Major histocompatibility complex genes and susceptibility to systemic lupus erythematosus in northern India

Role of HLA alleles polymorphism in systemic lupus erythematosus: A prospective study from North India

Background

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder and has complex etiopathogenesis. The most appropriate hypothesis states that genetic susceptibility in the presence of environmental risk factors predisposes to SLE. HLA class II alleles are critical to immune response and are highly polymorphic. Various alleles in HLA-DR and -DQ regions were analyzed in SLE patients and healthy controls to see their role in susceptibility or protection to SLE.

Materials and Methods

This was a prospective observational study, in which a total of 100 SLE patients and 100 controls were analyzed. HLA typing was done by polymerase chain reaction (PCR)-sequence-specific oligonucleotide (SSO) method (SSO probe).

Results

DRβ1*0301 was significantly increased in SLE patients when compared to controls and had the highest odds ratio. Other risk factor alleles found to be increased were DRβ1*0701, DQβ1*0202, and DQβ1*0301, which had a significant positive association with SLE, suggesting their role in susceptibility to SLE. In contrast, DRβ1*0401, DRβ1*1401, DRβ1*1404, DRβ1*1501, DQβ1*0501, and DQα1*0201 showed statistically significant reduction in SLE patients, while these were much more common in controls, suggesting their protective role.

Conclusion

This study is only the second study in patients from North India and it determines the role of DRβ1*0301, DRβ1*0701, DQβ1*0202, and DQβ1*0301 alleles as risk factors in SLE patients.

Association of Human Leucocyte Antigen Class II, with viral load and immune response to Epstein-Barr virus in adult and pediatric Systemic lupus erythematosus patients

OBJECTIVE

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which is known to be associated with HLA-DRB1 and Epstein-Barr virus (EBV) infection. In the Indian subcontinent where there is high seroendemicity of EBV, we postulated that the association of this virus in adult SLE (aSLE) and pediatric SLE (pSLE) patients would be different and differentially associate with the HLA-DRB1 susceptibility and protective genes.

METHODS

A total of 109 aSLE, 52 pSLE, 215 adult healthy and 63 pediatric healthy controls were recruited. HLA-DRB1 genotyping by PCR-SSP, EBV load estimation by real-time PCR and antibody profiling (IgG & IgM) to EBV antigens by line blot assay were performed.

RESULTS

DRB1*15 was found predominant in pSLE patients and DRB1*03 in aSLE patients. DRB1*15/X heterozygous was predominant in overall SLE patients, although disease severity, like hypocomplementemia, higher autoantibody levels and more organ involvement was observed in *15/*15 homozygous state. EBV strongly associated with pSLE patients showing higher percent of EA-D IgG (p < 0.0001) and p22 IgG (p = 0.035) along with higher viral load (p = 0.001) as compared to healthy controls. In addition, the higher EBV DNA load significantly associated with anti-EA-D IgG (p = 0.013) and DRB1*15/*15 (p = 0.007) in pSLE patients as compared to aSLE patients.

CONCLUSIONS

This study therefore indicates that different HLA-DRB1 allotypes confer susceptibility to SLE in children and adults and disease may be triggered by increased EBV reactivation.

Development of autoantibodies precedes clinical manifestations of autoimmune diseases: A comprehensive review

The etiology of autoimmune diseases is due to a combination of genetic predisposition and environmental factors that alter the expression of immune regulatory genes through various mechanisms including epigenetics. Both humoral and cellular elements of the adaptive immune system play a role in the pathogenesis of autoimmune diseases and the presence of autoantibodies have been detected in most but not all autoimmune diseases before the appearance of clinical symptoms. In some cases, the presence or levels of these autoantibodies portends not only the risk of developing a corresponding autoimmune disease, but occasionally the severity as well. This observation is intriguing because it suggests that we can, to some degree, predict who may or may not develop autoimmune diseases. However, the role of autoantibodies in the pathogenesis of autoimmune diseases, whether they actually affect disease progression or are merely an epiphenomenon is still not completely clear in many autoimmune diseases. Because of these gaps in our knowledge, the ability to accurately predict a future autoimmune disease can only be considered a relative risk factor. Importantly, it raises the critical question of defining other events that may drive a patient from a preclinical to a clinical phase of disease.

Defining the role of the MHC in autoimmunity: a review and pooled analysis

The major histocompatibility complex (MHC) is one of the most extensively studied regions in the human genome because of the association of variants at this locus with autoimmune, infectious, and inflammatory diseases. However, identification of causal variants within the MHC for the majority of these diseases has remained difficult due to the great variability and extensive linkage disequilibrium (LD) that exists among alleles throughout this locus, coupled with inadequate study design whereby only a limited subset of about 20 from a total of approximately 250 genes have been studied in small cohorts of predominantly European origin. We have performed a review and pooled analysis of the past 30 years of research on the role of the MHC in six genetically complex disease traits - multiple sclerosis (MS), type 1 diabetes (T1D), systemic lupus erythematosus (SLE), ulcerative colitis (UC), Crohn's disease (CD), and rheumatoid arthritis (RA) - in order to consolidate and evaluate the current literature regarding MHC genetics in these common autoimmune and inflammatory diseases. We corroborate established MHC disease associations and identify predisposing variants that previously have not been appreciated. Furthermore, we find a number of interesting commonalities and differences across diseases that implicate both general and disease-specific pathogenetic mechanisms in autoimmunity.

Analysis of human leukocyte antigens class II-DR in Brazilian children and adolescents with systemic lupus erythematosus

OBJECTIVE

To analyze the frequency of human leukocyte antigens class II-DR in children and adolescents with systemic lupus erythematosus.

PATIENTS AND METHODS

Fifty-fiveBrazilian systemic lupus erythematosus children and adolescents and 308 healthy individuals were studied. Gender, race, and age of onset of systemic lupus erythematosus were recorded. The human leukocyte antigens typing of class II-DR was carried out by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP). Data were analyzed statistically using the chi square test with Yates' correction, Fisher's exact test, and Bonferroni's correction.

RESULTS

Human leukocyte antigen-DR 15 was the most frequently detected antigen in this group of children and adolescents, and it also occurred more frequently in the female group, in children with onset of systemic lupus erythematosus between 0 and 9 years and between 10 to 14 years, and in the Black race group, but these associations were not statistically significants.

CONCLUSION

In this group of children and adolescents with a high degree of racial admixture, we could not verify a significant association between human leukocyte antigens class II-DR and systemic lupus erythematosus.

The genetics of systemic lupus erythematosus: putting the pieces together

With lambda(s) estimates of 10 to 20 and other evidence of familial aggregation, as well as a monozygotic twin concordance rate >20, systemic lupus erythematosus (SLE) would appear to be a very promising phenotype using modern genetic approaches. Indeed, genetic associations are already known at numerous candidate loci including various HLA alleles, complement component genes, Fcgamma receptors, and others, and murine genetic studies of lupus models have provided additional candidate genes and potential syntenic linkages to evaluate in man. The completed genetic linkage studies performed on various collections of pedigrees multiplex for SLE have identified 60 susceptibility loci with varying degrees of evidence for linkage in man. Seven of these meet or exceed the threshold for significant linkage (LOD > or = 3.3 or P < or = 0.00005) at 1q22-23, 1q41, 2q37, 4p16, 6p21-11, 16q13 and 17p13. In addition, these linkages usually dominate in one ethnicity or another, suggesting that the responsible polymorphisms, once identified, will also vary by ethnicity. Evidence that these linkages can be reproduced range from outright independent confirmation (1q41, 4p16 and 6p21) to additional suggestive evidence in the genomic region of the purported linkage (1q22-23 and 2q37). The results now available suggest that human lupus genetics are robust and that gene identification should be possible using existing genetic approaches and technologies.

Systemic lupus erythematosus in India

The first case of systemic lupus erythematosus (SLE) was reported from India in 1995 followed by two more case reports and further, a series of eight cases, till 1969. Since the establishment of a clinical immunology laboratory at a major teaching institution in New Delhi in 1968, SLE was extensively studied and reported from that centre. From mid-1980 onwards several other centres in different regions in India including Chennai (old name Madras), Mumbai (old name Bombay), Calcutta and Hydrabad, also published their regional experience on SLE. Based on these data, the present report describes the clinical and laboratory characteristics of 1366 SLE patients seen in different regions of India. Arthritis, rash, photosensitivity, seizures and psychosis were seen in comparable proportions to other racial groups. Similarly, ANA and anti-DNA antibody positivity was also within the range seen in other racial groups. When compared with other series, however, alopecia, renal lupus, oral ulcers and neurological involvement was seen in higher proportions, reaching statistically significant figures in comparison to some racial groups. In contrast, haematological manifestations were seen in significantly less proportions in comparison to some of the racial groups. Serositis and discoid lesions were also seen in lower proportions than in most of other races. The proportion of those with anti-Sm antibodies was in between two extremes of highest among Africans and Israelis and lowest among Chinese and Europeans. Other manifestations were comparable to most other racial groups. Compared to North American and European reports, significantly low 5 and 10 year survival was observed among patients from India. This could be related to the general public health situation in the country including less than optimal management facilities in hospitals, delay in diagnosis due to lack of awareness of the disease, referral bias where only serious patients reach major city hospitals, or a truly severe disease among Indians, or a combination of these genetic, environmental and/or sociocultural factors. The Main causes of death were irreversible renal damage, infections and neurological involvement. Despite a comparable prevalence of anticardiolipin antibodies (aCL) and lupus anticoagulants (LAC), clinical antiphospholipid syndrome was significantly less common. Genetic studies showed appreciable increase of HLA DR4 (37.5%) among patients compared with controls (18%). Additionally the haplotype B8-DR3 was encountered frequently in the patient group.

Systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE) of childhood is a complex and challenging disease which can occur at any age. Identification of disease early in it's course and aggressive, appropriate management leads to improved outcome for an individual child. The history of SLE indicates how much progress has been made in the last quarter century. A discussion of the etiopathogenesis of SLE demonstrates the complexity of the syndrome. This is followed by a description of clinical manifestations, including diagnostic criteria, differential diagnosis and suggested methods for eliciting important symptoms to make the diagnosis. Evaluation of specific organs is next reviewed highlighting critical organ manifestations that are significant for future prognosis. Treatment of SLE includes a variety of medications, including non-steroidal anti-inflammatory medications, steroids and immuno-suppressive drugs. Attention to physical activity, stress and nutrition is equally important. Signs and symptoms that indicate disease flare or infection are described. Lastly, related syndromes are reviewed.

SLE in Indian men: analysis of the clinical and laboratory features with a review of the literature

Data on the clinical and laboratory profile of 39 male lupus patients has been analysed. An attempt has been made to (1) delineate the pattern of SLE in Indian males, (2) compare it with that reported in the world literature, (3) find out differences, if any, between male children and adults with the disease, and (4) compare it with our previously published data on Indian females with SLE. Several important points were brought out in this study. First, SLE in Indian males has an earlier age of disease onset, a higher incidence of mucocutaneous and renal involvement and a lower incidence of neuropsychiatric, gastrointestinal and hematological disease in comparison to those published from the developed countries. Second, leucopenia and lymphopenia, a reflection of disease severity, occur significantly more in male children compared with adults. Thrombocytopenia is exclusively noted in adult males and virtually non-existent in children. Third, male patients overall have a less severe form of the disease in comparison with their female counterpart, as was evident by significantly less patients with hypocomplementemia, diffuse proliferative lupus nephritis and psychosis. Finally, a higher frequency of infection, particularly tuberculosis, was seen in male patients, which was the cause of death in some.