Antiphospholipid antibodies from patients with the antiphospholipid syndrome induce monocyte tissue factor expression through the simultaneous activation of NF‐κB/Rel proteins via the p38 mitogen‐activated protein kinase pathway,and of the MEK‐1/ERK pathway

Objective

Antiphospholipid syndrome (APS) is characterized by thrombosis and the presence of antiphospholipid antibodies (aPL). In patients with primary APS, expression of tissue factor (TF) on the surface of monocytes is increased, which may contribute to thrombosis in these patients. However, the intracellular mechanisms involved in aPL‐mediated up‐regulation of TF on monocytic cells are not understood. This study was undertaken to investigate the intracellular signals induced by aPL that mediate TF activation in monocytes from APS patients.

Methods

We analyzed, both in vivo and in vitro, aPL interactions with proteins that have signaling functions, including mitogen‐activated protein kinases (MAP kinases) and NF‐κB/Rel proteins.

Results

In vivo studies demonstrated significantly higher levels of both TF messenger RNA and TF protein in monocytes from APS patients compared with controls. At the molecular level, increased proteolysis of IκBα and activation of NF‐κB were observed. Constitutive activation of both p38 and ERK‐1 MAP kinases was also found. Treatment of normal monocytes with aPL activated ERK‐1 and p38 MAP kinases, as well as the IκB/NF‐κB pathway, in a dose‐dependent manner. NF‐κB activation and IκBα degradation induced by aPL were inhibited by the NF‐κB inhibitor SN50 and the p38 MAP kinase inhibitor SB203580, thus suggesting crosstalk between these pathways. However, the MEK‐1/ERK inhibitor PD98059 did not affect aPL‐induced NF‐κB binding activity. TF expression induced by aPL was significantly inhibited by combined treatment with the 3 inhibitors.

Conclusion

Our results suggest that aPL induces TF expression in monocytes from APS patients by activating, simultaneously and independently, the phosphorylation of MEK‐1/ERK proteins, and the p38 MAP kinase–dependent nuclear translocation and activation of NF‐κB/Rel proteins.

     

Mycophenolate mofetil in systemic lupus erythematosus: efficacy and tolerability in 86 patients

OBJECTIVE: To assess the indications, efficacy, and tolerability of mycophenolate mofetil (MMF) in patients with systemic lupus erythematosus (SLE) resistant to other immunosuppressive therapy. METHODS: Records of 93 patients with SLE were retrospectively reviewed. Seven patients were excluded. The remaining 86 patients received other immunosuppressive drugs before MMF. Efficacy was measured by changes in daily oral prednisolone dose, European Consensus Lupus Activity Measurement Index (ECLAM), erythrocyte sedimentation rate (ESR), C-reactive protein, and dsDNA antibody titer. In renal patients, changes in serum creatinine, creatinine clearance, chromium-51 EDTA glomerular filtration rate (EDTA-GFR), and 24 hour urine protein excretion were also evaluated. RESULTS: Indications for MMF were mainly renal involvement (59% of patients), uncontrolled disease activity (14%), and other SLE related manifestations (13%). Overall, we found a significant reduction in the steroid dosage, ECLAM, ESR, and anti-dsDNA antibody titer. Renal patients (n = 35) showed a significant reduction in urinary 24 hour protein excretion. Levels of serum creatinine, creatinine clearance, and EDTA-GFR showed no significant change during treatment. Thirty-seven patients (42.8%) developed adverse events. Gastrointestinal intolerance in 25 (29%) and infections in 20 (23.2%) were the most frequent. The drug was discontinued in 14 (16.3%) patients due to side effects and 6 patients discontinued MMF because they achieved disease remission and were trying to conceive. MMF was stopped due to lack of efficacy in 12 patients. CONCLUSION: Our data suggest that MMF is a good therapeutic alternative for patients with SLE and renal involvement or refractory disease activity.     

Autoantigen-specific regulatory T cells, a potential tool for immune-tolerance reconstitution in type-2 autoimmune hepatitis

Effector CD4 and CD8 T cell immune responses to cytochrome P450IID6 (CYP2D6), the autoantigen of autoimmune hepatitis type 2 (AIH-2), are permitted by a numerical and functional impairment of CD4(pos) CD25(high) regulatory T cells (T-regs). We aimed to investigate whether T-regs specific for CYP2D6 immunodominant regions and restricted by the appropriate human leukocyte antigen (HLA)-DR molecule can be generated in patients with AIH-2 and can control CD4 and CD8 T cell effectors targeting identical or overlapping CYP2D6 regions. CYP2D6-specific regulatory T cells (CYP2D6 T-regs) were obtained from peptide-pulsed monocyte-depleted peripheral blood mononuclear cells of 17 patients with AIH-2, who were positive for the predisposing HLA-DR7 and/or HLA-DR3 alleles. Their antigen specificity was assessed by cytofluorimetry using HLA class II tetramers and their cytokine profile by intracellular staining. T-reg ability to suppress was ascertained by measuring reduction of CD4(pos) CD25(neg) cell proliferation/effector cytokine secretion and of CD8 T cell cytotoxicity. The most efficient suppression of effector T cell proliferation, inflammatory cytokine release, and cytotoxicity was obtained by coculturing T-regs with CYP2D6-peptide-loaded semimature dendritic cells (smDCs), and smDC-CYP2D6 T-regs also expressed high levels of FOXP3 (forkhead box P3). Possession of the appropriate HLA-DR molecule and recognition of the CYP2D6 autoantigenic sequence were critical to the synergistic smDC-CYP2D6 T-reg immunoregulatory functions, and lack of either element led to poor control of responder cell proliferation and cytokine secretion. Moreover, interferon-γ neutralization significantly boosted the suppressive ability of CYP2D6 T-regs. CONCLUSION: T-regs generated under CYP2D6-specific conditions and cocultured with smDCs are highly effective at controlling autoreactive T cells, thus providing the basis for a powerful and tailored form of immunotherapy for AIH-2.     

Gene expression profiling in male genital lichen sclerosus

Male genital lichen sclerosus (MGLSc) has a bimodal distribution in boys and men. It is associated with squamous cell carcinoma (SCC). The pathogenesis of MGLSc is unknown. HPV and autoimmune mechanisms have been mooted. Anti extracellular matrix protein (ECM)1 antibodies have been identified in women with GLSc. The gene expression pattern of LSc is unknown. Using DNA microarrays we studied differences in gene expression in healthy and diseased prepuces obtained at circumcision in adult males with MGLSc (n = 4), paediatric LSc (n = 2) and normal healthy paediatric foreskin (n = 4). In adult samples 51 genes with significantly increased expression and 87 genes with significantly reduced expression were identified; paediatric samples revealed 190 genes with significantly increased expression and 148 genes with significantly reduced expression. Concordance of expression profiles between adult and paediatric samples indicates the same disease process. Functional analysis revealed increased expression in the adult and child MGSLc samples in the immune response/cellular defence gene ontology (GO) category and reduced expression in other categories including genes related to squamous cancer. No specific HPV, autoimmune or squamous carcinogenesis-associated gene expression patterns were found. ECM1 and CABLES1 expression were significantly reduced in paediatric and adult samples respectively.     

Lupus and pregnancy: integrating clues from the bench and bedside

Adequate pregnancy care of women with systemic lupus erythematosus (SLE) rests on three pillars: a coordinated medical-obstetrical care, an agreed and well-defined management protocol and a good neonatal unit. Pregnancy should be planned following a preconceptional visit for counselling. Women with severe active disease or a high degree of irreversible damage, such as those with symptomatic pulmonary hypertension, heart failure, severe restrictive pulmonary disease or severe chronic renal failure should best avoid pregnancy. Treatment is based on hydroxychloroquine, low-dose steroids and azathioprine. Patients with antiphospholipid antibodies/syndrome should receive low-dose aspirin +/- low molecular weight heparin. The addition and the dose of heparin depend on the clinical profile of the patient, i.e. a previous history of miscarriage, foetal loss, placental insufficiency or thrombosis. A close surveillance, with monitoring of blood pressure, proteinuria and placental blood flow by Doppler studies helps the early diagnosis and treatment of complications such as preeclampsia and foetal distress. Postpartum follow-up is important.     

Severity of the compensatory anti-inflammatory response determined by monocyte HLA-DR expression may assist outcome prediction in cirrhosis

Purpose  

To investigate variations in expression of the monocyte antigen presentation molecule HLA-DR in cirrhosis.