Lymphocyte subpopulations and intima media thickness in primary antiphospholipd syndrome

mTOR-dependent loss of PON1 secretion and antiphospholipid autoantibody production underlie autoimmunity-mediated cirrhosis in transaldolase deficiency

Transaldolase deficiency predisposes to chronic liver disease progressing from cirrhosis to hepatocellular carcinoma (HCC). Transition from cirrhosis to hepatocarcinogenesis depends on mitochondrial oxidative stress, as controlled by cytosolic aldose metabolism through the pentose phosphate pathway (PPP). Progression to HCC is critically dependent on NADPH depletion and polyol buildup by aldose reductase (AR), while this enzyme protects from carbon trapping in the PPP and growth restriction in TAL deficiency. Although AR inactivation blocked susceptibility to hepatocarcinogenesis, it enhanced growth restriction, carbon trapping in the non-oxidative branch of the PPP and failed to reverse the depletion of glucose 6-phosphate (G6P) and liver cirrhosis. Here, we show that inactivation of the TAL-AR axis results in metabolic stress characterized by reduced mitophagy, enhanced overall autophagy, activation of the mechanistic target of rapamycin (mTOR), diminished glycosylation and secretion of paraoxonase 1 (PON1), production of antiphospholipid autoantibodies (aPL), loss of CD161+ NK cells, and expansion of CD38+ Ito cells, which are responsive to treatment with rapamycin in vivo. The present study thus identifies glycosylation and secretion of PON1 and aPL production as mTOR-dependent regulatory checkpoints of autoimmunity underlying liver cirrhosis in TAL deficiency.

Risk of Subclinical Atherosclerosis in Patients with Antiphospholipid Syndrome and Subjects With Antiphospholipid Antibody Positivity: A Systematic Review and Meta-analysis

Currently, the guidelines for the prevention of atherosclerosis in patients with antiphospholipid syndrome (APS) do not differ substantially from those in the general population. We aimed to assess the risk of subclinical atherosclerosis in patients with APS and subjects with antiphospholipid antibody (aPL) positivity. Systematic literature search was conducted through Medline and Scopus until January 2023. Random effects meta-analyses were performed to examine the differences in markers of subclinical atherosclerosis between APS patients, subjects positive for aPLs and healthy controls. Patients with APS had significantly higher values of common carotid artery (CCA) intima-media thickness (IMT) (MD = 0.07 mm; P < 0.0001), internal carotid artery IMT (MD = 0.06 mm; P < 0.01), carotid bifurcation IMT (MD = 0.14 mm; P < 0.01) and were more frequently diagnosed with atherosclerotic plaques compared to controls (OR = 3.73; P < 0.01). Similarly, APS patients showed a decreased flow and nitrate-mediated dilation (MD = -4.52 %; <0.01, MD = -1.25 %; P < 0.05, respectively). Interestingly, comparable were the results for subjects with aPL positivity, who had higher CCA-IMT (MD = 0.06 mm; P < 0.01) and higher prevalence of atherosclerotic plaques (OR = 2.59; P = 0.08) compared to controls. Sensitivity analysis conducted on primary APS patients revealed that the risk of atherosclerosis is associated with APS per se and is not exclusively driven by other underlying conditions. Patients with APS and subjects with aPLs have an increased risk of subclinical atherosclerosis and require early and disease-specific prevention of atherosclerosis.

Lymphocyte Disturbances in Primary Antiphospholipid Syndrome and Application to Venous Thromboembolism Follow-Up

Among patients with venous thromboembolism (VTE), the persistent detection of antiphospholipid (aPL) antibodies (Ab) represents an independent high risk factor for recurrence. However, oral anticoagulation vitamin K antagonist therapy, frequently used in these patients, is problematic in assessing and/or confirming a diagnosis of primary aPL syndrome (pAPS), suggesting use of alternative strategies. For this reason, and by analogy with other autoimmune diseases, a flow cytometer approach testing peripheral T cell subsets (CD3, CD4, and CD8), B cell subsets (B1, transitional, naive, and memory), and NK cells can be proposed. As an example and to validate the concept, pAPS patients selected from the monocentric VTE case-control EDITH's cohort were selected during their follow-up. As suspected and in contrast to non-APS VTE patients, other autoimmune diseases, and controls, pAPS VTE patients displayed specific lymphocyte disturbances. Quantitative and qualitative modifications were related to total CD4⁺ T cell reduction, a lower CD4/CD8 ratio, and disturbance in B cell homeostasis with increased proportions of B1 cells, transitional B cells (CD24⁺⁺CD38⁺⁺), and naive B cells (IgD⁺CD27^-), while memory B cells (IgD⁺CD27⁺ and IgD^-CD27⁺) were reduced. Interestingly, the absolute number of CD4⁺ T cells positively correlated with IgG anti-cardiolipin Ab levels. Altogether, disturbances of T and B cell homeostasis characterized pAPS VTE patients during their follow-up. This suggests a means of profiling that could be used in addition to existing criteria to characterize them.

Delineating the deranged immune system in the antiphospholipid syndrome

The antiphospholipid syndrome (APS) is a systemic autoimmune disease that is characterized serologically by the presence of antiphospholipid antibodies (aPL) and clinically by vascular thrombosis and obstetric complications. The protein β2 glycoprotein I (β2GPI) is identified as the most important autoantigen in this syndrome. Activation of endothelial cells, thrombocytes and placental tissue by anti-β2GPI antibodies relates to the clinical manifestations of APS. This review describes genetic and environmental factors in relation to APS and summarizes the current knowledge on abnormalities in components of both the innate and adaptive immune system in APS. The role of dendritic cells, T-cells, B-cells, monocytes, neutrophils and NK-cells as well as the complement system in APS are discussed. Several gaps in our knowledge on the pathophysiology of APS are identified and a plea is made for future extensive immune cell profiling by a systems medicine approach in order to better unravel the pathogenesis of APS, to gain more insight in the role of the immune system in APS as well as having the potential to reveal biomarkers or novel therapeutic targets.

Markers of cardiovascular risk in patients with antiphospholipid syndrome: a meta-analysis of literature studies

Several studies reported on the association between antiphospholipid syndrome (APS) and venous thrombosis. In contrast, little is known about cardiovascular (CV) risk in APS. We performed a meta-analysis on the impact of APS on major markers of CV risk. Studies on the relationship between APS and common carotid artery intima-media thickness (CCA-IMT), internal carotid artery IMT (ICA-IMT), carotid bifurcation IMT (BIF-IMT), prevalence of carotid plaques, flow-mediated dilation (FMD), nitrate-mediated dilation (NMD), and ankle-brachial index (ABI) were systematically searched in PubMed, Web of Science, Scopus, and EMBASE databases. Twenty case-control studies (668 cases, 678 controls) were included. Compared to controls, APS patients showed a higher CCA-IMT (mean difference [MD] 0.11 mm; 95% CI 0.07, 0.14), ICA-IMT (MD 0.08 mm; 95% CI 0.05, 0.11), BIF-IMT (MD 0.09 mm; 95% CI 0.06, 0.12) and a higher frequency of carotid plaques (OR 3.87; 95% CI 1.61, 9.31). Moreover, a lower FMD was found in APS subjects than in controls (MD -4.49%; 95% CI -6.20, -2.78), with no differences in NMD (MD -1.80%; 95% CI -4.01, 0.42). Finally, an increased prevalence of pathological ABI was found in APS patients compared to controls (OR 7.26; 95% CI 1.77, 29.71). Despite heterogeneity among studies, APS appears significantly associated with markers of subclinical atherosclerosis and CV risk. These findings can be useful to plan adequate prevention strategies and therapeutic approaches.

Circulating naive and memory CD4+ T cells and metabolic syndrome in patients with systemic lupus erythematosus: data from a primarily Mestizo population

OBJECTIVE

The aim of this study was to determine whether the proportions of naive and memory CD4(+) T cell are independently associated with the metabolic syndrome (MetS) in patients with SLE.

METHODS

This cross-sectional study was conducted in SLE patients seen at our rheumatology department between September 2013 and April 2014. CD4(+) T cell subpopulations were examined by flow cytometry. The association of MetS and CD4(+) T cell subpopulations was examined by Mann-Whitney U-test and by multivariable analysis, adjusting for all possible confounding variables.

RESULTS

One hundred and seventeen patients were evaluated. Their mean age was 44.6 years (S.D. 12.6), 109 (93.2%) were female and all patients were Mestizo (mixed Caucasian and Amerindian ancestry). Fifty-two patients (44.4%) presented with MetS. Disease duration was 7.6 years (S.D. 6.8). The percentage of naive CD4(+) T cells was 25.0 (S.D. 12.7) and memory CD4(+) T cells was 66.7 (S.D. 13.2) and the memory:naive CD4(+) T cell ratio was 4.3 (S.D. 5.6). In multivariable analysis, the percentage of naive CD4(+) T cells was negatively associated with the presence of MetS [odds ratio (OR) 0.959 (95% CI 0.923, 0.997), P = 0.033], whereas the percentage of memory CD4(+)T cells and the memory:naive CD4(+) T cell ratio were positively associated with its presence [OR 1.040 (95% CI 1.003, 1.078), P = 0.031 and OR 1.238 (95% CI 1.041, 1.472), P = 0.016, respectively].

CONCLUSION

In the SLE patients studied, a lower percentage of naive CD4(+) T cells, a higher percentage of memory CD4(+) T cells and the memory:naive CD4(+) T cell ratio were independently associated with the presence of MetS. This association could reflect the impact of immunosenescence among SLE patients with cardiovascular morbidity.

White blood cell subsets are associated with carotid intima-media thickness and pulse wave velocity in an older Chinese population: the Guangzhou Biobank Cohort Study

Cross-sectional associations between white blood cell (WBC) count, lymphocyte and granulocyte numbers, and carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (PWV) were examined in a novel older Chinese community sample. A total of 817 men and 760 women from a sub-study of the Guangzhou Biobank Cohort Study had a full blood count measured by an automated hematology analyzer, carotid IMT by B-mode ultrasonography and brachial-ankle PWV by a non-invasive automatic waveform analyzer. Following adjustment for confounders, WBC count (β=0.07, P<0.001) and granulocyte (β=0.07, P<0.001) number were significantly positively related to PWV, but not lymphocyte number. Similarly, WBC count (β=0.08, P=0.03), lymphocyte (β=0.08, P=0.002) and granulocyte (β=0.03, P=0.04) number were significantly positively associated with carotid IMT, but only the association with lymphocyte count survived correction for other cardiovascular risk factors. In conclusion, higher WBC, particularly lymphocyte and granulocyte, count could be used, respectively, as markers of cardiovascular disease risk, measured through indicators of atherosclerosis and arterial stiffness. The associations for WBC count previously observed by others were likely driven by higher granulocytes; an index of systemic inflammation.

Quantitative abnormalities of peripheral blood distinct T, B, and natural killer cell subsets and clinical findings in obstetric antiphospholipid syndrome

OBJECTIVE

Few studies have assessed immunophenotypic abnormalities on lymphocyte subsets in patients with antiphospholipid syndrome (APS). We performed an extended immunological study to define alterations of distinct T, B, and natural killer (NK) cell subsets in obstetric patients with APS and their relationship with APS-associated complications.

METHODS

PATIENTS AND CONTROLS

36 women with APS [Sydney criteria, Group A1 without thrombosis (n=26), Group A2 with thrombosis (n=10)]; and 36 age matched women with recurrent abortion without antiphospholipid antibodies (disease controls; Group B), 36 healthy parous women (healthy controls; Group C), and 36 healthy nonparous women (healthy controls; Group D). Thrombotic events occurred after history of abortions in all A2 women. Three-color whole-blood flow cytometry was used to characterize the distinct immunophenotypes.

RESULTS

A1 patients had significantly higher percentages of CD4+CD45RA-CCR7+ central memory cells (A1 vs D), higher percentages of activated CD4+CD25+ T cells (A1 vs D), and lower percentages and absolute counts of CD4+CD45RA-CCR7- effector memory cells (A1 vs D). Group A2 patients had higher percentages and absolute numbers of CD19+CD27-IgD+ naive B cells (A2 vs A1 vs all controls), lower percentages and absolute numbers of CD3-CD56+CD16+ NK cells (A2 vs all controls), and higher percentages of activated CD4+DR+ (A2 vs all controls), CD8+DR+ (A2 vs A1 vs C vs D), CD4+CD38+DR+ (A2 vs D), and CD4+CD25+DR+ T cells (A2 vs all controls). Increased percentages of CD8+DR+ T cells [relative risk (RR) 2.43, 95% CI 1.09-5.44, p=0.02] and of naive B cells (RR 3.05, 95% CI 1.30-7.11, p=0.009) were associated with development of thrombosis.

CONCLUSION

In obstetric patients with APS we documented significant changes in T, B, and NK cell homeostasis. Increased levels of CD8+DR+ and CD19+CD27-IgD+ cells might identify obstetric patients with APS at risk of having thrombosis.