Immune thrombocytopaenic purpura: an autoimmune cross-link between infections and vaccines

Predictors of progression to chronicity in newly diagnosed primary immune thrombocytopenia: a retrospective multicenter French study

BACKGROUND

The long-term outcome of primary immune thrombocytopenia (ITP) is unpredictable. Chronic ITP is common in adults, requiring second-line treatments with increased morbidity and mortality. Our study aimed to identify predictive factors of chronicity at the time of diagnosis in primary adult ITP.

RESEARCH DESIGN AND METHODS

This retrospective multicenter study included adult patients newly diagnosed with primary ITP. Patients with a normal platelet count and no ongoing medication twelve months after disease onset were categorized in the complete remission ITP group, otherwise in the chronic ITP group.

RESULTS

219 patients were included, 110 in the complete remission ITP group and 109 in the chronic ITP group. In multivariate analysis, predictive factors of progression to chronicity included the absence of an infectious event preceding ITP onset (p = 0.048), the absence of bleeding manifestations (p = 0.002) and a platelet count >10 x 109/L at disease onset (p = 0.02). A poor response to initial corticosteroid treatment was also associated with chronicity, including corticosteroid dependence (p<0.001) and corticosteroid resistance (p = 0.001).

CONCLUSIONS

In this retrospective French cohort, predictors of chronicity in newly diagnosed primary adult ITP included the absence of preceding infectious event, platelet >10 x 109/L and absence of bleeding manifestations at onset.

The Impact of COVID-19 Vaccination on Oxidative Stress and Cardiac Fibrosis Biomarkers in Patients with Acute Myocardial Infarction (STEMI), a Single-Center Experience Analysis

The relationship between the classical cardiac biomarker and acute myocardial infarction (STEMI) in patients with COVID-19 is far from being elucidated. Furthermore, superoxide dismutase (SOD), a marker for oxidative stress, was associated with cardiac ischemia. Also, Galectin-3 is significant for defining the relationship between cardiac fibrosis and COVID-19. There are no studies on the effect of SARS-CoV-2 virus infection and vaccination on patients with STEMI and biomarkers above-mentioned.

AIM

our single-center prospective study assesses the relationship between COVID-19 infection with/without vaccination and the value of SOD and Galectin-3 in STEMI patients.

MATERIAL AND METHODS

In total, 93 patients with STEMI and SARS-CoV-2 virus infection were included in the analysis, patients were divided in two groups based on COVID-19 vaccination status. Echocardiographic and laboratory investigations for cardiac ischemia, oxidative stress, and cardiac fibrosis biomarkers were investigated.

RESULTS

In total, 93 patients were included, the majority of which were male (72.0%), 45.2% (n = 42) were vaccinated against SARS-CoV-2; the mean age of vaccinated patients is 62 years, and 57% (n = 53) are smokers; blood pressure is found with a higher frequency in unvaccinated people (62.7%) compared to 28.6% in vaccinated people (p = 0.015), and 90.5% of the vaccinated people presented STEMI, compared with 96.1% of the unvaccinated ones. Revascularization with one stent was achieved in 47.6% of the vaccinated people and 72.5% for the unvaccinated people (p = 0.015). Galectin-3 was slightly more reduced in the vaccinated patients compared to the unvaccinated patients (0.73 vs. 0.99; p = 0.202), and the average level of Cu/ZnSOD was slightly more reduced in vaccinated patients compared to the unvaccinated patients (0.84 vs. 0.91; p = 0.740).

CONCLUSIONS

Regarding patient's SARS-CoV-2 infection functional status, the results from our single-center analysis did not find a statistically significant decrease in oxidative stress and cardiac fibrosis biomarkers along with cardiovascular complication following STEMI treated with percutaneous coronary angioplasty (PCI) in the case of patients with COVID-19 vaccination compared with patients who did not receive COVID-19 vaccine. Anyway, our data suggest that contemporary PCI techniques may offer an alternative revascularization strategy that enables complex CAD COVID-19 patients to be safely discharged from hospital.

Construction of a clinical prediction model for the diagnosis of immune thrombocytopenia based on clinical laboratory parameters

PURPOSE

Primary immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by isolated thrombocytopenia that is often misdiagnosed due to the lack of a gold standard for diagnosis and currently relies on exclusionary approaches. This project combines several laboratory parameters to construct a clinical prediction model for adult ITP patients.

METHODS

A total of 428 patients with thrombocytopenia who visited the West China Hospital of Sichuan University between January 2021 and March 2023 were enrolled. Based on the diagnostic criteria, we divided those patients into an ITP group and a non-ITP group. A total of 34 laboratory parameters were analyzed via univariate analysis and correlation analysis, and the least absolute shrinkage and selection operator regression analysis was used to establish the model. The training and validation sets were divided at a ratio of 7:3, and we used a fivefold cross-validation method to construct the model.

RESULTS

The model included the following variables: red blood cell, mean corpuscular hemoglobin concentration, red blood cell distribution width-standard deviation, platelet variability index score, immature platelet fraction, lymphocyte absolute value. The prediction model exhibited good performance, with a sensitivity of 0.89 and a specificity of 0.83 in the training set and a sensitivity of 0.90 and a specificity of 0.87 in the validation set.

CONCLUSION

The clinical prediction model can assess the probability of ITP in thrombocytopenic patients and has good predictive accuracy for the diagnosis of ITP.

The many facets of immune-mediated thrombocytopenia: Principles of immunobiology and immunotherapy

Immune thrombocytopenia (ITP) is a rare autoimmune condition, due to peripheral platelet destruction through antibody-dependent cellular phagocytosis, complement-dependent cytotoxicity, cytotoxic T lymphocyte-mediated cytotoxicity, and megakaryopoiesis alteration. This condition may be idiopathic or triggered by drugs, vaccines, infections, cancers, autoimmune disorders and systemic diseases. Recent advances in our understanding of ITP immunobiology support the idea that other forms of thrombocytopenia, for instance, occurring after immunotherapy or cellular therapies, may share a common pathophysiology with possible therapeutic implications. If a decent pipeline of old and new agents is currently deployed for classical ITP, in other more complex immune-mediated thrombocytopenic disorders, clinical management is less harmonized and would deserve further prospective investigations. Here, we seek to provide a fresh overview of pathophysiology and current therapeutical algorithms for adult patients affected by this disorder with specific insights into poorly codified scenarios, including refractory ITP and post-immunotherapy/cellular therapy immune-mediated thrombocytopenia.

Platelet dropping, bleeding and new treatment requirements in ITP patients after inactivated COVID-19 vaccination

Significant decreases in platelet counts and ITP relapses have been documented in ITP patients receiving COVID-19 mRNA vaccines; however, the effect of the inactivated COVID-19 vaccine on ITP patients remains unclear. The present study aimed to investigate the impact of inactivated COVID-19 vaccines on ITP patients, with a focus on platelet dropping events, bleeding events/scores, and the requirement of a new round of treatment. A total of 118 ITP patients, with 97 chronic ITP and 21 persistent ITP, who received inactivated COVID-19 immunization were investigated retrospectively. Following vaccination (within 1 month), ITP patients reported platelet dropping (31.36 %), new bleeding events (22.88 %), increases in bleeding scores (23.73 %), and new treatment requirements (22.03 %). Among them, persistent ITP patients with disease duration of 3-12 months had higher ratios of the above adverse events (71.43 %, 57.14 %, 61.90 % and 71.43 %, respectively) than chronic ITP patients with duration > 1 year (22.68 %, 15.46 %, 15.46 % and 11.34 %, respectively); patients' disease duration was negatively correlated with platelet dropping events and new treatment requirements. Furthermore, logistic regression analysis also supported the above findings, revealing that persistent ITP patients had 9.40-9.70, 7.24-10.08, and 27.17-28.51 times incidence of having platelet dropping events, new bleeding events, and new treatment requirements after vaccination, respectively, when compared to chronic ITP patients. In conclusion, the present study demonstrates that after receiving inactivated COVID-19 vaccines, ITP patients may experience platelet dropping, which may lead to new bleeding events and the requirement of a new round of treatment for ITP recurrence. As a result, platelet level monitoring is crucial for ITP patients during the vaccination, especially those with persistent ITP.

Adverse events following COVID-19 mRNA vaccines: A systematic review of cardiovascular complication, thrombosis, and thrombocytopenia

BACKGROUND AND OBJECTIVES

Since publishing successful clinical trial results of mRNA coronavirus disease 2019 (COVID-19) vaccines in December 2020, multiple reports have arisen about cardiovascular complications following the mRNA vaccination. This study provides an in-depth account of various cardiovascular adverse events reported after the mRNA vaccines' first or second dose including pericarditis/myopericarditis, myocarditis, hypotension, hypertension, arrhythmia, cardiogenic shock, stroke, myocardial infarction/STEMI, intracranial hemorrhage, thrombosis (deep vein thrombosis, cerebral venous thrombosis, arterial or venous thrombotic events, portal vein thrombosis, coronary thrombosis, microvascular small bowel thrombosis), and pulmonary embolism.

METHODS

A systematic review of original studies reporting confirmed cardiovascular manifestations post-mRNA COVID-19 vaccination was performed. Following the PRISMA guidelines, electronic databases (PubMed, PMC NCBI, and Cochrane Library) were searched until January 2022. Baseline characteristics of patients and disease outcomes were extracted from relevant studies.

RESULTS

A total of 81 articles analyzed confirmed cardiovascular complications post-COVID-19 mRNA vaccines in 17,636 individuals and reported 284 deaths with any mRNA vaccine. Of 17,636 cardiovascular events with any mRNA vaccine, 17,192 were observed with the BNT162b2 (Pfizer-BioNTech) vaccine, 444 events with mRNA-1273 (Moderna). Thrombosis was frequently reported with any mRNA vaccine (n = 13,936), followed by stroke (n = 758), myocarditis (n = 511), myocardial infarction (n = 377), pulmonary embolism (n = 301), and arrhythmia (n = 254). Stratifying the results by vaccine type showed that thrombosis (80.8%) was common in the BNT162b2 cohort, while stroke (39.9%) was common with mRNA-1273 for any dose. The time between the vaccination dosage and the first symptom onset averaged 5.6 and 4.8 days with the mRNA-1273 vaccine and BNT162b2, respectively. The mRNA-1273 cohort reported 56 deaths compared to the 228 with BNT162b2, while the rest were discharged or transferred to the ICU.

CONCLUSION

Available literature includes more studies with the BNT162b2 vaccine than mRNA-1273. Future studies must report mortality and adverse cardiovascular events by vaccine types.

The Frequency and Patterns of Post-COVID-19 Vaccination Syndrome Reveal Initially Mild and Potentially Immunocytopenic Signs in Primarily Young Saudi Women

Vaccination is the most promising approach for ending or containing the SARS-CoV-2 pandemic. However, serious post-COVID-19 vaccine reactions, including immunocytopenia (ITP) syndrome, have been increasingly reported. Several factors cause increased risks including multiple doses, age-dependent heterogeneity in immune-responses, platelet cross-reactions with microbial components, and Long-COVID syndrome. Thus, in the absence of widely available specific therapeutics, vigilance is important while more studies are needed. Using a structured questionnaire sent to different regions in Saudi Arabia, we conducted a comprehensive investigation on the frequency, rates, disease patterns, and patient demographics of post-COVID-19 vaccine side effects on febrile patients after administration three major vaccines. Results indicated that the majority of respondents administered Pfizer BioNtech vaccine (81%, n = 809); followed by AstraZeneca (16%, n = 155); and Moderna (3%, n = 34). Overall 998 participants, 74% (n = 737) showed no serious symptoms; however, 26.2% (n = 261) revealed typical syndromes. In a focused group of 722 participants, the following rates were identified: shortness of breath (20%), bruises or bleeding (18%), inattention (18%), GIT symptoms (17.6%), skin irritation (8.6%), and anosmia and ageusia (8%) were the most prominent among those who showed typical symptoms. The onset time was mostly between 1–3 days in 49% (n = 128), followed by 4–7 days in 21.8% (n = 57), 8–14 days in 16.5% (n = 43), and more than a month in 12.6% (n = 33). The onsets occurred mostly after the first, second, or both doses, 9%, 10%, and 7% of participants, respectively. The frequency of symptoms was significantly higher after Moderna® vaccine (p-value = 0.00006) and it was significantly lower in participants who received Pfizer (p-value = 0.00231). We did not find significant difference in symptoms related to differences in regions. Similarly, the region, age, sex, education, and nationality had no influence on the dose and onset timings. The findings of this study have significant clinical implications in disease management strategies, preventive measures, and vaccine development. Future vertical studies would reveal more insights into the mechanisms of post-COVID-19 vaccine syndrome.

Cardiovascular Complications of COVID-19 Vaccines

Coronavirus disease 2019 (COVID-19) has become a global public health catastrophe. Vaccination against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is proven to be the most effective measure to suppress the pandemic. With the widespread application of the four vaccines, namely, ChAdOx1, Ad26.COV2.S, BNT162b2, and mRNA-1273.2, several adverse effects have been reported. The most serious type of complication is cardiovascularly related, including myocarditis, immune thrombocytopenia (ITP), cerebral sinus venous thrombosis, among others. All these adverse events undermine the health of the vaccinees and affect the administration of the vaccines. As the distribution of COVID-19 vaccines is surrounded by suspicion and rumors, it is essential to provide the public with accurate reports from trusted experts and journals. Monitoring the safety of COVID-19 vaccines is an important and ongoing process that is also urgent. Thus, we summarized the cardiovascular complications of the major types of COVID-19 vaccines, including mRNA vaccines, which are now generally considered to be innovative vaccines, and the future for vaccination against COVID-19, in addition to the underlying pathogenesis and potential therapeutics.

Acquired Hemophilia A Developed Post COVID-19 Vaccine: An Extremely Rare Complication

Acquired hemophilia A (AHA) is a rare autoimmune bleeding disorder caused by circulating autoantibodies (inhibitor) directed against coagulation factor VIII (FVIII). We report a 39-year-old single female who presented to emergency department with sudden onset gross hematuria 10 days following her first dose of Pfizer-BioNTech severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA (coronavirus disease 2019 (COVID-19)) vaccine. Coagulation profile revealed isolated prolongation of the activated partial thromboplastin time due to FVIII deficiency with normal von Willebrand factor and activity. Mixing study revealed time-dependent inhibitor pattern that was successively identified as directed against FVIII using the Nijmegen-modified Bethesda assay. FVIII inhibitor in a titer of 17.2 Bethesda Units/mL was detected. While thrombosis is a frequent complication of severe COVID-19 infection, on the other hand, bleeding is rare in the setting of COVID-19 infection/vaccination with no anticoagulants. Till date, a couple of cases of acquired hemophilia developed after receiving mRNA derived COVID-19 vaccines (Pfizer-BioNTech SARS-CoV-2 mRNA vaccine and Moderna mRNA vaccines) had been reported. It is important to raise the awareness about this rare side effect that might be directly induced by the mRNA COVID-19 vaccine or that the vaccine could have triggered it in a genetically predisposed individual. We recommend considering screening for an inhibitor (by mixing study) in cases with otherwise unexplained onset hemorrhagic disorder and/or isolated activated partial thromboplastin time prolongation.

Immune thrombocytopenic purpura secondary to Helicobacter pylori

Immune thrombocytopenic purpura is a disorder characterized by decreased platelet count that may be secondary to infectious or autoimmune etiologies. We present a patient with upper gastrointestinal bleeding complicated by severe thrombocytopenia. Endoscopy revealed gastritis with pathology positive for Helicobacter pylori. Platelet count normalized after triple antibiotic therapy. The precise mechanism by which H. pylori causes immune thrombocytopenic purpura remains unclear; however, there are several plausible mechanisms. This case highlights the importance of keeping H. pylori in the differential in patients presenting with thrombocytopenia.

Rapid response to mycophenolate mofetil in combination with romiplostim in a case of severe refractory immune thrombocytopenia post COVID-19 vaccination

Vaccine mediated immune mediated thrombocytopenia (ITP) is exceedingly rare. We present a case of a young female who developed severe refractory ITP with multiple bleeding sites post second dose of COVID-19 vaccination. She was treated with a combination of romiplostim and mycophenolate mofetil that resulted in rapid platelet count recovery.

Platelet variability index: a measure of platelet count fluctuations in patients with immune thrombocytopenia

Fluctuations in platelet count levels over time may help distinguish immune thrombocytopenia (ITP) from other causes of thrombocytopenia. We derived the platelet variability index (PVI) to capture both the fluctuations in platelet count measurements and the severity of the thrombocytopenia over time. Raw PVI values, ranging from negative (less severe thrombocytopenia and/or low fluctuations) to positive (more severe thrombocytopenia and/or high fluctuations) were converted to an ordinal PVI score, from 0 to 6. We evaluated the performance characteristics of the PVI score for consecutive adults with thrombocytopenia from the McMaster ITP Registry. We defined patients with definite ITP as those who achieved a platelet count response after treatment with intravenous immune globulin or high-dose corticosteroids and possible ITP as those who never received ITP treatment or did not respond to treatment. Of 841 patients with thrombocytopenia, 104 had definite ITP, 398 had possible ITP, and 339 had non-ITP thrombocytopenia. For patients with definite ITP, the median PVI score was 5 [interquartile range (IQR) 5, 6] for patients with possible ITP, the median PVI score was 3 (1, 5); and for patients with non-ITP thrombocytopenia, the median PVI score was 0 (0, 2). A high PVI score correlated with the diagnosis of definite ITP even when calculated at the patient's initial assessment, before any treatment had been administered. Platelet count fluctuations alone contributed to the specificity of the overall PVI score. The PVI score may help clinicians diagnose ITP among patients who present with thrombocytopenia for evaluation.

Oxford-AstraZeneca Coronavirus Disease-2019 Vaccine-Induced Immune Thrombocytopenia on Day Two

Introduction

Vaccines have been one of the most impactful human discoveries that have significantly changed life expectancy. Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by platelet damage, life-threatening thrombocytopenia, and haemorrhage when the platelet count reaches below 20 × 10⁹/mcL. Its pathogenesis involves viral mimicry or T-cell-induced immune destruction in antibody-negative cases. The clinical manifestations of thrombocytopenia vary according to the severity (level of platelets) and range from being asymptomatic to severe haemorrhage. ITP is treated with immunosuppression. Case Presentation. A 26-year-old Iraqi male laboratory analyst with an unremarkable medical history presented with severe thrombocytopenia 2 days after receiving the Oxford-AstraZeneca coronavirus disease-2019 vaccine. The patient was asymptomatic with unremarkable examination findings. However, his low platelet count was discovered accidentally, and the patient did not exhibit the resistance pattern of ITP and recovered successfully with regular immunosuppressant treatment.

Conclusion

Patients with a history of thrombocytopenia can develop vaccine-induced thrombocytopenia earlier than the expected onset. Close monitoring, through regular complete blood counts, is highly recommended for patients with previous thrombocytopenia because the immune modulation process of the vaccine can worsen preexisting thrombocytopenia.

Vigilance regarding immune thrombocytopenic purpura after COVID-19 vaccine

INTRODUCTION

Based on the severity of thrombocytopenia, patients with immune thrombocytopenic purpura (ITP) are at an increased risk of mucocutaneous or major bleeding.

DISCUSSION

There has been an increased risk of ITP after administration of various vaccines like influenza, measles-mumps-rubella, hepatitis B, and diphtheria-tetanus-pertussis. The pathogenesis of vaccine-related thrombocytopenia is not completely clear and is probably caused by molecular mimicry. Till date, there have been few reported cases of thrombocytopenia in the pharmacovigilance databases after patients received the Pfizer and Moderna coronavirus disease-19 (COVID-19) vaccines.

CONCLUSION

Emergency physicians should be aware of the occurrence of vaccine-induced ITP in patients who present with bleeding manifestations, especially after the current boost in COVID-19 vaccination drive worldwide.

Comparative study between chronic immune thrombocytopenia patients and healthy population on Epstein-Barr virus infection status by polymerase chain reaction

BACKGROUND

Immune thrombocytopenia (ITP) has been known to be associated with assorted virus infections. This study aims to investigate the Epstein-Barr virus infection status in chronic ITP patients by real-time quantitative polymerase chain reaction.

METHODS

42 chronic ITP patients and 42 healthy donors were retrospectively included via propensity score matching with gender and age. EBV-DNA levels in whole blood of patients and donors were assessed by RT-qPCR, and correlations between virus load and platelet count were analyzed.

RESULTS

The positive rate of EBV-DNA in lymphocytes of chronic ITP patients was significantly higher than that in donors (52.4% vs 31.0%, p = 0.046). Platelet count [18(8-45)×10⁹/L] of patients with high virus load in lymphocytes was significantly lower than that [51(30-87)×10⁹/L] of patients with low virus load (p = 0.0001), whereas no difference was observed in platelet count between EBV-DNA-positive and negative subgroups of donors (p = 0.984). And a significant inverse correlation was observed between EBV-DNA levels in lymphocytes and platelet count (r = -0.4958, p = 0.019) in patients, which was independent from the presence of platelet-associated IgG.

CONCLUSIONS

EBV infection has a potential role in the development of chronic ITP. Identification and control of this underlying infection should be emphasized in the treatment of chronic ITP.

Immune thrombocytopenic purpura risk by live, inactivated and simultaneous vaccinations among Japanese adults, children and infants: a matched case-control study

This case–control study investigated immune thrombocytopenic purpura (ITP) risk following live, inactivated, and simultaneous vaccination, with a focus on infants aged < 2 years. We matched case patients with ITP to one or two control patients with other diseases by institution, hospital visit timing, sex, and age. We calculated McNemar’s pairwise odds ratios (ORs [95% confidence interval]) with 114 case–control pairs. The case group had 27 (44%) males and 22 (35%) infants, and the control group included 49 (43%) males and 42 (37%) infants. For all age groups, the McNemar’s OR for ITP occurrence was 1.80 (0.54–6.84, p = 0.64) for all vaccines. Among infants, these were 1.50 (0.17–18.0, p = 0.50) for all vaccines, 2.00 (0.29–22.1, p = 0.67) for live vaccines, and 1.00 (0.01–78.5, p = 0.50) for inactivated vaccines. Sex-adjusted common ORs for simultaneous vaccination were 1.52 (0.45–5.21, p = 0.71) for all vaccines, 1.83 (0.44–7.59, p = 0.40) for inactivated vaccines only, and 1.36 (0.29–6.30, p = 0.69) for mixed live and inactivated vaccines. In infants, these were 1.95 (0.44–8.72, p = 0.38), 1.41 (0.29–6.94, p = 0.67) and 2.85 (0.43–18.9, p = 0.28), respectively. These limited data suggest no significant ITP risk following vaccinations or simultaneous vaccination in any age group, including infants.

Causality assessment of adverse events following immunization: the problem of multifactorial pathology

The analysis of Adverse Events Following Immunization (AEFI) is important in a balanced epidemiological evaluation of vaccines and in the issues related to national vaccine injury compensation programs. If manufacturing defects or vaccine storage and delivering errors are excluded, the majority of adverse reactions to vaccines occur as excessive or biased inflammatory and immune responses. These unwanted phenomena, occasionally severe, are associated with many different endogenous and exogenous factors, which often interact in complex ways. The confirmation or denial of the causal link between an AEFI and vaccination is determined pursuant to WHO guidelines, which propose a four-step analysis and algorithmic diagramming. The evaluation process from the onset considers all possible "other causes" that can explain the AEFI and thus exclude the role of the vaccine. Subsequently, even if there was biological plausibility and temporal compatibility for a causal association between the vaccine and the AEFI, the guidelines ask to look for any possible evidence that the vaccine could not have caused that event. Such an algorithmic method presents some concerns that are discussed here, in the light of the multifactorial nature of the inflammatory and immune pathologies induced by vaccines, including emerging knowledge of genetic susceptibility to adverse effects. It is proposed that the causality assessment could exclude a consistent association of the adverse event with the vaccine only when the presumed "other cause" is independent of an interaction with the vaccine. Furthermore, the scientific literature should be viewed not as an exclusion criterion but as a comprehensive analysis of all the evidence for or against the role of the vaccine in causing an adverse reaction. These issues are discussed in relation to the laws that, in some countries, regulate the mandatory vaccinations and the compensation for those who have suffered serious adverse effects.

Causality assessment of adverse events following immunization: the problem of multifactorial pathology

The analysis of Adverse Events Following Immunization (AEFI) is important in a balanced epidemiological evaluation of vaccines and in the issues related to vaccine injury compensation programs. The majority of adverse reactions to vaccines occur as excessive or biased inflammatory and immune responses. These unwanted phenomena, occasionally severe, are associated with many different endogenous and exogenous factors, which often interact in complex ways. The confirmation or denial of the causal link between an AEFI and vaccination is determined pursuant to WHO guidelines, which propose a four-step analysis and algorithmic diagramming. The evaluation process from the onset considers all possible "other causes" that might explain the AEFI and thus exclude the role of the vaccine. Subsequently, even if there was biological plausibility and temporal compatibility for a causal association between the vaccine and the AEFI, the guidelines ask to look for any possible evidence that the vaccine could not have caused that event. Such an algorithmic method presents several concerns that are discussed here, in the light of the multifactorial nature of the inflammatory and immune pathologies induced by vaccines, including emerging knowledge of genetic susceptibility to adverse effects. It is proposed that the causality assessment could exclude a consistent association of the adverse event with the vaccine only when the presumed "other cause" is independent of an interaction with the vaccine. Furthermore, the scientific literature should be viewed not as an exclusion criterion but as a comprehensive analysis of all the evidence for or against the role of the vaccine in causing an adverse reaction. Given these inadequacies in the evaluation of multifactorial diseases, the WHO guidelines need to be reevaluated and revised. These issues are discussed in relation to the laws that, in some countries, regulate the mandatory vaccinations and the compensation for those who have suffered serious adverse effects.

Eltrombopag: Efficacy and Safety in Steroid Refractory Lupus-Associated Immune Thrombocytopenia

BACKGROUND

Eltrombopag, a thrombopoietin receptor agonist, is effective in chronic immune thrombocytopenia (ITP). The data in lupus ITP are sparse. This study aimed to assess the efficacy and safety of eltrombopag in lupus ITP.

METHODS

This is a single-center study conducted between 2012 and 2017 of 12 subjects with systemic lupus erythematosus-associated ITP. Patients with inadequate or suboptimal response to steroids and other immunosuppressants treated with eltrombopag were included in the study. Time taken for response to therapy (defined as platelets >1 lakh), dose, duration of treatment, and adverse effects of the drug were noted.

RESULTS

A total of 12 subjects were included in the study. The median platelet count at initiation of eltrombopag was 19,000 per μL. The time taken for response to therapy was 8 days. The median platelet count at 1-month follow-up was 241,000 per μL. All patients were concurrently treated with steroids and other immunosuppressants. Sustained benefit after stopping eltrombopag was noted in all patients. No adverse events including thrombotic complication were noted.

CONCLUSIONS

Eltrombopag is a new drug in our arsenal for treatment of ITP in lupus. It is a rapidly effective, safe, and orally administered medication. It indirectly contributes to reduction in the dose of steroids and immunosuppressants, thereby minimizing their cumulative adverse effects. It is a promising and safe option for the treatment of lupus-associated thrombocytopenia, but this needs further confirmation from multicenter, multiethnic, randomized controlled trials.

Infections: a double-edge sword in autoimmunity

PURPOSE OF REVIEW

Infections play a role in the pathogenesis of autoimmune diseases (AID). Several bacterial and viral pathogens play a double role, as both inducers and inhibitors of AID. In this review, we will present current evidence and discuss different aspects of this notion.

RECENT FINDINGS

Infectors that both inhibit and induce AID include Helicobacter pylori, Klebsiella pneumoniae, hepatitis B virus, group B Coxsackieviruses, Epstein-Barr virus and Lymphocytic choriomeningitis virus. Numerous AID are affected by infections, including polyarteritis nodosa, inflammatory bowel disease, and type 1 diabetes. Some pathogens, such as group B Coxsackieviruses, may induce and inhibit the development of the same AID. This reveals a complex role of infections in autoimmunity pathogenesis.

SUMMARY

Elucidating the exact role of each pathogen on each specific AID is important, as this will enable evaluating the manipulation of these infections in the treatment of AID.

The Role of the Microbiota in the Diabetic Peripheral Artery Disease

Vascular complications of diabetes mellitus represent a major public health problem. Although many steps forward have been made to define the causes and to find the best possible therapies, the problem remains crucial. In recent years, more and more evidences have defined a link between microbiota and the initiation, promotion, and evolution of atherosclerotic disease, even in the diabetic scenario. There is an urgency to develop the knowledge of modern medicine about the link between gut microbiota and its host's metabolic pathways, and it would be useful to understand and justify the interindividual diversity of clinical disease presentation of diabetic vascular complication even if an optimization of pharmacological treatment has been made or in the case of young patients where hypertension, dyslipidemia, and diabetes are not able to justify a very quick progress of atherosclerotic process. The aim of the present review is to gather all the best available evidence in this regard and to define a new role of the microbiota in this field, from biomarker to possible therapeutic target.

Epistaxis and gross haematuria with severe thrombocytopaenia associated with influenza vaccination

Epistaxis may be attributed to many causes during the winter including dry mucous membranes from low indoor humidity from heating. However, epistaxis may also be due to thrombocytopaenia. Immune thrombocytopaenia purpura (ITP) is an autoimmune disorder causing thrombocytopaenia. Viral infections sometimes lead to ITP. Vaccines, predominantly the measles-mumps-rubella vaccine, have been associated with the development of ITP. There are several published case reports regarding influenza vaccine induced ITP. However, an association between ITP and influenza vaccination has not been firmly proven yet. We report the case of an adult with three episodes of epistaxis, each within 1 week of receiving a yearly influenza trivalent inactivated vaccine, the last episode being more severe and also featuring gross haematuria.

Inter-Pathogen Peptide Sharing and the Original Antigenic Sin: Solving a Paradox

Aims:

To analyse the peptide commonality among viral, bacterial, and protozoan pathogens, and the immunopathologic consequences in the human host.

Methods:

HPV16, HCMV,C. diphtheriae, B. pertussis, C. tetani, T. gondii,andT. cruziwere analysed for common amino acid sequences that are additionally shared with the human host. The pentapeptide, a minimal immune determinant in humoral and cellular immune recognition, was used as a measurement unit of the peptide similarity level. Molecular modeling was applied to compare the amino acid contexts containing common minimal determinants.

Results:

Twenty-nine pentapeptides were found to occur, even hundreds of times, throughout the analyzed pathogen proteomes as well as in the human proteome. Such vast peptide commonalities together with molecular modeling data support the possibility that a pre-existing immune response to a first pathogen can be boosted by a successive exposure to a second different pathogen,i.e., the primary response to a pathogen can be transformed into a secondary response to a previously encountered different pathogen. Two possible consequences emerge. Firstly, no responses might be elicited against the pathogen lastly encountered either by infection or active immunization, but reactions could occur only with the early sensitizing pathogen, which is no more present in the organism. Secondly, the immune response boosted by the pathogen lastly encountered will find a way out by cross-reacting with human proteins.

Conclusion:

This study might explain the “original antigenic sin” phenomenon described seven decades ago [Francis T. Jr. Ann Intern Med 1953;39:203], thus providing explanations for vaccine failures and offering possible clues for designing successful vaccines.

Temporal Association of Certain Neuropsychiatric Disorders Following Vaccination of Children and Adolescents: A Pilot Case-Control Study

BACKGROUND

Although the association of the measles, mumps, and rubella vaccine with autism spectrum disorder has been convincingly disproven, the onset of certain brain-related autoimmune and inflammatory disorders has been found to be temporally associated with the antecedent administration of various vaccines. This study examines whether antecedent vaccinations are associated with increased incidence of obsessive-compulsive disorder (OCD), anorexia nervosa (AN), anxiety disorder, chronic tic disorder, attention deficit hyperactivity disorder, major depressive disorder, and bipolar disorder in a national sample of privately insured children.

METHODS

Using claims data, we compared the prior year's occurrence of vaccinations in children and adolescents aged 6-15 years with the above neuropsychiatric disorders that were newly diagnosed between January 2002 and December 2007, as well as two control conditions, broken bones and open wounds. Subjects were matched with controls according to age, gender, geographical area, and seasonality. Conditional logistic regression models were used to determine the association of prior vaccinations with each condition.

RESULTS

Subjects with newly diagnosed AN were more likely than controls to have had any vaccination in the previous 3 months [hazard ratio (HR) 1.80, 95% confidence interval 1.21-2.68]. Influenza vaccinations during the prior 3, 6, and 12 months were also associated with incident diagnoses of AN, OCD, and an anxiety disorder. Several other associations were also significant with HRs greater than 1.40 (hepatitis A with OCD and AN; hepatitis B with AN; and meningitis with AN and chronic tic disorder).

CONCLUSION

This pilot epidemiologic analysis implies that the onset of some neuropsychiatric disorders may be temporally related to prior vaccinations in a subset of individuals. These findings warrant further investigation, but do not prove a causal role of antecedent infections or vaccinations in the pathoetiology of these conditions. Given the modest magnitude of these findings in contrast to the clear public health benefits of the timely administration of vaccines in preventing mortality and morbidity in childhood infectious diseases, we encourage families to maintain vaccination schedules according to CDC guidelines.

Zika virus (ZIKV) infection related with immune thrombocytopenic purpura (ITP) exacerbation and antinuclear antibody positivity

A 30-year-old Colombian woman with past history of immune thrombocytopenia (ITP) presented to the emergency room with two days of global headache, arthralgia, myalgia, and low level fever and generalized erythematous rash. Platelets dropped to 9 × 10⁹/L (fourth day of symptoms) without hemorrhagic manifestations but recovered to 30 × 10⁹/L in 24 hours (fifth day). Dengue virus infection, as well as other viral infections, was ruled out. Zika virus (ZIKV) was evaluated in serum and urine samples by real-time reverse-transcriptase polymerase chain reaction (genomic regions within E protein and NS2b protein). Urine sample was positive and serum sample negative for ZIKV, confirming a recent ZIKV infection with urinary tract virus excretion at 7^th day after disease onset. To our knowledge this is the first description of a case of severe immune thrombocytopenia exacerbation and antinuclear antibody positivity induced by ZIKV infection.

Clinical course and prognostic factors of childhood immune thrombocytopenia: single center experience of 10 years

Purpose

This study aimed to evaluate the clinical course of childhood immune thrombocytopenia (ITP) and to assess the risk factors for developing chronic ITP.

Methods

The records of 64 children diagnosed with ITP from November 2005 and December 2014 at single center were retrospectively analyzed.

Results

The median age at diagnosis and the median platelet count were 1 year (range, 1 month to 15 years) and 9×10⁹/L (range, 0–84×10⁹/L), respectively. No patient experienced severe bleeding. Nineteen children (29.7%) spontaneously recovered their platelet count to ≥100×10⁹/L at a median of 10 days. In total 45 patients (70.3%) received intravenous immunoglobulin (IVIG) as first-line therapy, and showed platelet recovery at 1 week. The final diagnosis of 55 (85.9%) and 9 patients (14.1%) was acute and chronic ITP, respectively. Older age, absence of prior infection and insidious onset of symptoms were significantly associated with the development of chronic ITP. Among the patients who received IVIG, those with platelet count <45×10⁹/L at 1 month after IVIG showed a significantly higher incidence of chronic ITP compared to those with platelet count ≥45×10⁹/L (88.8% vs. 44.4%, P<0.01).

Conclusion

In most patients, ITP runs a benign course and approximately 86% of them recover within 1 year of their initial diagnosis. The potential impact of the risk factors of chronic ITP on clinical practice needs to be explored and further studies are warranted to determine whether IVIG influences the course of ITP.

Canine autoimmune hemolytic anemia: management challenges

Immune-mediated hemolytic anemia is one of the most common manifestations of canine immune-mediated disease, yet treatment regimens remain nonstandardized and, in some cases, controversial. The main reason for this, as for most diseases in veterinary medicine, is the lack of large-scale placebo-controlled trials so that the efficacy of one treatment over another can be established. Most of the evidence used for treatment comes from retrospective studies and from personal preference and experience, and because of this, treatment regimens tend to vary among institutions and individual clinicians. Management of immune-mediated hemolytic anemia includes immunosuppression, thromboprophylaxis, and supportive care measures to help prevent and treat concurrent conditions.

Microbiota at the crossroads of autoimmunity

Autoimmune diseases have a multifactorial etiology including genetic and environmental factors. Recently, there has been increased appreciation of the critical involvement of the microbiota in the pathogenesis of autoimmunity, although in many cases, the cause and the consequence are not easy to distinguish. Here, we suggest that many of the known cues affecting the function of the immune system, such as genetics, gender, pregnancy and diet, which are consequently involved in autoimmunity, exert their effects by influencing, at least in part, the microbiota composition and activity. This, in turn, modulates the immune response in a way that increases the risk for autoimmunity in predisposed individuals. We further discuss current microbiota-based therapies.

Vaccinations and secondary immune thrombocytopenia with antiphospholipid antibodies by human papillomavirus vaccine

A 13-year-old girl developed immune thrombocytopenic purpura (ITP) and concomitant positive antiphospholipid antibodies (aPL) following vaccination with a quadrivalent human papillomavirus (HPV) vaccine. During the course of a disease, she developed clinical manifestation with bleeding and she was treated with intravenous immunoglobulins. Consequently, the number of her platelets remained critically low and she was put on corticosteroids and rituximab. Since then, her platelet count remain within the normal range, but her aPL are still present.

Viruses, anti-viral therapy, and viral vaccines in children with immune thrombocytopenia

Immune thrombocytopenia (ITP) might be preceded by silent or overt viral infections. Similarly, anti-viral drugs and viral vaccines could also trigger ITP and might play a central role in its pathogenesis. The seasonal nature of childhood ITP suggests that viral infections might initiate immune responses that increase the predisposition and occurrence of ITP. Active cytomegalovirus or Epstein-Barr virus should be considered in differential diagnosis when thrombocytopenia is associated with lymphadenopathy, especially with splenomegaly. This review will focus on the specific association of ITP in association with viral disease and vaccinations, and will discuss the effectiveness of current therapies in light of our current understanding of viral-associated ITP.

Postinfluenza Vaccination Idiopathic Thrombocytopenic Purpura in Three Elderly Patients

The etiologies of secondary idiopathic thrombocytopenic purpura (ITP) include infection, autoimmune disease, and immunodeficiency. We report the cases of three elderly patients who developed ITP after receiving influenza vaccinations. The platelet count of an 81-year-old woman fell to 27,000/μL after she received an influenza vaccination. A 75-year-old woman developed thrombocytopenia (5,000 platelets/μL) after receiving an influenza vaccination. An 87-year-old woman whose laboratory test values included a platelet count of 2,000/μL experienced genital bleeding after receiving an influenza vaccination. After Helicobacter pylori (HP) eradication or corticosteroid treatment, all of the patients' platelet counts increased. Influenza vaccination is an underlying etiology of ITP in elderly patients. HP eradication or corticosteroid treatment is effective for these patients. Clinicians should be aware of the association between ITP and influenza vaccinations.

Desialylation is associated with apoptosis and phagocytosis of platelets in patients with prolonged isolated thrombocytopenia after allo-HSCT

BACKGROUND

Prolonged isolated thrombocytopenia (PT) is a frequent complication in patients who undergo allogeneic hematopoietic stem cell transplantation (allo-HSCT), and it is associated with an adverse prognosis. In this study, we hypothesized that desialylation on platelet surfaces was associated with PT after allo-HSCT. The mechanisms participating in this process may include NEU1 translocation, platelet apoptosis, and phagocytosis by macrophages.

METHODS

PT was defined as a peripheral platelet count less than 100 × 10(9)/L without sustained anemia or leukopenia for more than 3 months after allo-HSCT. 34 patients were identified consecutively from a cohort of 255 patients who underwent allo-HSCT for hematologic malignancies between May and October 2014 at Peking University Institute of Hematology. Desialylation, enzyme expression, and phagocytosis were detected using flow cytometry, immunofluorescence, RT-PCR, Western blot, and so on.

RESULTS

Platelets from the PT patients had significantly fewer sialic acids (P = .001) and increased β-galactose exposure indicative of desialylation on the surface (P = .042), and serum from the PT patients showed a higher sialic acid concentration (8.400 ± 0.2209 μmol/L, P < .001). The sialidase NEU1 was over-expressed from mRNA to protein levels, and its catalytic activity was increased in platelets from the PT patients. Desialylation of GPIbα in the PT patients was correlated with changes in 14-3-3ζ distribution, which, relative to Bad activation, modulated the expression of Bcl-2 family proteins, depolarized the inner membrane of the mitochondria, and initiated the intrinsic mitochondria-dependent pathway of apoptosis. Macrophages derived from the THP-1 cell line preferred to phagocytize desialylated platelets from the PT patients in vitro. We also revealed that oseltamivir (400 μmol/L) could inhibit 50 % of the sialidase activity on platelets and could protect 20 % of platelets from phagocytosis in vitro.

CONCLUSIONS

Desialylation of platelets was associated with platelet apoptosis and phagocytosis, whereas oseltamivir could reduce platelet destruction in the periphery, indicating a potential novel treatment for PT after allo-HSCT.

Helicobacter pylori Infection in Pediatrics

This review includes the main pediatric studies published from April 2014 to March 2015. The host response of Treg cells with increases in FOXP3 and TGF-β1 combined with a reduction in IFN-γ by Teff cells may contribute to Helicobacter pylori susceptibility in children. Genotypic variability in H. pylori strains influences the clinical manifestation of the infection. Helicobacter pylori infection is associated with variables indicative of a crowded environment and poor living conditions, while breast-feeding has a protective effect. Intrafamilial infection, especially from mother to children and from sibling to sibling, is the dominant transmission route. Studies showed conflicting results regarding the association between H. pylori infection and iron deficiency anemia. One study suggests that H. pylori eradication plays a role in the management of chronic immune thrombocytopenic purpura in H. pylori-infected children and adolescents. The prevalence of H. pylori was higher in chronic urticaria patients than in controls and, following H. pylori eradication, urticarial symptoms disappeared. An inverse relationship between H. pylori infection and allergic disease was reported. Antibiotic resistance and insufficient compliance to treatment limit the efficacy of eradication therapy. Sequential therapy had no advantage over standard triple therapy. In countries where H. pylori infection is prevalent, studies focusing on virulence factors and antibiotic susceptibility may provide anticipation of the prognosis and may be helpful to reduce morbidity and mortality.

Vaccines, adjuvants and autoimmunity

Vaccines and autoimmunity are linked fields. Vaccine efficacy is based on whether host immune response against an antigen can elicit a memory T-cell response over time. Although the described side effects thus far have been mostly transient and acute, vaccines are able to elicit the immune system towards an autoimmune reaction. The diagnosis of a definite autoimmune disease and the occurrence of fatal outcome post-vaccination have been less frequently reported. Since vaccines are given to previously healthy hosts, who may have never developed the disease had they not been immunized, adverse events should be carefully accessed and evaluated even if they represent a limited number of occurrences. In this review of the literature, there is evidence of vaccine-induced autoimmunity and adjuvant-induced autoimmunity in both experimental models as well as human patients. Adjuvants and infectious agents may exert their immune-enhancing effects through various functional activities, encompassed by the adjuvant effect. These mechanisms are shared by different conditions triggered by adjuvants leading to the autoimmune/inflammatory syndrome induced by adjuvants (ASIA syndrome). In conclusion, there are several case reports of autoimmune diseases following vaccines, however, due to the limited number of cases, the different classifications of symptoms and the long latency period of the diseases, every attempt for an epidemiological study has so far failed to deliver a connection. Despite this, efforts to unveil the connection between the triggering of the immune system by adjuvants and the development of autoimmune conditions should be undertaken. Vaccinomics is a field that may bring to light novel customized, personalized treatment approaches in the future.

Immune thrombocytopenic purpura (ITP) associated with vaccinations: a review of reported cases

Immune thrombocytopenic purpura (ITP) is an autoimmune condition characterized by low platelet count with mucocutaneous and other bleedings. Clinical manifestations may range from spontaneous formation of purpura and petechiae, especially on the extremities, to epistaxis, bleeding at the gums or menorrhagia, any of which occur usually if the platelet count is below 20,000 per μl. A very low count may result in the spontaneous formation of hematomas in the mouth or on other mucous membranes. Fatal complications, including subarachnoid or intracerebral, lower gastrointestinal or other internal bleeding can arise due to an extremely low count. Vaccines may induce ITP by several mechanisms. Vaccine-associated autoimmunity may stem not only from the antigen-mediated responses but also from other constituents of the vaccine, such as yeast proteins, adjuvants, and preservatives diluents. The most likely is through virally induced molecular mimicry. The binding of pathogenic autoantibodies to platelet and megakaryocytes may cause thrombocytopenia by different mechanisms, such as opsonization, direct activation of complement, or apoptotic pathways. The autoantibodies hypothesis is not sufficient to explain all ITP cases: In the anti-platelet antibody-negative cases, a complementary mechanism based on T cell immune-mediated mechanism has been suggested. In particular, T cell subsets seem dysregulated with an increased production of pro-inflammatory cytokines, as IFN-γ and TNF, and chemokines, as CXCL10. Vaccines are one of the most striking discoveries in human history that changed dramatically life expectancy. Nonetheless, the occurrence of adverse events and autoimmune phenomena has been described following vaccination, and ITP may represent one of this.

Need for an improved vaccination rate in primary immune thrombocytopenia patients exposed to rituximab or splenectomy. A nationwide population-based study in France

International guidelines on immune thrombocytopenia (ITP) management recommend vaccination against Streptococcus pneumoniae (S.p.), Haemophilus influenza b (Hib) and Neisseiria meningitidis (N.m.) before splenectomy. French guidelines also recommend these vaccinations before rituximab. The aim of this study was to assess the application of these recommendations. The French Adult ITP: a French pHarmacoepidemiological study (FAITH, n°ENCEPP 4574) is aimed at following in the French national health insurance system database (SNIIRAM) the cohort of all incident and persistent or chronic primary ITP adults treated in France. We assessed vaccine exposure in the 1,106 patients who entered the FAITH cohort between 2009 and 2011. Vaccination was said "recommended" if performed at least 2 weeks before rituximab or splenectomy accordingly with French guidelines. Among the 423 non-splenectomized patients exposed to rituximab, vaccination rates against S.p., Hib and N.m. were respectively 32.4%, 18.9%, and 3.8%. It was recommended in 12.8%, 6.6%, and 1.2% of the patients, respectively. Among the 178 splenectomized patients, vaccination rates were 70.2%, 47.0%, and 11.9%, respectively (recommended: 60.1%, 35.7%, and 9.5%). Among the splenectomized patients previously exposed to rituximab (n = 67), 53.3% of the vaccinations occurred during the semester following a rituximab infusion that is during the maximal B-cell depletion period. In multivariate analyses, a disease duration exceeding 3 months was the sole factor associated to recommended vaccination in rituximab-treated patients as well as in splenectomized patients. This study stresses the need of better and earlier vaccination of ITP patients.

Association between Bacterial Infection and Peripheral Vascular Disease: A Review

There are an increasing number of data showing a clinically important association between bacterial infection and peripheral artery disease (PAD). Bacteria suspected of being involved in PAD pathogenesis are: periodontal bacteria, gut microbiota, Helicobacter pylori, and Chlamydia pneumoniae. Infectious agents may be involved in the pathogenesis of atherosclerosis via activation of a systemic or local host immunological response to contamination of extravascular tissues or the vascular wall, respectively. A systemic immunological reaction may damage vascular walls in the course of autoimmunological cross-reactions between anti-pathogen antibodies and host vascular antigens (immunological mimicry), pathogen burden mechanisms (nonspecific activation of inflammatory processes in the vascular wall), and neuroendocrine-immune cross-talk. Besides activating the inflammatory pathway, bacterial infection may trigger PAD progression or exacerbation by enhancement of platelet reactivity, by a stimulatory effect on von Willebrand factor binding, factor VIII, fibrinogen, P-selectin activation, disturbances in plasma lipids, increase in oxidative stress, and resistance to insulin. Local inflammatory host reaction and induction of atherosclerotic plaque progression and/or instability result mainly from atherosclerotic plaque colonization by microorganisms. Despite these premises, the role of bacterial infection in PAD pathogenesis should still be recognized as controversial, and randomized, controlled trials are required to evaluate the outcome of periodontal or gut bacteria modification (through diet, prebiotics, and probiotics) or eradication (using antibiotics) in hard and surrogate cardiovascular endpoints.