Toll-like receptors in autoimmunity with special reference to systemic lupus erythematosus.

The Toll-like receptor (TLR) family plays a fundamental role in host innate immunity by mounting a rapid and potent inflammatory response to pathogen infection. TLRs recognize distinct microbial components and activate intracellular signaling pathways that induce expression of host inflammatory genes. Several studies have indicated that TLRs are implicated in many inflammatory and immune disorders. Extensive research in the past decade to understand TLR-mediated mechanisms of innate immunity has enabled pharmaceutical companies to begin to develop novel therapeutics for the purpose of controlling an inflammatory disease. The roles of TLRs in the development of autoimmune diseases have been studied. TLR7 and TLR9 have key roles in production of autoantibodies and/or in development of systemic autoimmune disease. It remains to be determined their role in apoptosis, in the pathogenesis of RNA containing immune complexes, differential expression of TLRs by T regulatory cells.

Anti-nucleosome antibodies as a disease marker in systemic lupus erythematosus and its correlation with disease activity and other autoantibodies.

Background: Detection of anti-nucleosome antibodies (anti-nuc) in patients with systemic lupus erythematosus (SLE) has been well established and it is claimed that their presence is associated with disease activity. Aims: The aim of this study is to evaluate the incidence of anti-nuc antibodies and to correlate them with disease activity and its association with other autoantibodies like anti-nuclear antibodies (ANA), anti-double stranded DNA (anti-dsDNA), anti-histone antibodies (AHA), as well as autoantibodies to histone subfractions like H1, (H2A-H4) complex, H2B, and H3. Methods: This cross-sectional study included 100 SLE patients referred from the Rheumatology, Dermatology, and Nephrology Departments. SLE disease activity was evaluated by using SLE-Disease Activity Index (SLEDAI) score. A patient was defined as having active SLE when the SLEDAI score was more than 5.0. Fifty normal controls were also tested as a healthy control group. Anti-nuc antibodies, anti-dsDNA, and AHA were tested by Enzyme-Linked Immunosorbent Assay (ELISA) and ANA was detected by an indirect immunofluorescence test. Results: All patients studied were in an active stage of disease and were untreated, of which 44 patients had renal biopsy-proven kidney involvement, which was categorized as lupus nephritis (LN) and 56 patients did not show any renal manifestations (SLE without LN). Anti-nuc antibodies were positive in 88%, anti-dsDNA in 80%, and AHA in 38% of the cases. ANA was positive in all SLE patients studied. None of the normal controls was found to be positive for these antibodies. Although a slightly higher incidence of autoantibodies were noted in LN, there was no statistical difference noted between LN and SLE without LN groups for anti-nuc and anti-dsDNA antibodies (p > 0.05). A higher incidence of autoantibodies to ANA specificities were noted in anti-nuc positive cases, but there was no statistical difference between anti-nuc positive and anti-nuc negative cases for ANA specificities among LN and SLE without nephritis groups (p > 0.05). Conclusions: Anti-nuc antibody detection could be a better tool for the diagnosis of SLE. Although there was no significant difference in LN and SLE without LN groups, this study suggests that anti-nuc detection can be useful as an additional disease activity marker to other laboratory tests.

ANCA: serology in Wegener's granulomatosis.

BACKGROUND AND OBJECTIVES: Wegener's granulomatosis (WG) is being increasingly diagnosed in India, which exists in two forms, the 'limited Wegener's granulomatosis' (LWG) having upper respiratory tract (URT) and lower respiratory tract (LRT) involvement and the 'classical Wegener's granulomatosis' (CWG), with the triad of URT, LRT involvement along with kidney involvement. Cytoplasmic ANCA (C-ANCA) or anti-Proteinase3 (anti-PR3), which is highly diagnostic for WG, rarely perinuclear ANCA (P-ANCA) may exist. AIMS: To detect anti-neutrophil cytoplasmic antibodies (ANCA) and correlate it with serological, hematological parameters, and the Birmingham Vasculitis Activity Score (BVAS). SETTINGS AND DESIGN: Twenty-three clinically and histopathologically proven WG (16 CWG, 7 LWG) were studied. MATERIAL AND METHODS: C-ANCA and P-ANCA patterns were identified by immunofluorescence and specificities were confirmed by 'alpha granule' enzyme linked immunosorbent assay (ELISA), anti-PR3, anti-MPO (myeloperoxidase) and anti-Lactoferrin (anti-LF) by ELISA. RESULTS: LRT involvement was seen in 91.3%, URT in 78.3%, and renal manifestations in 69.6% cases. The BVAS in CWG was significantly higher than BVAS in the LWG. Decreased hemoglobin, increased WBC counts, ESR, CRP and Creatinine were seen in CWG as compared to LWG. The C-ANCA was present in 65.2% patients and P-ANCA in 13% cases. Anti-PR3 was seen in 69.6% patients and anti-LF in 17.4% cases. Severity of disease and ANCA was higher in CWG than in LWG. CONCLUSIONS: Vasculitis syndromes are known to overlap and many go undetected; therefore ANCA testing, along with the clinical and histopathological observations may be helpful in early detection and management of WG cases.

Anti-neutrophil cytoplasmic antibodies (ANCA) in systemic lupus erythematosus: prevalence, clinical associations and correlation with other autoantibodies.

AIM: This study was undertaken to clarify the nature of anti-neutrophil cytoplasmic antibodies (ANCA) along with other autoantibodies in lupus nephritis (LN) patients and in systemic lupus erythematosus (SLE) patients without nephritis and to know their correlation with clinical manifestations and presence of other autoantibodies. MATERIAL AND METHODS: Fourty one LN patients and 18 SLE patients without nephritis were studied. LN patients were subdivided into diffuse proliferative glomerulonephritis (DPGN), focal proliferative glomerulonephritis (FPGN), rapidly progressive glomerulonephritis (RPGN) and membranoproliferative glomerulonephritis (MPGN). Anti-neutrophil cytoplasmic antibodies (ANCA) were detected by indirect immunofluorescence and confocal laser scanning microscope using PMN and HL60 cells. ANCA specificities like anti-myeloperoxidase (anti-MPO), anti-proteinase 3 (anti-PR3), anti-lactoferrin (anti-LF) and anti-cathepsin G (anti-CG) were detected by ELISA. Other autoantibodies like anti-nuclear antibodies (ANA), anti-double stranded DNA (anti-dsDNA), anti-single stranded DNA(anti-ssDNA), anti-ribonucleoproteins (anti-nRNP), anti-Smith antibodies (anti-Sm) and rheumatoid factor (RF) were also tested. RESULTS: ANCA was detected in 37.3% patients. The predominant ANCA pattern was perinuclear (p-ANCA). ANCA positivity was higher in LN patients and when confirmed by ELISA, 54.5% ANCA positives had anti-myeloperoxidase (anti-MPO). The cytoplasmic ANCA (c-ANCA) pattern was not seen in any patient. Two patients having FPGN with crescents showed atypical 'X-ANCA' pattern with dual specificity to anti-MPO and anti-PR3 by ELISA. The titers of ANCA were more in LN as compared to SLE without nephritis. LN cases having DPGN, FPGN, RPGN with crescents had higher titer p-ANCA positivity with corresponding anti-MPO antibodies, along with ANA, anti-dsDNA, anti-ssDNA and anti-Sm + anti-nRNP and also high SLEDAI scores. CONCLUSION: ANCA in SLE may be used as a serological marker along with clinical and histopathological assessment to differentiate vasculitides in LN cases from SLE without nephritis.

Spectrum of anti-neutrophil cytoplasmic antibodies in patients with pulmonary tuberculosis overlaps with that of Wegener's granulomatosis.

BACKGROUND AND OBJECTIVES: Mycobacterial infections are known to induce the development of autoantibodies and a few of these antibodies are also known to be diagnostic markers for some other diseases and it is uncertain whether these autoantibodies play a role in the pathogenesis of autoimmune disorders. This study was undertaken to determine the prevalence of autoantibodies like anti-neutrophil cytoplasmic antibodies (ANCA), anti-nuclear antibodies (ANA), anti-double stranded antibodies (anti-dsDNA) and anti-histone antibodies (AHA)in pulmonary Tuberculosis. MATERIALS & METHODS: Seventy consecutive pulmonary TB patients, 30 patients of interstitial lung disease and 100 normal individuals were studied. ANCA and ANA were detected by indirect immunofluorescence test (IIF). Anti-dsDNA and AHA were tested by ELISA. RESULTS: ANCA was detected in 30% cases, and of these 52.4% showed perinuclear pattern (p-ANCA), 38.1% cytoplasmic (c-ANCA) and 9.5% showed an "atypical" pattern. ANCA specificities by ELISA revealed that, 47.6% had anti-Myeloperoxidase (anti-MPO), 28.6% had anti-Proteinase3 (anti-PR3) and 19.1% had anti-Lactoferrin (anti-LF) antibodies. ANA and AHA were present in 24.3% and 21.4% cases respectively whereas anti-ds DNA antibodies were absent. Normal controls showed 4% and 2% positivity for ANA and ANCA whereas disease control group of ILD showed 7% of ANA and ANCA posititivy. CONCLUSION: The presence of autoantibodies in TB patients could have a multifactorial etiology. Clinically relevant is the presence of anti-PR3 antibodies. This finding along with pulmonary and renal manifestations could lead to a false diagnosis of Wegener's granulomatosis or vice versa because these autoantibodies may be present in both diseases.

Antibodies to Ro/SS-A and La/SS-B in systemic lupus erythematosus and other autoimmune disorders.

AIM: 1. To study the presence of anti-Ro/SS-A, anti-La/SS-B, anti-Sm and anti-nRNP in diagnosed antinuclear factor (ANF) positive systemic lupus erythematosus (SLE) cases and their association with various organ involvement. 2. To study autoantibodies in other autoimmune disorders. MATERIAL AND METHODS: A total of 4050 suspected cases of autoimmune disorders referred for serological work up were evaluated for ANF by indirect immunofluorescence technique, anti-dsDNA by PHA, autoantibodies to Ro-SS-A and La/SS-B by ELISA and rheumatoid factor was tested by latex agglutination using commercial kits. RESULTS: Out of 4050 patients 19.5% were ANF positive and 5% were anti-dsDNA positive. Out of these 50 diagnosed ANF positive cases of SLE, an incidence of anti-dsDNA 54%, anti-Sm 25.9%, anti-nRNP 29.6%, anti-Ro/SS-A 10% and anti-La/SS-B was 22% was observed. In rheumatoid arthritis, 17.4% positivity of anti-Ro/SS-A and 39.1% positivity for anti-La/SS-B was observed. In SLE with renal involvement, joint complaints and skin or malar rash were seen in 66%, 56% and 46%, respectively. CONCLUSION: Determining anti-Ro/SS-A and anti-La/SS-B antibody could be important in evaluating patients with suspected connective tissue disorders, who usually show diverse clinical presentations like skin, kidney and joint manifestations. The most prominent feature in anti-Ro/SS-A and anti-La/SS-B positive patients was skin involvement and sicca complex in 60% of SLE patients.