IgA is the predominant isotype of anti-β2 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-β2 glycoprotein I antibodies (aβ2GPI) were determined in sera of adult patients hospitalized with COVID-19. Immunoglobulin (Ig)G, IgA, IgM aCL, and aβ2GPI 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 aβ2GPI) were detected in 24 patients (28.9%). IgG, IgA and IgM aβ2GPI 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 aβ2GPI was significantly higher than aCL (34.2% vs 13.2%, P = .03) and aβ2GPI-IgA were significantly more frequent than aβ2GPI-IgG (21.1% vs 2.6%, P = .028).

CONCLUSION

In this cross-sectional study, aPL and particularly aβ2GPI-IgA were common in patients with COVID-19.

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 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.

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 (aβ2GPI) 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 aβ2GPI 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, aβ2GPI 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 aβ2GPI.

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 〈10^-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 〈10^-6). In PBC patients, RF were more frequent than CCP-Ab (64.3% vs. 15.7%; p 〈10^-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 〈10^-3); 0% for RF-IgA (p 〈10^-6); and 6.2% for RF-IgM (p 〈10^-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 (aβ2GPI) 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 aβ₂ GPI (24.9%) was significantly higher in patients than in HBD (10.9%). The frequency of aβ2GPI was 23.6% in patients and 9.4% in the control group (p < 10^-3 ). aβ2GPI-IgA was significantly more frequent in patients than in the control group (20.4% vs. 7.5%, p < 10^-3 ). aβ2GPI was most commonly observed than aCL in patients (23.6% vs. 6.4%, p < 10^-6 ). IgA isotype of aβ2GPI 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 β₂ GPI. The role of these antibodies remains to be specified.

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-β2 glycoprotein I antibodies

Aim

To determine the frequency of serological markers of RA in patients with anti‐β2 glycoprotein I antibodies (aβ2GPI) of IgA isotype.

Material and Methods

A retrospective study was conducted on 67 patients with aβ2GPI‐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 aβ2GPI‐IgA and CCP‐Ab (r = 0.082, p = 0.51). There was no correlation between the level aβ2GPI‐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 aβ2GPI‐IgA suggesting that these patients are susceptible to developing RA.

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.

Anti-gp210 and anti-Sp100 antibodies in primary biliary cholangitis

BACKGROUND AND STUDY AIMS

To determine the sensitivity and specificity of anti-gp210 and anti-Sp100 autoantibodies in primary biliary cholangitis (PBC) PATIENTS AND METHODS: Sera of 106 PBC patients with positive anti-mitochondrial antibodies and 58 healthy blood donors were analyzed. A line immunoassay was used to evaluate the reactivity of anti-gp210 and anti-Sp100 antibodies.

RESULTS

The frequency of anti-gp210 and anti-Sp100 autoantibodies was 29.2% and 28.3%, respectively. Eight patients had both anti-gp210 and anti-Sp100 antibodies. Of 106 patients, 23 (21.7%) had anti-gp210 antibody, although not anti-Sp100 antibody, and 22 (20.7%) had anti-Sp100, although not anti-gp210 antibodies. Their combination increased the frequency of anti-gp210 and anti-Sp100 antibodies from 29.2% to 50% (P = 0.002) and 28.3% to 50% (P = 0.0012), respectively. In the control group, two subjects had anti-gp210 antibody and none had anti-Sp100 antibody. Thus, the specificity of anti-gp210 and anti-Sp100 antibodies was 96.5% and 100%, respectively. The positive predictive value (PPV) of anti-gp210 antibody was 94%; its negative predictive value (NPV) was 42.7%. The PPV and NPV of anti-Sp100 antibody were 100% and 43.3%, respectively.

CONCLUSION

It is important to combine anti-gp210 and anti-Sp100 antibodies in the immunological exploration of PBC.

IgA is the predominant isotype of anti-β2 glycoprotein I antibodies in rheumatoid arthritis

Background

The aim of this study was to determine the frequency of anti‐cardiolipin antibodies (aCL) and anti‐β2 glycoprotein I antibodies (aβ2GPI) 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 aβ2GPI of isotype IgG, IgA and IgM were detected by ELISA.

Result

The frequency of antiphopholipid antibodies (aPL) (aCL and/or aβ2GPI) was significantly higher in patients with RA than in HBD (35.5% vs 11.1%, P = .0001). The frequencies of aCL and aβ2GPI 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). aβ2GPI‐IgA were significantly more frequent in patients than in the control group (26.7% vs 7.8%, P = .0007). In patients, aβ2GPI‐IgA were significantly more frequent than aβ2GPI‐IgG (26.7% vs. 6.7%, P = .0003) and aβ2GPI‐IgM (26.7% vs 5.6%, P = .0001). In RA patients, the frequency of aβ2GPI was significantly higher than that of aCL (32.2% vs 15.5%, P = .008). aβ2GPI‐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 aβ2GPI‐IgA and anti‐CCP (r = .235, P = .026).

Conclusions

aPL and particularly aβ2GPI‐IgA are frequent in RA and are correlated with anti‐CCP.

Screening for celiac disease, by endomysial antibodies, in patients with unexplained hypertransaminasaemia

OBJECTIVE

To do a serological screening for celiac disease in patients with unexplained liver cytolysis.

MATERIALS AND METHODS

Fifty-six patients with liver cytolysis without known aetiology were studied. Endomysial antibodies were determined by indirect immunofluorescence on human umbilical cord. Two thousand and five hundred blood donors served as control group. For statistical analysis, we used Chi-square or Fisher's exact test.

RESULTS

The frequency of IgA endomysial antibodies in our patients was significantly higher than in the control group (8.92% vs. 0.28%, p < .001). In female, endomysial antibodies were significantly more frequent in patients than in healthy subjects (12.12% vs. 0.4%; p < .001). In male, endomysial antibodies were significantly more frequent in patients than in healthy subjects (4.34% vs. 0.22%; p = .006). The frequency of positive EMA in female patients was higher than in male, but the difference was not statistically significant (12.12% vs. 4.43%; p = .6). Two patients were non-compliant with the gluten-free diet. One patient was out of touch. For the two other patients, transaminase levels reverted to normal level within six months of strict gluten withdrawal.

CONCLUSIONS

A screening for celiac disease should be included within the diagnosis protocol of liver cytolysis.

Anti Saccharomyces cerevisiae Antibodies in Patients With Anti-β2 Glycoprotein I Antibodies

BACKGROUND

In this study, cross-reactive epitopes on β2 glycoprotein I and Saccharomyces cerevisiae have been described. The objective of our study was to determine the frequency of anti S. cerevisiae antibodies (ASCA) in patients with anti-β2 glycoprotein I antibodies (aβ2GPI).

METHODS

A retrospective study was conducted in 77 patients with aβ2GPI (aβ2GPI-IgG or aβ2GPI-IgA). Eighty blood donors were used as a control group. ASCA IgG and ASCA IgA were determined by Enzyme Linked Immunosorbent Assay (ELISA).

RESULTS

Thirteen patients among 77 had ASCA. ASCA (IgA or IgG) was significantly more frequent in patients than in healthy subjects (16.9% vs. 3.7%, P = 0.01). The positivity of both ASCA IgG and ASCA IgA is higher in patients than in control group (6.5% vs. 0%, P = 0.02). The frequency of ASCA IgG was significantly higher in patients than in the control group (15.6% vs. 2.5%, P = 0.009). In females, the frequency of ASCA IgG was significantly higher in patients than in control group (17.5% vs. 3.7%, P = 0.03). The average titer of ASCA IgG was significantly higher in patients than in the control group (9.7 ± 23 U/ml vs. 2.2 ± 2.8 U/ml; P = 0.004). ASCA IgG was significantly more frequent than ASCA IgA in all patients (15.6% vs. 7.8%, P = 0.04).

CONCLUSION

The frequency of ASCA was significantly higher in patients with aβ2GPI than in the control group.

Endothelial protein C receptor gene 6936A/G single-nucleotide polymorphism as a possible biomarker of thrombotic risk in acute myeloid leukemia

Protein C (PC) is a natural anticoagulant, which interacts with the endothelial PC receptor (EPCR). EPCR single-nucleotide polymorphism (SNP) 6936A/G results in high levels of a free soluble form of EPCR (sEPCR) and may affect the risk of coagulation. The objective of this study was to assess whether the 6936A/G SNP of the EPCR gene is involved in the procoagulant activity displayed by hematological malignancies. EPCR 6936A/G polymorphism analysis was performed in 205 patients with hematological malignancies and in 63 healthy controls. All the subjects were genotyped for the EPCR 6936A/G SNP (AA, AG and GG genotypes). The 6936A/G polymorphism distribution was similar between healthy donors and patients. The association between EPCR 6936A/G SNP and thrombosis was investigated in 110 patients. The disease-wise break-up revealed that 55 of the patients suffered from acute myeloid leukemia (AML). In AML patients, the incidence of thrombosis was 28.3% and significantly higher in the 6936AG compared with that in the 6936AA genotype (50 vs. 22%, respectively). In conclusion, this study revealed a significant association of the 6936AG genotype of EPCR with thrombotic events in AML. Therefore, the presence of the 6936AG genotype in AML patients may be considered as a risk indicator of thrombosis.

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 (aβ2GPI IgG, IgA, and IgM).

RESULTS

The frequency of antiphospholipid antibodies (aCL and/or aβ2GPI) 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 aβ2GPI 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 aβ2GPI IgG, aβ2GPI IgA, and aβ2GPI 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 aβ2GPI) were present in the majority of patients with PBC, reflecting the ability of these antibodies to engage mediators of damage.

Phenotypic abnormalities of peripheral blood mononuclear cells in patients with Behçet's disease and association with HLA-B51 expression

The aim of this study was to investigate the subclasses and the immunophenotypic profile of peripheral mononuclear cells in patients with Behçet's disease (BD) and to assess associations between the expression of HLA-B51 antigen and that of other cell markers. Thirty healthy volunteer blood donors and forty patients with BD were enrolled into this study. Phenotyping was performed using two color flow cytometry. HLA-B51 typing was performed using the complement dependent microlymphocytotoxicity assay. Unlike controls, patients with BD presented a modified immunophenotypic profile of lymphocytes. Compared to those in the remission phase, patients with active BD showed an increased mean of MFI ratio of CD56 on CD16+CD56+ cells (32.47 ± 14.26 versus 23.87 ± 10.3; p = 0.032), increased absolute numbers of CD4(-)CD8(bright) and CD4(+)CD8(+) cells (657.1 ± 463.6 cells/µL versus 319.24 ± 116.4 cells/µL; p = 0.017 and 40.77 ± 36.41 cells/µL versus 10.77 ± 9.78 cells/µL; p < 0.0001, respectively) and an elevated mean of MFI ratio of CD19 on B cells (252.3 ± 56.7 versus 205.67 ± 32.3; p = 0.021). However, expression of HLA-B51 was not associated with any specific immunophenotypic profile. In conclusion, abnormal immunophenotypic profile of peripheral lymphocytes was found in patients with BD, especially in active phase, reflecting an immune dysregulation. Moreover, HLA-B51 expression was not found to be related to the expression of other cell markers.

Epigenetic dysregulation in salivary glands from patients with primary Sjögren's syndrome may be ascribed to infiltrating B cells

Sjögren's syndrome (SS) is an autoimmune exocrinopathy characterized by an epithelium injury with dense lymphocytic infiltrates, mainly composed of activated T and B cells. Present at the interface of genetic and environmental risk factors, DNA methylation is suspected to play a key role in SS. To clarify this point, global DNA methylation was tested within salivary gland epithelial cells (SGEC), peripheral T cells and B cells from SS patients. Global DNA methylation was reduced in SGEC from SS patients, while no difference was observed in T and B cells. SGEC demethylation in SS patients was associated with a 7-fold decrease in DNA methyl transferase (DNMT) 1 and a 2-fold increase in Gadd45-alpha expression. The other DNA methylation/demethylation partners, tested by real time PCR (DNMT3a/b, PCNA, UHRF1, MBD2, and MBD4), were not different. Interestingly, SGEC demethylation may be attributed in part to the infiltrating B cells as suspected in patients treated with anti-CD20 antibodies to deplete B cells. Such hypothesis was confirmed using co-culture experiments with human salivary gland cells and B cells. Furthermore, B cell-mediated DNA demethylation could be ascribed to an alteration of the PKC delta/ERK/DNMT1 pathway. As a consequence, part of the SGEC dysfunction in SS may be linked to epigenetic modifications, thus opening new therapeutic perspectives in SS.

Anti-Saccharomyces cerevisiae antibodies are elevated in Graves' disease but not in Hashimoto's thyroiditis

BACKGROUND

Anti-Saccharomyces cerevisiae antibodies (ASCA) had been known to be specific for Crohn's disease, but they had also been found in many other autoimmune diseases.

AIM

The aim of this study was to evaluate the prevalence of ASCA in patients with autoimmune thyroid disease (AITD).

PATIENTS AND METHODS

One hundred and ninety-seven patients with AITD and 160 healthy controls were included in the study. One hundred and nineteen patients had Graves' disease (GD) and 78 patients had Hashimoto's thyroiditis (HT). ASCA IgG and IgA were determined by ELISA.

RESULTS

ASCA IgG were significantly more frequent in patients with GD than in control group (11.8% vs. 3.1%, p = 0.002). In HT, the frequency of ASCA IgG was similar to that of the control group (3.8% and 3.1% respectively). The frequency of ASCA IgA was similar in GD (0.8%), HT (2.6%), and the control group (3.1%). In all GD patients, the frequency of ASCA IgG was significantly higher than that of ASCA IgA (11.8% vs. 0.8%, p = 0.001). These results were also true even in male and female groups (10.4% vs. 1.3%, p = 0.01 and 14.3% vs. 0%, p = 0.01, respectively). ASCA IgG levels were significantly higher in GD patients (6.7 ± 11.1 vs. 2.2 ± 2.8, p = 3 × 10(-6)) and in HT patients (4.2 ± 4.7 vs. 2.2 ± 2.8, p = 0.0002) than those in the control group. ASCA IgA levels were comparable among patients with GD, HT, and the control group. In GD patients, the mean titer of ASCA IgG was significantly higher than that of ASCA IgA (6.7 ± 11.1 vs. 3.6 ± 4.2, p = 0.005).

CONCLUSION

Patients with GD had a higher frequency of ASCA IgG than controls.

Performance of anti-deamidated gliadin peptides antibodies in celiac disease diagnosis

OBJECTIVES

To assess the usefulness of anti-deamidated gliadin peptides antibodies (a-DGP), in the diagnostic of celiac disease (CD).

PATIENTS AND METHODS

One hundred and three untreated CD patients (67 children and 36 adults) and 36 celiac patients under gluten-free diet were studied. Two hundred and seventy-four subjects served as controls (114 healthy blood donors, 80 healthy children and 80 patients with primary biliary cirrhosis). a-DGP (IgG and IgA) and anti-tissue transglutaminase antibodies (AtTG) were detected by enzyme-linked immunosorbent assay (Elisa). Anti-endomysium antibodies (AEA) were detected by indirect immunofluorescence on human umbilical cord.

RESULTS

The sensitivitiy of IgG and IgA a-DGP were 94% and 97% respectively, compared to 96% for AEA and AtTG. The specificity of a-DGP was 93.6% for IgG and 92% for IgA. The specificity of AEA and AtTG were 100%. The frequency of IgG and IgA a-DGP was significantly higher in patients with CD than in control group (94% vs. 4.4%, P<10(-7); 97% vs. 8%, P<10(-7)). The frequency of IgG a-DGP was the same in children and adult (94%). The frequency of IgA a-DGP were similar in children and adults (95.5% vs. 100%).

CONCLUSION

Our study shows that a-DGP increases neither the sensitivity nor the specificity of AEA and AtTG.

Altered patterns of epigenetic changes in systemic lupus erythematosus and auto-antibody production: is there a link?

The prominent feature of immunological defects in systemic lupus erythematosus (SLE) is the production of autoantibodies (auto-Abs) to nuclear antigens including DNA, histones and RNP. In addition, there is growing evidence that epigenetic changes play a key role in the pathogenesis of SLE. Autoreactive CD4(+) T cells and B cells in patients with SLE have evidence of altered patterns of DNA methylation as well as post-translational modifications of histones and ribonucleoproteins (RNP). A key question that has emerged from these two characteristic features of SLE is whether the two processes are linked. New data provide support for such a link. For example, there is evidence that hypomethylated DNA is immunogenic, that anti-histone auto-Abs in patients with SLE bind epigenetic-sensitive hot spots and that epigenetically-modified RNP-derived peptides can modulate lupus disease. All in all, the available evidence indicates that a better understanding of dysregulation in epigenetics in SLE may offer opportunities to develop new biomarkers and novel therapeutic strategies.

Thyroid-related autoantibodies in Tunisian patients with type 1 diabetes

AIM

To evaluate, retrospectively, the frequency of antithyroid antibodies (ATA) in patients with type 1 diabetes (T1D).

MATERIALS AND METHODS

Antithyroperoxidase antibodies (TPO-Ab), antithyroglobulin antibodies (TG-Ab), and antithyroid-stimulating hormone receptor antibodies (TSHR-Ab) were determined by enzyme-linked immunosorbent assay. Sera of 312 patients (166 children and 146 adults) with T1D were analyzed. Sera of 276 healthy subjects (87 children and 189 blood donors) served as controls.

RESULTS

Out of 312 patients with T1D, 44 (14%) had ATA (TPO-Ab or TG-Ab or TSHR-Ab). The frequency of ATA in patients with T1D was significantly higher than in the control group (14% vs. 2.8%; p<10(-5)). ATA were significantly more frequent in adult patients with T1D than in the blood donor group (20% vs. 1.6%; p<10(-8)). The frequency of ATA in adult patients was significantly higher than in pediatric patients (20% vs. 9%; p=0.006). The frequency of TPO-Ab and TG-Ab was significantly higher in patients with T1D than in the control group (13.5% vs. 2%; p<10(-8) and 7% vs. 2.2%, p=0.008), respectively. Out of 312 patients with T1D, only one had TSHR-Ab. The simultaneous presence of three autoantibodies was found in one patient with T1D.

CONCLUSION

ATA were frequent in patients with T1D. Serological screening of autoimmune thyroid disease is suggested in patients with T1D.

Anti-cardiolipin and anti-beta 2-glycoprotein I antibodies in celiac disease

AIMS

To determine the frequency of anti-cardiolipin (aCL) and anti-β2-glycoprotein I antibodies (aβ2GPI) in celiac disease (CD) patients.

PATIENTS AND METHODS

Sixty-three untreated CD patients and 40 healthy blood donors (HBD) were studied. IgG, IgA and IgM aCL and aβ2GPI were detected by Elisa.

RESULTS

The frequency of antiphospholipid antibodies (aPL) (aCL and/or aβ2GPI) was significantly higher in CD patients (12 out of 63) than in HBD (two out of 40) (19% vs 5%, P=0.04). Six CD patients out of 63 (9.5%) and one HBD out of 40 (2.5%) had aCL. Ten CD patients (15.9%) and two HBD (5%) had aβ2GPI. Only aβ2GPI-IgA was significantly more frequent in CD patients than in HBD (14.3% vs 2.5%, P=0.048). In CD patients, aβ2GPI-IgA (nine out of 63) was significantly more frequent (14.3%) than aβ2GPI-IgG (1.6%) and IgM (1.6%) (P=0.008). In CD patients, the frequency of aCL-IgA and IgM was 6.3% (four out of 63) and aCL-IgG were not detected. Simultaneous presence of positive antibodies was found in four CD patients: one patient had four aPL, one had three aPL and two had two aPL. The four patients who had aCL-IgA had also aβ2GPI-IgA and three of them had a titer higher than 50 units. Among nine patients with aβ2GPI-IgA, four had a titer higher than 100 units. The highest titers were found in adults.

CONCLUSIONS

aPL and particularly aβ2GPI-IgA are frequent in CD. The significance of these antibodies has to be determined.

Anti-Saccharomyces cerevisiae antibodies are frequent in type 1 diabetes

Anti-Saccharomyces cerevisiae antibodies (ASCA) have been described in many autoimmune diseases in which there is an increased intestinal permeability. Also in type 1 diabetes (T1D), there is an increased intestinal permeability. Since no data are available about ASCA in T1D, we evaluated, retrospectively, the frequency of ASCA in this disease. ASCA, IgG, and IgA, were determined by ELISA in sera of 224 T1D patients in which coeliac disease has been excluded and 157 healthy control group. The frequency of ASCA (IgG or IgA) was significantly higher in T1D patients than in the control group (24.5% vs. 2.5%, p < 10(-7)). The same observation was found in children and in adult patients when we compare them to healthy children and blood donors group respectively. Compared to children, adult patients with T1D showed significantly higher frequencies of ASCA of any isotype (38% vs. 13.7%, p < 10(-4)), both ASCA IgG and IgA (12% vs. 1.6%, p = 0.002), ASCA IgG (35% vs. 9.8%, p < 10(-5)) and ASCA IgA (15% vs. 5.6%, p = 0.001). The frequency of ASCA was statistically higher in females of all T1D than in males (30.8% vs.17.7%, p = 0.03), in girls than in boys (22% vs.6.2%, p = 0.017), and significantly higher in men than in boys (35.7% vs. 6.2%, p < 10(-4)). The frequency of ASCA IgG was significantly higher than that of ASCA IgA in all T1D patients (21% vs. 9.8%, p < 0.002), in all females (26.5% vs. 10.2%, p < 0.002), in women (37.9% vs. 12%, p < 0.001). The frequency of ASCA was significantly higher in all long-term T1D than in an inaugural T1D (29% vs. 14.5%, p = 0.019). The same observation was found in adults (45.8% vs. 17.8%, p = 0.01). In long-term T1D patients, ASCA were significantly more frequent in adults than children (45.8% vs. 14.5%, p < 10(-4)). The frequency of ASCA IgG was significantly higher in long-term T1D than in an inaugural T1D (25.2% vs. 11.6%, p = 0.03). Patients with T1D had a high frequency of ASCA.

Uveitis responding on gluten free diet in a girl with celiac disease and diabetes mellitus type 1

A 9-year old girl with a history of diabetes mellitus type 1, presented with visual loss of the left eye. The right eye examination was unremarkable. Slit-lamp examination revealed few small and fine keratic precipitates. We noted 2+ flare in the vitreous. There was no choroiditis, papillitis or retinal vasculitis. No aetiology was found. The patient was treated by topical and systemic corticosteroids without any improvement. Celiac disease was discovered by the presence of celiac antibodies in the work-up of joint pain and diabetes mellitus type 1. Antiendomysium antibodies and anti-transglutaminase antibodies were both positive. A small bowel biopsy confirmed celiac disease. A gluten free diet was set up and corticosteroids were tapered off. Recovery of the uveitis was obvious during gluten free diet and normalized within two months.

HLA-B27 and HLA-B51 determination in Tunisian healthy subjects and patients with suspected ankylosing spondylitis and Behçet's disease

The aim of this retrospective study is to assess the frequency of HLA-B27 and HLA-B51 in healthy subjects from the center of Tunisia and to investigate their usefulness in the diagnosis of ankylosing spondylitis (AS) and Behçet's disease (BD), respectively. Microlymphocytotoxicity test was used to perform serologic HLA typing in a group of 124 healthy volunteers and a group of 365 patients suffering from clinical manifestations of AS and/or BD. HLA-B27 was found in 3.2% of healthy subjects and in 42.9% of patients with AS (P < 0.00006). HLA-B51 is, however, found in 16.1% of healthy subjects and in 30.0% of patients with BD (P > 0.05). Unlike HLA-B51, which seems to be as frequent in Tunisian patients with BD as in healthy subjects, HLA-B27 is more frequent in patients with AS than in controls. This highlights the usefulness of HLA-B27, rather than that of HLA-B51, in the diagnosis of the respective diseases.

Improvement of rituximab efficiency in chronic lymphocytic leukemia by CpG-mediated upregulation of CD20 expression independently of PU.1

Lipopolysaccharide (LPS), CpG-containing phosphothioate oligonucleotides (CpG) and various cytokines impact chronic lymphocytic leukemia (CLL) B cells. For example, they influence cell cycle entry, expression of co-receptors, and CD20. Rituximab (RTX), for which CD20 molecule is the target, proved to be less efficient in CLL than in lymphoma. This is accounted for by a lower CD20 level in the former than in the latter B lymphocytes. CD20 transcription is mediated by four transcription factors, of which only purine-rich box-1 (PU.1) is reduced in CLL. We thus examined the effects of LPS, CpG, tumor necrosis factor-alpha, interferon-alpha, interleukin (IL)-3, IL-4, IL-21, granulocyte macrophage-colony stimulating factor (CSF), and granulocyte-CSF on the transcription of PU.1, and the subsequent expression of CD20. It appeared that CpG was unique in that it raised the membrane expression of CD20 on malignant B cells, owing to a PU.1 independent increase in its gene transcription. Moreover, RTX-induced complement-mediated lysis was also ameliorated. Thus, CpG accelerates the transcription of CD20 independently of PU.1, and thereby improves the efficacy of RTX in CLL.

Angiogenic activity in sera of patients with systemic lupus erythematosus

Angiogenesis plays a critical role in the pathogenesis of several connective tissue diseases. There is, however, relatively little information available on the role of angiogenesis in systemic lupus erythematosus (SLE). The aim of this study was to investigate the angiogenic activity in sera of patients with SLE and to determine the association between angiogenic activity and clinical complications. Sera from 66 Tunisian females with SLE and from 32 healthy blood donors were studied for their angiogenic activity using the in-vitro tube formation test on Matrigel. Samples were divided into five groups according to their angiogenic activity, which was scored from 0 (no angiogenesis) to 4 (high angiogenic activity). Samples from each group were then tested randomly to assess serum concentration of vascular endothelial growth factor (VEGF). No correlation was found between angiogenic activity scores and serum VEGF levels. Considering angiogenesis assessment in-vitro, sera of patients with SLE showed a much higher angiogenic activity than healthy controls since a high angiogenic score (score 4) is present in 43.9% of patients and in 6.3% of controls ( P < 0.0002). This high angiogenic activity is not correlated with disease activity; however, SLE patients with anti-dsDNA antibodies and those with nephritis showed higher angiogenic activity compared with patients without these complications since score 4 is found in 50.9% and 67.9% versus 9.1% ( P = 0.017) and 26.3% ( P < 0.001), respectively. In conclusion, our study showed that high serum angiogenic activity in SLE was not correlated with the VEGF levels. We suggest the use of the ‘in-vitro’ tube formation test as a better tool to study the angiogenic potential of sera. We found that in patients with SLE, serum angiogenic activity is increased compared with healthy controls. This high angiogenic activity is associated with renal complications and with the presence of anti-dsDNA antibodies. These findings suggest an involvement of angiogenesis disturbance in the pathogenesis of SLE.

[Antineutrophil cytoplasmic antibodies and associated diseases]

Antineutrophil cytoplasmic antibodies are classical serological markers of small-vessels vasculitis. However, they have been described in many other pathological situations. The aim of this study was to determine through our experience, the main antineutrophil cytoplasmic antibodies-associated diseases and to investigate antigen targets of these antibodies. Forty complete observations of antineutrophil cytoplasmic antibodies (ANCA) positive patients either by indirect immunofluorescence or by enzyme immunoassay were analysed. Only five (12.5%) patients have small-vessels vasculitis. Among these, antineutrophil cytoplasmic antibodies were detected only by Elisa in one patient and they were exclusively directed against bactericidal permeability increasing protein in another one. Our study confirms the presence of antineutrophil cytoplasmic antibodies in different diseases. It demonstrates that antineutrophil cytoplasmic antibodies should be investigated by Elisa when indirect immunofluorescence is negative. In small-vessels vasculitis, Proteinase 3 and myeloperoxidase are mainly but not exclusively the antigenic targets of antineutrophil cytoplasmic antibodies.

Thyroid-related autoantibodies in Tunisian patients with coeliac disease

BACKGROUND

The aim of our study was to evaluate, retrospectively, the frequency of anti-thyroid antibodies (ATA) in coeliac disease (CD) patients.

METHODS

ELISA was used to determine the frequency of anti-thyroid stimulating hormone receptor antibodies, thyroperoxidase antibodies and thyroglobulin antibodies in sera of 104 adult patients with CD. Patients were divided into three groups: group I, 56 untreated patients; group II, 21 patients on a strict gluten-free diet (GFD); and group III, 27 patients who did not comply with a GFD. Sera of 189 healthy blood donors served as controls.

RESULTS

Out of 104 patients with CD, five (4.8%) had ATA. The frequency of ATA found in the control group (1.6%) was not significantly different from that found in all CD patients. However, the frequency of ATA in CD patients on a GFD was significantly higher than that found in the control group (8.3% vs. 1.6%, p=0.03). The frequency of ATA in groups I, II and III was 1.8%, 9.5% and 7.4%, respectively.

CONCLUSIONS

ATA were found in CD patients even on a GFD.

B cell-ablative therapy: where are we now?

Based on their multifaceted functions, B cells participate in several pathological settings such as lymphoproliferative disorders, autoimmune diseases and graft rejection. B cell-ablative therapy has thus emerged as a mainstay in these diseases. A number of anti-B cell antibodies (Abs) have been generated, among which anti-CD20 Abs appear to be efficient. Rituximab (RTX) is one of these anti-CD20 monoclonal Abs. Originally approved for the treatment of non-Hodgkin lymphoma, RTX is now being administered in other malignant proliferations, applied to an increasing number of autoimmune diseases and required to prevent rejection of a graft. Although this medication is remarkably safe, a handful of laboratory tests have been proposed to monitor RTX-treated patients. The efficacy in different diseases, and the emergence of new anti-CD20 Abs raise many questions. Thus, their detailed understanding can lead to a better issue for inhibition of immune responses.

Detection of M2 antimitochondrial antibodies by dot blot assay is more specific than by enzyme linked immunosorbent assay

AIMS

The objective of our study was, in one hand, to determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ELISA and dot blot assay to investigate IgG M2 antimitochondrial antibodies (M2 AMA) and, on the other hand, to compare these results with those of indirect immunofluorescence technique (IIF).

METHODS

Sera from patients suffering from primary biliary cirrhosis (PBC) (n=55), systemic lupus erythematosus (n=21), celiac disease (n=30) and blood donors (n=75) were analyzed. M2 AMA were detected by ELISA and dot blot using pyruvate dehydrogenase purified from porcine heart and by IIF on cryostat sections of rat liver-kidney-stomach.

RESULTS

IIF was more sensitive (98%) than ELISA (93%) and dot blot (91%). The specificity of AMA for PBC using IIF, ELISA and dot blot reached 100%, 92% and 100%, respectively. The PPV of IIF, ELISA and dot blot was 100%, 93% and 100%, respectively. The NPV was 98% for IIF, 92% for ELISA and 91% for dot blot.

CONCLUSION

Dot blot, using purified pyruvate dehydrogenase, had a higher specificity than ELISA and may be useful in confirming the specificity of AMA in cases of doubt with IIF.

Anti-Saccharomyces cerevisiae antibodies in coeliac disease

OBJECTIVE

To evaluate, retrospectively, the frequency of anti-Saccharomyces cerevisiae antibodies (ASCA) in patients with coeliac disease.

MATERIAL AND METHODS

ASCA, IgG and IgA were determined by ELISA in sera of 238 coeliac patients. The patients were divided into three groups: group I - 125 untreated patients; group II - 42 patients under a strict gluten-free diet (GFD); and group III - 71 patients who did not comply with a GFD. Sera of 80 healthy blood donors served as controls.

RESULTS

The frequency of ASCA (IgG or IgA) was significantly higher in untreated coeliac patients than in the control group (27.2% versus 3.7%, p=10(-5)). In 238 coeliac patients, the frequency of ASCA was significantly higher in adults than in children (35.4% versus 21.1%, p=0.01). In group III, the frequency of ASCA was significantly higher in adults than in children (60% versus 26.1%, p=0.004). In 238 coeliac patients, ASCA IgG were significantly more frequent than ASCA IgA in both children (19% versus 6.3%, p=0.001) and adults (33.3% versus 12.5%, p=5.10(-4)). In children, ASCA IgG were negative in group II and positive in 20% of group I (p=0.01). In adults, the frequency of ASCA IgG was also significantly lower in group II than in group I (9.5% versus 34%, p=0.03).

CONCLUSIONS

A high frequency of ASCA has been found in coeliac patients. The frequency of ASCA was not statistically different between patients with successful adherence to GFD and healthy controls.

Is the c-Cbl Proto-Oncogene Involved in Chronic Lymphocytic Leukemia?

Chronic lymphocytic leukemia (CLL) is characterized by survival advantage and accumulation of CD5+ mature B lymphocytes. Expression of zeta-chain-associated protein-70 (ZAP-70), normally present in T lymphocytes or immature B cells, is associated with disease aggressiveness, as IgVH mutational status, and some proteins implicated in survival signal pathways are found to be constitutively activated in CLL cells. ZAP-70 signaling is regulated through molecular adaptors, such as the proto-oncogene product c-Casitas B lineage lymphoma (c-Cbl). The aim of this study was to determine the implication of this proto-oncogene product in CLL in survival signals. It appeared that expression of c-Cbl was increased in CLL and not correlated to that of B cell linker protein or ZAP-70. Furthermore, c-Cbl was significantly hypophosphorylated in progressive disease, so that hypophosphorylated form of c-Cbl (c-Cbl.P) along with ZAP-70, set a cutoff ratio distributing patients with stable situation below 1, and those with progressive disease equal or above 1. Given that phospholipase gamma 2 (PLC gamma 2) function is also influenced by c-Cbl hypophosphorylation, the ratio of PLC gamma 2 to c-Cbl.P was measured in CLL B cells and consistently found to be >or= 1 in Binet stage B CLL patients, as opposed to stage A CLL patients. These findings invite analysis of the role of c-Cbl in CLL.

Screening by anti-endomysium antibodies for celiac disease in Tunisian children with type 1 diabetes mellitus

AIM

Celiac disease (CD) and type 1 diabetes mellitus (DM1) can frequently coexist, presumably due to a common genetic predisposition. The present study was designed to evaluate the frequency of CD among Tunisian children with DM1.

PATIENTS AND METHODS

A total of 205 diabetic children (92 girls, 113 boys, age range 6 months-15 years, median 11 years) were screened for CD by determination of IgA anti-endomysium antibodies (EMA).

RESULTS

EMA were positive in 17 out of 205 (8.3%) children with DM1. The median age of DM1 at onset was significantly lower in patients with EMA than those without EMA (P<10(-7)). In 13 of 17 EMA-positive patients, duodenal biopsy could be performed and a destructive type of CD was confirmed in 11 of them: 8 patients showed total villous atrophy, 3 patients showed a partial villous atrophy. The other two patients showed a normal histological picture with normal number of intraepithelial lymphocytes. Parents of the remaining EMA-positive children refused endoscopy. Thus the prevalence of biopsy-proven CD was 5.3% (11/205). It was 7.6% (7/92) in girls and 3.5% (4/113) in boys but the difference was not statistically significant. Seventy three percent of patients with CD were asymptomatic.

CONCLUSIONS

The prevalence of clinically unrecognized CD, found by EMA screening, is high in Tunisian children with DM1. We suggest that children with diabetes should be screened for CD.