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.

Effectiveness of infliximab in refractory FDG PET-positive sarcoidosis.

Inconclusive evidence for the efficacy of infliximab in sarcoidosis hinders the global use of this potentially beneficial drug. To study infliximab efficacy in a clinical setting, we performed a prospective open-label trial in patients refractory to conventional treatment. Patients (n=56) received eight infusions of 5 mg·kg(-1) infliximab. Pulmonary function, disease activity measured by (18)F-fluorodeoxyglucose (FDG) by positron emission tomography (PET) and quality of life were part of the clinical work-up. Infliximab levels were measured before every infusion. After 26 weeks of infliximab treatment, mean improvement in forced vital capacity (FVC) was 6.6% predicted (p=0.0007), whereas in the 6 months before start of treatment, lung function decreased. Maximum standardised uptake value (SUVmax) of pulmonary parenchyma on (18)F-FDG PET decreased by 3.93 (p<0.0001). High SUVmax of pulmonary parenchyma at baseline predicted FVC improvement (R=0.62, p=0.0004). An overall beneficial response was seen in 79% of patients and a partial response was seen in 17% of patients. No correlation between infliximab trough level (mean 18.0 µg·mL(-1)) and initial response was found. In conclusion, infliximab causes significant improvement in FVC in refractory (18)F-FDG PET positive sarcoidosis. Especially in pulmonary disease, high (18)F-FDG PET SUVmax values at treatment initiation predict clinically relevant lung function improvement. These results suggest that inclusion of (18)F-FDG PET is useful in therapeutic decision-making in complex sarcoidosis.

Increased expression of CD16, CD69, and very late antigen-1 on blood monocytes in active sarcoidosis.

BACKGROUND: Different types of immune cells are involved in the formation of granulomas, a hallmark of pulmonary sarcoidosis. Proinflammatory monocytes are activated circulating monocytes thought to be related to the initial events of granuloma formation. We tested the hypothesis that peripheral blood monocytes in patients with active pulmonary sarcoidosis have an activated phenotype and, secondly, that measuring this activation status can provide a new tool for monitoring disease activity. METHODS: Blood was collected of 23 steroid-naive patients presenting with pulmonary sarcoidosis and 10 healthy control subjects. Expression of CD16 (Fc-gamma type III receptor), CD69 (a general activation marker of cells of the hematopoietic lineage), and the integrin very late antigen (VLA)-1 (on interaction with extracellular matrix compounds mediates cell adhesion) was measured by flow cytometry. RESULTS: Percentages of monocytes expressing CD16, CD69, and VLA-1 in patients vs control subjects were 56.2 +/- 4.1% vs 12.2 +/- 2.4% (p < 0.0001), 87.3 +/- 2.1% vs 8.6 +/- 3.3% (p < 0.0001), and 66.5 +/- 3.6% vs 11.2 +/- 2.3% (p < 0.0001), respectively. Moreover, the CD69+VLA-1+ monocyte subset, abundantly present at disease presentation, was found to decrease to normal levels during follow-up with disease remission. CONCLUSIONS: Peripheral blood monocytes from patients with pulmonary sarcoidosis show a highly activated phenotype. Phenotyping circulating monocytes might be a promising tool for monitoring sarcoidosis disease activity but needs further investigation.

Development of functional Haemophilus influenzae type b antibodies after vaccination.

Sixteen autologous stem cell transplant recipients received three vaccinations with conjugated haemophilus influenzae type b vaccine. Quantitative and qualitative aspects of the antibody response were studied. The vaccination schedule resulted in high antibody response rates and functional maturation of antibodies, as measured by antibody avidity and phagocytosis-inducing capacity.

ACE and sIL-2R correlate with lung function improvement in sarcoidosis during methotrexate therapy.

INTRODUCTION: In sarcoidosis, the search for disease activity markers that correlate with treatment response is ongoing. The aim of this study was to investigate the pattern of two proposed markers, serum angiotensin-converting enzyme (ACE) and soluble IL-2 receptor (sIL-2R) during methotrexate (MTX) therapy in sarcoidosis patients. MATERIALS AND METHODS: We analysed 114 sarcoidosis patients who used MTX for six months, consisting of a subgroup of 76 patients with a pulmonary indication for treatment and a subgroup of 38 patients with an extra-pulmonary indication. ACE and sIL-2R serum levels were measured at baseline and after six months of treatment. Correlation coefficients (R) and odds ratios (ORs) were calculated to study the correlation and predictive effect of serum ACE and sIL-2R levels for pulmonary improvement. RESULTS: High baseline levels of ACE correlated significantly with lung function improvement after treatment (R = 0.45, p < 0.0001; stronger in the pulmonary subgroup R 0.57, p < 0.0001). ACE baseline levels >90 U/l predicted a 10% improvement in overall lung function (OR 3.55; CI 1.34-9.38), with the highest prediction level for 10% improvement in DLCO (OR 4.63; CI 1.23-17.4). After six months of MTX, mean ACE decreased with 17.2 U/l (p < 0.0001) and sIL-2R with 1850 pg/ml (p < 0.0001). Decreases in both ACE and sIL-2R correlated with an increase in lung function. The strongest correlation was found with change in DLCO in the pulmonary subgroup (ACE R = 0.63, P < 0.0001; sIL-2R R = 0.56, P < 0.0001). CONCLUSION: Baseline and serial serum ACE and sIL-2R levels correlate well with lung function improvement during MTX treatment. Serial measurements of these biomarkers are helpful in monitoring treatment effects in sarcoidosis patients.

The effect of ranitidine on antibody responses to polysaccharide vaccines in patients with B-cell chronic lymphocytic leukaemia.

OBJECTIVES: To analyse the effects of ranitidine treatment on vaccination induced antibody responses in patients with chronic lymphocytic leukaemia (CLL). METHODS: Fifty CLL patients were vaccinated with tetanus conjugated Hib vaccine and a 23-valent pneumococcal polysaccharide vaccine with (n = 25) or without (n = 25) ranitidine treatment in a matched case--control setting. Anti tetanus toxoid (TT), anti-Hib and anti-pneumococcal antibody levels were determined before and after vaccination. Additionally, cytokine levels were assessed in patients treated with ranitidine. RESULTS: Vaccination-induced increases in anti-Hib and anti-TT antibody levels were higher in the ranitidine group compared with the control group. Anti-pneumococcal antibody responses were not improved by administration of ranitidine. Higher levels of IL-18 were found in patients treated with ranitidine compared with healthy controls. Levels of IL-6, IL-8, IL-18, RANTES, IP-10, sVCAM-1 and sICAM-1 were within normal ranges and did not change during ranitidine treatment. CONCLUSION: Ranitidine treatment improves vaccination-induced T-cell dependent antibody responses in patients with CLL but has no beneficial effect on the response to vaccination with unconjugated polysaccharide antigens.