Von Willebrand factor, red cell fragmentation, and disease activity in systemic lupus erythematosus

Type I Interferon as cardiovascular risk factor in systemic and cutaneous lupus erythematosus: A systematic review

OBJECTIVE

Patients with systemic lupus erythematosus (SLE) have a high burden of cardiovascular disease (CVD) of multifactorial origin. The aim of this systematic review is to analyze the role of the interferon I (IFN-I) signature and fibroblast growth factor-23 (FGF-23) in patients with SLE or cutaneous lupus erythematosus (CLE) herein.

MATERIALS AND METHODS

We conducted a systematic literature search in PubMed and Scopus using keywords for major adverse cardiovascular events (MACE) and intermediate outcomes (endothelial dysfunction, subclinical atherosclerosis, platelet activation) associated with IFN-I or FGF-23 in patients with SLE and CLE.

RESULTS

4745 citations were screened, of which 12 studies were included. IFN-I was associated with MACE in two third of the studies and the association was strongest for cardiac events. An association of IFN-I was found in all studies investigating impaired vascular function, but only in 50% (respectively 40%) of reports examining the relation of IFN-I and platelet activation (respectively subclinical atherosclerosis). Altogether the reports were of variable bias and quality due to high variability of examined IFN-I biomarkers and inconsistent results for different outcome measures. No studies investigating the cardiovascular risk of circulating IFN-I in CLE, nor FGF-23 in SLE or CLE were found.

CONCLUSION

Clinical studies measuring the association between IFN-I and direct / intermediate measures of CVD are rare and ambiguous in SLE and nonexistent in CLE, hampering a definite conclusion.

Post-Partum Thrombotic Thrombocytopenic Purpura (TTP) in a Patient with known Idiopathic (Immune) Thrombocytopenic Purpura: a case report and review of the literature

Background

Incidences of immune thrombocytopenic purpura occur in 1 in every 1000–10,000 pregnancies accounting for 3% of all thrombocytopenic pregnancies. A pre-existing immune thrombocytopenic purpura is known to be a risk factor for developing thrombocytopenia during pregnancy. We present here the treatment regime and management of a patient with known immune thrombocytopenic purpura who developed postpartum thrombotic thrombocytopenia with atypical response to traditional therapy.

Pregnant women are more vulnerable to immune thrombocytopenic purpura or thrombotic thrombocytopenia. Pregnancy or postpartum thrombotic thrombocytopenia accounts for 10–25% of all thrombotic thrombocytopenia.

Case presentation

This case report deals with the treatment regime and management of a patient with known immune thrombocytopenic purpura who developed postpartum thrombotic thrombocytopenia. A 30-year-old Middle Eastern woman, with a prior diagnosis of chronic immune thrombocytopenic purpura had remained off-the-treatment for many years. After primary unexplained infertility for 8 years, for which she underwent six failed trials of in vitro fertilization, she delivered a healthy baby through caesarean section. Two days post-surgery, she had persistent thrombocytopenia, ecchymoses, bruises, and hemolysis. Her blood film revealed leukoerythroblastic anemia. Her blood tests also revealed a very low level of haptoglobin, and low level of ADAMTS13. A diagnosis of thrombotic thrombocytopenia was suspected. Plasma exchange therapy was started with partial response. We showed that rituximab in conjunction with mycophenolate mofetil following plasma exchange therapy was effective in controlling the low platelet count in our patient.

Conclusions

Rituximab in conjunction with mycophenolate mofetil following plasma exchange therapy was effective in controlling the low platelet count in our patient. Only two doses of rituximab were sufficient to normalize our patient. We present here a case of safe and effective use of rituximab in pregnancy-induced thrombotic thrombocytopenia.

Evaluation of Impact of Interferon-Induced Helicase C Domain-Containing Protein 1 Gene in Egyptian Systemic Lupus Erythematosus Patients and its Relationship With Vascular Manifestations of the Disease

Objectives

This study aims to investigate the impact of interferon-induced helicase C domain-containing protein 1 (IFIH1) gene single nucleotide polymorphism on interferon pathway signaling in systemic lupus erythematosus (SLE) patients specifically with vascular affection.

Patients and methods

The cross-sectional study included 30 consecutive SLE patients (2 males, 28 females; mean age 28±3.4 years; range 16 to 40 years) diagnosed according to the American College of Rheumatology revised criteria and 10 healthy age- and sex-matched controls (2 males, 8 females; mean age 27±2.5 years; range 22 to 23 years). SLE patients and controls were compared in terms of quantitative reverse transcriptase polymerase chain reaction gene expression of IFIH1 gene, von Willebrand factor, carotid intima-media thickness, and ankle brachial index.

Results

Interferon-induced helicase C domain-containing protein 1 gene expression was significantly higher in SLE patients than controls (1.7±0.6 and 0.5±0.2, respectively) (p<0.0001). IFIH1 gene expression was highly related to vascular complication with a cutoff point at 1.74 and it positively correlated with other endothelial dysfunction markers.

Conclusion

Interferon-induced helicase C domain-containing protein 1 gene (single nucleotide polymorphism 1990670) is associated with SLE in Egyptian patients. Expression of IFIH1 gene is related to disease activity and may serve as a novel predictor of vascular affection in SLE.

Increased von Willebrand factor levels in patients with systemic lupus erythematosus reflect inflammation rather than increased propensity for platelet activation

Background

von Willebrand factor (VWF) is involved in platelet plug formation and protein transport. Increased VWF levels in systemic lupus erythematous (SLE) are considered risk factors for vascular events. VWF protein levels, however, do not accurately reflect its platelet-aggregating function, which has not been examined in SLE.

Methods

Cross-sectional study with clinical and laboratory data obtained in patients with SLE (n=92) from a regional lupus registry. VWF function was determined by ristocetin-induced platelet aggregation (VWF ristocetin cofactor, VWF:RCo) and VWF levels by turbidimetric assay (VWF antigen, VWF:Ag). The platelet-aggregating activity per VWF unit was estimated by the VWF RCo/Ag ratio. Healthy controls served as comparators and associations were evaluated by non-parametric methods.

Results

VWF:Ag (142% vs 107%, p=0.001) and VWF:RCo levels (123% vs 78%, p<0.041) were increased in patients with SLE, but VWF RCo/Ag ratio was similar as in controls (0.83 vs 0.82, p=0.8). VWF:Ag levels were higher in patients experiencing serositis but unrelated to other manifestations, thrombotic disease, Systemic Lupus Erythematous Disease Activity Index 2000 or Systemic Lupus International Collaborative Clinics-Damage Index. VWF:Ag levels correlated significantly with VWF:RCo levels (Rs 0.8, p<0.001), erythrocyte sedimentation rate (ESR) (Rs 0.32, p<0.01), anti-dsDNA Ab (Rs 0.27, p<0.01), total IgG (Rs 0.33 p<0.01), fibrinogen (Rs 0.28, p<0.01) and ceruloplasmin (Rs 0.367, p<0.01) levels. VWF:RCo levels were not related to clinical findings but were correlated with ESR, anti-dsDNA and transferrin levels. No serological associations existed for VWF RCo/Ag ratio (all p>0.2).

Conclusions

In this SLE cohort, VWF:Ag behaved similarly to acute-phase reactants, but VWF:Ag increases were not matched by increases in functional activity per unit of VWF. Thus, more VWF did not increase the propensity for platelet aggregation in SLE.

Loss of Immune Tolerance Is Controlled by ICOS in Sle1 Mice

ICOS, a member of the CD28 family, represents a key molecule that regulates adaptive responses to foreign Ags. ICOS is prominently expressed on T follicular helper (TFH) cells, a specialized CD4(+) T cell subset that orchestrates B cell differentiation within the germinal centers and humoral response. However, the contribution of ICOS and TFH cells to autoantibody profiles under pathological conditions has not been thoroughly investigated. We used the Sle1 lupus-prone mouse model to examine the role of ICOS in the expansion and function of pathogenic TFH cells. Genetic deletion of ICOS impacted the expansion of TFH cells in B6.Sle1 mice and inhibited the differentiation of B lymphocytes into plasma cells. The phenotypic changes observed in B6.Sle1-ICOS-knockout mice were also associated with a significant reduction in class-switched IgG, and anti-nucleosomal IgG-secreting B cells compared with B6.Sle1 animals. The level of vascular cell adhesion protein 1, a molecule that was shown to be elevated in patients with SLE and in lupus models, was also increased in an ICOS-dependent manner in Sle1 mice and correlated with autoantibody levels. The elimination of ICOS-expressing CD4(+) T cells in B6.Sle1 mice, using a glyco-engineered anti-ICOS-depleting Ab, resulted in a significant reduction in anti-nucleosomal autoantibodies. Our results indicate that ICOS regulates the ontogeny and homeostasis of B6.Sle1 TFH cells and influences the function of TFH cells during aberrant germinal center B cell responses. Therapies targeting the ICOS signaling pathway may offer new opportunities for the treatment of lupus and other autoimmune diseases.