Serological screening for celiac disease, by endomysial antibodies, in patients with rheumatoid arthritis.

Celiac disease (CD) and rheumathoid arthritis (RA) are both multi-factorial chronic inflammatory auto-immune diseases. In this retrospective study, we determined the frequency of CD in patients with RA using IgA anti-endomysial antibodies (EmA) and tried to explain this association. Indirect immunofluorescence on human umbilical cord was used to detect EmA in 215 patients with seropositive RA collected over a 4-year-period. Two thousand and five hundred healthy blood donors (HBD) served as control group. Among the 215 patients with RA, 12 (9 females) were found positive for EmA while only 7 were positive for EmA in control group, EmA are significantly more frequent in RA patients than in HBD (5.58% vs. 0.28%, p < 10-6; 95% CI [8.21-54.01]; odds ratio: 21.05). In RA patients, the frequency of EmA was not statistically different between males and females. The frequency of EmA was significantly higher in female patients than in healthy females (5.32% vs. 0.40%, p < 10-3). Patients with RA can be considered as a high-risk group for CD based on the high frequency of EmA positivity observed in our study.

IgA is the predominant isotype of anti-ß2 glycoprotein I in patients with COVID-19.

OBJECTIVE: The aim of this research was to determine the frequency of antiphospholipid antibodies (aPL) in patients with COVID-19. METHODS: The frequency and titers of anticardiolipin antibodies (aCL) and anti-ß2 glycoprotein I antibodies (aß2GPI) were determined in sera of adult patients hospitalized with COVID-19. Immunoglobulin (Ig)G, IgA, IgM aCL, and aß2GPI were measured using enzyme-linked immunosorbent assay. RESULTS: Eighty-three patients were included in the study. The mean age of patients was 62 ± 13.9 years, ranging from 23 to 86 years. Stratification according to severity of infection divided patients in 2 groups: 45 patients with moderate infection and 38 patients with critical or severe infection. Out of the 83 patients suffering from COVID-19, aPL (aCL or aß2GPI) were detected in 24 patients (28.9%). IgG, IgA and IgM aß2GPI were positive in 2.4%, 16.9% and 8.4%, respectively. IgG, IgA and IgM aCL showed positivity in 7.2%, 0%, and 4.8%, respectively. The frequency of aPL was 36.8% in patients with critical/severe infection and 22.2% in patients with moderate infection. In critical/severe patients, the frequency of aß2GPI was significantly higher than aCL (34.2% vs 13.2%, P = .03) and aß2GPI-IgA were significantly more frequent than aß2GPI-IgG (21.1% vs 2.6%, P = .028). CONCLUSION: In this cross-sectional study, aPL and particularly aß2GPI-IgA were common in patients with COVID-19.

Frequency of serological markers of rheumatoid arthritis in patients with Hashimoto's thyroiditis.

BACKGROUND: Hashimoto's thyroiditis (HT) is an autoimmune disease that is frequently associated with other autoimmune conditions. OBJECTIVE: To perform serological screening for rheumatoid arthritis (RA) in patients with HT. METHODS: Our study included 88 consecutive serum specimens of patients with confirmed HT and 88 sex- and age-matched healthy subjects. All study participants were tested for anti-cyclic citrullinated peptides antibodies (CCP-Ab) and rheumatoid factor (RF). CCP-Ab and RF were performed using ELISA commercial kits. Statistical analysis was conducted using Epi Info, version 3. RESULTS: Out of 88 patients with HT, 15 (17.0%) had CCP-Ab or RF. The frequency of serological markers of RA was significantly higher in patients than in control individuals (17.0% vs 4.5%; P = .007). RF was more frequent in patients than in the control group, and the difference was statistically significant (13.6% vs 3.4%; P = .01). Isolated RF-IgM was absent in all controls and present in 6 patients with HT (6.8% vs 0%; P = .02). Out of 14 male patients, 3 (21.4%) had antibodies of RA. There was no significant difference in age between patients with CCP-Ab or RF and those without. CONCLUSION: A high frequency of serological markers of RA was highlighted in patients with HT.

Anti-cardiolipin and anti-beta 2 glycoprotein I antibodies in patients with type 1 diabetes.

To determine the frequency of anti-phospholipid antibodies (aPL) in particular anti-cardiolipin antibodies (aCL) and anti-beta 2 glycoprotein I antibodies (aß2GPI) in Tunisian patients with type 1 diabetes. One hundred and two patients with type 1 diabetes (34 children, 68 adults) were studied. As control groups, we used sera of 156 adults and 65 children without type 1 diabetes. aCL and aß2GPI were detected by ELISA. The frequency of aPL was significantly higher in type 1 diabetes patients than in control group (18.6% vs. 5.9%, p < 0.001). In patients, aPL were significantly more frequent in adults than in children (25% vs. 5.9%, p = 0.04). In the whole group of type 1 diabetes, aCL were significantly more frequent in long-term type 1 diabetes than in inaugural type 1 diabetes (21.2% vs. 7.2%, p = 0.04). In adults, aß2GPI were significantly more frequent in inaugural type 1 diabetes than in controls (20% vs. 1.9%, p < 0.001), and the frequency of aCL was significantly higher in long-term type 1 diabetes than in controls (21.9% vs. 1.9%, p < 0.001). Female adults with type 1 diabetes had high frequency of aCL and aß2GPI.

Frequency of antithyroid antibodies in patients with primary biliary cholangitis.

OBJECTIVE: Primary biliary cholangitis (PBC) is an autoimmune disease of liver that may be associated with other conditions, including autoimmune thyroid diseases. We aimed to investigate the frequency of anti-thyroperoxidase antibodies (TPO-Ab), antithyroglobulin antibodies (TG-Ab), and anti-thyrotropin receptor antibodies (TSHR-Ab) in Tunisian patients with PBC. METHODS: Sera of 80 patients with PBC were collected over a 9-year period. A total of 189 healthy blood donors (HBD) were included in the control group. Measurements of TPO-Ab and TG-Ab were performed using indirect enzyme-linked immunosorbent assay (ELISA). Competitive ELISA was used to assess TSHR-Ab. RESULTS: Antithyroid antibodies (ATA) were significantly more frequent in PBC patients than in the control group (13.7% vs 1.6%; P < 10-3). Out of 11 patients with ATA, 10 (90.9%) were female. Nine patients and 2 HBD had TPO-Ab (11.2% vs 1%; P < 10-3). TG-Ab were more frequent in patients than in healthy subjects but the difference was not statistically significant (6.2% vs 1.6%; P = .1). TPO-Ab and TG-Ab were present together in 3 patients (3.7%). TSHR-Ab were absent in patients and controls. CONCLUSION: This study shows that PBC is associated with a high frequency of ATA but not TG-Ab or TSHR-Ab.

Serological markers of rheumatoid arthritis in patients with primary biliary cholangitis and the vice versa: A Tunisian study.

BACKGROUND: Primary biliary cholangitis (PBC) is an autoimmune disease of the liver characterized by destructive lymphocytic cholangitis and anti-mitochondrial antibodies (AMA). Anti-gp210 and anti-Sp100, are used for the diagnosis of PBC in AMA-negative PBC patients. Patients with PBC have a propensity to have an extrahepatic manifestation which is especially autoimmune. OBJECTIVE: We aimed to determine the frequency of serological markers of rheumatoid arthritis (RA) (CCP-Ab or RF) in PBC patients and to do the vice versa. METHODS: Our PBC study included 70 patients with PBC and 80 healthy blood donors (HBD) and our RA study included 75 patients with RA and 75 HBD. Anti-cyclic citrullinated peptide antibodies (CCP-Ab) and rheumatoid factor (RF) were performed by indirect ELISA. AMA, anti-Sp100 and anti-gp210 were determined by indirect immunofluorescence. RESULTS: RA autoantibodies (CCP-Ab or RF) were more frequent in PBC patients than in HBD (65.7% vs. 8.7% p ã€ˆ10-6). CCP-Ab were significantly more frequent in patients than in controls (15.7% vs. 2.5%; p = 0.004). Nine patients had both CCP-Ab and RF vs. none of controls (12.8% vs. 0%; p = 0.001). RF were detected in 45 patients with PBC and in 5 HBD (64.3% vs. 6.2%; p ã€ˆ10-6). In PBC patients, RF were more frequent than CCP-Ab (64.3% vs. 15.7%; p ã€ˆ10-6). RF-IgG were present in 18.5% of patients; RF-immunoglobulin (Ig) A in 34.3% and RF-IgM in 54.3%. These frequencies were significantly higher than those found in control group (1.2% for RF-IgG (p ã€ˆ10-3); 0% for RF-IgA (p ã€ˆ10-6); and 6.2% for RF-IgM (p ã€ˆ10-6)). In our PBC patients, RF-IgA were more frequent than RF-IgG (34.3% vs. 18.5%; p = 0.03) and than CCP-Ab (34.3% vs. 15.7%; p = 0.01). Six patients had only RF-IgA versus none of the control group (8.6% vs. 0%; p = 0.01). AMA, anti-Sp100 and anti-gp 210 were absent in all RA patients. CONCLUSIONS: Serological markers of RA were more frequent in PBC patients than in HBD and the vice versa was not true.

Anticardiolipin and anti-beta 2-glycoprotein I antibodies in patients with unexplained articular manifestations.

OBJECTIVE: To determine the frequency of antiphospholipid antibodies (aPL) in patients with unexplained articular manifestations. MATERIAL AND METHODS: Three hundred thirteen patients suffering from arthritis or arthralgia without evident cause and 266 healthy blood donors (HBD) were included in the study. Anticardiolipin antibodies (aCL) and anti-beta 2-glycoprotein I antibodies (aß2GPI) were measured by ELISA. RESULT: Out of the 313 patients, 250 were females and 63 were males. The mean age of patients was 49 ± 14 years (17-87 years). One hundred eleven patients have arthralgia and 202 have arthritis. The frequency of aCL and/or aß2 GPI (24.9%) was significantly higher in patients than in HBD (10.9%). The frequency of aß2GPI was 23.6% in patients and 9.4% in the control group (p < 10-3 ). aß2GPI-IgA was significantly more frequent in patients than in the control group (20.4% vs. 7.5%, p < 10-3 ). aß2GPI was most commonly observed than aCL in patients (23.6% vs. 6.4%, p < 10-6 ). IgA isotype of aß2GPI was the most frequent in 20.4% of patients while IgG and IgM were detected in 5.4% and 2.9% respectively. CONCLUSION: This study showed that aPL were common in patients with articular manifestations and were mainly directed against ß2 GPI. The role of these antibodies remains to be specified.

Antiphospholipid antibodies in autoimmune thyroid diseases.

BACKGROUND: Antiphospholipid (aPL) antibodies have been reported in several autoimmune diseases. The aim of this study was to evaluate the frequency of aPL (anti-cardiolipin antibodies (aCL) and anti-ß2 glycoprotein I antibodies (aß2GPI)) in patients with autoimmune thyroid diseases (AITD). METHODS: One hundred and ninety-five patients with AITD (139 Hashimoto's thyroiditis (HT) patients and 56 Graves' disease (GD) patients) and 90 healthy blood donors (HBD) were studied. IgG, IgA and IgM aCL and aß2GPI were determined by ELISA. RESULTS: One hundred fifty-four AITD patients were women and 41 were men. Fifty-six healthy subjects were women and 34 were men. The median age of patients and the control group was 45 and 38.5 years, respectively. The frequency of aPL was significantly higher in patients with AITD and in patients with HT than in HBD (33.3% vs 11.1%, p < 10-3 and 38.1% vs 11.1%, p < 10-3 ). The frequency of aPL in GD was significantly lower than in HT (21.4% vs 38.1%, p = 0.025). In patients with HT, aß2GPI (34.5%) was significantly more frequent than aCL (13.6%) (p < 10-3 ). The frequency of aß2GPI was significantly higher in patients with HT than in healthy population (34.5% vs 11.1%, p < 10-3 ). In HT patients, IgA isotype of aß2GPI was significantly more common than in HBD and in GD patients (27.3% vs 7.8%, p < 10-3 and 27.3% vs 12.5%, p = 0.02, respectively). CONCLUSION: aß2GPI and not aCL were frequent in AITD. IgA was the predominant isotype of aß2GPI. aß2GPI-IgA was more frequent in HT than in GD.

Anti-Saccharomyces cerevisiae antibodies in patients with COVID-19.

BACKGROUND AND STUDY AIM: Anti-Saccharomyces cerevisiae antibodies (ASCA) have been described in many autoimmune diseases (AIDs). Coronavirus disease 2019 (COVID-19) could trigger AIDs. This study aimed to determine the frequency of ASCA in patients with COVID-19. PATIENTS AND METHODS: This study included 88 adult patients with severe COVID-19, 51 mild COVID-19, and 160 healthy blood donors. ASCA of isotype immunoglobulin (Ig)G and IgA were detected by enzyme-linked immunosorbent assay. RESULTS: The frequency of ASCA (IgG or IgA) was significantly higher in patients with severe COVID-19 (21.6 % vs 3.7 %, p < 10-3) and in patients with mild COVID-19 than in the healthy controls (13.7 % vs 3.7 %, p = 0.03). ASCA-IgA was significantly more frequent in patients with severe COVID-19 than in healthy controls (15.9 % vs 0.6 %, p < 10-3). ASCA-IgG was significantly more frequent in patients with mild COVID-19 than in healthy controls (13.7 % vs 3.1 %, p = 0.02). ASCA (IgG or IgA) were more frequent in severe than in mild COVID-19, but the difference was not statistically significant (21.6 % vs 13.7 %). ASCA-IgA was significantly more frequent in patients with severe than those with mild COVID-19 (15.9 % vs 0 %, p = 0.003). The mean ASCA-IgG and ASCA-IgA levels were significantly higher in patients with severe COVID-19 than in healthy controls (5.8 U/mL ± 11.8 vs 2.3 U/mL ± 2.8, p < 10-3 and 9.2 U/mL ± 21.5 vs 3.4 U/mL ± 1.7, respectively, p < 10-3). The mean ASCA-IgG levels were significantly higher in patients with mild COVID-19 than in healthy controls (6.2 U/mL ± 12.9 vs 2.3 U/mL ± 2.8, p < 10-3). The mean ASCA-IgA levels were significantly higher in patients with severe than in those with mild COVID-19 (9.2 U/mL ± 21.5 vs 2.6 U/mL ± 1.2, p = 0.03). CONCLUSION: ASCA was more frequent in patients with COVID-19 than in healthy controls.

Frequency of serological markers of rheumatoid arthritis in patients with IgA anti-ß2 glycoprotein I antibodies.

AIM: To determine the frequency of serological markers of RA in patients with anti-ß2 glycoprotein I antibodies (aß2GPI) of IgA isotype. MATERIAL AND METHODS: A retrospective study was conducted on 67 patients with aß2GPI-IgA. Ninety healthy blood donors (HBD) were used as a control group. IgG anti-cyclic citrullinated peptides antibodies (CCP-Ab) and rheumatoid factors (RF) IgG, IgA, and IgM were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: Seventeen patients and eight HBD had CCP-Ab and/or RF (25.4% vs. 8.9%, p = 0.005, CI 95% [14.95; 35.79], odds ratio = 3.5). The frequency of CCP-Ab was significantly higher in patients than in healthy subjects (14.9% vs. 3.3%, p = 0.009). IgA isotype of RF was significantly higher in patients than in controls (7.5% vs. 0%, p = 0.02). In male patients, CCP-Ab and/or RF were more frequent than in healthy male subjects (37.5% vs. 11.8%, p = 0.02). In patients, no correlation was found between the levels of aß2GPI-IgA and CCP-Ab (r = 0.082, p = 0.51). There was no correlation between the level aß2GPI-IgA and the level of the isotypes of RF (IgG, IgA, and IgM) in patients (r = 0.1, p = 0.37; r = 0.17, p = 0.17 and r = 0.07, p = 0.59 respectively). CONCLUSION: Frequencies of CCP-Ab and RF are high in patients with aß2GPI-IgA suggesting that these patients are susceptible to developing RA.

Anti-Saccharomyces cerevisiae Antibodies in Rheumatoid Arthritis.

OBJECTIVE: This study was conducted to evaluate the frequency of anti-Saccharomyces cerevisiae antibodies (ASCA) in patients with rheumatoid arthritis (RA). METHODS: Eighty-three RA patients with positive anti-cyclic citrullinated antibodies (anti-CCP) and 160 healthy blood donors were included in this study. ASCA IgG and IgA were assessed with enzyme-linked immunosorbent assay. RESULTS: The frequency of ASCA was significantly higher in RA patients than in healthy subjects (22.9% vs 3.7%, P < 10-3). Both ASCA IgG and ASCA IgA were significantly more frequent in RA patients than in the control group (20.5% vs 3.1%, P < 10-3and 9.6% vs 0.6%, P = .002, respectively). ASCA IgG and ASCA IgA levels were significantly higher in RA patients than in healthy subjects (7.8 ±â€…8.4 U/mL vs 2.3 ±â€…2.8 U/mL, P < 10-6 and 6.2 ±â€…10.9 U/mL vs 3.4 ±â€…1.7 U/mL, P = .002, respectively). CONCLUSION: A high frequency of ASCA IgG and ASCA IgA has been found in RA patients.

IgA anti-beta-2 glycoprotein I antibodies in chronic hepatitis C.

BACKGROUND AND STUDY AIMS: Antiphospholipid antibodies (aPL) have been reported not only in various autoimmune conditions but also in other infections, such as chronic hepatitis C (CHC) infection. The aim of this study is to evaluate the frequency of aPL in patients with CHC. PATIENTS AND METHODS: Ninety-six CHC patients and 90 healthy blood donors (HBD) were studied. Fifty-three of the patients were under treatment, and 43 had not yet received any treatment. IgG, IgA, and IgM antibodies against cardiolipin (aCL) and beta-2 glycoprotein I (aß2GPI) were detected by ELISA. RESULTS: We found that the frequency of aPL (aCL and/or aß2GPI) was significantly higher in CHC patients than in controls (51% vs 11.1%, p <10-6). The frequencies of aCL and aß2GPI were significantly higher in patients than in HBD (27.1% vs 5.5%, p < 10-3, and 44.8% vs 11.1%, p < 10-6, respectively). The isotype distribution of aCL and aß2GPI demonstrated that aCL-IgG and aß2GPI-IgA were more frequent in patients than in healthy subjects (21.9% vs 2.2%, p < 10-3, and 38.5% vs 7.8%, p < 10-6, respectively). In CHC patients, the frequency of aß2GPI was significantly higher than that of aCL (44.8% vs 27.1%, p = 0.01). aß2GPI-IgA was significantly more frequent than aß2GPI-IgG (38.5% vs 7.3%, p <10-6), aß2GPI-IgM (38.5% vs 9.4%, p <10-3), and aCL-IgG (38.5% vs 21.9%, p = 0.01). No difference in aPL frequency was observed between the treated and untreated patients. CONCLUSION: On the basis of the findings of this study, aPL, particularly aß2GPI-IgA and aCL-IgG, are frequent in CHC patients.

Frequency of serological markers of rheumatoid arthritis in adult patients with active celiac disease.

BACKGROUND: Celiac disease (CD) and rheumatoid arthritis (RA) are multisystem autoimmune diseases affecting 1% of general populationa. Both diseases share genetic and immunological features. AIM: In this retrospective study, we aim to determine the frequency of auto-antibodies of RA in adult patients with CD. MATERIALS AND METHODS: Seventy seven adult patients with active CD were included in the present study. Ninety healthy blood donors (HBD) served as control group. Anti-cyclic citrullinated peptides antibodies (CCP-Ab) and rheumatoid factors (RF; IgA, IgG and IgM) were determined by enzyme linked immunosorbent assay (ELISA) for patients and control group. For statistical analysis, we used Chi-square or Fisher's exact test. RESULTS: Our study included 77 adult patients with active celiac disease (57 female, 20 male). Twenty-four (31.2%) active celiac patients and 7 (7.8%) blood donors had CCP-Ab or RF (31.2% vs 7.8%, p < 10-4). Only two patients (2.6%) had both CCP-Ab and RF. IgA was the predominant isotype of RF in celiac patients (n = 18; 23.4%) while none of healthy blood donors had RF-IgA (23.4% vs 0.0%, p < 10-4). CONCLUSION: The current study has shown that CD is associated with a high frequency of RF-IgA suggesting that celiac patients could be at a higher risk of developing RA.

Positive myositis-specific autoantibodies during COVID-19: a case report.

Viral infection is known to be a trigger of autoimmune diseases. Numerous cases of coronavirus disease 2019 (COVID-19) with autoimmune manifestations have been reported and several authors have highlighted the relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and autoimmune diseases. Autoimmune myopathies being one of these manifestations. A 27-year-old diabetic woman was admitted for management of acido-ketosis decompensation of her diabetes secondary to SARS-CoV-2 infection. During hospitalization, she developed muscle weakness and increased creatine kinase levels, which led us to assay the autoimmunity pattern which became positive for myositis-specific autoantibodies against single recognition particle (anti-SRP). The patient was treated with intense hydration with clinical and biological improvement and anti-SRP disappeared two months later. Positive myositis auto-antibodies are one of the autoimmune complications that could be seen during and after the SARS-CoV-2 infection.

Frequency of auto-antibodies of type 1 diabetes in adult patients with celiac disease.

Both celiac disease (CD) and type 1 diabetes (T1D) are autoimmune diseases resulting from a complex interplay between genetic susceptibility and environmental factors. AIM: In this retrospective study, we determined the frequency of auto-antibodies of T1D in adult patients with active CD. MATERIALS AND METHODS: Eighty adult patients with active CD were included in our study. Ninety healthy blood donors (HBD) served as control group. Anti-glutamic acid decarboxylase IgG antibodies (GAD-Ab), anti-tyrosine phosphatase IgG antibodies (IA2-Ab), and anti-zinc transporter IgG antibodies (Zn-T8-Ab) were determined by enzyme-linked immunosorbent assay (ELISA) for patients and control group. For statistical analysis, we used Chi-square or Fisher's exact test. RESULTS: Out of 80 patients, 10 (12.50%) had auto-antibodies of T1D vs. only one in control group (1.11%) (p = 0.003). Simultaneous presence of GAD-Ab, IA2-Ab, and Zn-T8-Ab was found in one patient (1.25%). Nine patients had only GAD-Ab. IA2-Ab and Zn-T8-Ab were absent in all HBD. The frequency of GAD-Ab was significantly higher in CD patients than in HBD (12.5% vs 1.11%, p = 0.003). CONCLUSION: The present study has shown that CD is associated with a high frequency of auto-antibodies of T1D. Screening for T1D in this population, at risk for other autoimmune diseases, may be useful.

IgA is the predominant isotype of anti-ß2 glycoprotein I antibodies in rheumatoid arthritis.

BACKGROUND: The aim of this study was to determine the frequency of anti-cardiolipin antibodies (aCL) and anti-ß2 glycoprotein I antibodies (aß2GPI) among Tunisian patients with rheumatoid arthritis (RA). METHODS: Ninety RA patients with positive anti-cyclic citrullinated antibodies (anti-CCP) and 90 healthy blood donors (HBD) were studied. aCL and aß2GPI of isotype IgG, IgA and IgM were detected by ELISA. RESULT: The frequency of antiphopholipid antibodies (aPL) (aCL and/or aß2GPI) was significantly higher in patients with RA than in HBD (35.5% vs 11.1%, P = .0001). The frequencies of aCL and aß2GPI were significantly higher in patients than in healthy subjects (15.5% vs 5.5%, P = .04 and 32.2% vs 11.1%, P = .0005 respectively). aß2GPI-IgA were significantly more frequent in patients than in the control group (26.7% vs 7.8%, P = .0007). In patients, aß2GPI-IgA were significantly more frequent than aß2GPI-IgG (26.7% vs. 6.7%, P = .0003) and aß2GPI-IgM (26.7% vs 5.6%, P = .0001). In RA patients, the frequency of aß2GPI was significantly higher than that of aCL (32.2% vs 15.5%, P = .008). aß2GPI-IgA was significantly more frequent than aCL-IgA (26.7% vs 4.4%, P = .00005). The average titer of anti-CCP in aPL positive patients was significantly higher than in aPL negative patients (170.6 ± 50 RU/mL vs 147.7 ± 51 RU/mL, P = .04). Significant correlation was found between aß2GPI-IgA and anti-CCP (r = .235, P = .026). CONCLUSIONS: aPL and particularly aß2GPI-IgA are frequent in RA and are correlated with anti-CCP.

STIM1 at the plasma membrane as a new target in progressive chronic lymphocytic leukemia.

BACKGROUND: Dysregulation in calcium (Ca2+) signaling is a hallmark of chronic lymphocytic leukemia (CLL). While the role of the B cell receptor (BCR) Ca2+ pathway has been associated with disease progression, the importance of the newly described constitutive Ca2+ entry (CE) pathway is less clear. In addition, we hypothesized that these differences reflect modifications of the CE pathway and Ca2+ actors such as Orai1, transient receptor potential canonical (TRPC) 1, and stromal interaction molecule 1 (STIM1), the latter being the focus of this study. METHODS: An extensive analysis of the Ca2+ entry (CE) pathway in CLL B cells was performed including constitutive Ca2+ entry, basal Ca2+ levels, and store operated Ca2+ entry (SOCE) activated following B cell receptor engagement or using Thapsigargin. The molecular characterization of the calcium channels Orai1 and TRPC1 and to their partner STIM1 was performed by flow cytometry and/or Western blotting. Specific siRNAs for Orai1, TRPC1 and STIM1 plus the Orai1 channel blocker Synta66 were used. CLL B cell viability was tested in the presence of an anti-STIM1 monoclonal antibody (mAb, clone GOK) coupled or not with an anti-CD20 mAb, rituximab. The Cox regression model was used to determine the optimal threshold and to stratify patients. RESULTS: Seeking to explore the CE pathway, we found in untreated CLL patients that an abnormal CE pathway was (i) highly associated with the disease outcome; (ii) positively correlated with basal Ca2+ concentrations; (iii) independent from the BCR-PLCγ2-InsP3R (SOCE) Ca2+ signaling pathway; (iv) supported by Orai1 and TRPC1 channels; (v) regulated by the pool of STIM1 located in the plasma membrane (STIM1PM); and (vi) blocked when using a mAb targeting STIM1PM. Next, we further established an association between an elevated expression of STIM1PM and clinical outcome. In addition, combining an anti-STIM1 mAb with rituximab significantly reduced in vitro CLL B cell viability within the high STIM1PM CLL subgroup. CONCLUSIONS: These data establish the critical role of a newly discovered BCR independent Ca2+ entry in CLL evolution, provide new insights into CLL pathophysiology, and support innovative therapeutic perspectives such as targeting STIM1 located at the plasma membrane.

A TRAF6 genetic variant is associated with low bone mineral density in rheumatoid arthritis.

OBJECTIVES: This study was aimed to investigate the association of the single nucleotide polymorphism of tumor necrosis factor receptor associated factor 6 (TRAF6), rs540386, with low bone mineral density (BMD) among patients with rheumatoid arthritis (RA). METHODS: TRAF6 rs540386 genotyping was performed by mutagenically separated PCR in a cohort of 188 (23 men, 165 women, median age, 56.2 years) adult RA patients and 224 age and gender-matched controls. BMD was measured using dual-energy X-ray absorptiometry (DXA) (Lunar Prodigy advance scans, GE Healthcare, USA). RESULTS: Among the RA patients, 64 (55 women, 9 men) had low BMD comprising of 57 patients with osteoporosis and 7 with osteopenia. Whereas TRAF6 rs540386 was not associated with RA susceptibility, it was however found to be a risk factor for reduced lumbar spine Z-score in the recessive model (OR = 3.34, 95% CI = (1.01-11.00), p = 0.038). This association was confirmed further in the multivariate logistic regression analysis taking into account several potential confounding factors (OR = 3.34 (1.01-11.00), p = 0.048). In addition, mean total femur Z-score was found to be reduced in TT patients when compared to CC + CT patients (- 1.30 ± 1.32 versus - 0.60 ± 1.05, p = 0.034). No association between TRAF6 rs540386 and local bone damage was observed. CONCLUSIONS: This study for the first time ever demonstrated an association between a genetic variant of TRAF6 and low BMD among patients with RA. Further investigations are needed to elucidate the exact role of this variant.

CD5 expression promotes IL-10 production through activation of the MAPK/Erk pathway and upregulation of TRPC1 channels in B lymphocytes.

CD5 is constitutively expressed on T cells and a subset of mature normal and leukemic B cells in patients with chronic lymphocytic leukemia (CLL). Important functional properties are associated with CD5 expression in B cells, including signal transducer and activator of transcription 3 activation, IL-10 production and the promotion of B-lymphocyte survival and transformation. However, the pathway(s) by which CD5 influences the biology of B cells and its dependence on B-cell receptor (BCR) co-signaling remain unknown. In this study, we show that CD5 expression activates a number of important signaling pathways, including Erk1/2, leading to IL-10 production through a novel pathway independent of BCR engagement. This pathway is dependent on extracellular calcium (Ca2+) entry facilitated by upregulation of the transient receptor potential channel 1 (TRPC1) protein. We also show that Erk1/2 activation in a subgroup of CLL patients is associated with TRPC1 overexpression. In this subgroup of CLL patients, small inhibitory RNA (siRNA) for CD5 reduces TRPC1 expression. Furthermore, siRNAs for CD5 or for TRPC1 inhibit IL-10 production. These findings provide new insights into the role of CD5 in B-cell biology in health and disease and could pave the way for new treatment strategies for patients with B-CLL.

High frequency of antiphospholipid antibodies in primary biliary cirrhosis.

AIM: To evaluate, retrospectively, the frequency of autoantibodies of antiphospholipid syndrome (APLS) in Tunisian patients with primary biliary cirrhosis (PBC). PATIENTS AND METHODS: We analyzed 80 PBC sera and 80 sera from blood donors. ELISA was used to determine the frequency of antibodies against cardiolipin (aCL IgG, IgA, and IgM) and beta 2 glycoprotein I (aß2GPI IgG, IgA, and IgM). RESULTS: The frequency of antiphospholipid antibodies (aCL and/or aß2GPI) was significantly higher in PBC patients than in controls (70 vs. 5%, P < 10(-6)). The frequency of aCL antibodies (IgG, IgA or IgM) was significantly higher in PBC patients than in the control group (23.7 vs. 3.7%, P = 0.0005). The frequencies of aCL IgA and aCL IgM in PBC patients' sera were significantly higher than those in the control group (10 vs. 0%, P = 0.003 and 20 vs. 2.5%, P = 0.001, respectively). Two patients of eighty (2.5%) had aCL IgG, aCL IgA and aCL IgM. The frequency of aß2GPI antibodies (IgG, IgA, or IgM) was significantly higher in PBC patients than in the control group (70 vs. 1.2%, P < 10(-6)). The frequencies of aß2GPI IgG, aß2GPI IgA, and aß2GPI IgM in PBC patients' sera were significantly higher in patients than in the control group (12.5 vs. 0%, P = 0.003; 62.5 vs. 1.2%, P < 10(-6); and 21.2 vs. 0%, P < 10(-4), respectively). CONCLUSION: Autoantibodies related to APLS (aCL and aß2GPI) were present in the majority of patients with PBC, reflecting the ability of these antibodies to engage mediators of damage.