Expression of the matrix metalloproteinases MMP-2 and MMP-9 and their inhibitors TIMP-1 and TIMP-2 in systemic lupus erythematosus patients.

BACKGROUND: The study aimed to look at alterations in expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) and their potential use as biomarkers in the pathogensis of SLE. METHODS: SLE patients (n = 41) and healthy controls (n = 50) were recruited. Quantitative RT-PCR/ELISA assays were performed for expression of MMP and TIMP mRNA in whole blood and PBMC; and corresponding serum protein levels. Intracellular levels of MMP-2 and MMP-9 proteins were analysed by flow cytometry. RESULTS: Based on SLEDAI scores patients were grouped into active (SLEDAI ≥ 10) and inactive cases (SLEDAI < 10). In active cases, MMP-2 expression significantly increased and TIMP-2 expression was decreased (p < 0.0001) both at serum secretion (p = 0.0003) and mRNA (p < 0.0001) levels as compared to inactive cases. MMP-9 and TIMP-1 showed significantly reduced serum secretion and mRNA expression (p < 0.0001) in active cases as compared to inactive cases. Intracellular concentration of MMP-9 was reported to be higher in neutrophils, while MMP-2 was mainly found in lymphocytes of SLE patients as compared to controls. MMP/TIMP ratio profile was altered as SLE disease progresses. INTERPRETATION & CONCLUSIONS: Findings suggest disturbed MMP and TIMP levels have a role in the pathogenesis of SLE.

Impact of functional IL-18 polymorphisms on genetic predisposition and diverse clinical manifestations of the disease in Indian SLE patients.

Several studies have demonstrated associations between interleukin-18 polymorphisms and risk of systemic lupus erythematosus in different populations except one of Indian origin. We therefore investigated for the influence of interleukin-18 (-1297T/C, -607A/C, -137G/C; + 105A/C) polymorphisms on genetic susceptibility and clinical expression of the disease in Indian systemic lupus erythematosus patients. A total of 200 systemic lupus erythematosus patients and 201 controls were recruited. Genotyping of interleukin-18 polymorphisms were performed by polymerase chain reaction-restriction fragment length polymorphism. Serum interleukin-18 levels were measured by enzyme-linked immunosorbent assay. Interleukin-18 (-1297T/C; -137G/C) polymorphisms showed significant association with genetic susceptibility to the disease in our systemic lupus erythematosus cohort. Stratification analysis revealed -1297CC and -1297C associated with renal involvement (odds ratio = 3.4, correcting p value = 0.0207), (odds ratio = 2.0, correcting p value = 0.0054) respectively. Additionally, -1297C allele frequency was significantly increased in patients with anti-nucleosome antibody (odds ratio = 2.1, correcting p value = 0.0301). Haplotype analysis showed CC haplotype strongly associated with serositis (odds ratio = 9.1, correcting p values = 0.0009) and neurologic involvement (odds ratio = 9.3, correcting p value = 0.0018). We reported a 2.7-fold increase in serum interleukin-18 levels in patients (511.5 ± 242.3 pg/ml) compared to controls (189.4 ± 80.8 pg/ml) ( p < 0.0001). Furthermore, interleukin-18 levels were positively correlated with disease activity ( r = 0.548, p = 0.0001) and renal involvement in the patients with lupus nephritis ( r = 0.569, p < 0.0001). In summary, interleukin-18 polymorphisms elucidated in this study appear to confer genetic susceptibility to the disease and are associated with renal, serositis and neurologic involvement in Indian systemic lupus erythematosus patients.

A Comparitive Study of Anticardiolipin Antibodies among Systemic Lupus Erythematosus Patients from Western and Eastern India.

INTRODUCTION: Anti-phospholipid antibodies (APA) like anticardiolipin antibodies (ACA) are important cause of venous and arterial thrombosis and other occlusive vascular diseases. Prevalence of these antibodies in SLE patients at the time of diagnosis is not known in Indian SLE patients. This study was conducted to evaluate the prevalence of ACA in SLE patients from Eastern and Western India and to correlate them with disease activity. MATERIAL AND METHODS: Seventy SLE patients from Assam Medical College, Dibrugarh, Assam and 85 SLE patients from Rheumatology Department, KEM Hospital, Mumbai were studied. SLE disease activity was evaluated by SLE Disease Activity Index (SLEDAI) score at the time of evaluation. All patients studied were in an active stage of disease. RESULTS: Demographic data showed significant variations in the clinical manifestations of SLE between two regions. Renal manifestations were higher (42.9%) among SLE patients from Eastern region as compared with 37.6% patients from Western region. These patients were categorized as Lupus Nephritis (LN) and patients that did not show any renal manifestations were categories as non-LN. ACA to IgG and IgM subclasses were tested by ELISA. IgGACA positivity was 20%, 12.9% and IgM-ACA positivity was 18.6%, 12.9% where asIgG + IgM ACA positivity as found in 12.9%, 3.5% patients respectively among SLE patients from Eastern and Western India. CONCLUSIONS: ACA positivity was higher among LN patients from Eastern India whereas the same was higher among non-LN patients from Western India. Hence detection of ACA alongwith associated clinical manifestations were helpful to evaluate their possible association with disease severity in SLE patients. A long term follow up of patients having ACA antibodies without thrombotic event is needed to detect their possible thrombotic event in future along with their clinical presentation from these two different geographic regions from India.

Role of MMP-7 in the pathogenesis of systemic lupus erythematosus (SLE).

Systemic lupus erythematosus (SLE) is a clinically heterogeneous chronic, inflammatory autoimmune disorder. The association of MMP-7 and disease severity is still unclear. A total of 150 SLE patients and matched healthy controls were recruited for this study. Disease activity was scored according to SLEDAI (98 active and 52 inactive disease). Mean serum MMP-7 levels were significantly higher in SLE patients than controls ( p < 0.001). Patients with active disease showed higher levels (16.24 ± 6.2 ng/ml) as against inactive disease (10.50 ± 3.97 ng/ml) ( p ≤ 0.0001). Mean MMP-7 mRNA expression was significantly higher in patients (RQ = 3.16 ± 0.93) as compared to controls (RQ = 2.21 ± 0.89, p = 0.006). A positive correlation between MMP-7 levels, mRNA expression and SLEDAI score was observed ( r = 0.563, r = 0.427). The MMP-7 -181 G allele was found to be significantly higher among SLE patients ( p < 0.0001). A significant association was noted between MMP-7 -181 A/G +G/G genotypes with renal ( p = 0.0027) and CNS ( p = 0.0031) manifestations and anti-dsDNA autoantibodies ( p = 0.0312). Serum MMP-7 levels and mRNA expression were elevated in advanced stages of SLE, indicating that MMP-7 is associated with disease activity in SLE.

Do high sensitivity C-reactive protein and serum interleukin-6 levels correlate with disease activity in systemic lupus erythematosuspatients?

INTRODUCTION: Systemic Lupus Erythematosus (SLE) is an inflammatory autoimmune disease where an interplay between acute phase proteins and cytokines are involved in disease activation. AIM AND OBJECTIVES: This case control study was performed to investigate interrelationship between high sensitivity C-reactive proteins (hs-CRP), Interleukin-6 (IL-6) levels and disease activity among SLE patients. MATERIALS AND METHODS: One hundred forty one clinically diagnosed SLE cases were included and disease activity was noted by SLE Disease Activity Index (SLEDAI). Serum IL-6 levels were measure by cytokine multiplex assay. Serum hs-CRP, C3 and C4 levels were measure by nephelometer. The Pearson correlation test was used for correlation between hs-CRP, Il-6 and SLEDAI. RESULTS: Based on SLEDAI, 126 patients (89.4 %) had active disease and 15 patients (10.6%) had inactive disease. Mean hs-CRP levels in SLE patients were significantly higher (12.1+ 11.5 mg/L) than controls (2.41+ 1.37 mg/L) (P < 0.0001). Hs-CRP levels among active SLE were significantly higher (13.5+ 11.4 mg/L) as compared with inactive SLE (4.4 + 2.9 mg/L) (P=0.0002). Similarly, IL-6 levels in SLE patients were significantly higher among active SLE (26.9 + 15.5 pg/ml) as compared with inactive SLE (13.9+ 10.2 pg/ml) (P=0.0001). An inverse correlation between Il-6 and hemoglobin levels between active and inactive SLE was noted (r=-0.46, P <0.0001). CONCLUSION: This study suggests a good correlation between hs-CRP, IL-6 and SLE disease activity indicating their direct involvement in inflammatory conditions associated with disease.

Distribution of HLA-DRß1 alleles among well-characterized rheumatoid arthritis patients from Western India.

An association between human leukocyte antigen-DRß1*04 and rheumatoid arthritis (RA) has been known for more than 25 years. It has been observed in many different populations, and it accounts for approximately one-third of the genetic component of RA susceptibility. Our aim was to study the distribution of HLA-DRß1 alleles in well-characterized RA patients from Western India. Polymerase chain reaction-based sequence-specific oligonucleotide probing (PCR-SSOP) technique was used to identify HLA-DRß1 alleles among 80 clinically well-defined patients and 90 normal controls from same ethnicity. A significant increase in the frequency of DRß1*04 was observed among RA patients (PF% 30 vs. 7.7, OR 4.959, p value 0.00018), whereas DRß1*03 and *14 were significantly decreased among patients when compared with controls (DRß1*03, PF% 8.75 vs. 26.6, OR 0.2637, p value 0.00253; DRß1*14, PF% 17.5 vs. 30.0, OR 0.4949, p value 0.05722). Our results suggest that DRß1*04 was strongly associated with well-characterized RA patients from Western India, whereas DRß1*03 and *14 may be protective alleles for RA. The identification of susceptible allele in patients with RA may help physician to make early decisions regarding initiation of early intensive therapy with disease modifying anti-rheumatic drugs and biological agents to decrease disability in RA patients.

Anti-C reactive protein antibodies in Indian patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is characterized by over production of autoantibodies. C-reactive protein (CRP) is a phylogenetically highly conserved plasma protein that participates in the systemic response to inflammation. Anti-CRP antibodies might have biological functions of pathogenetic interest in SLE. We evaluated anti-CRP antibodies in Indian SLE patients and their association with anti-dsDNA antibodies and complement levels (C3 and C4). One hundred SLE patients diagnosed according to the American College of Rheumatology criteria were included. Disease activity was assessed using SLE disease activity index (SLEDAI). Anti-CRP autoantibodies were detected by enzyme linked immunosorbent assay. Anti-dsDNA antibodies were detected by indirect immunofluroscence test (Euroimmun Lubeck, Germany). High sensitivity CRP and complement levels (C3, C4) were detected using a Nephelometer. (BN ProSpec, Dade Behring, Germany). Anti-CRP antibodies were detected in 26% of SLE patients. Mean age of disease onset among anti-CRP positives was 22.4 ± 7.5, and 26.6 ± 9.3 years among anti-CRP negatives (P > 0.05). Anti-dsDNA positivity was significantly higher among anti-CRP positives (32.7%) as compared to anti-CRP negatives (16%) (P = 0.00519). No statistically significant difference was observed in SLEDAI scores of anti-CRP positive group and anti-CRP negative group (P > 0.05). We observed a positive correlation between anti-CRP antibodies and anti-dsDNA antibodies.

The angiotensin-converting enzyme gene insertion/deletion polymorphism in Indian patients with vitiligo: a case-control study and meta-analysis.

BACKGROUND: Vitiligo is a common, acquired, idiopathic depigmenting skin disorder. Although the exact pathogenesis remains unknown, genetic susceptibility and autoimmune responses play a role in vitiligo development. Previous studies have suggested that the D allele of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene is associated with vitiligo in Indians and Koreans. Furthermore, significantly higher serum ACE levels have been demonstrated in patients with some autoimmune and autoinflammatory disorders. OBJECTIVES: The objectives were to investigate any association between the ACE I/D polymorphism and vitiligo susceptibility in an Indian population, and to compare serum ACE levels in patients with vitiligo and healthy subjects. METHODS: The ACE I/D genotypes of 79 patients with vitiligo and 100 normal individuals were determined by polymerase chain reaction amplification. A meta-analysis was done to compare the distribution of the ACE I/D alleles and genotypes in the current and three previous studies. Serum ACE levels were evaluated by enzyme-linked immunosorbent assay. RESULTS: A significant increase in the frequency of the ACE I/D D allele was evident in patients with vitiligo in both the case-control study [P=0·005; odds ratio (OR) 1·87; 95% confidence intervals (CI) 1·22-2·85] and the meta-analysis (P=0·044; OR 1·44; 95% CI 1·01-2·06). Serum ACE levels were significantly increased in patients with vitiligo compared with healthy subjects (P<0·0001). CONCLUSIONS: In agreement with earlier reports, the ACE I/D D allele is associated with vitiligo susceptibility in the Indian population. The significantly elevated serum ACE levels in our cohort of patients with vitiligo concur with those previously found in patients with some other autoimmune diseases.

Vitiligo patients from India (Mumbai) show differences in clinical, demographic and autoantibody profiles compared to patients in western countries.

BACKGROUND: Vitiligo is a common, idiopathic skin disorder characterized by depigmented skin due to the loss of cutaneous melanocytes. Several studies have reported the clinical and demographic characteristics of Indian vitiligo patients, however, none has characterized their antibody profiles. OBJECTIVE: To establish the clinical, demographic and serological details of a population of vitiligo patients from Mumbai, India, and to evaluate the data for any associations between clinical presentations and the occurrence of antibody responses. METHODS: Vitiligo patients (n = 79) were recruited to the study and their clinical and demographic details recorded. Serum antibodies, including those against melanocyte-specific antigens, thyroid antigens and keratinocytes, were evaluated. RESULTS: The prevalence of vitiligo was independent of sex, and non-segmental vitiligo was the most common form of the disease occurring in 65% of the patients. Patients with segmental vitiligo (mean age = 14.4 ± 4.6 years) presented at a younger age than those with non-segmental disease (mean age = 32.5 ± 17.8 years). Personal and family histories of other autoimmune diseases occurred in 3% and 8% of patients, respectively. Antibodies were detected against tyrosinase, tyrosine hydroxylase, thyroid peroxidase, thyroglobulin and keratinocytes at frequencies of 11%, 22%, 18%, 24% and 27%, respectively. Overall, antibodies were more common in patients with non-segmental vitiligo (50-67%) than in those with segmental disease (0-17%), and were detected more frequently in patients with shorter disease durations (<10 years). CONCLUSION: Our study provides novel information relative to the clinical details, demographic features and serological parameters of a population of vitiligo patients from Mumbai, India. Important distinctions from similar surveys conducted in European patients were evident such as an infrequency of family history, a low prevalence of clinical autoimmune disease, and an absence of particular antibody specificities. These differences may have a bearing on the pathogenesis and course of the disease in Indian patients.

Clinical and immunological profile of systemic lupus erythematosus.

Pediatric onset systemic lupus erythematosus (SLE) is not uncommon and female to male ratio varies. Pediatric SLE patients have more severe disease at onset, higher rates of organ involvement and more aggressive clinical course than adults. We compared the clinical and immunological parameters among pediatric SLE and adult SLE from Western India. Twenty five children and 60 adult patients fulfilling American College of Rheumatology SLE criteria were included. Antinuclear antibodies, anti-dsDNA and complement (C3, C4) levels were tested. Of 25 pediatric SLE patients studied, 24% showed CNS involvement vs. 8.3% in adults SLE (P=0.0499). Lupus nephritis was seen in 75% adult patients vs. 52% among children. Hepatosplenomegaly was noted more among adult SLE 26.8% vs 12% among children. Alopecia was an exclusive features among adult SLE.

Anti-C1q antibodies and their association with complement components in Indian systemic lupus erythematosus patients.

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease, characterized by immune complex formation and systemic inflammation. Complement components such as C1q and mannose-binding lectin (MBL) play an important role in the clearance of immune complexes. Anti-C1q antibodies are associated with lupus nephritis and reduced levels of the complement components. The objective of this study was to detect anti-C1q antibodies in SLE patients and to evaluate their association with the complement components. Sixty SLE patients were included, of whom 75% had lupus nephritis (LN) and 25% were without renal manifestations (non-LN). The disease activity was assessed at the time of evaluation by the systemic lupus erythematosus disease activity index (SLEDAI). Anti-C1q antibodies, circulating immune complexes, and serum MBL levels were detected by enzyme-linked immunosorbent assay. The anti-C1q antibody prevalence was 58.3%. The LN patients showed 60% anti-C1q positivity with a higher percentage in membranoproliferative glomerulonephritis patients (51.9%). Anti-dsDNA positivity was slightly higher among the anti-C1q positives than in the anti-C1q negatives (65.7% vs. 60%). A higher percentage of reduced C3 and C4 levels was noted among the anti-C1q positives. The LN patients showed a higher percentage of low MBL levels among anti-C1q negatives than in the anti-C1q positives (61.1% vs. 55.6%). Non-LN patients showed a higher percentage of low MBL levels among anti-C1q positives than among anti-C1q negatives (87.5% vs. 57.1%). Anti-C1q antibodies were found in both LN and non-LN patients, but there was no correlation with the clinical severity of the disease.

Autoantibody profile and other immunological parameters in recurrent spontaneous abortion patients.

BACKGROUND: An autoimmune cause and related immunological alterations resulting in recurrent spontaneous abortion (RSA) have been suggested in patients with unknown etiology. MATERIALS AND METHODS: This study evaluated the autoantibody profile and other immunological parameters among RSA patients and normal pregnant women from Mumbai western India. Fifty RSA patients with unknown cause and greater than three consecutive abortions along with 50 normal pregnant women were studied for various auto antibodies such as ANA, anti-dsDNA, ANCA, AECA, 2 micro globulin, anti-HLA antibodies and ACLA using immunofluorescence microlymphocytotoxicity and ELISA. Immunological parameters such as HLA class I monoclonal antibody expression, CD3 (T cell), CD19 (B cell), and CD56 (NK cell) were estimated by flow cytometry. RESULTS: The results revealed 34% positivity of all auto antibodies tested among patients. ANA(12%), ANCA (20%), AECA (24%), ACLA (8%), anti-dsDNA(0%), ß2 microglobulin (14%), and anti-HLA antibodies(10%) among RSA patients were identified. An increased expression of HLA class I specific monoclonal antibody (10%) with HLA A3 (16%) specificity were found to correlate with shared HLA alleles among the RSA couples. Among normal pregnant (control) group ANA (2%), ANCA (2%), AECA (3%), ACLA (4%) and increased expression of CD56 with reduced HLA class I monoclonal were observed. CONCLUSION: Our findings suggest a possible role of various autoantibodies along with the related immunological parameters underlying RSA.

PTPN22 gene polymorphisms in autoimmune diseases with special reference to systemic lupus erythematosus disease susceptibility.

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease. SLE is a result of one or more immune mechanisms, like autoantibody production, complement activation, multiple inflammation and immune complex deposition leading to organ tissue damage. SLE affected patients are susceptible to common and opportunistic infections. There are several reports suggesting that Mycobacterium tuberculosis infection precipitates SLE in patients from endemic areas. Genetic factors and environmental factors also play an important role in the overall susceptibility to SLE pathophysiology. Recently, protein tyrosine phosphatase, non-receptor type 22 (PTPN22) gene, has been found to be associated with several autoimmune diseases like SLE, Grave's disease and Hashimoto thyroiditis. The missense R620W polymorphism, rs 2476601, in PTPN22 gene at the nucleotide 1858 in codon 620 (620Arg > Trp) has been associated with autoimmune diseases. The PTPN22 locus is also found to be responsible for development of pulmonary tuberculosis in certain populations. The PTPN22 1858C/T gene locus will be ideal to look for SLE susceptibility to tuberculosis in the Indian population. In this review, we focus on human PTPN22 gene structure and function as well as the association of PTPN22 gene polymorphisms with SLE susceptibility.

Choice of test for association in small sample unordered r x c tables.

Pearson's chi-squared, the likelihood-ratio, and Fisher-Freeman-Halton's test statistics are often used to test the association of unordered r x c tables. Asymptotical, exact conditional, or exact conditional with mid-p adjustment methods are commonly used to compute the p-value. We have compared test power and significance level for these test statistics and p-value calculations in small sample r x c tables, mostly 3 x 2 and some with both r and c are greater than 2. After extensive simulations, in general we recommend using an exact conditional mid-p test with Pearson's chi-squared or Fisher-Freeman-Halton's statistic, which usually is the most powerful test yet preserve the approximate significance level. Moreover, we recommend that the asymptotic Pearson's chi-squared or other asymptotic tests not be used for small sample r x c tables.

Methane and nitrous oxide emission from bovine manure management practices in India.

We report seasonal variation in CH(4) and N(2)O emission rate from solid storage of bovine manure in Delhi as well as emission factors and emission inventory from manure management systems in India. Emission flux observed in the year 2002-2003 was 4.29+/-1, 4.84+/-2.44 and 12.92+/-4.25 mg CH(4)kg(-1)dung day(-1), as well as 31.29+/-4.93, 72.11+/-16.22 and 6.39+/-1.76 microgN(2)O kg(-1)dung day(-1) in winter, summer and rainy seasons, respectively. CH(4) emission factors varied from 0.8 to 3.3 kg hd(-1)year(-1) for bovines and were lower than IPCC-1996 default values. N(2)O emission factors varied from 3 to 11.7 mg hd(-1)year(-1) from solid storage of manure. Inventory estimates were found to about 698+/-27 Gg CH(4) from all manure management systems and 2.3+/-0.46 tons of N(2)O from solid storage of manure for the year 2000.

Immunogenetic association in patients with antineutrophil cytoplasmic antibodies (ANCA) from Mumbai, Maharashtra, India.

Considerable genetic evidence exit for ANCA-associated vasculitis and pathogenesis. HLA A and B alleles identified serologically from 84 ANCA-positive patients were compared with 101 controls. Further subtyping were done in the 27 "pauci-immune" vasculitis patients using the polymerase chain reaction based PCR-SSOP technique and compared with controls (67). The results revealed that HLA A1 (OR=4.00; p value 2.72E-05), B17 (OR=3.38; p value 0.0008) and HLA B40 (OR=2.74; p value 0.001) were significantly increased among ANCA-positive patients when compared with the controls. Further, the molecular subtypes A*0101 (OR=5.04; p value 0.0005), B*5801 (OR=4.47; p value 0.0002) and haplotype A*0101-B*5801 (OR=4.47; p value 0.0001) were significantly increased among the autoimmune patients. The study revealed that HLA A1, B17 and B40 alleles are associated in production of antineutrophil autoantibodies and A*0101-B*5801 haplotype is significantly associated with autoimmune diseases and they may be invariably involved in disease pathogenesis in India.

Anti-myeloperoxidase antibodies in patients with microscopic polyangiitis.

BACKGROUND & OBJECTIVES: Anti-neutrophil cytoplasmic antibodies in active necrotizing and crescentic glomerulonephritis are associated with systemic vasculitides like Wegener's granulomatosis, Microscopic polyangitiis and Churg Strauss Syndrome. This study shows the incidence of ANCA with specificities to Myeloperoxidase and Proteinase3 in MPA cases and gives the correlation of ANCA with Birmingham Vasculitis Activity Score. MATERIAL & METHODS: Eighteen cases of MPA were diagnosed as per Chapel Hill Consensus Criteria. ANCA was detected by indirect immunofluorescence microscopy using fluorescence and Confocal Laser Scanning Microscopes. Anti-MPO and anti-PR3 were identified by commercial ELISAs and anti-MPO subclass and IgG isotypes were also detected. RESULTS: MPA patients showed a male preponderance with BVAS ranging from 17-30. Systemic involvement was seen in 88.9%, lower respiratory tract involvement in 77.8% and upper respiratory tract in only 33.3% cases. All these patients had perinuclear pattern on IIF, where titers ranged from 80-640 and ELISA showed anti-MPO; values ranging from 20-80 units/ml. IIF and ELISA showed a good correlation (r=0.77). Two patients having FPGN had dual specificities and had both anti-MPO and anti-PR3 which could be picked up only by ELISA. A good correlation (r=0.78) was observed between BVAS and ANCA levels as well. IgG ANCA was detected in 88.7% and 11.1% had IgG+IgM and IgG1+IgG4 ANCA was detected in 50% patients. CONCLUSION: p-ANCA with anti-MPO is highly specific for MPA; both IIF and ELISA should be carried out for true positivity and to identify rare cases of dual specificities. Confocal laser scanning microscopy is useful in identifying ANCA patterns especially when ANA is also positive. ANCA testing with BVAS assessment will surely help in early diagnosis and estimating the severity of this life threatening disease.

A study of anti-neutrophil cytoplasm antibodies in systemic vasculitis and other related disorders.

BACKGROUND: Anti-neutrophil cytoplasm antibodies (ANCA) play an important role as specific and sensitive markers for small vessel vasculitis and in some other systemic disorders. Indirect immunofluorescence test, known as the "Gold Standard" for screening of ANCA, can be further substantiated by ELISA for confirmation and for identifying sub-specificities like anti-Myeloperoxidase (anti-MPO), anti-Proteinase 3 (anti-PR3) and anti-Lactoferrin (anti-LF). AIMS: The present study was undertaken to investigate the incidence, specificities and strength of ANCA in suspected vasculitis cases and to correlate their presence with that of these auto-antibodies and with the disease. SUBJECTS AND METHODS: Sera from 130 clinically suspected vasculitis patients were studied. Indirect immunofluorescence microscopy (IIF) was used to identify cytoplasmic (c-ANCA), perinuclear (p-ANCA) and atypical (X-ANCA) patterns using ethanol and formalin fixed polymorphonuclear cells (PMN) and HL-60 cells from a human promyelocytic leukaemic cell line as substrates. ELISA was performed for identifying ANCA sub-specificities to anti-MPO and anti-PR3 and HEp-2 cells were used for detection of anti-nuclear antibodies (ANA). RESULTS: ANCA positivity was noted in 42.3% of these patients, wherein p-ANCA positivity rate was 34.6% and c-ANCA positivity was noted in 5.4% subjects. Three patients showed the unusual X-ANCA positivity. ELISA determined the sub-specificities: Out of 45 p-ANCA positive patients, 38 patients (84.4%) had anti-MPO and out of 7 c-ANCA positive patients, 5 patients (71.4%) had anti-PR3 antibodies. One patient with Class IV Lupus Nephritis, showed both anti-MPO and anti-PR3 antibodies and 17.8% p-ANCA positive patients had anti-Lactoferrin antibodies. CONCLUSIONS: Use of the Immunofluorescence method coupled with identification of ANCA sub-specificities by ELISA, is recommended for detection of ANCA in clinically suspected cases of small vessel and other systemic vasculitis.