Synergetic Interaction of HLA-DRB1*07 Allele and TNF-Alpha - 863 C/A Single Nucleotide Polymorphism in the Susceptibility to Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease which is characterized by dysregulation of various cytokines propagating the inflammatory processes that is responsible for tissue damage. Tumor necrosis factor alpha (TNF-α) is one of the most important immunoregulatory cytokines that has been implicated in the different autoimmune diseases including SLE. Two hundred and two patients with SLE and 318 controls were included in the study. The TNF-α gene promoter region (from - 250 to - 1000 base pairs) was analyzed by direct Sanger's DNA sequencing method to find promoter variants associated with South Indian SLE patients. We have analyzed six TNF-α genetic polymorphisms including, - 863C/A (rs1800630), - 857C/T (rs1799724), - 806C/T (rs4248158), - 646G/A (rs4248160), - 572A/C (rs4248161) and - 308G/A (rs1800629) in both SLE patients and controls. We did not find association of TNF-α gene promoter SNPs with SLE patients. However, the - 863A (rs1800630) allele showed association with lupus nephritis phenotype in patients with SLE (OR: 1.62, 95%CI 1.04-2.53, P = 0.034). We found serum TNF-α level was significantly elevated in SLE cases as compared to control and found no association with any of the polymorphisms. The haplotype analysis revealed a significant protective association between the wild TNF-α alleles at positions - 863C, - 857C, - 806C, - 646G, - 572A and - 308G (CCCGAG) haplotype with lupus nephritis phenotype (OR 0.53, 95% CI 0.35-0.82, P = 0.004). Additionally, the TNF-α - 863 C/A (rs1800630) polymorphism and HLA-DRB1*07 haplotype showed significant differences between SLE patients and controls (OR 4.79, 95% CI 1.73-13.29, P = 0.0009). In conclusion, TNF-α - 863A allele (rs1800630) polymorphism is associated with increased risk of nephritis in South Indian SLE patients. We also found an interaction between HLA-DRB1*07 allele with TNF-α - 863 C/A promoter polymorphism giving supportive evidence for the tight linkage disequilibrium between TNF-α promoter SNPs and MHC class II DRB1 alleles.

Comparison of different immunoassays for the detection of antibodies against Intrinsic Factor and Parietal Cells

OBJECTIVES

In the diagnostic work up of autoimmune gastritis several immunological methods are available for the detection of antibodies against Intrinsic Factor (IF) and Parietal Cells (PC). However, there are no recent reports directly comparing all the available assays and methods. The objective of this study was to compare the performance of several commercially available anti-IF and anti-PC antibody assays from different manufacturers in a multi-center multi-cohort setting.

METHODS

Sera were used from 5 different cohorts consisting of samples from 25 healthy elderly, 20 HCV or HIV positive patients and 150 patients positive for anti-IF or anti-PC antibodies or in whom these antibodies were requested. These cohorts were tested for anti-IF antibodies with 6 different assays (IIF, ELISA, DIA and EliA) and for anti-PC antibodies with 7 different assays (IIF, ELISA, DIA and EliA). Performance was evaluated by calculating the concordance and relative sensitivity and specificity.

RESULTS

Good concordance was found between the assays for both antibody specificities, ranging from 81 to 100% and 91-100% for anti-IF and anti-PC antibodies, respectively. Highest relative sensitivity was found with the (automated) ELISA based methods. However, all assays had a relative sensitivity between 85 and 100% for anti-IF antibodies and between 95 and 100% for anti-PC antibodies. The relative specificity ranged between 76 and 100% for anti-IF antibodies and between 96 and 100% for anti-PC antibodies.

CONCLUSIONS

We conclude that most assays perform well and are concordant to each other, despite the methodological differences and the different sources of antigen used. However, the method used affects the sensitivity and specificity. The (automated) ELISA based assays have the highest relative sensitivity and relative specificity. Care should be taken in the interpretation of positive results by IIF and negative results by the Blue Diver when testing for anti-IF antibodies.

[Non-identified antinuclear antibodies in systemic sclerosis]

INTRODUCTION

Systemic sclerosis is a rare auto immune disease characterized by a local or diffuse skin condition and a variable visceral impairment. Anti nuclear antibodies (ANA) can be found in 95 % of patients. The most frequent are the anti topoisomerase 1 or anti Scl 70 and the anti-centromeres. Other antibodies have been reported but they are not conventionally sought in clinical practice. They are referred to as " non identified " ANA.

OBJECTIVE

To seek the " non identified " antibodies in patients with scleroderma at Erasme Hospital, to assess their prevalence in this cohort and to correlate their presence with the clinical characteristics.

METHODS

89 patients out of the cohort of Erasme hospital patients with scleroderma have been looked at. Their clinical and biological data have been identified and a detection of antibodies have been performed by first an immonudot technique and second an EliA technique.

RESULTS

17 out of the 89 patients of our cohort had " non identified " ANA. Among them, antibodies in 11 patients have been identified by the immunodot, among which 7 anti-PmScl 75 and/or 100,3 RNA polymerase III and 1 antifibrillarin. The EliA technique identif ied antibodies in 10 patients among which 5 anti- PmScl, 2 anti RNA polymerase, 2 anti-fibrillarin and 1 anti-centromere.

CONCLUSION

Auto antibodies other than the antitopoisomerase and anti-centromere have been found in patients with scleroderma in our cohort. Certain links exist between the presence of a given antibody and clinical features. We still have to define whether there exist other auto antibodies of which we still are unaware since in some patient no antibodies were detected.

Update on immunoglobulin A nephropathy, Part I: Pathophysiology

Immunoglobulin A (IgA) nephropathy is one of the most common glomerulonephritis and its frequency is probably underestimated because in most patients the disease has an indolent course and the kidney biopsy is essential for the diagnosis. In the last years its pathogenesis has been better identified even if still now several questions remain to be answered. The genetic wide association studies have allowed to identifying the relevance of genetics and several putative genes have been identified. The genetics has also allowed explaining why some ancestral groups are affected with higher frequency. To date is clear that IgA nephropathy is related to auto antibodies against immunoglobulin A1 (IgA1) with poor O-glycosylation. The role of mucosal infections is confirmed, but which are the pathogens involved and which is the role of Toll-like receptor polymorphism is less clear. Similarly to date whether the disease is due to the circulating immunocomplexes deposition on the mesangium or whether the antigen is already present on the mesangial cell as a “lanthanic” deposition remains to be clarified. Finally also the link between the mesangial and the podocyte injury and the tubulointerstitial scarring, as well as the mechanisms involved need to be better clarified.

Evaluation of serum vitamin B12 levels and its correlation with anti-thyroperoxidase antibody in patients with autoimmune thyroid disorders

Vitamin B12 deficiency has been reported in patients with Autoimmune thyroid disorders. However there is limited data on exact prevalence of low B12 and its correlation with anti-thyroperoxidase antibody (anti-TPO) levels in these patients. The aim of our study was to estimate serum vitamin B12 levels in autoimmune thyroid disorders and to correlate B12 levels with anti-TPO. 350 patients were selected by convenient sampling. Vitamin B12 levels and thyroid parameters were estimated using fully automated chemiluminescence method on Access 2. Results of our study shows that using the manufacturer's cut-off of 145 pg/mL, the prevalence of low serum vitamin B12 was found to be 45.50 %. Higher prevalence (55 %) was seen based on the published cut-off of 200 pg/mL The study however did not demonstrate any significant correlation between vitamin B12 levels and anti-TPO (r = -0.11 and p value of 0.30).

Cholinergic Autoantibodies from Primary Sjögren's Syndrome Inhibit Mucin Production via Phospholipase C and Cyclooxygenase-2 In the Rat Submandibular Gland

BACKGROUND

Patients with primary Sjögren's syndrome (pSS) produce functional IgG against cholinoreceptor of exocrine glands modifying their activity. The aim of the present work was to demonstrate pSS IgG antibodies (pSS IgG) interacting with M(3) muscarinic acetylcholine receptors (mAChR) of rats submandibular glands that alter mucin release and production via phospholipase C (PLC) and cyclooxigenase-2 (COX-2) pathways.

METHODS

Mucin release and production of prostaglandin E2 (PGE2), and total inositol phosphates (InsP) were measured in rat submandibular gland in the presence of pSS IgG auto antibodies.

RESULTS

The auto antibodies interacting with M3 mAChR decreased mucin release and production through stimulation of PLC and COX-2. This stimulation leads to an incremental increase in InsP production and in PGE2 generation, inducing signalling through the prostaglandin membrane receptors subtype 2 (EP2). Moreover, the decrease in mucin production had negative correlation with PGE(2) generation and InsP accumulation.

CONCLUSION

IgG in patients with pSS could play an important role in the pathoetiology of dry mouth, decreasing the salivary mucin through the production of proinflammatory substances and leading to the reduction in the protection of the oral tissues.

Etiological approach to chronic urticaria

BACKGROUND

In 1769, William Cullen introduced the word "urticaria" (transient edematous papules, plaque with itching). Urticaria affects 15-25% of people at least once in their life time. It is a clinical reaction pattern triggered by many factors causing the liberation of vasoactive substances such as histamine, prostaglandins and kinins. Urticaria is classified according to its duration into acute (< 6 weeks duration) and chronic (>6 weeks duration). Various clinical investigations may be initiated to diagnosis the cause.

AIMS

To evaluate the types of chronic urticaria with reference to etiology from history and investigations.

MATERIALS AND METHODS

A total of 150 patients with chronic urticaria of more than six weeks were studied. Autologous serum skin test (ASST) was performed after physical urticarias were excluded. Standard batteries of tests were performed after ASST in all patients; and other specific investigations were done where necessary. Skin prick test was done in idiopathic urticaria.

RESULTS

The study sample consisted of 62 male and 88 female patients with a mean age of 21-40 years. About 50% of patients showed an ASST positive reaction, 3.9% were positive for antinuclear antibody (ANA), IgE titer was elevated in 37%, H. pylori antibodies was positive in 26.7%. Thyroid antibodies were positive in 6.2%. Giardia and entamoeba histolytica was reported in 3.3% on routine stool examination and on urinalysis 8% had elevated WBC counts; 12% showed para nasal sinusitis, with maxillary sinusitis of 7.3%. Random blood sugar was high in 5.3%. Four patients had ASOM, two had positive KOH mount for dermatophytes, abdominal USG showed cholecystitis in two patients. Recurrent tonsillitis was noted in two patients. Urticaria following intake of NSAIDs was observed in four patients and with oral contraceptive pills in one patient. Contact urticaria to condom (latex) was seen in one patient. Cholinergic (4.7%) and dermographic (4.7%) urticaria were the predominant physical urticarias. Prick test was performed in idiopathic urticaria with maximum reactions to food antigens (25%) where brinjal was the commonest, 9% to dust in which spider web was the most common, 8% to pollen where parthenium and amaranthus were the commonest, followed by A. flavus in fungi, pigeon in epithelia and cockroach in insects.

CONCLUSION

Nearly half of the patients had chronic autoimmune urticaria on the basis of ASST. A significant number of them had serological makers of autoimmune activity. ASST provides an easy, inexpensive investigation in CU and helps direct attention to underlying systemic auto immune diseases. The presence of these auto antibodies was significantly associated with more frequent and longer lasting urticarial attacks. Exhaustive work ups with extensive laboratory diagnostics, challenge tests, and prick testing should be reserved for individual cases following detailed history.

Immune hemolytic anemia: a report of two cases

The transfusion-medicine specialists and physicians are often in a difficult situation when the patient has severe worsening anemia and all the blood is mismatched. This situation can arise in patients with red cell autoantibodies or alloantibodies due to previous transfusions. We report two cases of immune hemolysis – one due to warm auto antibodies and the second due to alloimmunization from multiple transfusions.