Non-organ-specific autoimmunity in adult 47,XXY Klinefelter patients and higher-grade X-chromosome aneuploidies.

Current literature regarding systemic autoimmune diseases in X-chromosome aneuploidies is scarce and limited to case reports. Our aim was to evaluate the frequency of anti-nuclear (ANAs), extractable nuclear (ENA), anti-double-stranded DNA (dsDNAs), anti-smooth muscle (ASMAs) and anti-mitochondrial (AMAs) antibodies in a large cohort of adults with Klinefelter's syndrome (KS, 47,XXY) and rare higher-grade sex chromosome aneuploidies (HGAs) for the first time. Sera from 138 X-chromosome aneuploid patients [124 adult patients with 47,XXY KS and 14 patients with HGA (six children, eight adults)] and 50 age-matched 46,XY controls were recruited from the Sapienza University of Rome (2007-17) and tested for ANAs, ENAs, anti-dsDNAs, ASMAs and AMAs. Non-organ-specific immunoreactivity was found to be significantly higher in patients with 47,XXY KS (14%) than in the controls (2%, p = 0.002). Among all the antibodies investigated, only ANAs were observed significantly more frequently in patients with 47,XXY KS (12.1%) than in the controls (2%, p = 0.004). No anti-dsDNA immunoreactivity was found. Stratifying by testosterone replacement therapy (TRT), non-organ-specific autoantibody frequencies were higher in TRT-naive (p = 0.01) and TRT-treated groups than in controls. No patients with HGA were found positive for the various autoantibodies. Non-organ-specific autoantibodies were significantly present in 47,XXY adult patients. Conversely, HGAs did not appear to be target of non-organ-specific immunoreactivity, suggesting that KS and HGAs should be considered as two distinct conditions. The classification and diagnosis of systemic autoimmune diseases is frequently difficult. To support a correct clinical evaluation of KS disease and to prevent eventual secondary irreversible immune-mediated damages, we highlight the importance of screening for non-organ-specific autoimmunity in Klinefelter's syndrome.

Acromegaly and joint pain: is there something more? A cross-sectional study to evaluate rheumatic disorders in growth hormone secreting tumor patients.

PURPOSE: The aim of the present study was to evaluate the rheumatic profile in acromegalic patients to better characterize joint pain. METHODS: The immunological pattern (rheumatoid factor; antinuclear antibodies-ANA, extractable nuclear antigens-ENA-Ab; anti-citrullinated protein antibodies; erythrocyte sedimentation rate) was evaluated in 20 acromegaly subjects (AS) and 20 control subjects (CS). Bilateral joint ultrasound of hands/wrists and nail capillaroscopy were also performed. RESULTS: Articular pain was more frequent in AS than in CS (p = 0.027). No difference was detected in immunological parameters. ANA and ENA-Ab were positive in only 10% of AS and in 5% of CS, while no difference was found in anti-citrullinated protein antibodies. No difference was detected between rheumatoid factor positivity, but threefold higher IgG were detected in AS compared to CS. The erythrocyte sedimentation rate was significantly higher in AS than CS (p = 0.040), while in AS, there was a trend in increased Power Doppler (PWD) articular uptake. The capillaroscopic evaluation showed a significant difference in almost each parameter (presence and number of tortuous capillaries, capillary enlargements, and hemorrhages), showing a moderate-to-severe microangiopathy in AS. CONCLUSION: The results of our study suggest that joint damage in acromegaly has not an autoimmune etiology. Increased erythrocyte sedimentation rate levels and PWD alteration in acromegalic population reflect a possible inflammatory nature, while the capillaroscopic findings suggest a moderate-to-severe microangiopathy that could help to identify patients with a greater macroangiopathic risk.

From HDL-cholesterol to HDL-function: cholesterol efflux capacity determinants.

PURPOSE OF REVIEW: The validity of HDL-cholesterol (HDL-C) elevation as a therapeutic target has been questioned, in comparison to enhancing HDL functionality. Cholesterol efflux capacity (CEC) is an in-vitro assay that measures the ability of an individual's HDL to promote cholesterol efflux from cholesterol donor cells such as macrophages. CEC of HDL is a predictor of cardiovascular risk independent of HDL-C levels. However, molecular determinants of CEC and the effects of diseases and therapeutic interventions on CEC have not been completely defined. RECENT FINDINGS: We review here recent findings on elevated HDL-C and disease risk, as well as determinants of CEC, from genetics and proteomics to pathophysiology and therapeutic interventions that contribute to our understanding of CEC as a biomarker of HDL functionality. SUMMARY: Elevated HDL-C levels are not always protective against cardiovascular disease and mortality. CEC is a heritable trait, and genetic polymorphisms in genes involved in HDL and triglycerides metabolism are associated with CEC. Multiple HDL proteins correlate positively with CEC levels and inversely with noncalcified plaque burden. Differences in CEC assays that make comparisons between studies difficult are also emphasized. CEC should be measured in clinical trials of lipid-modifying and anti-inflammatory therapies to determine whether increases are cardioprotective.

A functional variant that affects exon-skipping and protein expression of SP140 as genetic mechanism predisposing to multiple sclerosis.

Several variants in strong linkage disequilibrium (LD) at the SP140 locus have been associated with multiple sclerosis (MS), Crohn's disease (CD) and chronic lymphocytic leukemia (CLL). To determine the causal polymorphism, we have integrated high-density data sets of expression quantitative trait loci (eQTL), using GEUVADIS RNA sequences and 1000 Genomes genotypes, with MS-risk variants of the high-density Immunochip array performed by the International Multiple Sclerosis Genetic Consortium (IMSGC). The variants most associated with MS were also correlated with a decreased expression of the full-length RNA isoform of SP140 and an increase of an isoform lacking exon 7. By exon splicing assay, we have demonstrated that the rs28445040 variant was the causal factor for skipping of exon 7. Western blots of peripheral blood mononuclear cells from MS patients showed a significant allele-dependent reduction of the SP140 protein expression. To confirm the association of this functional variant with MS and to compare it with the best-associated variant previously reported by GWAS (rs10201872), a case-control study including 4384 MS patients and 3197 controls was performed. Both variants, in strong LD (r(2) = 0.93), were found similarly associated with MS [P-values, odds ratios: 1.9E-9, OR = 1.35 (1.22-1.49) and 4.9E-10, OR = 1.37 (1.24-1.51), respectively]. In conclusion, our data uncover the causal variant for the SP140 locus and the molecular mechanism associated with MS risk. In addition, this study and others previously reported strongly suggest that this functional variant may be shared with other immune-mediated diseases as CD and CLL.

Apoptosis of keratinocytes and serum DNase I activity in patients with cutaneous lupus erythematosus: relationship with clinical and immunoserological parameters.

BACKGROUND: Dysregulation of apoptosis has an important role in the induction of autoimmunity. OBJECTIVE: To evaluate the influence of keratinocyte apoptosis and deoxyribonuclease I (DNase I) activity on the clinical and immunoserological parameters of cutaneous lupus erythematosus (CLE). METHODS: We studied 69 CLE patients (39 with discoid LE (DLE), 12 with subacute CLE (SCLE), 12 with acute and 6 with intermittent CLE). Thirty of sixty-nine patients fulfilled criteria for systemic LE (SLE). Apoptotic index (AI) was evaluated immunohistochemically in lesional and non-lesional, photoprotected skin. Serum DNase I activity, antichromatin and anti-ENA antibodies were measured by ELISA. Disease activity was determined by SLEDAI-2K, SLICC/ACR, CLASI and RCLASI. RESULTS: AI in lesions was higher than in non-lesional skin (P < 0.001). There was no difference in AI between CLE and SLE patients. Patients with SCLE had higher lesional AI than patients with DLE (P < 0.05). We found a positive correlation between the lesional AI with CLASI A (P < 0.05) and RCLASI D (P < 0.05). CLE and SLE patients had significantly lower DNase I activity than healthy controls (P < 0.001). Patients with normal DNase I activity and low AI had significantly lower CLASI A than patients with decreased DNase I activity and/or elevated AI (P < 0.05). CONCLUSIONS: Increased keratinocyte apoptosis characterizes lesions of all CLE forms, especially of SCLE. AI correlates with CLE markers of acute and chronic inflammation. Normal level of apoptosis and DNase I activity simultaneously reduce the level of acute inflammation in CLE. Serum DNase I activity and AI might be important biomarkers in the evaluation of CLE patients.

Comparison of the clinical utility of the Elia CTD Screen to indirect immunofluorescence on Hep-2 cells.

BACKGROUND: We compared the Elia CTD Screen (ECS), a fluoroenzymeimmunoassay incorporating 17 human antinuclear antigens (ANA), with indirect immunofluorescence (IIF) on Hep-2 cells in order to determine the clinical utility of the ECS in additon to or without IIF. METHODS: We examined 1708 consecutive serum samples submitted for ANA testing using the ECS and IIF in parallel. Positive screen results were further examined by quantitative fluoroenzymeimmunoassays and/or immunoblots for antibody identification. The medical records were evaluated for systemic rheumatic disorders. RESULTS: Concordance between ECS and IIF was observed in 1344 (78.8%) samples. ECS had a better detection rate for anti-dsDNA, -SSA/Ro, -SSB/La, -U1RNP and -Jo-1 antibodies, whereas IIF was superior in the detection of anti-CENP-B antibodies as well as anti-histone, -nucleosome and -Pl-12 antibodies, which are not included in the ECS antigen panel. ECS had a 100% sensitivity for Sjögren's syndrome, systemic sclerosis and Sharp syndrome. The sensitivity for Sjögren's syndrome was slightly higher for ESC than for IIF (94%). IIF had a higher diagnostic sensitivity for systemic lupus erythematosus, indeterminated connective tissue disease, Raynaud's syndrome and limited scleroderma, compared to ESC (100% vs. 80%, 100 vs. 75%, 89 vs. 57%, 100 vs. 88.9%). CONCLUSIONS: Our results suggest that the ECS represents an appropriate diagnostic tool for ANA screening. However, since some antigens are not incorporated in the ECS panel, and some ANA can also be missed by IIF, sequential or parallel screening with ECS and IIF may be reasonable when the clinical suspicion for connective tissue disease is high.

Ultrasound of the salivary glands is a strong predictor of labial gland biopsy histopathology in patients with sicca symptoms.

BACKGROUND: The international classification criteria for Sjögren's syndrome necessitate the presence of either extractable nuclear antibody or a characteristic focal inflammatory infiltrate in a minor salivary gland. Thus, patients who are extractable nuclear antibody-negative will need to have a labial salivary gland biopsy, which is an invasive procedure associated with morbidity. The aim of this study was to evaluate the viability of ultrasound imaging of the major salivary glands as a predictor of the histology to explore whether ultrasound can help in stratifying Sjögren's patients and reduce the need for biopsy. METHODS: The records of 85 patients suspected of having Sjögren's syndrome and who have had biopsy and ultrasound were analysed retrospectively. The histology and the ultrasound were reported by experts independently. The reporting was impartial as the examiners were blinded to the results of the other investigations and to the diagnosis. RESULTS: Out of the 85 patients, 34 had positive ultrasound, 29 of whom also had positive histology. Fifty-one patients had negative ultrasound, of whom 49 were also negative for histological features of Sjögren's syndrome. The results show that the ultrasound had a positive predictive value of 85% and a striking negative predicative value of 96% of the histology results. The overall concordance between the ultrasound and the histology was 91% (Kappa = 0.826). CONCLUSIONS: Our study shows that potentially the ultrasound has a role in stratifying patients who are extractable nuclear antibody-negative and can help to prioritize the biopsy for those who have sonographic evidence of SS.

[Frequency of antibodies against surface and nuclear antigens of hepatitis B virus in population of St. Petersburg in 2013].

AIM: Determine the frequency of antibodies to surface (anti-HBs) and core (anti-HBc) antigens of hepatitis B in population of St. Petersburg of various age for evaluation of protective herd immunity against hepatitis B virus (HB). MATERIALS AND METHODS: Blood sera of 970 individuals (491 males, 479 females) of 10 age groups from 0 to 50 years and older were examined for the presence of anti-HBs and anti-HBc IgG by enzyme immunoassay using commercial diagnostic test-systems. RESULTS: In general anti-HBs at the level of 5 mIU/ml and above were detected in 603 of the examined individuals (62.2%). Anti-HBs at the level of 10 mIU/ml and above were detected in 53.9%. The frequency of anti-HBs in protective titers in males and females in general turned out to be similar (52.6% and 55.2%, respectively). Juxtaposition of age-specific parameters of seroprotection and acute HB morbidity in St. Petersburg revealed an inverse correlation of medium strength (r = - 0.54). CONCLUSION: Results of the study confirm high effectiveness of the program of HB vaccine prophylaxis in St. Petersburg and emphasize the necessity of further implementation of broad measures of population immunization against HB.

Assessment of autoantibodies to meningioma in a population-based study.

Meningioma is an intracranial tumor with few confirmed risk factors. Recent research points to an impact on meningioma risk from factors related to immune function and development, such as allergy, immunoglobulin E, and Varicella infection status. To further explore an association with immune function, the authors assessed individual seroreactivity to meningioma tumor-associated antigens among participants enrolled in a multicenter, population-based US case-control study of meningioma (2006-2009). Serum samples from cases (n = 349) and controls (n = 348) were screened for autoantibody reactivity to 3 proteins identified in previous studies: enolase 1 (ENO1), NK-tumor recognition protein (NKTR), and nuclear mitotic apparatus protein 1 (NUMA1). Case-control differences were not strong overall (adjusted odds ratio (OR)(ENO1 (continuous)) = 1.1, 95% confidence interval (CI): 0.6, 1.9 (P(trend) = 0.3); adjusted OR(NKTR (continuous)) = 1.3, 95% CI: 0.7, 2.4 (P(trend) = 0.02); and adjusted OR(NUMA1 (continuous)) = 1.1, 95% CI: 0.7, 1.8 (P(trend) = 0.06)); however, antibodies to NKTR and NUMA1 were detected at higher levels in cases than in controls, particularly among men (for men, adjusted OR(ENO1 (continuous)) = 1.6, 95% CI: 0.5, 4.7 (P(trend) = 0.24); adjusted OR(NKTR (continuous)) = 4.3, 95% CI: 1.2, 15 (P(trend) = 0.009); and adjusted OR(NUMA1 (continuous)) = 3.6, 95% CI: 1.1, 11 (P(trend) = 0.006)). These results indicate that men with meningioma commonly react with a serologic antimeningioma response; if supported by further research, this finding suggests a distinctive etiology for meningioma in men.

Antinuclear antibody test.

The antinuclear antibody (ANA) test is widely used as a serological marker of autoimmune disease. Antinuclear antibodies are immunoglobulins or antibodies that bind to one or more antigens expressed within the nucleus of human cells. Used selectively, the ANA test can be a useful laboratory tool to help confirm or exclude the diagnosis of systemic rheumatic disease. However, the relatively high prevalence of ANAs in other inflammatory conditions, as well as healthy individuals, can make a positive result difficult to interpret.

Cerebrospinal fluid IL-21 levels in Neuromyelitis Optica and multiple sclerosis.

BACKGROUND: Neuromyelitis optica (NMO) and multiple sclerosis (MS) are inflammatory demyelinating diseases of human central nervous system (CNS) with complex pathogenesis. IL-21/IL-21R regulates activation, proliferation and survival of both T cells and B cells, which are involved in the pathogenesis of NMO and MS. High levels of serum IL-21 were observed in NMO patients. However, concentration of cerebrospinal fluid (CSF) IL-21 in MS and NMO patients still remain unknown. OBJECT: To detect the CSF concentration of IL-21 in NMO and MS patients and to evaluate its relationship with disease activity, particularly concerned about its impact on humoral immunity. METHODS: CSF IL-21 was detected by an enzyme-linked immunosorbent assay (ELISA) in NMO patients (n=21), MS patients (n=20) and controls (n=16). RESULTS: CSF concentration of the IL-21 was noticeably elevated in NMO (p=0.012) and borderline significantly increased in MS (p=0.115). In addition, this occurrence was associated with humoral immune activity as shown by a correlation between IL-21 and complement in NMO cohort (p=0.023) and high IL-21 levels in autoantibody-positive subgroup (p=0.027). CONCLUSIONS: The concentration of CSF IL-21 was noticeably elevated and might have a positive correlation with humoral immune activity in NMO.

Analysis of a multiple nuclear dots pattern in a large cohort of dermatological patients.

BACKGROUND: Anti-multiple nuclear dots (MND) antibodies are the markers of primary biliary cirrhosis (PBC), but can also be found in patients with other autoimmune diseases. METHODS: We looked for MND in 9189 sera belonging to 6240 patients stored for autoimmune diseases with prevalent cutaneous features. RESULTS: Fifty sera proved anti-MND-positive and came from 15 different patients: 6 had lupus erythematosus, 2 dermatomyositis, 2 lichen planus, 1 stroke, 1 telogen effluvium, 1 autoimmune thrombocytopenia, and 2 undifferentiated connective tissue disease. CONCLUSIONS: Anti-MND antibodies can be found not only in patients with PBC, but in connective tissue diseases as well. They can be associated with other fluoroscopic patterns and their titers can vary over the years, never correlating with the disease activity or with particular cutaneous features. Although anti-MND antibodies found are directed to the Sp100 antigen of the nuclear dots, it remains unclear whether their molecular target is the same amino-acid domain as in PBC.

[The optimization of techniques complex of serologic diagnostics of connective tissue systemic diseases].

The connective tissue systemic diseases originate from pathologic process following with antinuclear antibodies emergence. To detect these antibodies a significant number of diagnostic tests and techniques has been applied. Besides that, there is no conventional algorithm of antinuclear antibodies diagnostic. To detect antinuclear antibodies a two-fold diagnostic algorithm was applied In the capacity of screening techniques the indirect immunofluorescence technique was applied to the cells of line Hep-2 (antinuclear factor) and detection of antibodies to extractable nuclear antigen. The second stage of diagnostic included the detection of content of more specific antinuclear antibodies using the Lineblott method and the double-helical DNA antibodies. The blood serum from 981 patients with suspected connective tissue systemic diseases, 115 patients with systemic lupus erythematous and 57 healthy individuals was analyzed. The levels of antinuclear factor, nuclear antigen antibodies and double-helical DNA antibodies were detected. The antinuclear factor was detected in 84% and 86% of cases, double-helical DNA antibodies in 55% and 39% of cases depending of reagents using in detecting these characteristics. Among healthy individuals, antinuclear factor was detected in 5% (1/20) of blood serum samples in titers less than 1:160. In the group of patients with suspected connective tissue systemic diseases, antinuclear factor was detected in 48% (474/981) of cases and extractable nuclear antigen in 20% (326/981) of cases. The Lineblott test was positive in 33% (326/981) of patients with suspected connective tissue systemic diseases. Among antinuclear factor positive patients nuclear antigen antibodies were detected in 36% (171/474) and the Lineblott test was positive in 63% (298/474) of cases. Among antinuclear factor negative patients but positive under anti-nuclear antigen identification, the Lineblott test was positive in 6% (28/507) of cases. The two-fold algorithm of nuclear antigen testing is an effective technique to be applied in the clinical diagnostic laboratory. The results of effectiveness of this algorithm demonstrated that this method can ensure 33% of cost savings of testing individuals with higher incidence of diseases.

PML nuclear body component Sp140 is a novel autoantigen in primary biliary cirrhosis.

OBJECTIVES: Some patients with primary biliary cirrhosis (PBC) have antinuclear antibodies (ANAs). These ANAs include the "multiple nuclear dots" (MND) staining pattern, targeting promyelocytic leukemia protein (PML) nuclear body (NB) components, such as "speckled 100-kD" protein (Sp100) and PML. A new PML NB protein, designated as Sp140, was identified using serum from a PBC patient. The aim of this study was to analyze the immune response against Sp140 protein in PBC patients. METHODS: We studied 135 PBC patients and 157 pathological controls with type 1 autoimmune hepatitis, primary sclerosing cholangitis, and systemic lupus erythematosus. We used indirect immunofluorescence and a neuroblastoma cell line expressing Sp140 for detecting anti-Sp140 antibodies, and a commercially available immunoblot for detecting anti-Sp100 and anti-PML antibodies. RESULTS: Anti-Sp140 antibodies were present in 20 (15%) PBC patients but not in control samples, with a higher frequency in antimitochondrial antibody (AMA)-negative cases (53 vs. 9%, P<0.0001). Anti-Sp140 antibodies were found together with anti-Sp100 antibodies in all but one case (19 of 20, 90%) and with anti-PML antibodies in 12 (60%) cases. Anti-Sp140 positivity was not associated with a specific clinical feature of PBC. CONCLUSIONS: Our study identifies Sp140 as a new, highly specific autoantigen in PBC for the first time. The very frequent coexistence of anti-Sp140, anti-Sp100 and anti-PML antibodies suggests that the NB is a multiantigenic complex in PBC and enhances the diagnostic significance of these reactivities, which are particularly useful in AMA-negative cases.

Autoantibody profile in systemic sclerosis.

Systemic sclerosis is a generalized disorder of connective tissue clinically characterized by thickening and fibrosis of the skin and by distinctive forms of involvement of internal organs. One of the hallmarks of systemic sclerosis is the presence of serum autoantibodies against a variety of nuclear and cytoplasmic antigens. The primary purpose of this study was to identify the autoantibodies profile in the scleroderma sera and the secondary goal was to determine the correlation and discrepancy of autoantibody profile. Autoantibody profile was determined in 118 samples stored in the Advanced Diagnostic Laboratory at the University of Calgary. 78 sera were provided from Canadian and 40 sera were provided from Ukraine. We used the following techniques to identify autoantibodies profile in scleroderma patients: 1. Antinuclear antibody (ANA) by indirect immunofluorescence on human epithelial cell substrate 2. Detection and identification of specific autoantibodies by Innolia strip assay 3. Detection and identification of specific autoantibodies against extractable nuclear antigens. 111 out of 118 patients showed positive ANA results by indirect immunofluorescence and 7 patients had negative ANA results. Anti-ENA analyses by Inolia were positive in 84 patients, while by western blotting 81 patients showed positive results. In this study, we compared the results of anti-ENA antibody by Innolia with SLR technique. A significant correlation was found between anti-SC1-70 antibodies (P=0.000) and anti- RNP antibodies (P=0.001) and JO-1 antibodies (P=0.014). Thus, we may propose that SLR and Innolia techniques could be used for the detection of autoantibody in systemic sclerosis.

Detection of Anti-Extractable Nuclear Antigens in Patients with Systemic Rheumatic Disease via Fluorescence Enzyme Immunoassay and Its Clinical Utility.

PURPOSE: Testing for autoantibodies to extractable nuclear antigens (ENAs) plays an important role in the diagnosis and management of systemic rheumatic disease. Currently, no gold standard tests are available for detecting anti-ENAs. To address this gap, we aimed to identify an assay that exhibits satisfactory diagnostic performance in the detection of five common anti-ENAs by comparing two commonly used assays, an automated fluorescent enzyme immunoassay (FEIA) and a microplate ELISA assay. MATERIALS AND METHODS: Sera from 100 patients with systemic rheumatic disease were collected and assayed with FEIA and microplate ELISA to detect anti-ENAs. Statistical analyses were performed to check the agreement rate between the two platforms using kappa coefficients. Analytical sensitivity and specificity for each assay were calculated. RESULTS: The concordance rates between ELISA and FEIA ranged from 89% for anti-RNP to 97% for anti-Scl-70, and the kappa coefficients of the two assays were in the range of 0.44 to 0.82. Between the two assays, a significant difference in sensitivity and specificity was seen only for anti-Sm and anti-RNP, respectively. CONCLUSION: In this study, FEIA and ELISA showed comparable efficiency for detecting anti-ENAs.

Significance of the expression of major histocompatibility complex class II antigen, HLA-DR and -DQ, with recurrence of papillary thyroid cancer.

Normal thyroid epithelial cells lack major histocompatibility complex (MHC) Class II antigen. Oncogenic kinases involved in papillary thyroid carcinoma (PTC) trigger the expression of Class II transactivator and MHC Class II complex. However, the relationship between MHC Class II antigen expression and clinical outcome in PTC is unknown. To investigate the frequency of MHC Class II antigen expression in PTC and to identify the effects of MHC Class II antigen expression on clinical outcomes in PTC patients, the expression of HLA-DR/-DQ antigen was analyzed in surgical specimens from 77 PTCs and 44 benign nodules (23 nodular hyperplasias, 21 follicular adenomas). Of the 77 PTC cases, 36 (46.8%) cases expressed HLA-DR and 41 (53.2%) cases expressed HLA-DQ. Next, we investigated clinicopathological characteristics and found that HLA-DR(+) and/or HLA-DQ(+) PTC tended to present without nodal metastasis. Multivariate analyses clearly showed that HLA-DR(+) or HLA-DQ(+) PTC has a low risk of recurrence (HLA-DR OR = 0.22, CI, 0.06-0.9; p = 0.03, HLA-DQ OR = 0.25, CI, 0.07-0.9, p = 0.03). The Kaplan-Meier estimate revealed a significantly lower recurrence-free probability in patients with HLA-DR(-) PTC and HLA-DQ(-) PTC (Log-rank test; chi(2) = 4.59 and 6.07, p = 0.03 and 0.01, respectively). In conclusion, PTC frequently expresses MHC Class II antigen, and the expression of MHC Class II antigen correlated inversely with the risk of recurrence of PTC.

Association of autoantibodies with Ku and DNA repair proteins in connective tissue diseases.

OBJECTIVE: To analyse the autoimmune response to DNA damage response factors in systemic autoimmune rheumatic disease (SARD) patients and to determine their association with autoantibodies to Ku antigen. METHODS: We have screened the serum of 239 patients suffering from SARD, including systemic lupus erythematosus, systemic sclerosis and rheumatoid arthritis to detect the occurrence of autoantibodies to Ku and four other DNA damage response factors that form macromolecular complexes with Ku using an immunoprecipitation assay. RESULTS: We identified samples positive for autoantibodies to Ku (20.5%), DNA-dependent protein kinase catalytic subunit (DNA-PKcs, 8.4%) and poly(ADP-ribose) polymerase (5.9%), and report for the first time autoantibodies directed against two additional DNA repair proteins, Werner (6.3%) and Mre11 (9.6%). Remarkably, we found a striking correlation between the production of antibodies to Ku and the other four Ku-binding factors. Sixty-five percent of anti-Ku-positive sera were found to contain at least one of the four anti-DNA repair antibodies vs only 10% of the anti-Ku-negative sera. CONCLUSION: Our results suggest that the autoantibodies directed against Ku are elicited by macromolecular protein complexes containing Ku and the associated DNA damage proteins. The presence of autoantibodies directed against macromolecular complexes known to play roles in the DNA damage response provides evidence that B-cell responses to latent or persistent DNA damage may be present at the onset or during the development of autoimmunity in certain SARDs.

Analytical and clinical comparison of two fully automated immunoassay systems for the detection of autoantibodies to extractable nuclear antigens.

BACKGROUND: Detection of antinuclear antibodies (ANA) by indirect immunofluorescence assay (IIFA) is increasingly substituted by fully automated solid phase immunoassays. This study evaluated the performance of an automated chemiluminescence immunoassay (CIA) and fluorescence enzyme immunoassay (FEIA) and compared their performance to that of IIFA. METHODS: The study included an unselected prospective study population suspected of systemic autoimmune rheumatic disease. ANA were measured by IIFA, while in parallel sera were tested by CIA QUANTA Flash CTD Screen Plus on the BIO-FLASH® and FEIA EliA CTD Screen on the Phadia® 250 system. As validation, retrospective cohorts of patients with ANA-associated rheumatic disease (AARD) and healthy controls were tested. RESULTS: Prospectively, sensitivity of IIFA, CIA and FEIA was 90%, 99% and 92%, respectively. Specificity was 76%, 76% and 84%, respectively. Total percent agreements between the three methods were 75.2% (IIFA vs. CIA), 79.2% (IIFA vs. FEIA) and 85.4% (FEIA vs. CIA). The AUC values were 0.95 for CIA and 0.93 for FEIA and did not significantly differ. Retrospectively in individual AARD cohorts, similar results were obtained comparing both CTD screens. CONCLUSIONS: Both FEIA and CIA CTD screen significantly outperformed IIFA, with a higher specificity for FEIA and higher sensitivity for CIA. Based on ROC analysis, major contributor to the difference between the two solid phase immunoassays was the cut-off.