Vitamin B12 Deficiency in Thrombotic Thrombocytopenic Purpura-Like Cases.

Background: Thrombotic microangiopathies (TMA) are characterized by a triad of microangiopathic hemolytic anemia, thrombocytopenia, and organ damage which occur in the setting of endothelial damage and platelet activation. Vitamin B12 (cobalamin) deficiency could lead to a picture that resembles TMA, termed metabolic mediated TMA (MM-TMA). Case Presentation: A 60-year-old female was brought to the hospital after she was found unresponsive. On presentation, she was pale, lethargic, tachycardic, and febrile. Laboratory investigations revealed normocytic anemia, thrombocytopenia, and elevated bilirubin. Blood smear revealed schistocytes and tear drop cells. Given the presence of hemolytic anemia, thrombocytopenia, acute renal failure, and altered mental status, a presumptive diagnosis of thrombotic thrombocytopenic purpura (TTP) was made with a PLASMIC score of 7 indicating high risk. She received plasma exchange, caplacizumab, and intravenous methylprednisolone. Given the patient's low level of vitamin B12, she was initiated on intramuscular cyanocobalamin 1000 µg daily. The encephalopathy resolved and renal function improved. On day 6, ADAMTS13 activity was normal ruling out the diagnosis of TTP. Accordingly, plasmapheresis, steroids, and caplacizumab were discontinued. With continued aggressive B12 replacement, hemolysis resolved indicating severe vitamin B12 deficiency was the likely culprit of this patient's microangiopathic hemolytic anemia. Conclusion: This case serves to highlight the variable presentation of vitamin B12 deficiency. Severe vitamin B12 deficiency can even mimic TTP. If patients have markers of hemolysis, a low vitamin B12 level, and low reticulocyte count we should consider vitamin B12 deficiency as a likely cause of microangiopathic hemolytic anemia as early detection allows for early initiation of appropriate management. LEARNING POINTS: Vitamin B12 deficiency can be a cause of thrombotic microangiopathy.

The Highs and Lows of ADAMTS13 Activity.

Severe deficiency of ADAMTS13 (<10 iu/dL) is diagnostic of thrombotic thrombocytopenic purpura (TTP) and leads to accumulation of ultra-large vWF multimers, platelet aggregation, and widespread microthrombi, which can be life-threatening. However, the clinical implications of a low ADAMTS13 activity level are not only important in an acute episode of TTP. In this article, we discuss the effects of low ADAMTS13 activity in congenital and immune-mediated TTP patients not only at presentation but once in a clinical remission. Evidence is emerging of the clinical effects of low ADAMTS13 activity in other disease areas outside of TTP, and here, we explore the wider impact of low ADAMTS13 activity on the vascular endothelium and the potential for recombinant ADAMTS13 therapy in other thrombotic disease states.

Thiouracil and triazole conjugate induces autophagy through the downregulation of Wnt/ß-catenin signaling pathway in human breast cancer cells.

Autophagy is vital for maintaining cellular homeostasis by breaking down unnecessary organelles and proteins within cells. Its activity varies abnormally in several diseases, including cancer, making it a potential target for therapeutic strategies. The Wnt/ß-catenin signaling pathway significantly impacts cancer by stabilizing ß-catenin protein and promoting the transcription of its target genes. Therefore, we aimed to identify candidate substances targeting this signaling pathway. We designed and tested a thiouracil conjugate, discovering that TTP-8 had anti-tumor effects on human breast cancer cell lines MCF-7 and MDA-MB231. Our findings showed that TTP-8 upregulated the expression of LC3 protein, a marker of autophagy in breast cancer cells, suggesting that TTP-8 might induce autophagy. Further analysis confirmed an increase in autophagy-related proteins, with consistent results obtained from flow cytometry and confocal microscopy. Interestingly, the induction of LC3 expression by TTP-8 was even more pronounced in MCF-7 and MDA-MB231 cells transfected with ß-catenin siRNA. Thus, our research supports the idea that the Wnt/ß-catenin signaling pathway influences the regulation of autophagy-related proteins, thereby inducing autophagy. This suggests that TTP-8 could serve as a novel agent for treating breast cancer.

Pyrimidine-triazole-tethered tert-butyl-piperazine-carboxylate suppresses breast cancer by targeting estrogen receptor signaling and ß-catenin activation.

Several chemotherapeutics against breast cancer are constrained by their adverse effects and chemoresistance. The development of novel chemotherapeutics to target metastatic breast cancer can bring effective clinical outcomes. Many breast cancer patients present with tumors that are positive for estrogen receptors (ERs), highlighting the importance of targeting the ER pathway in this particular subtype. Although selective estrogen receptor modulators (SERMs) are commonly used, their side effects and resistance issues necessitate the development of new ER-targeting agents. In this study, we report that a newly synthesized compound, TTP-5, a hybrid of pyrimidine, triazole, and tert-butyl-piperazine-carboxylate, effectively binds to estrogen receptor alpha (ERα) and suppresses breast cancer cell growth. We assessed the impact of TTP-5 on cell proliferation using MTT and colony formation assays and evaluated its effect on cell motility through wound healing and invasion assays. We further explored the mechanism of action of this novel compound by detecting protein expression changes using Western blotting. Molecular docking was used to confirm the interaction of TTP-5 with ERα. The results indicated that TTP-5 significantly reduced the proliferation of MCF-7 cells by blocking the ERα signaling pathway. Conversely, although it did not influence the growth of MDA-MB-231 cells, TTP-5 hindered their motility by modulating the expression of proteins associated with epithelial-mesenchymal transition (EMT), possibly via the Wnt/ß-catenin pathway.

Thrombotic Thrombocytopenia Purpura (TTP) following emergent aortic valve replacement after a complicated TAVR procedure: a case report and review of the literature.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a rare hematological disorder. The occurrence of TTP subsequent to an emergent aortic valve replacement after a TAVR procedure is exceedingly uncommon with only a few reported cases worldwide. CASE PRESENTATION: We report the case of a 70-year-old female patient diagnosed with aortic insufficiency. Following a transcatheter aortic valve replacement, she underwent emergency aortic valve replacement under cardiopulmonary bypass on the subsequent day due to heart valve displacement. The postoperative diagnosis revealed TTP and symptomatic treatment involving plasma exchange was administered. After demonstrating steady improvement, the patient was eventually discharged. CONCLUSION: Aortic valve replacement after TAVR is a high-risk procedure and increases susceptibility for developing secondary TTP. The diagnosis and treatment of secondary TPP is considerably challenging, and early diagnosis with symptomatic treatment including plasma exchange can increase patient survival.

In a nutshell: TTP and pregnancy.

Acute thrombocytopenic purpura (TTP) may present at any stage of pregnancy and the puerperium. Without prompt diagnosis and therapy, serious maternal and fetal outcomes may result. ADAMTS13 replacement via plasma exchange and immunosuppression are the mainstay of treatment. There may be a role, however, for newer therapies, including caplacizumab and recombinant ADAMTS13. Differentiation of immune TTP and congenital TTP is vital, particularly to guide the management of subsequent pregnancies.

Small Bowel Ischemia and Ischemic Colitis Secondary to Thrombotic Thrombocytopenic Purpura in a Patient With Systemic Lupus Erythematous: A Rare Clinical Entity.

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening hematologic disorder characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ dysfunction. This report highlights a rare case of small bowel ischemia and ischemic colitis caused by TTP in a 35-year-old woman with systemic lupus erythematosus (SLE), hypertension, and end-stage renal disease on hemodialysis. She presented with severe abdominal pain, diarrhea, vomiting, and bloody bowel movements. Diagnosed through CT, EGD, and colonoscopy and confirmed by ADAMTS13 levels, she was treated with plasma exchange, steroids, and rituximab. After standard therapies failed, resection anastomosis surgery led to clinical improvement. This case underscores the importance of early recognition and treatment of TTP in SLE patients to improve prognosis and reduce morbidity and mortality.

Frontline use of rituximab may prevent ADAMTS13 inhibitor boosting during caplacizumab treatment in patients with iTTP: post hoc analysis of a phase 2/3 study in Japan.

BACKGROUND: A recent Phase 2/3 study in Japanese patients showed that caplacizumab was effective in treating immune-mediated thrombotic thrombocytopenic purpura (iTTP), with a low rate of iTTP recurrence. ADAMTS13 activity is monitored weekly during caplacizumab treatment to guide discontinuation of caplacizumab and consequently avoid exacerbations or relapse. The aim of this study was to assess changes in ADAMTS13 activity/inhibitor levels during caplacizumab treatment in this patient population. METHODS: A post hoc analysis of the Phase 2/3 study in Japanese patients was conducted. Patients ≥ 18 years old with confirmed iTTP received 10 mg of caplacizumab daily in conjunction with therapeutic plasma exchange (TPE) and immunosuppression for 30 days post-TPE. Outcomes included time to recovery of ADAMTS13 activity, ADAMTS13 activity level at treatment end, incidence of ADAMTS13 inhibitor re-elevation (ie, inhibitor boosting) during treatment, time to platelet count recovery, number of days of TPE, and safety. Outcomes according to presence of inhibitor boosting were also assessed. RESULTS: Nineteen patients had confirmed iTTP and were included in this analysis. Median (95% confidence interval) time to recovery of ADAMTS13 activity to ≥ 10%, ≥ 20%, and ≥ 60% was 14.6 (5.9-24.8), 18.5 (5.9-31.8), and 47.5 (18.5-60.9) days, respectively. Median (range) ADAMTS13 activity level at caplacizumab treatment end was 62.0% (29.0-101.0). Nine patients had ADAMTS13 inhibitor boosting. Delayed response of ADAMTS13 activity was observed in patients with inhibitor boosting. The median time to platelet count response and median number of TPE days were shorter in patients with inhibitor boosting compared with patients without inhibitor boosting. Rituximab was administered to almost all patients with inhibitor boosting (88.9%), after completion of TPE. Patients without inhibitor boosting who were treated with rituximab received it prior to completion of TPE. Only one patient experienced a recurrence, which occurred shortly after caplacizumab discontinuation due to an adverse event. CONCLUSIONS: In patients with iTTP, caplacizumab with TPE and immunosuppression may reduce the risk of ADAMTS13 inhibitor boosting if rituximab is administered early in the iTTP treatment period. Early administration of rituximab in addition to caplacizumab may prevent iTTP recurrence with inhibitor boosting. TRIAL REGISTRATION: NCT04074187.

Longitudinal characterization of symptoms, healthcare resource utilization, and costs among people with thrombotic thrombocytopenic purpura compared with non-thrombotic thrombocytopenic purpura controls.

AIMS: Thrombotic thrombocytopenic purpura (TTP) is an ultra-rare blood disorder, characterized by severe ADAMTS13 deficiency. Affected individuals present with potentially life-threatening acute events and may experience sub-acute and chronic TTP manifestations often resulting in long-term organ damage. Incremental symptom prevalence before, during, and after an acute event as well as healthcare resource utilization (HCRU) and costs during and after an acute event were compared between people with TTP and matched non-TTP controls. METHODS: This retrospective, matched study used data from Merative MarketScan Commercial Database and Medicare Supplemental Database (from January 1, 2008, through September 30, 2021) to identify people with TTP (inpatient diagnosis for "thrombotic microangiopathy (TMA)" or "congenital TTP," and ≥1 claim for plasma exchange or infusion). People with TTP were matched (1:2) with non-TTP controls on age, sex, geographic region, index year, and select Elixhauser comorbidities. RESULTS: 255 people with TTP were matched with 510 non-TTP controls. Both cohorts had a mean age of 43.9 years; 71% were female. Overall, more people with TTP reported symptoms compared with non-TTP controls prior to (51% vs 43%), during (99% vs 52%), and after an acute event (85% vs 50%; p < 0.05 for all periods). Symptom prevalence decreased following an acute event compared with during an acute event, but remained high-85% of people with TTP experienced symptoms compared with 50% of non-TTP controls. HCRU and mean costs per patient per month were significantly higher in all care settings among people with TTP compared with non-TTP controls (p < 0.05). LIMITATIONS: Identification of patient populations may have been limited due to coding errors, as the data were obtained from an administrative claims database. CONCLUSIONS: TTP is associated with a substantial symptom burden and increased costs and HCRU during and up to almost a year after acute events, demonstrating the longitudinal burden of this disease.

Stress granule-related genes during embryogenesis of an invertebrate chordate.

Controlling global protein synthesis through the assembly of stress granules represents a strategy adopted by eukaryotic cells to face various stress conditions. TIA 1-related nucleolysin (TIAR), tristetraprolin (TTP), and Ras-GTPase-activating protein SH3-domain-binding protein (G3BP) are key components of stress granules, allowing the regulation of mRNA stability, and thus controlling not only stress responses but also cell proliferation and differentiation. In this study, we aimed at investigating the roles of tiar, ttp, and g3bp during embryogenesis of the solitary ascidian Ciona robusta under both physiological and stress conditions. We carried out CRISPR/Cas9 to evaluate the effects of gene knockout on normal embryonic development, and gene reporter assay to study the time and tissue specificity of gene transcription, together with whole-mount in situ hybridization and quantitative real time PCR. To induce acute stress conditions, we used iron and cadmium as "essential" and "non-essential" metals, respectively. Our results highlight, for the first time, the importance of tiar, ttp, and g3bp in controlling the development of mesendodermal tissue derivatives during embryogenesis of an invertebrate chordate.

Interneurons in the CA1 stratum oriens expressing αTTP may play a role in the delayed-ageing Pol µ mouse model.

Neurodegeneration associated with ageing is closely linked to oxidative stress (OS) and disrupted calcium homeostasis. Some areas of the brain, like the hippocampus - particularly the CA1 region - have shown a high susceptibility to age-related changes, displaying early signs of pathology and neuronal loss. Antioxidants such as α-tocopherol (αT) have been effective in mitigating the impact of OS during ageing. αT homeostasis is primarily regulated by the α-tocopherol transfer protein (αTTP), which is widely distributed throughout the brain - where it plays a crucial role in maintaining αT levels within neuronal cells. This study investigates the distribution of αTTP in the hippocampus of 4- and 24-month-old Pol µ knockout mice (Pol µ-/-), a delayed-ageing model, and the wild type (Pol µ+/+). We also examine the colocalisation in the stratum oriens (st.or) of CA1 region with the primary interneuron populations expressing calcium-binding proteins (CBPs) (calbindin (CB), parvalbumin (PV), and calretinin (CR)). Our findings reveal that αTTP immunoreactivity (-IR) in the st.or of Pol µ mice is significantly reduced. The density of PV-expressing interneurons (INs) increased in aged mice in both Pol µ genotypes (Pol µ-/- and Pol µ+/+), although the density of PV-positive INs was lower in the aged Pol µ-/- mice compared to wild-type mice. By contrast, CR- and CB-positive INs in Pol µ mice remained unchanged during ageing. Furthermore, double immunohistochemistry reveals the colocalisation of αTTP with CBPs in INs of the CA1 st.or. Our study also shows that the PV/αTTP-positive IN population remains unchanged in all groups. A significant decrease of CB/αTTP-positive INs in young Pol µ-/- mice has been detected, as well as a significant increase in CR/αTTP-IR in older Pol µ-/- animals. These results suggest that the differential expression of αTTP and CBPs could have a crucial effect in aiding the survival and maintenance of the different IN populations in the CA1 st.or, and their coexpression could contribute to the enhancement of their resistance to OS-related damage and neurodegeneration associated with ageing.

Practical approach to thrombocytopenia in patients with sepsis: a narrative review.

Thrombocytopenia frequently occurs in patients with sepsis. Disseminated intravascular coagulation (DIC) may be a possible cause of thrombocytopenia owing to its high prevalence and association with poor outcomes; however, it is important to keep the presence of other diseases in mind in sepsis practice. Thrombotic microangiopathy (TMA), which is characterized by thrombotic thrombocytopenic purpura, Shiga toxin-producing Escherichia coli hemolytic uremic syndrome (HUS), and complement-mediated HUS, is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and organ damage. TMA has become widely recognized in recent years because of the development of specific treatments. Previous studies have reported a remarkably lower prevalence of TMA than DIC; however, its epidemiology is not well defined, and there may be cases in which TMA is not correctly diagnosed, resulting in poor outcomes. Therefore, it is important to differentiate DIC from TMA. Nevertheless, differentiating between DIC and TMA remains a challenge as indicated by previous reports that most patients with TMA can be diagnosed as DIC using the universal coagulation scoring system. Several algorithms to differentiate sepsis-related DIC from TMA have been suggested, contributing to improving the care of septic patients with thrombocytopenia; however, it may be difficult to apply these algorithms to patients with coexisting DIC and TMA, which has recently been reported. This review describes the disease characteristics, including epidemiology, pathophysiology, and treatment, of DIC, TMA, and other diseases with thrombocytopenia and proposes a novel practical approach flow, which is characterized by the initiation of the diagnosis of TMA in parallel with the diagnosis of DIC. This practical flow also refers to the longitudinal diagnosis and treatment flow with TMA in mind and real clinical timeframes. In conclusion, we aim to widely disseminate the results of this review that emphasize the importance of incorporating consideration of TMA in the management of septic DIC. We anticipate that this practical new approach for the diagnostic and treatment flow will lead to the appropriate diagnosis and treatment of complex cases, improve patient outcomes, and generate new epidemiological evidence regarding TMA.

Immune Thrombotic Thrombocytopenic Purpura: Pathophysiology, Diagnosis, Therapy and Open Issues.

Immune thrombotic thrombocytopenic purpura (iTTP) is a life-threatening thrombotic microangiopathy characterized by microangiopathic hemolytic anemia, thrombocytopenia, and ischemic end-organ injury due to microvascular platelet-rich thrombi. iTTP pathophysiology is based on a severe ADAMTS13 deficiency, the specific von Willebrand factor (vWF)-cleaving protease, due to anti-ADAMTS13 autoantibodies. Early diagnosis and treatment reduce the mortality. Frontline therapy includes daily plasma exchange (PEX) with fresh frozen plasma replacement and immunosuppression with corticosteroids. Caplacizumab has recently been added to frontline therapy. Caplacizumab is a nanobody that binds to the A1 domain of vWF, blocking the interaction of ultra-large vWF multimers with the platelet and thereby preventing the formation of platelet-rich thrombi. Caplacizumab reduces mortality due to ischemic events, refractoriness, and exacerbations after PEX discontinuation. Until now, the criteria for response to treatment mainly took into account the normalization of platelet count and discontinuation of PEX; with the use of caplacizumab leading to rapid normalization of platelet count, it has been necessary to redefine the response criteria, taking into account also the underlying autoimmune disease. Monitoring of ADAMTS13 activity is important to identify cases with a low value of activity (<10IU/L), requiring the optimization of immunosuppressive therapy with the addition of Rituximab. Rituximab is effective in patients with refractory disease or relapsing disease. Currently, the use of Rituximab has expanded, both in frontline treatment and during follow-up, as a pre-emptive approach. Some patients do not achieve ADAMTS13 remission following the acute phase despite steroids and rituximab treatment, requiring an individualized immunosuppressive approach to prevent clinical relapse. In iTTP, there is an increased risk of venous thrombotic events (VTEs) as well as arterial thrombotic events, and most occur after platelet normalization. Until now, there has been no consensus on the use of pharmacological thromboprophylaxis in patients on caplacizumab because the drug is known to increase bleeding risk.

[Advances in the treatment of thrombotic thrombocytopenic purpura].

Thrombotic thrombocytopenic purpura (TTP) is a fatal thrombotic disease caused by a marked decrease in the activity of ADAMTS13, a von Willebrand factor cleaving protease. In congenital TTP, ADAMTS13 activity is decreased by an abnormality in ADAMTS13, and in acquired TTP, by anti-ADAMTS13 autoantibody. Death from thrombosis in the acute phase has been an issue with conventional treatment of acquired TTP by plasma exchange or immunosuppressive therapy. However, the advent of caplacizumab, an anti-VWF nanobody, has made it possible to suppress thrombus formation and is expected to improve survival rates. In addition, some case series have shown the efficacy of caplacizumab without plasma exchange for acquired TTP, and this approach is being investigated in clinical trials. Fresh-frozen plasma is transfused to supply ADAMTS13 for congenital TTP, but frequent transfusions over a long period of time can lead to problems such as infection and allergic reactions. Novel therapies such as recombinant ADAMTS13 products and gene therapy are now under development, and show promise for future clinical use.

Role of plasma exchange in a post-partum case of severe thrombotic thrombocytopenic purpura with acute kidney injury.

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease present with the classic pentad of microangiopathic hemolytic anemia (MAHA), fever, neurologic changes, thrombocytopenia, and renal dysfunction. In a diagnostic dilemma, therapeutic plasma exchange (TPE) is a choice of life-saving intervention. In this, we assess the efficacy of TPE in a suspected case of post-partum TTP. A 27 years old female was admitted in an emergency on day 8 after a lower segment cesarian section (LSCS) with unresponsive behavior for 3 days and with TTP. She was normal 32 days back with her second, 7-month pregnancy. Ultrasonography (USG) showed an umbilical cord around the neck of the baby. On the fifth post-operative day, she was shifted to emergency with fever, generalized anasarca, gastrointestinal tract (GI) bleeding, low platelet count, and low Hb, with a poor Glasgow coma scale (GCS) of 6. On the bases of serum urea and serum creatinine, she presented acute kidney injury with encephalopathy. At emergency, she was unresponsive to mechanical ventilation and supportive treatment; hence, therapeutic plasma exchange was performed. After eight TPE cycles, the patient presented with an improved hematological and renal profile with good GCS. TPE is helpful and life-saving for suspected TTP patients with AKI.

The history of thrombotic thrombocytopenic purpura research: a narrative review.

Background and Objective: Thrombotic thrombocytopenic purpura (TTP) is a rare but debilitating thrombotic microangiopathy that results from severe deficiency of the enzyme ADAMTS13. The disorder was first described in the early 20th century, but the pathophysiology of the disease has only been elucidated in the past three decades. In this narrative review, we will summarize the milestone moments in the history of TTP research and discovery. Methods: We searched literature using PubMed from 1924 to 2023 using the following free text searches: "thrombotic thrombocytopenic purpura", "Moschcowitz disease", and "thrombotic microangiopathy". We found 6,917 peer-reviewed articles and sorted through these for relevant literature pertinent to the review. A total of 46 articles were included for review and the remainder were excluded. Key Content and Findings: The history of TTP research was reviewed, with a sampling of major events in the evolution of the understanding of the pathophysiology and treatment of the disease discussed here. There remains much to be learned about the nature of the disease in order to develop more specific and less harmful treatments. Conclusions: An overview of the major discoveries that have led to our current understanding of TTP reveals the results of collaboration of multiple groups of physicians and scientists through the past century, with additional breakthroughs likely to occur in the future because of that same collaborative spirit.

Acquired immune thrombotic thrombocytopenic purpura (TTP) associated with inactivated COVID-19 vaccine CoronaVac.

Corona virus disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has affected the whole world. Acquired thrombotic thrombocytopenic purpura (TTP) has been reported after administration of mRNA- or adenoviral vector-based COVID-19 vaccines, including Ad26.COV2-S, BNT162b2, mRNA-1273, and ChAdOx1 nCov-19. However, whether inactivated vaccines, such as CoronaVac, could cause TTP and whether the symptoms in TTPs caused by inactivated vaccines are different from previously reported cases are unknown. In this study, two cases were reported. Both cases developed TTP after the second CoronaVac vaccination shot, but not the first. They demonstrated symptoms of fever, neurological abnormalities, renal dysfunction, thrombocytopenia, and hemolysis. Both patients achieved complete remission through several sessions of plasma exchanges and immune suppression. The incidence of TTP in Nanjing area was analyzed. The number of patients with TTP was 12 in 2019, 6 in 2020, 16 in 2021, and 19 in 2022. To the authors' knowledge, this report is the first report of TTP associated with inactivated COVID-19 vaccine (CoronaVac). The rarity and delayed onset may be due to the relatively milder immune response caused by the inactivated vaccines than mRNA-based ones. Timely plasma exchange is a vital treatment for CoronaVac-related TTP, similar to activated vaccine-related TTP.

Clinical impact and potential utility of non-enhanced computed tomography performed immediately after transarterial chemoembolization for hepatocellular carcinoma.

Background: Intratumoral lipiodol deposition following transarterial chemoembolization (TACE) is associated with the prognosis of hepatocellular carcinoma (HCC) patients. However, there is insufficient evidence regarding the actual clinical significance of the imaging tests conducted to evaluate the lipiodol uptake after TACE. This study evaluates the clinical impact and potential utility of performing immediate post-TACE non-enhanced computed tomography (NECT) on the treatment of HCC. Methods: This retrospective study at a tertiary referral center included patients undergoing their first session of conventional TACE for initial treatment of HCC from November 2021 to December 2022 with available immediate post-TACE NECT. Patients were categorized based on lipiodol uptake into Cohorts A (incomplete uptake with additional treatment before the first follow-up 1 month after TACE), B incomplete uptake without additional treatment before first follow-up), and C (complete uptake). Survival curves for the time to progression (TTP) were estimated using the Kaplan-Meier method and were compared by using the log-rank test. Results: Out of 189 patients, 58 (29.6%) showed incomplete lipiodol uptake; 2 in Cohort A and 56 in Cohort B. Cohort C included 131 patients (69.3%). Cohort B had the highest rate of residual viable tumor (48.2%) 1 month after TACE, compared to the other cohorts (0% in Cohort A and 32.1% in Cohort C). The median TTP of Cohort B was 7.9 months [95% confidence interval (CI): 4.6-15.7 months], significantly shorter than the 15.4 months (95% CI: 10.9-20.9 months) for Cohort C (P=0.03). During follow-up, no progression occurred in Cohort A. Conclusions: Assessment of lipiodol uptake by performing immediate post-TACE NECT can stratify HCC patients and facilitate early prediction of therapeutic response. Identifying suboptimal lipiodol uptake immediately after TACE can aid future treatment adjustments and potentially improving oncologic outcomes.

Weibel-Palade bodies: function and role in thrombotic thrombocytopenic purpura and in diarrhea phase of STEC-hemolytic uremic syndrome.

Vascular endothelial cells are equipped with numerous specialized granules called Weibel-Palade bodies (WPBs). They contain a cocktail of proteins that can be rapidly secreted (3-5 min) into the vascular lumen after an appropriate stimulus such as thrombin. These proteins are ready without synthesis. Von Willebrand factor (VWF) and P-selectin are the main constituents of WPBs. Upon stimulation, release of ultralarge VWF multimers occurs and assembles into VWF strings on the apical side of endothelium. The VWF A1 domain becomes exposed in a shear-dependent manner recruiting and activating platelets. VWF is able to recruit leukocytes via direct leukocyte binding or via the activated platelets promoting NETosis. Ultralarge VWF strings are ultimately cleaved into smaller pieces by the protease ADAMTS-13 preventing excessive platelet adhesion. Under carefully performed flowing conditions and adequate dose of Shiga toxins, the toxin induces the release of ultralarge VWF multimers from cultured endothelial cells. This basic information allows insight into the pathogenesis of thrombotic thrombocytopenic purpura (TTP) and of STEC-HUS in the diarrhea phase. In TTP, ADAMTS-13 activity is deficient and systemic aggregation of platelets will occur after a second trigger. In STEC-HUS, stimulated release of WPB components in the diarrhea phase of the disease can be presumed to be the first hit in the damage of Gb3 positive endothelial cells.