.     

Type 1 reactions in leprosy--heterogeneity in T-cell functions related to the background leprosy type

Nineteen each of paucibacillary borderline tuberculoid (BT) and multibacillary borderline borderline (BB)/borderline lepromatous (BL) leprosy patients undergoing type 1 reactions were compared with nonreactional stable patients of the appropriate leprosy type. In the BT reactional group, both phytohemagglutinin-induced and, more importantly, antigen-induced lymphoproliferation was reduced in 80%-90% of the patients. On the other hand, leukocyte migration inhibition was reduced in 40% and remained unchanged in the others. Suppressor-cell activity as evaluated by a costimulant assay was also reduced in a majority of the reactional BT individuals. In contrast, the bacilliferous BB and BL patients in reaction showed significant general improvement in leukocyte migration inhibition (p less than 0.001) and antigen-induced lymphoproliferation (p less than 0.05) as compared to the expected hyporesponsive/anergic uncomplicated BB-BL patients. Suppressor-cell activity also recovered during the reactional phase. However, no significant differences were observed in either of the reactional or stable leprosy types in the numbers of total T cells (OKT3+) and their subsets as defined by OKT4+ (helper/inducer) and OKT8+ (suppressor/cytotoxic) functional phenotypes. Moreover, during type 1 reactions the 48-hr delayed-type hypersensitivity (DTH) responses after intradermal injection of Mycobacterium leprae antigens continued to reflect the background leprosy type rather than the functional perturbations in the circulating T cells. Only a marginal increase in DTH was observed in some BT reactional individuals. No consistent pattern in the above in vitro T-cell-related responses was discernable in the same individuals 4-6 months after subsidence of reactions. The clinical entity of type 1 reactions encompassing paucibacillary and multibacillary leprosy shows a heterogeneity/dichotomy in T-cell responses which may reflect different immunological mechanisms underlying the reactional state.     

A peptidoglycan protein complex purified from M. leprae cell walls contains most or all immunodominant M. leprae T-cell antigens

The outcome of an infection with Mycobacterium leprae is correlated with the T-cell-mediated immune response developed against this pathogenic agent. The identification of M. leprae antigens that are recognized by T cells is therefore of great importance. In this paper we present the results of in vitro lymphoproliferation assays in which T-cell reactivity was measured against a peptidoglycan-protein complex (PPC) which was purified from the cell wall of M. leprae. Twelve M. leprae-reactive T-cell clones with different antigen specificities from a tuberculoid (TT) leprosy patient showed proliferative responses, but only when PPC was presented by HLA-DR-matched antigen-presenting cells (APCs). Four of these clones were known to react with the recombinant mycobacterial 65-kDa protein. A tetanus-toxoid-reactive T-cell line from a healthy control was not stimulated by this complex, supporting the idea that the stimulation by PPC was antigen specific. Both PPD-reactive and M. leprae-reactive T-cell lines from healthy individuals were stimulated by PPC. However, when this complex was presented to PPD-reactive T-cell lines derived from two lepromatous (LL) leprosy patients, we did not observe any proliferative responses. From these results we conclude that PPC contains most or all of the antigens which stimulate M. leprae-reactive T cells in association with relevant HLA class II molecules, including the 65-kDa protein or at least some immunogenic parts of it.     

Effect of treatment on antibody activity against Mycobacterium leprae antigen 7 in tuberculoid leprosy

Anti-Mycobacterium leprae antigen 7 antibody activity was determined by radioimmunoassay during treatment in a longtime study of individual patients with newly diagnosed borderline tuberculoid (BT) leprosy and in BT leprosy patients who were suspected from their case histories to have dapsone (DDS) resistant leprosy. There was a strong correlation between clinical and antibody activity, and clinical improvement following treatment led to a marked decrease in antibody activity in most cases. A characteristic pattern of rapid and marked increase in antibody activity shortly after the initiation of treatment was observed in patients with newly diagnosed BT leprosy. This pattern may become of practical importance in the evaluation of patients with BT leprosy as an indicator that the therapy is effective, even though this pattern was associated with a transient increase in inflammatory activity in the skin lesions. The association of inflammatory activity with increased antibody activity strongly indicates that the underlying processes are associated with the stimulation of both humoral and cellular immune responses.     

Relation between anti-Mycobacterium leprae antibody activity and clinical features in borderline tuberculoid (BT) leprosy

Antibody activity against Mycobacterium leprae antigen 7 was determined by radioimmunoassay and IgG antibodies against various antigens present in an M. leprae sonicate by a solid phase radioimmunoassay in 77 patients with borderline tuberculoid (BT) leprosy. In both assays there was a wide variation in antibody activity in individual patients although all were diagnosed as having BT leprosy. The median antibody activity was lower in newly diagnosed cases than in patients appearing with active skin lesions or new skin lesions despite dapsone (DDS) treatment of long duration. Further comparison of patients with high and low antibody activity revealed that high antibody activity was significantly correlated statistically with active skin lesions, new skin lesions and neuritis despite DDS treatment of long duration. The reason for variation in antibody activity in newly diagnosed BT leprosy remains unclear, and this patient group is of particular interest for further characterization of the basis for variation in antibody activity in tuberculoid leprosy.     

Association of human leucocyte DR and DQ antigens in Crohn's disease in Asian Indians: a family study.

The pathogenesis of Crohn's disease (CD) involves an abnormal immune response to enteric bacteria in genetically susceptible individuals. There are no family studies regarding the association of CD with human leucocyte antigens (HLA) class II. In the present study, we have studied the association of HLA class II antigens in patients with CD and their first-degree relatives. Nine patients with CD and their first-degree relatives were studied. A group of 110 healthy unrelated and ethnically matched subjects were used as controls. Molecular HLA typing was done using the sequence-specific primer-based method. The transmission disequilibrium test (TDT) was used to analyze the results. A total of 65 individuals were included in the study; 52/56 first-degree relatives (92.8%) of 9 patients with CD consented to the study. The median age of patients was 40 years. When the distribution of the HLA class II antigens in patients was compared to that in controls no significant differences were observed even after applying the Yates correction. As the sample size of the population was small, the association of CD with DR and DQ alleles was further analyzed by using the TDT. Even after applying TDT, no significant association was observed. Familial aggregation of CD is uncommon in India. Crohn disease is not associated with HLA class II antigens in Indian patients. Genes of the major histocompatiblity complex are likely to contribute little to the susceptibility to Crohn disease in Indian patients.     

HLA antigens and toxicity to gold and penicillamine in rheumatoid arthritis

One hundred sixty-eight patients with rheumatoid arthritis treated with chloroquine (n = 87), gold salts (n = 133) and/or penicillamine (n = 77) were investigated for possible associations between HLA antigens and toxic reactions. Patients with 2 or more side effects to gold and/or penicillamine had a significantly increased frequency of antigens HLA-B8 and DR3 compared to patients with one or without adverse reactions. Proteinuria to gold or penicillamine was significantly associated with HLA-B8 (relative risk [RR] 4.2) and DR3 (RR 14.0) whereas nonnephrologic side effects to gold or penicillamine were associated with B7 and DR2 (RR 3.5 and 2.8). Patients with skin reactions to gold had a significantly greater frequency of HLA-B7. We found no correlation between chloroquine side effects and any HLA antigen. The results suggest a genetic predisposition to toxic reactions to gold or penicillamine based on an immunologic dysregulation.     

Human leukocyte antigens in forms of leprosy among Japanese patients

Human leukocyte antigens (HLA) class II alleles were analyzed among Japanese leprosy patients to ascertain whether immunogenetic differences exist among the leprosy classification forms of Ridley and Jopling. Ninety-three unrelated Japanese leprosy patients (21 lepromatous, 24 borderline lepromatous, 17 mid-borderline, 26 borderline tuberculoid, 5 tuberculoid) and 114 healthy control subjects were investigated. The frequencies of HLA-DRB1*1501, -DRB5*0101, -DQA1*0102 and DQB1*0602 were significantly increased in all of the Japanese leprosy patients. The frequencies of HLA-DRB1*0405, -DQA1*03 and -DQB1*0401 were significantly decreased in the Japanese patients after correction of the p value. Conversely, there were no significantly different distributions of the HLA-DRB1, -DRB5, -DQA1, DQB1 alleles in the five subgroups of these patients. We conclude that HLA class II alleles were not associated with the form of leprosy. Other HLA, a non-HLA gene, and/or environmental factors may play a critical role in the different manifestations of leprosy.     

Assessment of the immune deficit in leprosy patients and the effect of recombinant IL-2 in vitro

Although the mechanism of immunologic unresponsiveness in lepromatous leprosy remains unknown, it has been shown that interleukin-2 (IL-2) production is defective in these patients. Peripheral blood mononuclear cells (PBMC) were isolated from treated (less than 16 months) and untreated leprosy patients as well as household contacts; age, sex, ethnically matched control subjects; and laboratory staff. PBMC were cultured for 6 days with sonicated Mycobacterium leprae (1-10 micrograms/ml), Dharmendra lepromin (1:10), or phenolic glycolipid-I (PGL-I) (0.05-5.0 micrograms/ml) in medium supplemented with various concentrations of recombinant IL-2 (rIL-2) or cultured for 3 days with one of the three mycobacterial antigens in the presence of concanavalin A (ConA). TT/BT patients and household control subjects had a robust response to M. leprae and lepromin, but were unresponsive to PGL-I delivered in liposomes. PBMC from LL patients did not respond to any of the three antigen preparations. rIL-2 induced proliferation of PBMC both in leprosy patients and control subjects regardless of the presence or absence of the three leprosy antigen preparations. This antigen nonspecific augmentation of proliferation by the wide range of doses of rIL-2 employed makes difficult the interpretation of the enhanced thymidine incorporation noted when rIL-2 is added in the presence of antigen to cultures of lymphocytes from LL patients. Our studies are at variance with reports that leprosy antigens, specifically PGL-I, induce immunological suppression, in that mycobacterial antigens did not cause significant suppression of the ConA-induced proliferations of PBMC from patients.     

The prevalence of HLA-DR4 and HLA-DR3 in healthy persons with rheumatoid factor

The frequency of the HLA antigen DR4 has been determined in healthy individuals with serum IgM RF. HLA DR4 was found in 11.6% of these persons as compared with 27% in healthy controls. Thus, no association between IgM RF and HLA-DR4 could be found in this material of healthy individuals. HLA-DR3 was found in 35% of healthy RF-positive persons, which was no different from the 30% prevalence among healthy controls. HLA-DR3 did not seem to be associated with high immune responsiveness of RF in RF-positive individuals.     

Hla–Dr4 and Gm 1;21 haplotypes are associated with pseudolupus induced by venopyronum dragéeaes

The phenotypic frequencies of human major histocompatibility complex class I, II, and III antigens and immunoglobulin allotypes (Gm factors) were determined in 56 patients (55 women, 1 man) who had lupus-like disease induced by Venopyronum dragées. The findings in these patients were compared with those of a control group. We found a significant increase of HLA-DR4 (57.1% versus 26.5%, relative risk [RR] 3.7) and a decrease of HLA-DR3 (3.6% versus 19.1%, RR 0.16) in the patient group. In addition, the haplotype Gm 1;21 (60.7% versus 32.9%, RR 3.2), and the phenotype Gm 1,3;5,21 (46.4% versus 25.8%, RR 2.5) were significantly increased. Both the haplotype Gm 1;21 and the phenotype Gm 1,3;5,21 are associated with HLA–DR4 in pseudolupus patients but not in controls. The coincidence of HLA–DR4 and Gm 1;21 markedly increases the risk of acquiring pseudolupus (RR 6.9). We conclude that the pathogenesis of pseudolupus is influenced by at least 2 independent genetic factors, A similar HLA association has been described in hydralazine-induced lupus, and this suggests a common pathogenic mechanism.     

HLA antigen frequencies in end-stage idiopathic and ischaemic cardiomyopathy

We investigated the distribution of HLA antigens among 413 patients with ischaemic heart disease or dilated cardiomyopathy referred for cardiac transplantation to determine if possession of certain HLA antigens predisposed to end-stage heart failure. Of the patients studied, 234 had ischaemic heart disease (218 males), mean age 49 years (SD 7.1) and 179 patients had dilated cardiomyopathy (150 males), mean age 39 years (12.8). The control group comprised 2041 kidney donors reported to the United Kingdom Transplant Service between July and August 1985. We found a significant excess of HLA DR1 (odds ratio 1.64, 95% CI 1.16-2.33, attributable risk 5.0%) and DR5 antigens (odds ratio 1.47, 95% CI 0.99-2.18, attributable risk) among patients with dilated cardiomyopathy but not of HLA DR4 as previously reported. We found a lower frequency than expected of HLA B21 (10.44 expected, none observed) among patients with ischaemic heart disease but no other significant differences. This study provides some support for the concept of the risk of developing end-stage heart failure due to dilated cardiomyopathy being associated with possession of HLA DR1 and DR5, but no such evidence in ischaemic heart disease. Larger multi-centre studies are required to confirm the validity of these findings.     

A systematic study of HLA class II-beta DNA restriction fragments in insulin-dependent diabetes mellitus.

DNA restriction fragments of the genes encoding HLA class II-beta antigens were compared in 34 patients with insulin-dependent diabetes mellitus and 34 HLA-DR-matched healthy individuals. Ninety-three fragments, determined by six restriction enzymes (EcoRI, EcoRV, HindIII, BamHI, Pvu II, and Taq I), were analyzed: (i) A DR Taq I 12.7-kilobase-pair fragment might be a marker for the extended haplotype HLA-B8, DR3. (ii) In controls, DR4 haplotypes are associated with two distinct clusters of DQ restriction fragments (DQR4 and DQR5). Almost all (94%) DR4 patients belong to the DQR4 and not to the DQR5 cluster. This suggests that, among HLA-DR4 haplotypes, only DQR4 haplotypes are involved in susceptibility to insulin-dependent diabetes mellitus. (iii) A DR Taq I 14.5-kilobase-pair fragment was found to be strongly associated with DQR4, mainly in DR3/DR4 heterozygous patients (P = 5 X 10(-4). However, these results must be interpreted with caution, taking into account the high number of statistical tests performed.     

Increased expression of regulatory T cells and down-regulatory molecules in lepromatous leprosy

T regulatory cells (Tregs) play an important role in the mechanism of host's failure to control pathogen dissemination in severe forms of different chronic granulomatous diseases, but their role in leprosy has not yet been elucidated; 28 newly diagnosed patients (16 patients with lepromatous leprosy and 12 patients with tuberculoid leprosy) and 6 healthy Mycobacterium leprae-exposed individuals (contacts) were studied. Tregs were quantified by flow cytometry (CD4+ CD25+ Foxp3+) in peripheral blood mononuclear cells stimulated in vitro with a M. leprae antigenic preparation and phytohemagglutinin as well as in skin lesions by immunohistochemistry. The lymphoproliferative (LPR), interleukin-10 (IL-10), and interferon-γ (IFN-γ) responses of the in vitro-stimulated peripheral blood mononuclear cells and the in situ expression of IL-10, transforming growth factor-β (TGF-β), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) were also determined. We show that M. leprae antigens induced significantly lower LPR but significantly higher Treg numbers in lepromatous than tuberculoid patients and contacts. Mitogen-induced LPR and Treg frequencies were not significantly different among the three groups. Tregs were also more frequent in situ in lepromatous patients, and this finding was paralleled by increased expression of the antiinflammatory molecules IL-10 and CTLA-4 but not TGF-β. In lepromatous patients, Tregs were intermingled with vacuolized hystiocyte infiltrates all over the lesion, whereas in tuberculoid patients, Tregs were rare. Our results suggest that Tregs are present in increased numbers, and they may have a pathogenic role in leprosy patients harboring uncontrolled bacillary multiplication but not in those individuals capable of limiting M. leprae growth.     

HLA and rheumatoid arthritis: a combined analysis of 440 British patients.

Four hundred and forty unrelated British Caucasoid patients with rheumatoid arthritis (RA) have been HLA typed for class I and class II antigens. Analyses of HLA antigen associations were performed on the overall group and in patient subsets selected according to particular disease parameters or sex, or both. The results confirm previously reported positive associations of HLA-DR4, Dw4, and DRw53 and negative associations of HLA-DR2 and DR7 with RA. Patients subsets with severe erosions, seropositivity, and features of extra-articular disease showed a stronger association, also confirming earlier reports. The link between HLA and disease severity was emphasised by a significant trend of increased Dw4 frequency with increasing severity of radiological erosions. In addition, a positive association of RA with HLA-A2 was observed and a strong negative association with DR3. The frequency of HLA-B27 was significantly increased in patients with subluxation of the spine. Differences were observed between male and female patients in relation to the HLA association. In men an increase in the frequency of the haplotype HLA/Dw4/DR4/Bw62/Cw3/A2 was observed. This showed no relationship with parameters of disease severity other than extra-articular disease. In women only class II antigens (DRw53/Dw4/DR4) showed an increased frequency. This increase was strongly associated with disease severity. A significant decrease of this class II association was observed with increasing age of disease onset; this was not seen in men.