Elisavet Grouzi

Antiphospholipid syndrome (APS) is the most common acquired form of thrombophilia and is associated with the presence of antiphospholipid antibodies (aPL) in the patient’s serum. Until now, the “double-hit” hypothesis remains the prevailing theory for APS pathogenesis. According to this model, the presence of aPL (first hit) is insufficient to trigger thrombosis. A secondary event, such as an inflammatory trigger or vascular injury (second hit), is required to initiate immunothrombosis, which ultimately leads to thromboembolism. Although immunothrombosis has a critical role in several mechanisms, such as in defense against pathogens, chronic immune system activation by aPL appears to disrupt its protective function. In the last three decades, the role of the complement system has gained increasing recognition in the pathophysiology of APS. aPL are involved in the dysregulation of multiple components, such as platelets, β2-glycoprotein I, and complement factor H, resulting in excessive activation of the complement system. Thus, the complement system is a key driver of thrombosis in APS and stands as a promising target for the development of future therapeutic strategies. In the current review article, we aim to summarize the ongoing research regarding the role of complement system dysregulation in APS-associated thrombosis development, while recognizing potential therapeutic targets. In the era of precision medicine, more data concerning targeted therapeutics in the field of APS are essential.

(1) Background: Antiphospholipid syndrome (APS) is associated with thrombotic events and the laboratory identification of antiphospholipid antibodies (aPL), in which lupus anticoagulant (LA), anticardiolipin (aCL), and anti-β2 glycoprotein I antibodies are included. The aim of the current retrospective study is to examine clinical characteristics and risk factors of ischemic stroke as a clinical manifestation of APS. (2) Methods: Adult patients diagnosed with APS between 1 January 2009 and 1 June 2024 were retrospectively enrolled in this study. Sydney-revised Sapporo criteria were used for the diagnosis of APS, while ischemic stroke was diagnosed based on the acute onset of focal neurologic deficits and confirmed with radiological findings. (3) Results: We studied 115 patients with APS. Specifically, 28 (24.35%) patients, with a mean age (standard deviation) of 54 (±12.5), had ischemic stroke as a clinical manifestation of APS. In univariate analysis, stroke development was associated with the following factors: age (p < 0.001), livedo reticularis (p = 0.046), avascular necrosis (AVN) (p = 0.046), hypertension (p < 0.001), dyslipidemia (p = 0.013), aCL IgG (U/L) antibodies title (p = 0.035), and adjusted global APS score (aGAPSS) (p = 0.047), while in multivariate analysis, it was associated with age (p = 0.006), hypertension (p < 0.001), AVN (p = 0.006), livedo reticularis (p = 0.035), aCL IgG title (p = 0.004), and aGAPSS (p = 0.002). (4) Conclusions: Stroke is a common initial manifestation of APS, with cardiovascular risk factors, particularly hypertension, being highly prevalent.

The tumor microenvironment has a significant input on prognosis and also for predicting clinical outcomes in various types of cancers. However, tumor tissue is not always available, thus, rendering peripheral blood a preferable alternative in the search for prognostic and predictive gene signatures. Head and neck squamous cell carcinoma (HNSCC) constitutes a quite heterogeneous disease characterized by poor prognosis. Therefore, the discovery of novel therapeutics based on prognostic gene signatures for effective disease governance is of paramount importance. In this study, we report for the first time an immune-gene signature identified in the peripheral blood of HNSCC patients comprising five genes (CLEC4C, IL23A, LCK, LY9, and CD19) which were more than threefold downregulated as compared to healthy individuals and were associated with poor prognosis. By performing analyses of HNSCC tumor samples from The Cancer Genome Atlas (TCGA) database, we discovered that decreased expression of these genes, both as single genes and as a 5-gene signature (5-GS), was significantly correlated with worse overall survival (OS). Our data show that the levels of expression of the 5-GS represent an immune profile predicting OS in patients with HNSCC.

Paroxysmal Nocturnal Hemoglobinuria (PNH) constitutes a rare bone marrow failure syndrome characterized by hemolytic anemia, thrombotic events (TEs), and bone marrow aplasia of variable degrees. Thrombosis is one of the major clinical manifestations of the disease, affecting up to 40% of individuals with PNH. Venous thrombosis is more prevalent, affecting mainly unusual sites, such as intrabdominal and hepatic veins. TEs might be the first clinical manifestation of PNH. Complement activation, endothelial dysfunction, hemolysis, impaired bioavailability of nitric oxide, and activation of platelets and neutrophils are implicated in the pathogenesis of TEs in PNH patients. Moreover, a vicious cycle involving the coagulation cascade, complement system, and inflammation cytokines, such as interleukin-6, is established. Complement inhibitors, such as eculizumab and ravulizumab (C5 inhibitors), have revolutionized the care of patients with PNH. C5 inhibitors should be initiated in patients with PNH and thrombosis, while they constitute a great prophylactic measure for TEs in those individuals. Anticoagulants, such as warfarin and low-molecular-weight heparin, and, in selected cases, direct oral anticoagulants (DOACs) should be used in combination with C5 inhibitors in patients who develop TEs. Novel complement inhibitors are considered an alternative treatment option, especially for those who develop extravascular or breakthrough hemolysis when terminal inhibitors are administered.

Prostate cancer (PCa) is one of the most common male cancers worldwide and one of the deadliest if unsuccessfully treated. Τhe need for reliable, easily accessible immune-related molecular biomarkers that could be combined with clinically defined criteria, including PSA and Gleason score, to accurately predict PCa patients’ clinical outcomes is emerging. Herein, we describe for the first time a blood-identified immune-related gene signature comprising eight upregulated multi-functional genes associated with poor prognosis. Next-generation sequencing (NGS) analysis of PCa patients’ peripheral blood samples revealed a more than three-fold upregulation of each of the eight genes as compared to samples originating from healthy donors. The construction of gene and protein interaction networks revealed different extents of the functional implications of these genes in the regulation of cell proliferation and immune responses. Analysis of the available data from The Cancer Genome Atlas (TCGA) regarding gene expression and survival of prostate adenocarcinoma (PRAD) and pan-cancer (PANCAN) patients revealed that intra-tumoral upregulation of this eight-gene signature (8-GS) was associated with poor 5-year progression-free intervals in PCa patients, even in those with high Gleason scores, and also with an unfavorable prognosis for cancer patients irrespective of the cancer type and even in the early stages. These observations suggest that further investigation of the 8-GS prospectively in randomized clinical trials, in which clinical benefit in terms of evaluating time to disease progression can be assessed, is warranted.

Background: During pregnancy and puerperium women are at high VTE risk. Current guidelines recommend dynamic VTE-risk assessment during pregnancy. Based on related RCOG-guidelines we constructed a digital VTE-risk assessment tool: PATrisks (www.PATrisks.com). Using this tool, we retrospectively evaluated the thrombotic risk in 742 women from our previous work, women who received thromboprophylaxis based on clinical experience for A) pregnancy complications, B) IVF treatment and C) prothrombotic tendency, in order to investigate whether that practice was justified according to the PATrisks scoring system for VTE prevention. Methods: Women with pregnancy complications [Group-A: 445], women who had undergone IVF [Group-B:132] and women with a prothrombotic tendency (thrombophilia, family history of VTE, other) [Group-C:165] were assessed using the PATrisks scoring system for thrombotic risk. The women were assigned into one of the following risk categories: low (score ≤ 2), intermediate (score = 3) and high (score ≥ 4). Further analysis per risk factor type (pre-existing or obstetric) and for various combinations of them, was also performed. We evaluated thrombotic risk early in pregnancy, and in the peripartum period. Results: The mean risk score antepartum was higher for women in Group B (3.3 in comparison with 1.9 and 2.0 in Group A and Group C respectively). Moreover, the risk score increased significantly postpartum for all Groups. The chi-square test also proved that there was a higher percentage of women at high or intermediate risk in group B compared to C before birth (55.3% vs.26.1% respectively, p < 0.0001, OR: 3.5, 95% CI: 2.2 – 5.7) and similarly after birth (85.6% vs. 56.4%, OR: 4.6, 95%CI: 2.6–8.2, p < 0.0001). In total 12 (1.6%) out of 742 women experienced thrombotic events, whether pre- or post-partum. Conclusions: LMWHs are widely prescribed during pregnancy for a number of indications, even when a proven scientific basis for such a practice is lacking. However, a considerable percentage of women were already at VTE-risk according to PATrisks and might have derived an additional benefit from LMWH in the form of VTE prevention. The rational use of these drugs should be optimized by establishing and implementing routine risk assessment for all pregnant women and by providing the necessary education to healthcare professionals.

In-depth understanding of the immune response provoked by SARS-CoV-2 infection is necessary, as there is a great risk of reinfection and a difficulty in achieving herd immunity due to a decline in both antibody concentration and avidity. Avidity testing, however, could overcome variability in the immune response associated with sex or clinical symptoms, and thus differentiate between recent and past infections. In this context, here, we analyzed SARS-CoV-2 antibody kinetics and avidity in Greek hospitalized (26%) and non-hospitalized (74%) COVID-19 patients (N = 71) in the course of up to 15 months after their infection to improve the accuracy of the serological diagnosis in dating the onset of the infection. The results showed that IgG-S1 levels decline significantly at four months (p = 0.0239) in both groups of patients and are higher in hospitalized ones (up to 2.1-fold, p < 0.001). Additionally, hospitalized patients’ titers drop greatly and are equalized to non-hospitalized ones only at a time-point of twelve to fifteen months. Antibody levels of women in total remain more stable months after infection, compared to men. Furthermore, we examined the differential maturation of IgG avidity after SARS-CoV-2 infection, showing an incomplete maturation of avidity that results in a plateau at four months after infection. We also defined 38.2% avidity (sensitivity: 58.9%, specificity: 90.91%) as an appropriate “cut-off” that could be used to determine the stage of infection before avidity reaches a plateau.

Early recognition of coagulopathy is necessary for its prompt correction and successful management. Novel approaches, such as point-of-care testing (POC) and administration of coagulation factor concentrates (CFCs), aim to tailor the haemostatic therapy to each patient and thus reduce the risks of over- or under-transfusion. CFCs are an effective alternative to ratio-based transfusion therapies for the correction of different types of coagulopathies. In case of major bleeding or urgent surgery in patients treated with vitamin K antagonist anticoagulants, prothrombin complex concentrate (PCC) can effectively reverse the effects of the anticoagulant drug. Evidence for PCC effectiveness in the treatment of direct oral anticoagulants-associated bleeding is also increasing and PCC is recommended in guidelines as an alternative to specific reversal agents. In trauma-induced coagulopathy, fibrinogen concentrate is the preferred first-line treatment for hypofibrinogenaemia. Goal-directed coagulation management algorithms based on POC results provide guidance on how to adjust the treatment to the needs of the patient. When POC is not available, concentrate-based management can be guided by other parameters, such as blood gas analysis, thus providing an important alternative. Overall, tailored haemostatic therapies offer a more targeted approach to increase the concentration of coagulation factors in bleeding patients than traditional transfusion protocols.

COVID-19 is an ongoing pandemic with high morbidity and mortality. Despite meticulous research, only dexamethasone has shown consistent mortality reduction. Convalescent plasma (CP) infusion might also develop into a safe and effective treatment modality on the basis of recent studies and meta-analyses; however, little is known regarding the kinetics of antibodies in CP recipients. To evaluate the kinetics, we followed 31 CP recipients longitudinally enrolled at a median of 3 days post symptom onset for changes in binding and neutralizing antibody titers and viral loads. Antibodies against the complete trimeric Spike protein and the receptor-binding domain (Spike-RBD), as well as against the complete Nucleocapsid protein and the RNA binding domain (N-RBD) were determined at baseline and weekly following CP infusion. Neutralizing antibody (pseudotype NAb) titers were determined at the same time points. Viral loads were determined semi-quantitatively by SARS-CoV-2 PCR. Patients with low humoral responses at entry showed a robust increase of antibodies to all SARS-CoV-2 proteins and Nab, reaching peak levels within 2 weeks. The rapid increase in binding and neutralizing antibodies was paralleled by a concomitant clearance of the virus within the same timeframe. Patients with high humoral responses at entry demonstrated low or no further increases; however, virus clearance followed the same trajectory as in patients with low antibody response at baseline. Together, the sequential immunological and virological analysis of this well-defined cohort of patients early in infection shows the presence of high levels of binding and neutralizing antibodies and potent clearance of the virus.

COVID-19 is a global pandemic associated with increased morbidity and mortality. Convalescent plasma (CP) infusion is a strategy of potential therapeutic benefit. We conducted a multicenter phase II study to evaluate the efficacy and safety of CP in patients with COVID-19, grade 4 or higher. To evaluate the efficacy of CP, a matched propensity score analysis was used comparing the intervention (n = 59) to a control group (n = 59). Sixty patients received CP within a median time of 7 days from symptom onset. During a median follow-up of 28.5 days, 56/60 patients fully recovered and 1 patient remained in the ICU. The death rate in the CP group was 3.4% vs. 13.6% in the control group. By multivariate analysis, CP recipients demonstrated a significantly reduced risk of death [HR: 0.04 (95% CI: 0.004–0.36), p: 0.005], significantly better overall survival by Kaplan–Meir analysis (p < 0.001), and increased probability of extubation [OR: 30.3 (95% CI: 2.64–348.9), p: 0.006]. Higher levels of antibodies in the CP were independently associated with significantly reduced risk of death. CP infusion was safe with only one grade 3 adverse event (AE), which easily resolved. CP used early may be a safe and effective treatment for patients with severe COVID-19 (trial number NCT04408209).