Anti-D4GDI antibodies activate platelets in vitro: a possible link with thrombocytopenia in primary antiphospholipid syndrome.

BACKGROUND: Thrombocytopenia is a manifestation associated with primary antiphospholipid syndrome (PAPS), and many studies have stressed the leading role played by platelets in the pathogenesis of antiphospholipid syndrome (APS). Platelets are highly specialized cells, and their activation involves a series of rapid rearrangements of the actin cytoskeleton. Recently, we described the presence of autoantibodies against D4GDI (Rho GDP dissociation inhibitor beta, ARHGDIB) in the serum of a large subset of SLE patients, and we observed that anti-D4GDI antibodies activated the cytoskeleton remodeling of lymphocytes by inhibiting D4GDI and allowing the upregulation of Rho GTPases, such as Rac1. Proteomic and transcriptomic studies indicate that D4GDI is very abundant in platelets, and small GTPases of the RHO family are critical regulators of actin dynamics in platelets. METHODS: We enrolled 38 PAPS patients, 15 patients carrying only antiphospholipid antibodies without clinical criteria of APS (aPL carriers) and 20 normal healthy subjects. Sera were stored at - 20 °C to perform an ELISA test to evaluate the presence of anti-D4GDI antibodies. Then, we purified autoantibodies anti-D4GDI from patient sera. These antibodies were used to conduct in vitro studies on platelet activation. RESULTS: We identified anti-D4GDI antibodies in sera from 18/38 (47%) patients with PAPS, in sera from 2/15(13%) aPL carriers, but in no sera from normal healthy subjects. Our in vitro results showed a significant 30% increase in the activation of integrin αIIbß3 upon stimulation of platelets from healthy donors preincubated with the antibody anti-D4GDI purified from the serum of APS patients. CONCLUSIONS: In conclusion, we show here that antibodies anti-D4GDI are present in the sera of PAPS patients and can prime platelet activation, explaining, at least in part, the pro-thrombotic state and the thrombocytopenia of PAPS patients. These findings may lead to improved diagnosis and treatment of APS.

Usefulness of composite indices in the assessment of joint involvement in systemic lupus erythematosus patients: correlation with ultrasonographic score.

Specific indices are not available to evaluate systemic lupus erythematosus (SLE) joint involvement; indeed, the application of indices validated for rheumatoid arthritis has been suggested. We evaluated the usefulness of organ specific composite indices, i.e. the Disease Activity Score on 28 joints (DAS28), Simplified Disease Activity Index (SDAI), Clinical Disease Activity Index (CDAI), and the ratio of swollen to tender joints (STR), to assess SLE joint activity by analyzing the correlation between these indices and ultrasonography (US) inflammatory status. We evaluated SLE patients with arthralgia and/or arthritis: the above-mentioned indices were calculated and the SLE Disease Activity Index 2000 (SLEDAI-2k) was applied to assess global disease activity. US of I-V metacarpophalangeal, I-V proximal interphalangeal, wrist, and knee bilateral was performed. Synovial effusion/hypertrophy and power Doppler findings were scored according to a semi-quantitative scale (0-3) to obtain an inflammatory total score (0-216). One hundred and six patients (M/F 7/99, median age 49.5 years (IQR 17.0), median disease duration 8.5 years (IQR 17.0)) were enrolled. We identified a positive correlation between US score and DAS28-CRP ( r = 0.3, p = 0.007), STR ( r = 0.42, p = 0.0005), SDAI ( r = 0.33, p = 0.02), CDAI ( r = 0.29, p = 0.03); US score reflected different levels of clinimetric joint activity. In conclusion, we suggest the ability of composite indices in detecting SLE joint inflammation and their possible real-life use.

Anti-carbamylated protein antibodies in systemic lupus erythematosus patients with articular involvement.

Objective Several studies have evaluated the prevalence of rheumatoid factor (RF) and anti-citrullinated proteins antibodies (ACPA) in systemic lupus erythematosus (SLE) patients but no data are available on the anti-carbamylated proteins (anti-CarP), a new biomarker for rheumatoid arthritis (RA). We evaluated the anti-CarP prevalence in SLE patients with joint involvement and the associations with different phenotypes. Methods Seventy-eight SLE patients with joint involvement were enrolled (F/M 73/5; mean ± SD age 47.6 ± 11.2 years; mean ± SD disease duration 214.3 ± 115.6 months). As control groups, we evaluated SLE patients without joint manifestations ( N = 15), RA ( N = 78) and healthy individuals (HS, N = 98). Anti-CarP were assessed by home-made ELISA in all patients and controls, RF and ACPA in SLE patients with joint involvement (commercial ELISA kit). Results The prevalence of anti-CarP in SLE patients with joint involvement was similar to RA ( p = NS) and significantly higher compared with SLE without joint involvement and HS ( p < 0.0001, p < 0.0001, respectively). Four patients were positive for all three antibodies: seventy-five percent of these showed Jaccoud arthropathy. Fourty-five percent of ACPA-ve/RF-ve patients were anti-CarP + ve. Conclusions The evaluation of anti-CarP in SLE joint involvement demonstrated a prevalence of almost 50%, similar to RA and significantly higher than SLE without joint involvement and HS.

A polymorphism upstream MIR1279 gene is associated with pericarditis development in Systemic Lupus Erythematosus and contributes to definition of a genetic risk profile for this complication.

Recently, a study has shown that a polymorphism in the region of MIR1279 modulates the expression of the TRAF3IP2 gene. Since polymorphisms in the TRAF3IP2 gene have been described in association with systemic lupus erithematosus (SLE) susceptibility and with the development of pericarditis, our aim is to verify if the MIR1279 gene variability could also be involved. The rs1463335 SNP, located upstream MIR1279 gene, was analyzed by allelic discrimination assay in 315 Italian SLE patients and 201 healthy controls. Moreover, the MIR1279 gene was full sequenced in 50 patients. A case/control association study and a genotype/phenotype correlation analysis were performed. We also constructed a pericarditis genetic risk profile for patients with SLE. The full sequencing of the MIR1279 gene in patients with SLE did not reveal any novel or known variation. The variant allele of the rs1463335 SNP was significantly associated with susceptibility to pericarditis ( P = 0.017 and OR = 1.67). A risk profile model for pericarditis considering the risk alleles of MIR1279 and three other genes (STAT4, PTPN2 and TRAF3IP2) showed that patients with 4 or 5 risk alleles have a higher risk of developing pericarditis ( OR = 4.09 with P = 0.001 and OR = 6.04 with P = 0.04 respectively). In conclusion, we describe for the first time the contribution of a MIR1279 SNP in pericarditis development in patients with SLE and a genetic risk profile model that could be useful to identify patients more susceptible to developing pericarditis in SLE. This approach could help to improve the prediction and the management of this complication.

Joint involvement in patients affected by systemic lupus erythematosus: application of the swollen to tender joint count ratio.

Joint involvement is a common manifestation in systemic lupus erythematosus (SLE). According to the SLE disease activity index 2000 (SLEDAI-2K), joint involvement is present in case of ≥2 joints with pain and signs of inflammation. However this definition could fail to catch all the various features of joint involvement. Alternatively the Swollen to Tender joint Ratio (STR) could be used. This new index, which was originally proposed for rheumatoid arthritis (RA) patients, is based on the count of 28 swollen and tender joints. Our study is, therefore, aimed to assess joint involvement in a SLE cohort using the STR. SLE patients with joint symptoms (≥1 tender joint) were enrolled over a period of one month. Disease activity was assessed by SLEDAI-2K. We performed the swollen and tender joint count (0-28) and calculated the STR. Depending on the STR, SLE patients were grouped into three categories of disease activity: low (STR1.0). We also calculated the disease activity score based on a 28-joint count and the erythrocyte sedimentation rate (DAS28-ESR). We enrolled 100 SLE patients [F/M 95/5, mean±standard deviation (SD) age 46.3±10.6 years, mean±SD disease duration 147.1±103.8 months]. The median of tender and swollen joints was 4 (IQR 7) and 1 (IQR 2.5), respectively. The median STR value was 0.03 (IQR 0.6). According to the STR, disease activity was low in 70 patients, moderate in 23 and high in 7. A significant correlation was identified between STR values and DAS28 (r=0.33, p=0.001). The present study suggests a correlation between STR and DAS28, allowing an easier and faster assessment of joint involvement with the former index.

Biological therapies in rheumatic diseases.

The development of the biological drugs has revolutionized the therapeutic approach of the chronic inflammatory rheumatic diseases, particularly in patients resistant to standard treatment. These drugs are characterized by an innovative mechanism of action, based on the targeted inhibition of specific molecular or cellular targets directly involved in the pathogenesis of the diseases: pro-inflammatory cytokines (tumor necrosis factor, interleukin-1 and 6), CTLA-4, and molecules involved in the activation, differentiation and maturation of B cells. Their use has indeed allowed for a better prognosis in several rheumatic diseases (such as rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, systemic lupus erythematosus) and to obtain a clinical remission. In the present review we give an overview of the biological drugs currently available for the treatment of the rheumatic diseases, analyzing the different mechanism of action, the therapeutic indications and efficacy data, and adverse events.

Preventive mental health interventions in peacekeeping missions to Somalia and Haiti.

Mental health interventions of the 528th Combat Stress Control unit to limit the numbers of psychiatric casualties on recent peacekeeping missions are discussed. Similarities and differences in the mental health support of Operation Restore Hope (Somalia) and Operation Uphold Democracy (Haiti) are reviewed. The mission to Somalia was marked by unexpected combat casualties. The mission to Haiti was marked by unexpected self-inflected casualties. Lessons learned by mental health officers serving on these missions are discussed. Recommendations for prevention of psychiatric casualties on future missions are presented.