Rheumatoid factor isotype and Ro epitope distribution in primary Sjögren syndrome and rheumatoid arthritis with keratoconjunctivitis sicca.

Primary Sjögren syndrome (pS) is associated with autoantibodies such as rheumatoid factor (RF) and anti-nuclear antibodies such as anti-Ro (SS-A) and/or La (SS-B). Recent developments within autoimmune diagnostics allow quantitation of RF subclasses and anti-Ro epitopes. Will this refinement by autoimmune diagnostics help predicting development of extraglandular manifestations (EGM) in pS patients? A cohort of pS and rheumatoid arthritis (RA) patients with keratoconjunctivitis sicca (n = 35 and 16, resp) was included. Of the pS patients, 54% developed one or more EGM. Antibodies quantitated were IgM-RF, IgA-RF, IgG-RF, anti-Ro52, and anti-Ro60. Upon analysis of RF isotypes, pS patients generally displayed higher IgA-RF concentrations than RA patients (126 versus 49 U/ml, p = 0.015), while the dominant RF isotype in RA patients was IgM-RF (82.5 versus 38 U/ml, p = 0.012). No differences were observed regarding IgG-RF concentrations. In pS without/with EGM, the median RF IgM concentrations were similar, while RF IgA and IgG concentrations tended to be lower in pS patients with EGM > 1. Both Ro epitopes were strongly recognized by almost all pS patients, independent from EGM, while these antibodies were absent in RA patients. Primary Sjögren syndrome and RA patients have distinct serological profiles when analysing RF and Ro-specific antibodies. A longitudinal study of switched RF isotypes in pS patients is worthwhile from an immunological point of view, but its value is limited regarding identification of pS patients prone to developing EGM or RA patients prone to developing secondary sicca symptoms.

A multiplex assay to rapidly exclude HLA-DQ2.5 and HLA-DQ8 expression in patients at risk for celiac disease.

BACKGROUND: Celiac disease (CD) is an inflammatory disorder of the small intestine induced by gluten ingestion. CD has a strong genetic association with human leukocyte antigen (HLA)-DQ2.5 and HLA-DQ8. The absence of HLA-DQ2.5 and HLA-DQ8 has a strong negative predictive value for CD. Genetic screening of HLA-DQ2.5 and HLA-DQ8 in patients at risk is of great value. METHODS: We designed, developed, and validated a multiplex assay based on multiplex ligation-dependent probe amplification (MLPA) technology, allowing the simultaneous detection of DQA1*05-DQB1*02, encoding HLA-DQ2.5, and DQA1*03-DQB1*03:02, encoding HLA-DQ8. The amplified products were separated and identified using capillary electrophoresis. RESULTS: When compared with a polymerase chain reaction followed by single-strand conformation polymorphism/ heteroduplex analysis, one discrepancy was found. Sequencing analysis showed that the developed MLPA assay result was correct. Furthermore, we demonstrated that the MLPA method is able to distinguish between the heterozygote and homozygote expression of HLA-DQ2.5 or HLA-DQ8. CONCLUSIONS: This study shows that it is possible to rapidly and accurately screen for the absence of HLA-DQ2.5 and HLA-DQ8 using MLPA, excluding patients at risk for CD for further serological or histological follow-up. In addition, MLPA might be an accurate tool to screen for other specific HLA types in the context of disease association in a diagnostic laboratory setting.

Rapid HLA-B27 screening with real-time TaqMan PCR: a clinical validation in the Dutch population.

BACKGROUND: Human leukocyte antigen B27 (HLA-B27) is strongly associated with ankylosing spondylitis. The B27 allele is present in 90% of patients with this disease, whereas it is present in only 9% of Caucasians. Molecular detection of HLA-B27 is traditionally based on allele specific amplification of exon 2 (Olerup method) or exon 3 (Dominguez method) by PCR, followed by gel analysis. METHODS: We developed a real-time TaqMan PCR based on the Dominguez method with a ß-Globin PCR as internal control. RESULTS: A total of 544 clinical samples were used to compare the real-time TaqMan PCR with the traditional Dominguez PCR, the traditional Olerup PCR and a commercial Olerup based HLA-B27 detection kit (Olerup SSPTM HLA-B27, GenoVision). While 542 samples gave concordant results, two samples showed discrepancies and were further analyzed. One sample that showed a discrepancy was negative with the traditional Olerup method and positive with the three other procedures. Sequencing analysis showed the presence of HLA-B*2712 in this sample. The other sample, positive with both Olerup based PCRs and negative with both Dominguez based methods, turned out to be positive for HLA-B*2707 by sequence analysis. CONCLUSIONS: With a correct result for 543 out of 544 samples (99.8%), we consider our real-time HLA-B27 PCR is a reliable method to detect HLA-B27 in the Dutch population, with reduced hands-on time and contamination risk compared to traditional PCR methods.

Cytokines and Chemokines Are Detectable in Swivel-Derived Exhaled Breath Condensate (SEBC): A Pilot Study in Mechanically Ventilated Patients.

Introduction. Exhaled breath condensate (EBC) is a noninvasive method to collect samples from the respiratory tract. Usually, a thermoelectric cooling module is required to collect sufficient EBC volume for analyses. In here, we assessed the feasibility of cytokine and chemokine detection in EBC collected directly from the ventilator circuit without the use of a cooling module: swivel-derived exhaled breath condensate (SEBC). METHODS: SEBC was prospectively collected from the swivel adapter and stored at -80°C. The objective of this study was to detect cytokines and chemokines in SEBC with a multiplex immunoassay. Secondary outcomes were to assess the correlation between cytokine and chemokine concentrations in SEBC and mechanical ventilation parameters, systemic inflammation parameters, and hemodynamic parameters. RESULTS: Twenty-nine SEBC samples were obtained from 13 ICU patients. IL-1ß, IL-4, IL-8, and IL-17 were detected in more than 90% of SEBC samples, and significant correlations between multiple cytokines and chemokines were found. Several significant correlations were found between cytokines and chemokines in SEBC and mechanical ventilation parameters and serum lactate concentrations. CONCLUSION: This pilot study showed that it is feasible to detect cytokines and chemokines in SEBC samples obtained without a cooling module. Despite small sample size, correlations were found between cytokines and chemokines in SEBC and mechanical ventilation parameters, as well as serum lactate concentrations. This simple SEBC collection method provides the opportunity to collect EBC samples in large prospective ICU cohorts.

Chronic lymphocytic leukemia specific T-cell subset alterations are clone-size dependent and not present in monoclonal B lymphocytosis.

In patients with chronic lymphocytic leukemia (CLL), effector and memory CD4 + and CD8 + T cells are expanded. We investigated whether these CLL specific T-cell expansions also occur in monoclonal B lymphocytosis (MBL), the pre-leukemic state of CLL, which is currently distinguished from CLL by an arbitrarily chosen cut-off value of CD19 of 5.0 × 10(9)/L. Whereas an increase in effector and memory CD4 + and CD8 + T cells was found in CLL, these expansions could not be found in MBL. Although a significant correlation was found between absolute B cell count (CD19) and T cell numbers, correlation coefficients were rather low. Therefore, we analyzed whether an optimal threshold for CD19 number could be defined which best related to an expansion of T cells. The B-cell threshold that best predicted expansion of CD3 +, CD4 + and CD8 + T cells, respectively, was 10 × 10(9)/L. Our study indicates that a higher cut-off value than the current 5.0 × 10(9)/L relates better to the biological impact of CLL.

Comparison of two interferon-gamma assays and tuberculin skin test for tracing tuberculosis contacts.

BACKGROUND: The tuberculin skin test (TST) has low specificity. QuantiFERON-TB Gold (QFT-G) and T-SPOT.TB are based on interferon (IFN)-gamma responses to Mycobacterium tuberculosis-specific antigens. A novel in-tube format of QFT-G (QFT-GIT) offers logistical advantages. OBJECTIVE: To compare TST, QFT-GIT, and T-SPOT.TB in bacillus Calmette-Guérin unvaccinated contacts and correlate results with measures of recent exposure. METHODS: When a supermarket employee with smear-positive tuberculosis had infected most close contacts, a contact investigation among more than 20,000 customers was performed. We recruited subjects randomly on the day of TST administration (n = 469) and subjects with TST of more than 0 mm on the day of TST reading (n = 316). QFT-GIT and T-SPOT.TB were performed. Demographic data and measures of exposure were collected. TST results were analyzed at a cutoff of 10 or 15 mm. Blood tests were interpreted following the manufacturers' criteria and by varying cutoff levels. RESULTS: Among 785 study participants, TST results were associated with age, whereas positive IFN-gamma responses were significantly associated with cumulative shopping time, most markedly for QFT-GIT. Among participants with a TST of 15 mm or greater, sensitivity of QFT-GIT and T-SPOT.TB was 42.2 and 51.3%, respectively. Interassay agreement was 89.6% (kappa = 0.59). By varying cutoff values, agreement between the IFN-gamma assays was optimal at 93.6% (kappa = 0.71) using a cutoff of 0.20 IU/ml for QFT-GIT and 13 spots for T-SPOT.TB. CONCLUSIONS: Blood test results were associated with exposure, whereas the TST was not. A possible lack of sensitivity of IFN-gamma assays in detecting individuals with TST of 15 mm or greater, despite negative bacillus Calmette-Guérin vaccination status, warrants further investigation into alternative cutoff values.

HLA-DQB1*0201: a marker for good prognosis in British and Dutch patients with sarcoidosis.

Human leukocyte antigen (HLA)-DQB1 is one of the intriguing candidate genes in sarcoidosis. We performed high resolution molecular HLA-DQB1 typing on two groups of white patients (British [UK] and Dutch [NL]) in order to investigate the relationship between 19 DQB1 alleles and disease severity and progression. A total of 803 individuals were studied (133 UK and 102 NL patients, and 354 UK and 214 NL control subjects). Disease severity data included extrapulmonary disease, chest X-ray stage, lung diffusing capacity for carbon monoxide, and FVC. Progression was evaluated on follow-up chest radiographs (2 and 4 yr). The results showed DQB1*0201 to be strongly protective against severe sarcoidosis in both populations; in other words, it localized to Stage I at all time points (P < 0.0001, P(corrected) (P(c)) = 0.002), whereas another DQB1 allele, *0602, tended to have opposite effects. Further, a clear association was found between the *0201 allele and Löfgren's syndrome (P < 0.0001, P(c) = 0.001). More importantly, carriage of this allele reduced the risk of disease progression. In contrast, the other common split of DQB1*02, *0202, did not affect disease severity but was mildly protective against sarcoidosis in the UK population (P = 0.02, p(c) not significant). In conclusion, this study shows that DQB1*0201 is a strong marker for mild sarcoidosis. Additional mapping across the DQB1*0201-DRB1*0301 haplotype, including specific alleles at genes such as DRB3, tumor necrosis factor, lymphotoxin-alpha, I-kappa-B-like protein, and B-associated transcript 1, is necessary for a final localization of the protective effect on this haplotype.