Restoration of peripheral blood natural killer and B cell levels in patients affected by rheumatoid and psoriatic arthritis during etanercept treatment.

Etanercept (ETN) is an anti-tumour necrosis factor (TNF)-α agent used in rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Few studies focused on the effects of anti-TNF-α on peripheral blood cells. We aimed to evaluate peripheral blood cells in RA and PsA patients during ETN treatment and to explore their relationships with disease activity. RA (n = 82) and PsA (n = 32) patients who started ETN were included into the study and evaluated prospectively before the beginning of ETN therapy and after 14, 22, 54 and 102 weeks. Patients were studied in terms of disease activity score on 28 joints (DAS28), clinical response and laboratory findings. Natural killer (NK) cells, B cells and T cells were characterized by immunophenotyping. Both the RA and the PsA patients showed reduced NK and B cell count before ETN treatment compared with controls. A negative correlation was demonstrated between DAS28 and B cell count in RA patients at baseline. Sustained significant increase of NK and B cells up to normal levels was observed in RA and PsA patients along ETN treatment. Increase of NK cell count was associated with a good-moderate clinical response to ETN in both RA and PsA patients. During ETN treatment peripheral blood NK and B cells levels were restored in RA and PsA patients. Correlations between NK and B cells with disease activity were observed, suggesting that those effects could be mediated by ETN treatment.

The autoreactivity of B cells in hereditary angioedema due to C1 inhibitor deficiency.

Patients with hereditary angioedema (HAE) tend to produce autoantibodies and have a propensity to develop immunoregulatory disorders. We characterize the profile of autoantibodies in a group of HAE patients and investigate their memory B cells' phenotype and activation status. We studied the activity status phenotype, Toll-like receptor (TLR)-9 expression and total phosphotyrosine in B cells isolated from HAE patients. Additionally, the following autoantibodies were assessed in the serum of 61 HAE patients: anti-nuclear, rheumatoid factor, anti-cardiolipin, anti-tissue transglutaminase, anti-endomysial, anti-Saccharomyces cerevisiae, anti-thyroid and anti-neutrophil cytoplasmic antibodies. In 47·5% of HAE patients we detected at least one of the tested autoantibodies. Expression of CD69, CD5 and CD21 was found to be significantly higher on memory B cells from HAE patients compared to healthy controls (4·59 ± 4·41 versus 2·06 ± 1·81, P = 0·04, 8·22 ± 7·17 versus 3·65 ± 3·78, P = 0·05, 2·43 ± 0·54 versus 1·92 ± 0·41, P = 0·01, respectively). Total phosphotyrosine in B cells from HAE patients was significantly higher compared to healthy controls (4·8 ± 1·1 versus 2·7 ± 1·3, P = 0·0003). Memory B cells isolated from the HAE group contained higher amounts of TLR-9 compared to healthy controls (8·17 ± 4·1 versus 4·56 ± 1·6, P = 0·0027). Furthermore, the expression of TLR-9 in memory B cells from HAE patients with autoantibodies was significantly higher than the control group (10 ± 4·7 versus 4·56 ± 1·6, P = 0·0002) and from that in HAE patients without autoantibodies (10 ± 4·7 versus 5·8 ± 0·9, P = 0·036). HAE patients have enhanced production of autoantibodies due most probably to the increased activation of B cells, which was found to be in association with a high expression of TLR-9.

Complement system in psoriatic arthritis: a useful marker in response prediction and monitoring of anti-TNF treatment.

OBJECTIVES: Treatment with anti-TNF agents is well established in psoriatic arthritis (PsA). Anti-TNF agents are capable of modulating complement activity in vitro but there are no data on the in vivo effect. Anti-TNF have high costs and potential risks, thus, there is an urgent need for accurate predictors of response. We aimed at studying the usefulness of erythrocyte-sedimentation-rate (ESR), C-reactive protein (CRP), and complement for response prediction and monitoring of anti-TNF treatment in PsA patients. METHODS: Fifty-five patients were included consecutively before starting etanercept or adalimumab. ESR, CRP, plasma complement C3, C4, and C3 and B cleavage fragments were evaluated at baseline and after 22 weeks of anti-TNF treatment. Disease activity was measured with DAS28 and response to therapy with EULAR criteria. Complement was evaluated at baseline in 30 healthy subjects as well. RESULTS: At baseline, C3 and C4 levels were significantly higher than in controls (C3 126.9±22 vs. 110±25 mg/dl, p=0.000002; C4 31.2±9.2 vs. 22.7±8.3 mg/dl, p=0.0003). After anti-TNF therapy, C3 and C4 levels were significantly reduced to normalization (p=0.0009 and 0.0005, respectively) and ESR, CRP and DAS28 showed a significant reduction (p=0.002, 0.004 and 0.0001, respectively). Split products of C3 and B were not observed at baseline and after 22 weeks. Higher baseline C3 levels were associated with EULAR non-response (p=0.011). CONCLUSIONS: PsA patients with moderate to severe disease show elevated C3 and C4 levels, reverted by anti-TNF treatment. High C3 may be considered a hallmark of inflammation and C3 revealed the highest predictive value for response to anti-TNF.

Evidence of impaired sense of smell in hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) is an autosomal-dominant disorder resulting from C1-inhibitor (C1INH) deficiency. Smell impairments were found in patients affected with systemic lupus erythematosus, that, similarly to HAE, is characterized by the activation of the classical complement pathway with C4 consumption. In this study, we aimed at evaluating the sense of smell in patients with HAE. METHODS: Thirty patients with HAE and 30 healthy age- and sex-matched controls were evaluated for olfactory functions using the 3-stages Sniffin'-Sticks kit (threshold, discrimination, and identification [TDI]). TDI scores were analyzed according to complement levels (C1INH, C3, C4 and CH50), Beck depression inventory (BDI-II) and danazol treatment. RESULTS: A significant decrease in olfactory function was observed in patients affected with HAE compared with controls in total TDI score (P < 0.001), and in the discrimination (P < 0.001) and identification scores (P = 0.012). Anosmia was present only in patients with HAE (3.3%) who also exhibited more frequently hyposmia (53.3%vs 3.3%, P < 0.0001). Complement levels were reduced in patients with HAE. C4 serum levels showed positive correlation with total TDI score (P < 0.001), and with discrimination (P = 0.002) and identification (P = 0.011) scores. CH50 complement levels showed positive correlation with total TDI score (P < 0.001), and with threshold (P = 0.002) and discrimination (P = 0.011) scores. Sex, age, danazol treatment, BDI-II scores were not different between the patients and controls and did not influence TDI scores significantly. CONCLUSION: Evidence for an impaired sense of smell was found in patients with HAE. The reduction in olfactory function in these cases seems to correlate with complement C4 and CH50 levels. Immune and genetic mechanisms might play a role in this defect.