Joëlle Bénessiano

BACKGROUND: Apoptotic microparticles are responsible for almost all tissue factor activity of the plaque lipid core. We hypothesized that elevated levels of procoagulant microparticles could also circulate in the peripheral blood of patients with recent clinical signs of plaque disruption and thrombosis. METHODS AND RESULTS: We studied 39 patients with coronary heart disease, including 12 patients with stable angina and 27 patients with acute coronary syndromes (ACS), and 12 patients with noncoronary heart disease. We isolated the circulating microparticles by capture with annexin V and determined their procoagulant potential with a prothrombinase assay. The cell origins of microparticles were determined in an additional 22 patients by antigenic capture with specific antibodies. The level of procoagulant microparticles did not differ between stable angina patients and noncoronary patients (10.1+/-1.6 nmol/L phosphatidylserine [PS] equivalent versus 9.9+/-1.6 nmol/L PS equivalent, respectively). However, procoagulant microparticles were significantly elevated in patients with ACS (22.2+/-2.7 nmol/L PS equivalent) compared with other coronary (P<0.01) or noncoronary (P<0.01) patients. Microparticles of endothelial origin were significantly elevated in patients with ACS (P<0.01), which suggests an important role for endothelial injury in inducing the procoagulant potential. CONCLUSIONS: High levels of procoagulant endothelial microparticles are present in the circulating blood of patients with ACS and may contribute to the generation and perpetuation of intracoronary thrombi.

IMPORTANCE: Primary Sjögren syndrome is a systemic autoimmune disease characterized by mouth and eye dryness, pain, and fatigue. Hydroxychloroquine is the most frequently prescribed immunosuppressant for the syndrome. However, evidence regarding its efficacy is limited. OBJECTIVE: To evaluate the efficacy of hydroxychloroquine for the main symptoms of primary Sjögren syndrome: dryness, pain, and fatigue. DESIGN, SETTING, AND PARTICIPANTS: From April 2008 to May 2011, 120 patients with primary Sjögren syndrome according to American-European Consensus Group Criteria from 15 university hospitals in France were randomized in a double-blind, parallel-group, placebo-controlled trial. Participants were assessed at baseline, week 12, week 24 (primary outcome), and week 48. The last follow-up date for the last patient was May 15, 2012. INTERVENTIONS: Patients were randomized (1:1) to receive hydroxychloroquine (400 mg/d) or placebo until week 24. All patients were prescribed hydroxychloroquine between weeks 24 and 48. MAIN OUTCOMES AND MEASURES: The primary end point was the proportion of patients with a 30% or greater reduction between weeks 0 and 24 in scores on 2 of 3 numeric analog scales (from 0 [best] to 10 [worst]) evaluating dryness, pain, and fatigue. RESULTS: At 24 weeks, the proportion of patients meeting the primary end point was 17.9% (10/56) in the hydroxychloroquine group and 17.2% (11/64) in the placebo group (odds ratio, 1.01; 95% CI, 0.37-2.78; P = .98). Between weeks 0 and 24, the mean (SD) numeric analog scale score for dryness changed from 6.38 (2.14) to 5.85 (2.57) in the placebo group and 6.53 (1.97) to 6.22 (1.87) in the hydroxychloroquine group. The mean (SD) numeric analog scale score for pain changed from 4.92 (2.94) to 5.08 (2.48) in the placebo group and 5.09 (3.06) to 4.59 (2.90) in the hydroxychloroquine group. The mean (SD) numeric analog scale for fatigue changed from 6.26 (2.27) to 5.72 (2.38) in the placebo group and 6.00 (2.52) to 5.94 (2.40) in the hydroxychloroquine group. All but 1 patient in the hydroxychloroquine group had detectable blood levels of the drug. Hydroxychloroquine had no efficacy in patients with anti-SSA autoantibodies, high IgG levels, or systemic involvement. During the first 24 weeks, there were 2 serious adverse events in the hydroxychloroquine group and 3 in the placebo group; in the last 24 weeks, there were 3 serious adverse events in the hydroxychloroquine group and 4 in the placebo group. CONCLUSIONS AND RELEVANCE: Among patients with primary Sjögren syndrome, the use of hydroxychloroquine compared with placebo did not improve symptoms during 24 weeks of treatment. Further studies are needed to evaluate longer-term outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00632866.

INTRODUCTION: Cell stimulation leads to the shedding of phosphatidylserine (PS)-rich microparticles (MPs). Because autoimmune diseases (AIDs) are characterized by cell activation, we investigated level of circulating MPs as a possible biomarker in primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). METHODS: We measured plasma levels of total, platelet and leukocyte MPs by prothrombinase capture assay and flow cytometry in 43 patients with pSS, 20 with SLE and 24 with RA and in 44 healthy controls (HCs). Secretory phospholipase A2 (sPLA2) activity was assessed by fluorometry. Soluble CD40 ligand (sCD40L) and soluble P-selectin (sCD62P), reflecting platelet activation, were measured by ELISA. RESULTS: Patients with pSS showed increased plasma level of total MPs (mean +/- SEM 8.49 +/- 1.14 nM PS equivalent (Eq), P < 0.0001), as did patients with RA (7.23 +/- 1.05 n PS Eq, P = 0.004) and SLE (7.3 +/- 1.25 nM PS Eq, P = 0.0004), as compared with HCs (4.13 +/- 0.2 nM PS Eq). Patients with AIDs all showed increased level of platelet MPs (P < 0.0001), but only those with pSS showed increased level of leukocyte MPs (P < 0.0001). Results by capture assay and flow cytometry were correlated. In patients with high disease activity according to extra-glandular complications (pSS), DAS28 (RA) or SLEDAI (SLE) compared with low-activity patients, the MP level was only slightly increased in comparison with those having a low disease activity. Platelet MP level was inversely correlated with anti-DNA antibody level in SLE (r = -0.65; P = 0.003) and serum beta2 microglobulin level in pSS (r = -0.37; P < 0.03). The levels of total and platelet MPs were inversely correlated with sPLA2 activity (r = -0.37, P = 0.0007; r = -0.36, P = 0.002, respectively). sCD40L and sCD62P concentrations were significantly higher in pSS than in HC (P < or = 0.006). CONCLUSIONS: Plasma MP level is elevated in pSS, as well as in SLE and RA, and could be used as a biomarker reflecting systemic cell activation. Level of leukocyte-derived MPs is increased in pSS only. The MP level is low in case of more severe AID, probably because of high secretory phospholipase A2 (sPLA2) activity, which leads to consumption of MPs. Increase of platelet-derived MPs, sCD40L and sCD62P, highlights platelet activation in pSS.

The nitric oxide synthase (NOS) inhibitor nitro-L-arginine augmented the contractions to angiotensin (Ang) II in carotid artery rings without endothelium from spontaneously hypertensive rats (SHR) but not normotensive Wistar-Kyoto rats, suggesting the possibility of nonendothelial NOS activity in SHR arteries. In SHR artery without endothelium, the potentiation of Ang II contraction by nitro-L-arginine was prevented by L-arginine, but not by D-arginine, and was observed also in the presence of oxyhemoglobin, monomethyl-L-arginine, and 7-nitroindazole, but not in the presence of aminoguanidine. In further support of NOS activation by Ang II in nonendothelial cells, Ang II but not acetylcholine stimulated cGMP levels by 2-fold in SHR arteries without endothelium; nitro-L-arginine decreased both basal and Ang II-stimulated cGMP levels. When NOS activity in SHR arteries was measured, no calcium-independent L-citrulline formation was detectable, while up to 47% of the total calcium-dependent NOS activity was present in nonendothelial cells. Expression of neuronal NOS was revealed in the media of SHR arteries by immunohistochemistry, Western blot, and reverse transcriptase-polymerase chain reaction. Expression of this NOS isoform was greater in SHR than in Wistar-Kyoto rat preparations. Finally, endothelial NOS was observed in the endothelium, but no detectable levels of inducible NOS were found in these tissues. These results demonstrate the expression of neuronal NOS in rat vascular smooth muscle cells and its activation on stimulation by Ang II in spontaneously hypertensive, but not normotensive, animals.