In view of a high prevalence of hepatitis B virus infection in the Malaysian population, indirect immunofluorescence examination for hepatitis B surface antigen (HBsAg) was routinely performed on renal biopsy specimen at the University Hospital, Kuala Lumpur, over a 3-year period. Examination of renal tissue from 259 patients, including 47 with systemic lupus erythematosus (SLE), revealed 43 cases with HBsAg in glomerular immune complexes. A significantly high proportion (30/43) of these were SLE patients. The deposits were granular in nature, situated in both the capillary walls and mesangium and associated with immunoglobulin deposition. Morphological patterns of lupus nephritis involved were focal proliferative (one case), diffuse proliferative (23 cases) and membranous (six cases). None of these patients showed clinical evidence of liver disease. The significance of these findings remains uncertain, but the possibility exists that the hepatitis B virus may have a role in the pathogenesis of SLE in the tropics where both SLE and HBs antigenaemia are common.
Autoantibodies to the three extractable nuclear antigens (ENA), Anti-SSA (Ro), Anti-Sm, Anti-RNP and antinuclear antibodies were determined in 150 patients with SLE. Seventy patients (46.7%) had Anti-SSA (Ro), 40 (26.7%) Anti-Sm and 25 (16.7%) Anti-RNP antibodies. Ninety four percent patients had a positive Fluorescent anti-nuclear antibody (FANA) test. The commonest FANA pattern is the speckled pattern. Subclinical keratoconjunctivitis sicca (KCS) was present in 60% patients. No correlation could be demonstrated between the presence of ENA autoantibodies and the clinical features of patients.
Non-reactive SLE sera in an ELISA for anticardiolipin antibody (aCL) retested positive in the immunoassay when the sera were first heat-inactivated at 56 degrees C for 30 minutes. This was not a false positive phenomenon since the positive ELISA reactivity of the heated SLE sera was markedly reduced by inhibition with the cardiolipin antigen. Furthermore, the heat-potentiated ELISA reaction was abolished by prior IgG depletion of the SLE sera with Protein A preparation. The unmasked aCL in the heat-treated SLE sera also exhibited selective binding in ELISA to other negatively-charged phospholipids, namely phosphatidylserine and phosphatidic acid but not against either phosphatidylcholine or phosphatidyl-ethanolamine. The data strongly indicate an interaction between antiphospholipid antibodies and heat-sensitive serum component(s), a reduction of the latter resulting in the ELISA detection of the autoantibody.
Heat treatment of sera at 56 degrees C for 30 min results in positive ELISA reactions for anti-cardiolipin antibody (aCL) in sera that had undetectable or low levels of aCL before heat inactivation. The positive, potentiated reactivity of the heated sera in the aCL ELISA could be inhibited with the cardiolipin antigen and was abolished by prior IgG depletion using staphylococcal protein A. The heat-potentiating effect of aCL binding in ELISA was evident in both normal human sera and clinical sera including sera from patients with systemic lupus erythematosus and syphilis.
Heat-sensitive serum masking cofactor(s) of antiphospholipid antibody (aPL) in normal human sera (NHS) are specifically inactivated at 56 degrees C. The degree of binding in ELISA by unmasked aPL in NHS was equivalent to that in non-heated, aPL-reactive autoimmune SLE sera. Previously "negative" SLE sera also reacted equally strongly in the aPL ELISA when similarly heat-inactivated. Isotype studies by ELISA of the heat-potentiated aPL in 36 NHS revealed the presence of specific IgG (34/36), IgM (11/36) and IgA (24/36) aPL antibodies. 11/36 (31%) NHS had all three aPL isotypes while 13/36 (36%) had both IgG and IgA antibodies to phospholipid.
Low molecular weight IgM (LMW IgM) is the monomeric subunit of the naturally occurring pentameric IgM. It is not seen in health but has been previously observed in systemic lupus erythematosus (SLE) particularly in those patients with active disease and may reflect an adverse prognostic finding. We have therefore studied the presence of LMW IgM in 33 Chinese or Malay SLE patients (Singapore) and 21 Caucasian patients (Adelaide). LMW IgM was measured using filtration chromatography or by a sensitive immunoblotting technique. LMW IgM was observed in all patients in the Adelaide group and in 32 patients in the Singapore group with slightly greater quantities being seen in the Adelaide group. LMW IgM constituted up to 15.3% of the total IgM and was frequently associated with the presence of other low molecular weight IgM oligomers. In both groups LMW IgM correlated significantly with the total IgM levels (P less than 0.01). In a more detailed study in the Singapore group LMW IgM also correlated significantly with the IgM anticardiolipin levels (P = 0.02) but not with IgG anticardiolipin or with IgG or IgM anti-DNA levels or with rheumatoid factor. Patients with more extensive organ involvement had higher levels of LMW IgM but not at a significant level. We conclude that circulating LMW IgM occurs almost universally in SLE, is closely related to the total IgM levels and appears independent of ethnic background. The significance of LMW IgM in this disorder is unclear.
Systemic lupus erythematosus (SLE) is highly prevalent in Malaysia, which has a mixed population of Malays, Chinese, and Indians. A quantitative enzyme linked immunosorbent assay (ELISA) was used to determine anticardiolipin antibody (aCL) levels (total immunoglobulin, IgG, and IgM) in 200 patients with SLE (164 Chinese, 26 Malay, and 10 Indian) attending the University Hospital of Kuala Lumpur, Malaysia, and 103 matched controls. Only 33 (16.5%) of the patients had raised aCL levels; 26 had raised IgG aCL, five IgM aCL, and two both IgG and IgM aCL. There was a low prevalence of raised levels of aCL in the population studied, which was seen in conjunction with a rare occurrence of thrombosis. The classical association of high aCL levels with thrombocytopenia and recurrent abortions was noted, though not with cerebral disease. The low prevalence of aCL in this study population of mixed racial origin contrasts with findings in European patients with SLE and lends support to the influence of local factors, be they genetic or environmental, on the clinical manifestations of this disease.
We report a significantly increased prevalence of antiribosomal P protein antibodies in Malaysian Chinese patients (38%) with SLE compared to white Caucasian (13%) and Afro-Caribbean (20%) patients. The increased prevalence was not due to a generalized increase in autoantibody production because anti-dsDNA and anti-SSA antibodies were present in comparable frequencies in the three ethnic groups while anti-Sm and anti-SSB antibodies were rarely found in the Malaysian Chinese patients.
Cerebral infarction in the young is likely to be non-atheromatous. While in previous studies no cause has been found in 40% to 50% of patients, an increasing role for haemorheological factors is becoming apparent. Among these, an association between antiphospholipid antibodies (aPLs) and ischaemic cerebrovascular disease is now well-recognised. This entity has not been previously reported in Malaysian patients. In a study of 80 patients with stroke below the age of 50 years who were seen at the University Hospital, Kuala Lumpur, between January 1982 and May 1992, 3 patients with ischaemic cerebral infarction were found to have aPLs. aPLs was detected using ELISA method for anticardiolipin antibodies (aCLs), and presence of lupus anticoagulant (LA) was established by kaolin clotting time, thromboplastin inhibition test and platelet neutralisation procedure. Only 1 patient had active systemic lupus erythematous. Cerebrovascular events were recurrent in one of the 2 non-lupus patients. aPL-related stroke should be considered in young patients who have cerebral ischaemia occurring without obvious cause. More cases are likely to emerge in Malaysia with active screening.
Many studies have shown an association between human leucocyte antigens (HLA) and systemic lupus erythematosus (SLE) in the various study populations. Although SLE is not an uncommon disease in the Malaysian Archipelago, and appears to affect all three major racial groups equally (i.e. Southern Chinese, Malays and Southern Indians), very little information is available on the HLA profiles in the two latter groups. In phase I of our study of the HLA profiles in Malaysian SLE patients, the HLA phenotypes (class I: A, B, C; Class II: DR, DQ) of Malay patients with confirmed SLE and 91 normal Malay controls were determined using the microcytotoxicity assay. The strong association between DR (RR 3.28, P = 0.008) concurs with that reported among Chinese and Japanese populations. Moderate to strong associations with HLA-B 7 (RR 4.99, P = 0.02) and Cw 7 (RR 2.94, P = 0.003) were also found. We believe this is the first report of the association of HLA and SLE in the Malay population.
Antibodies to the ribosomal P protein are specific for SLE but their prevalence varies in different ethnic groups. In a group of Chinese SLE patients from Malaysia who have a high prevalence of this antibody, we have found an increased frequency of an uncharacterized HLA-DRB gene allele, DR16X, in patients who are positive for anti-P antibodies compared to antibody negative patients (31.3% vs 3.2%, P < 0.01, Pcorr not significant, relative risk = 13.6). DR16X has only been found in south east Asian populations and may be a genetic factor which influences the high prevalence of anti-P antibodies in Chinese.
Between January 1976 and December 1992, 17 patients on follow-up at Systemic Erythematosus (SLE) Clinic in the University Hospital, Kuala Lumpur had onset of the disease after the age of 50 years. This constituted about 4% of our total SLE patients. They formed a distinct subgroup of the lupus population with an insidious onset and have a benign course compared to the younger SLE patients. Arthritis and skin rashes were the commonest initial manifestations. Renal and central nervous system manifestations were uncommon but pulmonary involvement was frequent compared to young SLE patients. The prevalence of positive autoantibodies and hypocomplementaemia were lower. Disease activity showed no correlation with erythrocyte sendimentation rate, autoantibodies or complement levels. Overall prognosis in these late-onset patients was favourable with a good response to steroids and less frequent relapses.
Study site: SLE clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
One hundred and seventy patients with systemic lupus erythematosus (SLE) were studied for the prevalence of antibodies to the small RNA-associated proteins Ro/SSA, La/SSB, Sm, U1RNP and Sm. The relationship of these autoantibodies to different races, sexes and clinical manifestations of SLE was evaluated. Passive immunodiffusion was employed using human spleen extract as antigen source for Ro and rabbit thymus extract for La, Sm and U1RNP. We found the prevalence of antibodies to be as follows: anti-Ro/SSA, 36%; anti-La/SSB, 8%; anti-Sm, 15% ; anti-U1RNP, 21%. Except for a low prevalence of anti-La, the prevalence of these antibodies was similar to that in Western studies, The prevalence of anti-Ro/SSA is similar to that reported in the Western studies, but lower than that reported in the Oriental patients from Singapore and Hong Kong. Linkages of anti-Ro with anti-La antibodies were usual; however, although anti-Sm antibodies were usually associated with anti-U1RNP, they were more frequently associated with anti-Ro antibodies. The Malay patients had a high prevalence of anti U1RNP compared to other races. No gender difference was detected. Anti-Sm antibody was associated with serositis and anti-U1RNP antibodies with Raynaud's phenomenon. No association was found between the presence of skin renal or cerebral manifestations and any specific antibodies or combination of antibodies.
Systemic lupus erythematosus (SLE) is an autoimmune disease characterised by increased B cell activity and depressed T cell function. However, the contribution of the immunoregulatory system to its pathogenesis is still unclear. The recent development in the production of monoclonal antibodies and the availability of bench-top flow cytometers have allowed rapid quantitation of peripheral blood lymphocyte subsets. We analysed the distribution of the lymphocyte subsets in 24 patients with active SLE and 18 with inactive SLE. The distribution of immunoregulatory cells in 72 normal volunteers was used as control. Statistical analysis showed that there were significant differences between both the SLE groups and the normal controls, for total lymphocytes, T cells, B cells, T helper cells, T suppressor cells, T helper/suppressor ratio and natural killer cells. There was a significant difference for T helper cells between active and inactive SLE. T helper cells levels were found to be low in inactive SLE and lower in active SLE. It appears that treatment-induced remissions did not restore the levels of immunoregulatory cells to normal. Thus, T helper cell levels reflect disease activity and longitudinal assays of T helper cells may serve as an indicator of disease reactivation.
SLE is an autoimmune and polygenic disorder characterized by an accumulation and deposition of immune complexes. Several studies have indicated differential impact of FcgammaR polymorphism genotypes in different ethnic groups studied. The Fc receptor for IgG class IIA gene (FcgammaRIIA) occurs in two allelic forms. The allele FcgammaRIIA-H131 encodes a receptor with a histidine at the 131 amino acid position; the other allele FcgammaRIIA-R131 encodes an arginine. This polymorphism is believed to determine the affinity of the receptor for hIgG2 in immune complexes. FcgammaRIIA-H131 has a higher capacity for hIgG2 compared to FcgammaRIIA-R131 as measured by in vitro studies of insoluble immune complex clearance. We have investigated the polymorphism for FcgammaRIIA using a novel polymerase chain reaction-allele specific primer (PCR-ASP) method designed specifically to distinguish the two allelic forms. Our studies were based on 175 Chinese and 50 Malays SLE patients as well as 108 and 50 ethnically matched healthy controls for the respective groups. Analysis of the data (chi2 test with Yates correction factors and odds ratios) revealed that there were no significant differences between SLE patients and controls. We have not found evidence of a protective effect conferred by FcgammaRIIA-H131 in the ethnic groups studied.
The frequency of the HLA class II antigens/alleles (HLA-DR, DQ and DP) were studied in 70 Malaysian Chinese patients with systemic lupus erythematosus (SLE) to examine the contribution of these genes to disease susceptibility, their clinical expression and Immunological responses. This was done using modified PCR-RFLP technique. These samples were then compared with 66 ethnically matched controls. We found a strong association of the DQA1*0102 (p corr = 0.032, rr = 3.39), DQB1*0501 (p corr = 0.003, rr = 4.55), *0601 (p corr = 0.006, rr = 4.22) and DPB1* 0901(p corr = 0.02, rr = 4.58) with SLE. Clinically, we found a strong association of DR2 and DQA1*0301 with renal involvement and DQA1*0102 with alopecia. Immunologically, statistical analysis (Chi-square test ) showed a strong association of DQA1*0102 with anti-Ro/La antibodies while DQA1*0301 was observed to be strongly associated with antibodies to ds DNA. DQA1*0102 was found more frequently in those with a later disease onset (30 years of age or above). From these data we suggest that the HLA class II genes play a role in conferring disease susceptibility and clinical and immunological expression.
Study site: SLE clinics, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
BACKGROUND: Studies have shown that certain genes within the major histocompatibility complex predispose to systemic lupus erythematosus (SLE) and may influence clinical and autoantibody expression. Thus, we studied the frequency of HLA-DR, -DQA, -DQB and -DPB alleles in ethnic Malays with SLE to determine the role of these genes in determining disease susceptibility and their association with clinical and immunological manifestations.
METHODS: Fifty-six Malay SLE patients were enrolled into the study. Demographic, clinical and immunological findings were obtained from medical records. HLA-DR, DQ and DP typing were done using modified PCR-RELP. Controls were from ethnically-matched healthy individuals.
RESULTS: We found a strongly significant association of the DR2 and DQB1 *0501 and DQB1*0601 (pcorr = 0.03, rr = 3.83, pcorr = 0.0036, rr = 4.56 and pcorr = 0.0048 and rr = 6.0, respectively). There was also a weak increase of DQB1*0.201 and DPB1*0.0901 with a weak decrease of DQA1*0601 and DQB1*0503 and *0301 which were not significant after corrections for multiple comparisons were made. There was a significant positive association of DR2 and DQB1*0501 with renal involvement and DR8 with alopecia. A nonsignificant increase of DQB1*0503 in patients with photosensitivity was noted. Significant autoantibody associations were also found: DQB1*0601 with anti-Sm/RNP, DR2 with antiSSA (Ro)/SSB (La), and DR2, DQB1*0501 and *0601 with antibodies to ds DNA. There was no specific DR, DQ or DP associations with age of disease onset (below 30 years or those at or above 30 years).
CONCLUSION: Our data suggests the role of the HLA class II genes in conferring SLE susceptibility and in clinical and autoantibody expression.
Study site: SLE Clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
An analysis of the clinical and serological features of 12 male and 122 female patients with SLE was done to determine whether sex related differences exist. We found a lower incidence of mucocutaneous symptoms and arthritis but an increased incidence of discoid lesions, pleuritis and pericarditis in males at disease onset. During the disease course, there was a lower incidence of arthritis, a similar prevalence of mucocutaneous symptoms but an increased incidence of pleuritis in males with a trend towards renal involvement. These findings were however not statistically significant except for the higher incidence of thrombosis among males. Serologically, both groups showed similar frequencies of autoantibodies and hypocomplementaemia. Although the study was small, it was shown that several sex-related differences in the clinical and serological features exist in Malaysian SLE patients.
Study site: SLE Clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
The aim of this study was to investigate the incidence of IgG anticardiolipin antibody (ACL) and IgG anti-beta(2) glycoprotein I antibody (anti-beta2GPI) positivity in patients with primary or secondary antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE), to assess the association between IgG ACL and anti-beta2GPI, and the relationship between the presence of ACL and anti-beta2GPI with the clinical manifestations of APS. IgG ACL and IgG anti-beta2GPI levels were measured in 51 SLE patients, 20 patients with SLE and APS (secondary APS) and 11 primary APS patients using commercially available ELISA kits. Relationships between laboratory data and clinical manifestations of the patients were examined. The incidence of IgG ACL positivity was significantly higher in primary (36.4%) and secondary (40%) APS than in SLE (13.7%) patients (P = 0.02). The incidence of IgG anti-beta2GPI positivity was significantly higher in primary (54.5%) and secondary (35%) APS than in SLE (7.8%) patients (P = 0.0006). Mean levels of IgG ACL and anti-beta2GPI were significantly higher in the primary and secondary APS than in the SLE patients (P = 0.002 for both). A significant relationship was found between IgG ACL and IgG anti-beta2GPI (P = 0.01, R(2) = 0.56). There was a significant correlation between the presence of IgG ACL and a history of thrombosis in the combined primary and secondary APS group, but not in SLE patients. In conclusion, in this study IgG ACL and IgG anti-beta2GPI are closely related and mean levels of IgG ACL and IgG anti-beta2GPI are higher in patients with either primary or secondary APS than in SLE patients.
Study site: Rheumatology Clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
Anti-nuclear antibody (ANA) negative systemic lupus erythematosus (SLE) occurs in about 4-13% of SLE cases. A small group of ANA negative SLE patients with positive anti-Ro antibodies usually present with typical vasculitic skin lesions which can be associated with photosensitivity, renal disease, congenital heart block or neonatal lupus. We present a case of a persistently ANA negative patient who presented with joint pain, rashes, mouth ulcer and alopecia. Clinical diagnosis of systemic lupus erythematosus was made even though ANA was negative. She was started on steroids and went into remission. Later, she developed several episodes of convulsions associated with fever and prominent vasculitic lesions. The patient was also found to have microscopic hematuria, proteinuria, anemia and thrombocytopenia. Renal biopsy showed lupus nephritis class 1B. Due to the prominent skin lesions, we performed anti-extractable nuclear antigens (ENA) antibodies test and anti-Ro turned out to be positive. The final diagnosis was ANA negative SLE (Ro lupus) with cutaneous, renal, musculoskeletal, hematological and cerebral Involvement.