Immunomodulatory effects of therapeutic plasma exchange on monocytes in antiphospholipid syndrome

The role of monocytes in thrombotic diseases: a review

Cardiovascular and cerebrovascular diseases are the number one killer threatening people's life and health, among which cardiovascular thrombotic events are the most common. As the cause of particularly serious cardiovascular events, thrombosis can trigger fatal crises such as acute coronary syndrome (myocardial infarction and unstable angina), cerebral infarction and so on. Circulating monocytes are an important part of innate immunity. Their main physiological functions are phagocytosis, removal of injured and senescent cells and their debris, and development into macrophages and dendritic cells. At the same time, they also participate in the pathophysiological processes of pro-coagulation and anticoagulation. According to recent studies, monocytes have been found to play a significant role in thrombosis and thrombotic diseases of the immune system. In this manuscript, we review the relationship between monocyte subsets and cardiovascular thrombotic events and analyze the role of monocytes in arterial thrombosis and their involvement in intravenous thrombolysis. Finally, we summarize the mechanism and therapeutic regimen of monocyte and thrombosis in hypertension, antiphospholipid syndrome, atherosclerosis, rheumatic heart disease, lower extremity deep venous thrombosis, and diabetic nephropathy.

Thrombocytopenia in a cohort of primary and secondary antiphospholipid syndrome patients: Relation to clinical, laboratory manifestations and damage index

Objectives

This study aims to evaluate the prevalence of thrombocytopenia in a cohort of patients with primary and secondary antiphospholipid syndrome (APS) and to examine the relation of thrombocytopenia to the clinical, laboratory findings, and damage index for antiphospholipid syndrome (DIAPS).

Patients and methods

Between August 2018 and February 2019, a total of 168 patients (16 males, 152 females; mean age: 32.5±8.4 years; range, 18 to 59 years) who were followed in our clinic for APS were retrospectively analyzed. Medical records of the patients were screened and clinical data, laboratory investigations, and treatments applied were recorded. The DIAPS was calculated for all patients. The patients were divided into two groups according to the presence or absence of thrombocytopenia and both groups were compared regarding clinical, laboratory findings and DIAPS. Further subgroup analysis was done for patients with primary APS.

Results

The most common clinical manifestations in our patients were obstetric manifestations (77.4% in pregnant women), musculoskeletal manifestations (69%) and peripheral vascular thrombosis (54.8%). The prevalence of thrombocytopenia in our study was 42.3%, and it was significantly associated with musculoskeletal manifestations (p=0.043), vascular thrombosis (p=0.043), neurological manifestations (p=0.030), cutaneous manifestations (p=0.006), and use of immunosuppressives (p=0.047). The DIAPS was significantly higher in the thrombocytopenia group (p=0.034). Further subgroup analysis of patients with primary APS revealed that neurological manifestations (p=0.010) were significantly higher in the thrombocytopenia group, while the DIAPS was higher in the thrombocytopenia group, but it did not reach statistical significance (p=0.082).

Conclusion

Thrombocytopenia may be associated with a higher incidence of vascular thrombosis, neurological manifestations, musculoskeletal manifestations, use of immunosuppressive treatment, and DIAPS. In primary APS patients, thrombocytopenia may be a risk for neurological manifestations.

Evaluation of membrane-based therapeutic plasma exchange as adjunctive treatment for immune-mediated hematologic disorders in dogs

Background

Therapeutic plasma exchange (TPE) has been used increasingly to treat immunological diseases in dogs, although data concerning its efficacy are lacking.

Hypothesis/Objectives

To describe the clinic and the outcome of dogs with immune‐mediated hematological disorders (IMHD) treated with membrane filtration TPE.

Animals

One hundred forty‐six dogs diagnosed with IMHD, including 17 dogs treated with and 129 control dogs treated without TPE.

Methods

Retrospective study of cases selected with a search of all medical records for dogs diagnosed with IMHD (2010‐2019). Primary outcomes included the assessment of safety and efficacy of adjunctive TPE compared to medical treatment alone.

Results

The TPE group included 7 dogs with immune‐mediated hemolytic anemia (IMHA), 5 dogs with immune‐mediated thrombocytopenia (IMT), and 5 dogs with combined IMHA‐IMT; the control group included 63 dogs with IMHA, 47 dogs with IMT, and 19 dogs with IMHA‐IMT. Dogs treated with TPE were more often refractory to initial immunosuppression (71%) than controls (43%; P = .04). Complications were observed in 15/43 TPE treatments (35%). The response rate of dogs treated with TPE was 83% in IMHA (controls, 65%; P = .5) and 80% in IMT (controls, 70%; P = .71). Overall, 12/17 dogs (71%) treated with TPE reached complete remission, 2/17 (12%) partial remission, and 3/17 (18%) died or were euthanized. Eighty‐two percent of the dogs treated with TPE survived to discharge (controls, 69%; P = .4).

Conclusions and Clinical Importance

Despite a bias toward dogs refractory to initial immunosuppression, dogs treated with adjunctive TPE had a similar outcome as dogs treated medically.

Coumarin derivative 7-isopentenyloxycoumarin induces in vivo antitumor activity by inhibit angiogenesis via CCL2 chemokine decrease

Cancer is one of the most urgent problems in medicine. In recent years, cancer is the second leading cause of death globally. In search for more effective and less toxic treatment against cancer, natural products are used as prototypes in the synthesis of new anticancer drugs. The aim of this study was to investigate the in vivo toxicity and the mechanism of antitumor action of 7-isopentenyloxycoumarin (UMB-07), a coumarin derivative with antitumor activity. The toxicity was evaluated in vitro (hemolysis assay), and in vivo (micronucleus and acute toxicity assays). Ehrlich ascites carcinoma model was used to evaluate in vivo antitumor activity of UMB-07 (12.5, 25, or 50 mg/kg, intraperitoneally, i.p.), after 9 days of treatment, as well as toxicity. UMB-07 (2000 μg/mL) induced only 0.8% of hemolysis in peripheral blood erythrocytes of mice. On acute toxicity assay, LD₅₀ (50% lethal dose) was estimated at around 1000 mg/kg (i.p.), and no micronucleated erythrocytes were recorded after UMB-07 (300 mg/kg, i.p.) treatment. UMB-07 (25 and 50 mg/kg) reduced tumor volume and total viable cancer cells. In the mechanism action investigation, no changes were observed on the cell cycle analysis; however, UMB-07 reduced peritumoral microvessels density and CCL2 chemokine levels. In addition, UMB-07 showed weak toxicity on biochemical, hematological, and histological parameters after 9 days of antitumor treatment. The current findings suggest that UMB-07 has low toxicity and exerts antitumor effect by inhibit angiogenesis via CCL2 chemokine decrease.

Anti-domain 1 β2 glycoprotein antibodies increase expression of tissue factor on monocytes and activate NK Cells and CD8+ cells in vitro

Background

β2-Glycoprotein I (β2GPI) represents the major antigenic target for antiphospholipid antibodies (aPL), with domain 1 (D1) being identified as a risk factor for thrombosis and pregnancy complications in APS. We aimed to analyse the ability of aPL, and particularly anti-D1 β2GPI, to stimulate prothrombotic and proinflammatory activity of immune cells in vitro.

Methods

Peripheral blood mononuclear cells (PBMCs) from 11 healthy individuals were incubated with: (1) “anti-D1(+)”—pooled plasma derived from patients suspected of having APS contained anticardiolipin antibodies (aCL), lupus anticoagulant (LA), anti-β2GPI and anti-D1 β2GPI; (2) “anti-D1(−)”—pooled plasma from patients suspected of having APS contained aCL, LA, anti-β2GPI, and negative for anti-D1 β2GPI; (3) “seronegative”—negative for aPL.

Results

The presence of anti-D1(+) and anti-D1(−) plasma resulted in increased HLA-DR and CD11b on monocytes. While only anti-D1(+) plasma markedly increased the percentage and median fluorescence intensity (MFI) of CD142 (tissue factor, TF) on monocytes in comparison with those cultured with anti-D1(−) and seronegative plasma. Anti-D1(+) plasma resulted in increased percentage and MFI of activation marker CD69 on NK and T cytotoxic cells. Expression of IgG receptor FcγRIII(CD16) on monocytes and NK cells was down-regulated by the anti-D1(+) plasma.

Conclusions

Taking together, our study shows the ability of patient-derived aPL to induce immune cell activation and TF expression on monocytes. For the first time, we demonstrated the influence of anti-D1 β2GPI on the activation status of monocytes, NK and cytotoxic T cells. Our findings further support a crucial role of D1 epitope in the promotion of thrombosis and obstetrical complications in APS.

Environmental Triggers of Autoreactive Responses: Induction of Antiphospholipid Antibody Formation

Antiphospholipid antibodies (aPLs) comprise a diverse family of autoantibodies targeted against proteins with the affinity toward negatively charged phospholipids or protein-phospholipid complexes. Their clinical significance, including prothrombotic potential of anti-cardiolipin antibodies (aCLs), anti-β2-glycoprotein I antibodies (aβ2-GPIs), and lupus anti-coagulant (LA), is well-established. However, the ontogeny of these pathogenic aPLs remains less clear. While transient appearance of aPLs could be induced by various environmental factors, in genetically predisposed individuals these factors may eventually lead to the development of the antiphospholipid syndrome (APS). Since the first description of APS, it has been found that a wide variety of microbial and viral agents influence aPLs production and contribute to clinical manifestations of APS. Many theories attempted to explain the pathogenic potential of different environmental factors as well as a phenomenon termed molecular mimicry between β2-GPI molecule and infection-relevant structures. In this review, we summarize and critically assess the pathogenic and non-pathogenic formation of aPLs and its contribution to the development of APS.

Therapeutic plasma exchange versus double plasma molecular absorption system in hepatitis B virus-infected acute-on-chronic liver failure treated by entercavir: A prospective study

BACKGROUND

Therapeutic plasma exchange (TPE) and double plasma molecular absorption system (DPMAS) were two extracorporeal liver support systems. Few studies compared their efficacy profile.

OBJECTIVE

This study was to compare the efficacy of TPE and DPMAS on acute-on-chronic liver failure (ACLF) caused by hepatitis B virus (HBV-ACLF).

METHODS

60 HBV-ACLF patients were enrolled and prospectively studied. All patients received entecavir therapy, and were assigned to TPE group (n = 33) and DPMAS group (n = 27). Primary end-points were the effects of TPE and DPMAS on liver function and serum inflammatory markers.

RESULTS

Serum procalcitonin, interleukin (IL)-6, and high sensitive C-reactive protein (hsCRP) were significantly elevated in patients with HBV-ACLF. TPE achieved significantly higher removal rates of total bilirubin (TBIL, P = .002), direct bilirubin (DBIL, P = .006), and hsCRP (P = .010) than DPMAS, but DPMAS displayed lower loss rate of albumin (P = .000). TPE and DPMAS resulted in similarly increased serum IL-6 levels and comparable 12-week survivals (P > .05). Multivariate analysis showed that hospital stay (Relative Risk [RR]: 1.062, 95% Confidence Interval [CI]: 1.011-1.115, P = .016), prothrombin time (RR: 1.346, 95% CI: 1.077-1.726, P = .010), and international normalized ratio (RR: 0.013, 95% CI: 0.006-0.788, P = .041) were independent predictors for 12-week survival. Both TPE and DPMAS treatments were well-tolerated.

CONCLUSION

Compared to DPMAS, TPE was more efficient in eliminating TBIL, DBIL, and hsCRP, but it was associated with higher loss rate of albumin. TPE and DPMAS were similar in improving 12-week survivals in HBV-ACLF.