Histocompatibility antigen frequencies in patients with chronic lymphocytic leukaemia: possible identification of a subgroup with relatively benign disease

Birds, babies and blood

This is an autobiographical review describing the author's career in immunology research and summarizing his current understanding of the areas involved. Contributions to autoimmunity, immune deficiency, transfusion immunology, HLA-disease associations, reproductive immunology, cellular therapies, and innate immunity are included; also discussion of medical research ethics and various research-related activities.

Human leukocyte antigen class II allele association to disease progression in Iranian patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most frequent type of leukemia in Western countries, but its incidence is low in Asian populations. In the present study we determined the frequency of DRB1 and DQB1 alleles in 87 Iranian CLL patients and 100 healthy controls using a polymerase chain reaction (PCR) technique. An increased frequency of DRB1*07 (p = 0.04), DQB1*06 (p = 0.01) alleles, and DRB1*13/DQB1*03 haplotype (p = 0.01) and decreased frequency of the DQB1*03 (p = 0.01) allele were observed in our patients compared with healthy controls. Comparison between patients with indolent (n = 42) and progressive (n = 38) disease revealed a significant increase in DRB1*04 and DRB5 alleles in progressive patients. Similarly, a higher frequency of DRB5 (p = 0.01) allele was observed in CD38(+) compared with CD38(-) patients. Classification of the patients into immunoglobulin variable region heavy-chain genes mutated and unmutated subtypes did not reveal significant differences for the expression of any of the HLA alleles or haplotypes between these two subtypes. Our findings observed in an Iranian population indicate that CLL could be associated with distinct HLA class II alleles and haplotypes of which the DQB1*06 allele and DRB1*13/DQB1*03 haplotype have not already been reported in CLL patients from other ethnic backgrounds. Some HLA class II alleles may contribute to disease progression in CLL.

Association of chronic lymphocytic leukemia with specific alleles of the HLA-DR4:DR53:DQ8 haplotype in German patients

The etiology of chronic lymphocytic leukemia (CLL) remains unknown, though a genetic susceptibility has been suggested. Results of complete DNA typing of HLA alleles in CLL patients are lacking. We compared HLA class I and class II frequencies in 101 German CLL patients and 157 healthy German controls as determined by PCR-SSP/SSO DNA analysis and serologic typing. The most striking difference was the increased frequency of HLA-DRB4*0103 [relative risk (RR) = 2.74, p < 0.0025] among patients. The presence of alleles HLA-DRB1*0401, HLA-DQB1*0302 and HLA-DPB1*0301 as well as of homozygosity for HLA-DQB1 was also associated with a higher risk for CLL, though none of these differences remained significant after correction for multiple comparisons. No association was found for any HLA class I allele. Haplotype analysis revealed a CLL-specific linkage disequilibrium for HLA-DRB1*0401:DRB4*0103 and HLA-DRB4*0103:DQB1*0302. Our results suggest that CLL could be associated with distinct class II alleles of the Caucasian haplotype HLA-DR4:DR53:DQ8, which has also been related to a susceptibility for several auto-immune diseases. The positive, though weak, association of CLL with HLA-DPB1*0301 might represent an independent susceptibility factor since no linkage disequilibrium existed with any of the other CLL-associated alleles. None of the previously reported associations with HLA class I antigens was confirmed. Our results suggest that factors within or close to the human MHC class II region confer susceptibility to CLL.

HLA antigens in Iranian patients with B-cell chronic lymphocytic leukemia

The frequency of HLA class-I and class-II antigens was investigated in 32 Iranian patients with B-cell chronic lymphocytic leukemia (B-CLL), using the microlymphocytotoxicity method. A significant increase in the HLA-B13 (P<0.01) and DR53 (P < 0.05) and a significant negative association with the A11 (P < 0.05), B35 (P < 0. 05), Cw3 (P < 0.05), and DR1 (P < 0.02) antigens were observed in these patients, compared to the control normal population. These results suggest involvement of some HLA antigens in the multifactorial process of predisposition to B-CLL.

Influence of the major histocompatibility complex on age at onset of chronic lymphoid leukaemia

The major histocompatibility complex is one of the interactive factors in the multifactorial model of carcinogenesis. Its main influence in experimental models is on the age at onset of malignancies. We have previously shown a similar effect of homozygosity for HLA-DR53 in CML. In the present study, we investigated 79 patients with CLL and 329 local controls from Germany. In addition to full serotyping, all patients and 116 of controls were also typed by HLA-DRB PCR analysis. The homozygosity rates for DR53 in patients under and over the median age (60 years) were 18.6% and 2.9%, respectively (p = 0.03). Eight of the 9 homozygous patients were under the median age. The sex ratio in the DR53 homozygous group was reversed in favour of females. The homozygosity rates for DR53 were different in the overall groups of patients and controls, yielding a relative risk (RR) of 2.4 (p = 0.03). This association was stronger in the early-onset group compared to age-matched controls (RR = 4.4; p = 0.008) and for females with an early onset compared to age- and sex-matched controls (RR = 17.9; p = 0.0008). The simultaneous occurrence of the alleles of the haplotype A2B62DR4 showed a strong association with CLL (RR = 4.1; p = 0.002). This was probably the reason behind the association with HLA-DRB1*0401 (RR = 2.4; p = 0.009). Compared to the accelerating effect of HLA-DR53, HLA-DR52 showed a significant delaying effect on the onset of CLL. These findings confirmed the influence of the HLA complex on the development of another leukaemia.

Increased incidence of HLA antigen B35 in patients with chronic lymphocytic leukemia

We and others have reported an increased incidence of chronic lymphocytic leukemia (CLL) among Ashkenazi (ASH) Jews of European origin. We performed HLA Class I typing on all 50 CLL patients seen by us and compared them with 3886 controls consisting of healthy blood donors from the New York Blood Center. Thirty of our CLL patients were ASH Jews, 17 of whom (57%) expressed the B35 antigen compared with 462 ASH controls (26%). Seven (39%) of the CLL Caucasian patients expressed the B35 antigen compared with 305 (14.5%) of the Caucasian controls. Combining the information from the ASH Jews and the Caucasians the difference is highly significant, (p = 0.0001). The summary odds ratio was 3.7. These results indicate an increased incidence of the antigen B35 amongst ASH and Caucasian patients with CLL.

Chronic lymphatic leukaemia: an investigation of HLA antigen frequencies and white cell differential counts in patients, relatives and controls

Histocompatibility antigen (HLA) frequencies in chronic lymphatic leukaemia (CLL) patients and control subjects were compared with respect to disease susceptibility and prognosis. Additionally, HLA and full blood count data were compared in relatives of 25 patients and 31 controls. We found no association of HLA with susceptibility although the presence of HLA B12, alone or in combination with HLA A2, indicated better prognosis. Relatives HLA identical with the patients showed no evidence of white cell disorder when compared with haplo- or non-identical relatives, or controls. As a group, however, relatives of patients had fewer lymphocytes than relatives of controls.

Haplotype frequencies in south-east Scotland

One hundred and thirty-two families consisting of healthy babies born after normal pregnancies at an Edinburgh maternity unit and their parents were tissue-typed for HLA-A, B and DR antigens. The antigen frequencies and the commonest haplotype frequencies are reported.

Food antibodies, intestinal permeability and HLA status in IgA deficient blood donors identified by a new rapid screening test

Circulating food antibodies, intestinal permeability and HLA status were studied in twelve blood donors previously identified as being selectively IgA deficient from screening 10,000 donations by means of a latex agglutination inhibition test, and confirmed by laser nephelometry. Assessment of intestinal function also included clinical history and standard laboratory tests. The donors proved to be healthy with no evidence of autoimmune disease or allergy. Nine donors (75%) had precipitins to food antigens. None had increased intestinal permeability as measured by the cellobiose/mannitol absorption test. HLA-A, B and DR antigen distribution was normal. IgG sub-class distribution was normal with the exception of an IgG2 level slightly below normal in one donor (0.9 g/l). An unexpected finding was a return of IgA levels to normal in four donors (33%) within 6 months.

Expression of MHC class II antigens in human B-cell leukaemia and non-Hodgkin's lymphoma

In this review we have summarized our experiences of serological analysis of MHC class II antigen expression in human B cell malignant disease. Cells from a large number of cases of B-cell chronic lymphocytic leukaemia (CLL) and non-Hodgkin's lymphoma (NHL) have been examined for expression of class II antigens. Using a number of monoclonal antibodies which in some cases are specific for class II subregion products (DP, DQ and DR), MHC class II antigens were detected by indirect immunofluorescence and fluorescent activated cell sorter analysis in CLL and by immunohistochemical staining in NHL. At the cell surface in many cases of B cell malignant disease, products of the different class II subregion genes are non-coordinately expressed. The most commonly occurring pattern of non-coordinate expression of class II molecules is of expression of DP and DR antigens in the absence of detectable DQ expression. These findings are in contrast to normal B lymphocytes where DP, DQ and DR antigens are expressed together at the cell surface. There is considerable heterogeneity among cases comprising individual histopathological categories of B cell malignancy, and in many instances heterogeneous class II phenotypes are also found on cells from the same tumour. In chronic lymphocytic leukaemia, class II antigen expression is inducible in vitro by treating the cells with the phorbol ester TPA. CLL cells treated with TPA have much increased levels of class II antigen expression at the cell surface and much increased steady state levels of class II specific mRNA transcripts detectable with complementary DNA probes. Aberrant class II antigen expression may be involved in the pathogenesis of B cell malignant disease.