Immune Thrombocytopenia Secondary to COVID-19: a Systematic Review

Characterization of Unique Pathological Features of COVID-Associated Coagulopathy: Studies with AC70 hACE2 Transgenic Mice Highly Permissive to SARS-CoV-2 Infection

COVID-associated coagulopathy seemly plays a key role in post-acute sequelae of SARS- CoV-2 infection. However, the underlying pathophysiological mechanisms are poorly understood, largely due to the lack of suitable animal models that recapitulate key clinical and pathological symptoms. Here, we fully characterized AC70 line of human ACE2 transgenic (AC70 hACE2 Tg) mice for SARS-CoV-2 infection. We noted that this model is highly permissive to SARS-CoV-2 with values of 50% lethal dose and infectious dose as ~ 3 and ~ 0.5 TCID50 of SARS-CoV-2, respectively. Mice infected with 105 TCID50 of SARS-CoV-2 rapidly succumbed to infection with 100% mortality within 5 days. Lung and brain were the prime tissues harboring high viral titers, accompanied by histopathology. However, viral RNA and inflammatory mediators could be detectable in other organs, suggesting the nature of a systemic infection. Lethal challenge of AC70 hACE2 Tg mice caused acute onset of leukopenia, lymphopenia, along with an increased neutrophil-to-lymphocyte ratio (NLR). Importantly, infected animals recapitulated key features of COVID-19-associated coagulopathy. SARS-CoV-2 could induce the release of circulating neutrophil extracellular traps (NETs), along with activated platelet/endothelium marker. Immunohistochemical staining with anti-platelet factor-4 (PF4) antibody revealed profound platelet aggregates especially within blocked veins of the lungs. We showed that acute SARS-CoV-2 infection triggered a hypercoagulable state coexisting with ill-regulated fibrinolysis. Finally, we highlighted the potential role of Annexin A2 (ANXA2) in fibrinolytic failure. ANXA2 is a calcium-dependent phospholipid-binding protein that forms a heterotertrameric complexes localized at the extracellular membranes with two S100A10 small molecules acting as a co-receptor for tissue-plasminogen activator (t-PA), tightly involved in cell surface fibrinolysis. Thus, our results revealing elevated IgG type anti-ANXA2 antibody production, downregulated de novo ANXA2/S100A10 synthesis, and reduced ANXA2/S100A10 association in infected mice, this protein might serve as druggable targets for development of antithrombotic and/or anti-fibrinolytic agents to attenuate pathogenesis of COVID-19.

Assessing the impact of COVID-19 on acute leukemia patients: a comparative analysis of hematological and biochemical parameters

BACKGROUND

The impact of COVID-19 infection on the blood system remains to be investigated, especially with those encountering hematological malignancies. It was found that a high proportion of cancer patients are at an elevated risk of encountering COVID-19 infection. Leukemic patients are often suppressed and immunocompromised, which would impact the pathology following COVID-19 infection. Therefore, this research aims to bring valuable insight into the mechanism by which COVID-19 infection influences the hematological and biochemical parameters of patients with acute leukemia.

METHODS

This retrospective investigation uses repeated measures to examine changes in hematological and biochemical parameters among patients with acute leukemia before and after COVID-19 infection at a major Saudi tertiary center. The investigation was conducted at the Ministry of National Guard-Health Affairs in Riyadh, Saudi Arabia, on 24 acute leukemia patients with COVID-19 between April 2020 and July 2023. The impact of COVID-19 on clinical parameters, comorbidities, and laboratory values was evaluated using data obtained from the electronic health records at four designated time intervals. The relative importance of comorbidities, testing preferences, and significant predictors of survival was ascertained.

RESULTS

The majority of leukemic COVID-19-infected patients, primarily detected through PCR tests, were diagnosed with acute lymphoblastic leukemia (70.8%). The hematological and biochemical parameters exhibited stability, except for a brief increase in ALT and a sustained rise in AST. These changes were not statistically significant, and parameters remained normal at all time points. Additionally, an increase in monocyte count was shown at time point-3, as well as platelet counts at time point 2.

CONCLUSION

While this study did not detect statistically significant effects of COVID-19 on biochemical and hematological parameters in acute leukemia patients, further investigation is needed to fully understand the potential adverse reactions and modifications following COVID-19 infection.

COVID-19-induced immune thrombocytopenia management approach: A case report and literature review

Key Clinical Message

Vincristine therapy can be effective in refractory Immune thrombocytopenia (ITP) following COVID-19 vaccination. Our case report highlights the need for further research to establish standard management guidelines for COVID-19-vaccine-associated ITP.

Abstract

Adult immune thrombocytopenia (ITP) can occur as a rare complication following several viral infections or a rare adverse event or complication of vaccination. In this paper, we report a case of a 39-year-old male patient with severe refractory ITP that began 4-weeks after receiving his third (booster) dose of the COVID-19 vaccine (BNT162b2, Pfizer-BioNTech). He was given oral dexamethasone 40 mg daily for 4 days followed by prednisone at 1 mg/kg (85 mg daily) for 10 days. In the following weeks, we attempted several other lines of therapy to treat his ITP, including anti-RhD immunoglobulin, which, unfortunately, caused moderate hemolysis requiring packed red blood cell transfusion, intravenous immunoglobulin (given at a subtherapeutic dose of 0.4 g/kg for only 1 day since it was not available), rituximab, and eltrombopag. The patient, unfortunately, showed no response to any of these treatments. This was an indicator to initiate salvage therapy with vincristine 2 mg weekly for 3 weeks. The patient's platelet count started to increase remarkably during the third week of vincristine and normalized after 4 weeks. We review the findings, clinical characteristics, and management approaches that were reported in the literature regarding COVID-19-vaccine-induced ITP. More in-depth research is needed to delineate standard guidelines for the management of such cases. This report underscores the importance of resorting to vincristine and eltrombopag as great options for severe and refractory ITP related to the COVID-19 vaccine.

The creativity of cells: aneural irrational cognition

Evidence of cognition in aneural cells is well-establish in the literature. This paper extends the exploration of the mechanisms of cognition by considering whether or not aneural cells may be capable of irrational cognition, making associations based on coincidental similarities and circumstantial factors. If aneural cells do harness such semiosic qualities, as with higher-level creativity, this might be how they are able to overcome old algorithms and invent tools for new situations. I will look at three examples of irrational learning in aneural systems in terms of semiotics: (1) generalisation in the immune system, based on viral molecular mimicry, whereby immune cells attack the self, which seems to be an overgeneralisation of an icon sign based on mere similarity, not identity, (2) the classical conditioning of pea plants to trope toward wind as a sign of light, which seems to be an association of an index sign based on mere temporal proximity, and (3) a pharmaceutical intervention to prevent pregnancy, using a conjugate to encrypt self with non-self, which seems to be an example of symbol use. We identify irrational cognition easily when it leads to 'wrong' outcomes, but, if it occurs, it may also lead to favourable outcomes and 'creative' solutions.

Antibodies against Platelet Glycoproteins in Clinically Suspected VITT Patients

Vaccine-induced thrombotic thrombocytopenia (VITT) is a rare but severe complication following COVID-19 vaccination, marked by thrombocytopenia and thrombosis. Analogous to heparin-induced thrombocytopenia (HIT), VITT shares similarities in anti-platelet factor 4 (PF4) IgG-mediated platelet activation via the FcγRIIa. To investigate the involvement of platelet-antibodies in VITT, we analyzed the presence of platelet-antibodies directed against glycoproteins (GP)IIb/IIIa, GPV and GPIb/IX in the serum of 232 clinically suspected VITT patients determined based on (suspicion of) occurrence of thrombocytopenia and/or thrombosis in relation to COVID-19 vaccination. We found that 19% of clinically suspected VITT patients tested positive for anti-platelet GPs: 39%, 32% and 86% patients tested positive for GPIIb/IIIa, GPV and GPIb/IX, respectively. No HIT-like VITT patients (with thrombocytopenia and thrombosis) tested positive for platelet-antibodies. Therefore, it seems unlikely that platelet-antibodies play a role in HIT-like anti-PF4-mediated VITT. Platelet-antibodies were predominantly associated with the occurrence of thrombocytopenia. We found no association between the type of vaccination (adenoviral vector vaccine versus mRNA vaccine) or different vaccines (ChAdOx1 nCoV-19, Ad26.COV2.S, mRNA-1273, BTN162b2) and the development of platelet-antibodies. It is essential to conduct more research on the pathophysiology of VITT, to improve diagnostic approaches and identify preventive and therapeutic strategies.

Increase in venous thromboembolism in SARS-CoV-2 infected lung tissue: proteome analysis of lung parenchyma, isolated endothelium, and thrombi

AIMS

COVID-19 pneumonia is characterized by an increased rate of deep venous thrombosis and pulmonary embolism. To better understand the pathophysiology behind thrombosis in COVID-19, we performed proteomics analysis on SARS-CoV-2 infected lung tissue.

METHODS

Liquid chromatography mass spectrometry was performed on SARS-CoV-2 infected postmortem lung tissue samples. Five protein profiling analyses were performed: whole slide lung parenchyma analysis, followed by analysis of isolated thrombi and endothelium, both stratified by disease (COVID-19 versus influenza) and thrombus morphology (embolism versus in situ). Influenza autopsy cases with pulmonary thrombi were used as controls.

RESULTS

Compared to influenza controls, both analyses of COVID-19 whole-tissue and isolated endothelium showed upregulation of proteins and pathways related to liver metabolism including urea cycle activation, with arginase being among the top upregulated proteins in COVID-19 lung tissue. Analysis of isolated COVID-19 thrombi showed significant downregulation of pathways related to platelet activation compared to influenza thrombi. Analysis of isolated thrombi based on histomorphology shows that in situ thrombi have significant upregulation of coronavirus pathogenesis proteins.

CONCLUSIONS

The decrease in platelet activation pathways in severe COVID-19 thrombi suggests a relative increase in venous thromboembolism, as thrombi from venous origin tend to contain fewer platelets than arterial thrombi. Based on histomorphology, in situ thrombi show upregulation of various proteins related to SARS-CoV-2 pathogenesis compared to thromboemboli, which may indicate increased in situ pulmonary thrombosis in COVID-19. Therefore, this study supports the increase of venous thromboembolism without undercutting the involvement of in situ thrombosis in severe COVID-19.

The Aftermath of COVID-19: Exploring the Long-Term Effects on Organ Systems

BACKGROUND

Post-acute sequelae of SARS-CoV-2 infection (PASC) is a complicated disease that affects millions of people all over the world. Previous studies have shown that PASC impacts 10% of SARS-CoV-2 infected patients of which 50-70% are hospitalised. It has also been shown that 10-12% of those vaccinated against COVID-19 were affected by PASC and its complications. The severity and the later development of PASC symptoms are positively associated with the early intensity of the infection.

RESULTS

The generated health complications caused by PASC involve a vast variety of organ systems. Patients affected by PASC have been diagnosed with neuropsychiatric and neurological symptoms. The cardiovascular system also has been involved and several diseases such as myocarditis, pericarditis, and coronary artery diseases were reported. Chronic hematological problems such as thrombotic endothelialitis and hypercoagulability were described as conditions that could increase the risk of clotting disorders and coagulopathy in PASC patients. Chest pain, breathlessness, and cough in PASC patients were associated with the respiratory system in long-COVID causing respiratory distress syndrome. The observed immune complications were notable, involving several diseases. The renal system also was impacted, which resulted in raising the risk of diseases such as thrombotic issues, fibrosis, and sepsis. Endocrine gland malfunction can lead to diabetes, thyroiditis, and male infertility. Symptoms such as diarrhea, nausea, loss of appetite, and taste were also among reported observations due to several gastrointestinal disorders. Skin abnormalities might be an indication of infection and long-term implications such as persistent cutaneous complaints linked to PASC.

CONCLUSIONS

Long-COVID is a multidimensional syndrome with considerable public health implications, affecting several physiological systems and demanding thorough medical therapy, and more study to address its underlying causes and long-term effects is needed.

Egyptian Pediatric Guidelines for the Management of Children with Isolated Thrombocytopenia Using the Adapted ADAPTE Methodology-A Limited-Resource Country Perspective

BACKGROUND

Thrombocytopenia is a prevalent presentation in childhood with a broad spectrum of etiologies, associated findings, and clinical outcomes. Establishing the cause of thrombocytopenia and its proper management have obvious clinical repercussions but may be challenging. This article provides an adaptation of the high-quality Clinical Practice Guidelines (CPGs) of pediatric thrombocytopenia management to suit Egypt's health care context.

METHODS

The Adapted ADAPTE methodology was used to identify the high-quality CPGs published between 2010 and 2020. An expert panel screened, assessed and reviewed the CPGs and formulated the adapted consensus recommendations based on the best available evidence.

DISCUSSION

The final CPG document provides consensus recommendations and implementation tools on the management of isolated thrombocytopenia in children and adolescents in Egypt. There is a scarcity of evidence to support recommendations for various management protocols. In general, complete clinical assessment, full blood count, and expert analysis of the peripheral blood smear are indicated at initial diagnosis to confirm a bleeding disorder, exclude secondary causes of thrombocytopenia and choose the type of work up required. The International Society of Hemostasis and thrombosis-Bleeding assessment tool (ISTH-SCC BAT) could be used for initial screening of bleeding manifestations. The diagnosis of immune thrombocytopenic purpura (ITP) is based principally on the exclusion of other causes of isolated thrombocytopenia. Future research should report the outcome of this adapted guideline and include cost-analysis evaluations.

Can iron chelators ameliorate viral infections?

The redox reactivity of iron is a double-edged sword for cell functions, being either essential or harmful depending on metal concentration and location. Deregulation of iron homeostasis is associated with several clinical conditions, including viral infections. Clinical studies as well as in silico, in vitro and in vivo models show direct effects of several viruses on iron levels. There is support for the strategy of iron chelation as an alternative therapy to inhibit infection and/or viral replication, on the rationale that iron is required for the synthesis of some viral proteins and genes. In addition, abnormal iron levels can affect signaling immune response. However, other studies report different effects of viral infections on iron homeostasis, depending on the class and genotype of the virus, therefore making it difficult to predict whether iron chelation would have any benefit. This review brings general aspects of the relationship between iron homeostasis and the nonspecific immune response to viral infections, along with its relevance to the progress or inhibition of the inflammatory process, in order to elucidate situations in which the use of iron chelators could be efficient as antivirals.

Complex changes in serum protein levels in COVID-19 convalescents

The COVID-19 pandemic, triggered by severe acute respiratory syndrome coronavirus 2, has affected millions of people worldwide. Much research has been dedicated to our understanding of COVID-19 disease heterogeneity and severity, but less is known about recovery associated changes. To address this gap in knowledge, we quantified the proteome from serum samples from 29 COVID-19 convalescents and 29 age-, race-, and sex-matched healthy controls. Samples were acquired within the first months of the pandemic. Many proteins from pathways known to change during acute COVID-19 illness, such as from the complement cascade, coagulation system, inflammation and adaptive immune system, had returned to levels seen in healthy controls. In comparison, we identified 22 and 15 proteins with significantly elevated and lowered levels, respectively, amongst COVID-19 convalescents compared to healthy controls. Some of the changes were similar to those observed for the acute phase of the disease, i.e. elevated levels of proteins from hemolysis, the adaptive immune systems, and inflammation. In contrast, some alterations opposed those in the acute phase, e.g. elevated levels of CETP and APOA1 which function in lipid/cholesterol metabolism, and decreased levels of proteins from the complement cascade (e.g. C1R, C1S, and VWF), the coagulation system (e.g. THBS1 and VWF), and the regulation of the actin cytoskeleton (e.g. PFN1 and CFL1) amongst COVID-19 convalescents. We speculate that some of these shifts might originate from a transient decrease in platelet counts upon recovery from the disease. Finally, we observed race-specific changes, e.g. with respect to immunoglobulins and proteins related to cholesterol metabolism.

Recent advances in the management of immune thrombocytopenic purpura (ITP): A comprehensive review

Autoimmune disorders place a substantial burden on the healthcare system all over the world affecting almost 3% to 8% of the population. Immune thrombocytopenic purpura (ITP), also known as idiopathic thrombocytopenic purpura, is a blood disorder in which the body immune system destroys platelets, leading to low platelet counts in the blood (peripheral blood platelet count < 150 × 109/L). Although the pathophysiology of ITP is not fully understood, it is believed to result from a complex interplay between hereditary and environmental variables. Certain factors, such as a low platelet count, history of bleeding, and certain comorbidities can increase the risk of severe bleeding in patients with ITP. Corticosteroids, intravenous immunoglobulin (IVIG), immunosuppressants, rituximab, and thrombopoietin receptor agonists (TPO-RAs) are some of the advanced treatments for ITP. Although these therapies may be successful, they also carry the risk of negative effects. Recently, significant advancements have been made in the understanding and treatment of ITP. There is still much to learn about the disease, and new, more effective treatments are needed. This comprehensive review offers a comprehensive assessment of recent advancements in ITP management, with a focus on active research projects, novel therapeutic targets, new treatment modalities, and areas of uncertainty and unmet needs. According to research, it is crucial to develop individualized treatment plans for ITP patients based on their age, platelet count, risk of bleeding, and comorbidities. The article also looks at how future developments in gene editing, bispecific antibody therapies, and cellular therapy may completely change the treatment 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.

Haematological sequelae in the post-acute phase of symptomatic SARS-CoV-2 infection

Many patients surviving SARS-CoV-2 infection suffer from long-term symptoms (long COVID or post COVID) such as shortness of breath, fatigue, loss of taste or smell and cognitive deterioration. However, few data are available concerning blood cell counts and haematological parameters during the post-COVID period. We analysed haematological data from 83 patients previously admitted to the internal medicine unit of our institution because of symptomatic SARS-CoV-2 infection; all data were obtained within 1-12 months from disease onset. A control group of 70 apparently healthy, age- and sex-matched COVID-19 negative individuals was assessed for comparison. Blood cell counts improved in the post-COVID period, but 81% of patients had persistent abnormalities, compared with 50% in the control group, p < 0.001. Most common haematological findings included anaemia (40%), reduced lymphocyte (43%) or eosinophil counts (38%) and low IgM memory B cells and correlated with advanced age, number of chronic comorbidities, female gender, altered renal function, reduced baseline Hb and procalcitonin concentrations and increased RDW. Data on lymphocytes and IgM memory B cells show that impaired immune responses may persist for up to one year in the post-COVID period, possibly contributing to long-term symptoms, especially in female patients.

Thrombocytopenia Secondary to COVID-19: Outcomes Analysis in Terms of Thrombotic Microangiopathy, Acute Kidney Injury, and Mortality

Background: COVID-19 usually complicates respiratory failure; microvascular, macrovascular, and renal complications are common. Both micro and macrovascular complications are associated with multi-organ dysfunction and in-hospital mortality. Thrombotic microangiopathy (TMA) causes microvascular thromboses associated with organ failure, including acute kidney injury (AKI). Materials and Methods: This Retrospective Cohort study included 100 COVID-19 patients with thrombocytopenia, followed up in a university hospital's intensive care unit (ICU). The primary endpoints were in-hospital mortality or discharge from the hospital and assessing the occurrence of TMA and AKI during the hospitalization. The effect of thrombotic microangiopathy and acute kidney injury on mortality was investigated using logistic regression models in Stata software version 12.1. Results: The TMA and AKI were associated with in-hospital mortality in COVID-19 patients presenting with thrombocytopenia in multivariate regression analysis, adjusted for other variables. The effect of AKI on mortality was obtained (adjusted OR 4.09, 95% CI: 1.33-12.53, p = 0.01). Moreover, the odds of mortality due to TMA were ten-fold higher in the patients who had TMA than those who did not (adjusted OR 10.26, 95% CI: 1.26-83.76, p = 0.03). Conclusion: We outlined TMA in COVID-19 patients, which could be responsible for kidney injury and mortality in critically COVID-19 patients.

Persistent, Poorly Responsive Immune Thrombocytopenia Secondary to Asymptomatic COVID-19 Infection in a Child

Immune thrombocytopenic purpura (ITP) secondary to asymptomatic COVID-19 infection, especially in children, is not reported. Furthermore, persistent, treatment-resistant ITP secondary to COVID-19 is not reported. We report a previously healthy 14-year-old Asian boy who developed secondary ITP following an asymptomatic COVID-19 infection and is having a relapsing and remitting cause with poor response to immunosuppressants even after 21 months following the diagnosis. This case emphasizes the importance of testing for COVID-19 in newly diagnosed ITP patients and the need for follow-up platelet counts in patients who recover from COVID-19 as it may follow into developing secondary ITP yet being asymptomatic until you present with a bleeding complication of ITP. The poor response to standard immunosuppression warrants more understanding of the pathophysiology of persistently low platelets following COVID-19 infection. Long-term sequelae of the disease highlight the importance of getting vaccinated for COVID-19 despite COVID-19 being no longer a global emergency.

COVID-19 diagnosis using clinical markers and multiple explainable artificial intelligence approaches: A case study from Ecuador

The COVID-19 pandemic erupted at the beginning of 2020 and proved fatal, causing many casualties worldwide. Immediate and precise screening of affected patients is critical for disease control. COVID-19 is often confused with various other respiratory disorders since the symptoms are similar. As of today, the reverse transcription-polymerase chain reaction (RT-PCR) test is utilized for diagnosing COVID-19. However, this approach is sometimes prone to producing erroneous and false negative results. Hence, finding a reliable diagnostic method that can validate the RT-PCR test results is crucial. Artificial intelligence (AI) and machine learning (ML) applications in COVID-19 diagnosis has proven to be beneficial. Hence, clinical markers have been utilized for COVID-19 diagnosis with the help of several classifiers in this study. Further, five different explainable artificial intelligence techniques have been utilized to interpret the predictions. Among all the algorithms, the k-nearest neighbor obtained the best performance with an accuracy, precision, recall and f1-score of 84%, 85%, 84% and 84%. According to this study, the combination of clinical markers such as eosinophils, lymphocytes, red blood cells and leukocytes was significant in differentiating COVID-19. The classifiers can be utilized synchronously with the standard RT-PCR procedure making diagnosis more reliable and efficient.

Infant case of severe immune thrombocytopenia caused by COVID-19 infection

Immune thrombocytopenia (ITP) is a common childhood acute autoimmune bleeding disorder caused by numerous viruses and characterized by isolated thrombocytopenia. Although cases of ITP caused by coronavirus disease 2019 (COVID-19) infection have been reported in adults, pediatric reports are limited. We present the case of a 1-year-old girl who developed COVID-19-infection-related ITP with a very low platelet count (0.0 × 104/μL). We searched for COVID-19-related pediatric ITP cases and found 10 other cases, with the majority having platelet counts of <1.0 × 104/μL. Although pediatric ITP cases caused by COVID-19 infection may be severe, further studies are needed.

Identification of new drugs to counteract anti-spike IgG-induced hyperinflammation in severe COVID-19

Previously, we and others have shown that SARS-CoV-2 spike-specific IgG antibodies play a major role in disease severity in COVID-19 by triggering macrophage hyperactivation, disrupting endothelial barrier integrity, and inducing thrombus formation. This hyperinflammation is dependent on high levels of anti-spike IgG with aberrant Fc tail glycosylation, leading to Fcγ receptor hyperactivation. For development of immune-regulatory therapeutics, drug specificity is crucial to counteract excessive inflammation whereas simultaneously minimizing the inhibition of antiviral immunity. We here developed an in vitro activation assay to screen for small molecule drugs that specifically counteract antibody-induced pathology. We identified that anti-spike-induced inflammation is specifically blocked by small molecule inhibitors against SYK and PI3K. We identified SYK inhibitor entospletinib as the most promising candidate drug, which also counteracted anti-spike-induced endothelial dysfunction and thrombus formation. Moreover, entospletinib blocked inflammation by different SARS-CoV-2 variants of concern. Combined, these data identify entospletinib as a promising treatment for severe COVID-19.

A Review of Hematological Complications and Treatment in COVID-19

COVID-19, caused by SARS-CoV-2, and its variants have spread rapidly across the globe in the past few years, resulting in millions of deaths worldwide. Hematological diseases and complications associated with COVID-19 severely impact the mortality and morbidity rates of patients; therefore, there is a need for oversight on what pharmaceutical therapies are prescribed to hematologically at-risk patients. Thrombocytopenia, hemoglobinemia, leukopenia, and leukocytosis are all seen at increased rates in patients infected with COVID-19 and become more prominent in patients with severe COVID-19. Further, COVID-19 therapeutics may be associated with hematological complications, and this became more important in immunocompromised patients with hematological conditions as they are at higher risk of hematological complications after treatment. Thus, it is important to understand and treat COVID-19 patients with underlying hematological conditions with caution. Hematological changes during COVID-19 infection and treatment are important because they may serve as biomarkers as well as to evaluate the treatment response, which will help in changing treatment strategies. In this literature review, we discuss the hematological complications associated with COVID-19, the mechanisms, treatment groups, and adverse effects of commonly used COVID-19 therapies, followed by the hematological adverse events that could arise due to therapeutic agents used in COVID-19.

Beyond the Norm: A Case of Multiorgan Injury Triggered by Ibuprofen

We report the case of a 71-year-old African American male with a history of chronic obstructive pulmonary disease (COPD), heart failure, vitiligo, penicillin allergy, and cocaine use, who presented with respiratory symptoms and was diagnosed with sepsis, COVID-19 pneumonia, exacerbation of COPD, and acute kidney injury (AKI). Treatment included antibiotics and high-dose steroids. The patient developed thrombocytopenia, autoimmune hemolytic anemia, acute liver failure, and interstitial nephritis associated with prolonged ibuprofen use. High-dose steroids and ibuprofen discontinuation led to significant improvement. This case highlights the rare occurrence of multiorgan injury from ibuprofen use, possibly aggravated by COVID-19, emphasizing the need for cautious non-steroidal anti-inflammatory drug (NSAID) use and close patient monitoring.

Evaluation and validation of the prognostic value of platelet indices in patients with leukemia

Platelets (PLTs) are believed to play a role in the process by which tumors can accelerate their growth rate, as well as offer the physical and mechanical support necessary to evade the immunological system and metastasis. There is, however, no literature available if PLTs have a role in leukemia. It is significant for PLTs to play a part in hematological malignancies from a therapeutic standpoint and to have the capacity to serve as a prognostic marker in the evolution of leukemia. This is because PLTs play a crucial role in the development of cancer and tumors. In this study, it will be shown that PLT count can be used to predict long-term prognosis after chemotherapy especially in the case of acute myeloid leukemia patients. Furthermore, low PLT-to-lymphocyte ratio and mean PLT volume, as well as high PLT distribution width, are associated with poor prognosis and may represent a novel independent prognostic factor.

Long COVID-19 Pathophysiology: What Do We Know So Far?

Long COVID-19 is a recognized entity that affects millions of people worldwide. Its broad clinical symptoms include thrombotic events, brain fog, myocarditis, shortness of breath, fatigue, muscle pains, and others. Due to the binding of the virus with ACE-2 receptors, expressed in many organs, it can potentially affect any system; however, it most often affects the cardiovascular, central nervous, respiratory, and immune systems. Age, high body mass index, female sex, previous hospitalization, and smoking are some of its risk factors. Despite great efforts to define its pathophysiology, gaps remain to be explained. The main mechanisms described in the literature involve viral persistence, hypercoagulopathy, immune dysregulation, autoimmunity, hyperinflammation, or a combination of these. The exact mechanisms may differ from system to system, but some share the same pathways. This review aims to describe the most prevalent pathophysiological pathways explaining this syndrome.

Crosstalk between Platelets and SARS-CoV-2: Implications in Thrombo-Inflammatory Complications in COVID-19

The SARS-CoV-2 virus, causing the devastating COVID-19 pandemic, has been reported to affect platelets and cause increased thrombotic events, hinting at the possible bidirectional interactions between platelets and the virus. In this review, we discuss the potential mechanisms underlying the increased thrombotic events as well as altered platelet count and activity in COVID-19. Inspired by existing knowledge on platelet-pathogen interactions, we propose several potential antiviral strategies that platelets might undertake to combat SARS-CoV-2, including their abilities to internalize the virus, release bioactive molecules to interfere with viral infection, and modulate the functions of immune cells. Moreover, we discuss current and potential platelet-targeted therapeutic strategies in controlling COVID-19, including antiplatelet drugs, anticoagulants, and inflammation-targeting treatments. These strategies have shown promise in clinical settings to alleviate the severity of thrombo-inflammatory complications and reduce the mortality rate among COVID-19 patients. In conclusion, an in-depth understanding of platelet-SARS-CoV-2 interactions may uncover novel mechanisms underlying severe COVID-19 complications and could provide new therapeutic avenues for managing this disease.

Jerne's "immune network theory", of interacting anti-idiotypic antibodies applied to immune responses during COVID-19 infection and after COVID-19 vaccination

Niels Kaj Jerne has proposed the "immune network theory" of interactions among anti-idiotypic antibodies, able to interfere with humoral responses to certain antigens. After the occurrence of the primary generation of antibodies, against an antigenic epitope, idiotypes of these antibodies induce anti-idiotypic antibodies that modulate the intensity of the first response, and so on. Adverse effects following SARS-COV-2 COVID-19 vaccines are occasionally similar to the symptoms of COVID-19 infection. Rare events linked to SARS-CoV-2 vaccines also resemble some rarely reported COVID-19 complications. Safety data from product information by European Medicines Agency suggest that spectra do overlap for four main vaccines. The proposition is that vaccine events and COVID-19 complications are related to anti-idiotypic antibodies whose spatial shape can lead to interactions with ACE2 molecules, in individuals with a prolonged Spike protein synthesis. The vaccines target cells by their affinity to the vaccine vector, or to engulf lipid nanoparticles. Anti-idiotypic antibodies shaped similarly to the Spike protein possibly interact with ACE2 molecules and cause diverse signs and symptoms.

Primary and secondary immune thrombocytopenia (ITP): Time for a rethink

There are not many publications that provide a holistic view of the management of primary and secondary ITP as a whole, reflecting the similarities and differences between the two. Given the lack of major clinical trials, we believe that comprehensive reviews are much needed to guide the diagnosis and treatment of ITP today. Therefore, our review addresses the contemporary diagnosis and treatment of ITP in adult patients. With respect to primary ITP we especially focus on establishing the management of ITP based on the different and successive lines of treatment. Life-threatening situations, "bridge therapy" to surgery or invasive procedures and refractory ITP are also comprehensively reviewed here. Secondary ITP is studied according to its pathogenesis by establishing three major differential groups: Immune Thrombocytopenia due to Central Defects, Immune Thrombocytopenia due to Blocked Differentiation and Immune Thrombocytopenia due to Defective Peripheral Immune Response. Here we provide an up-to-date snapshot of the current diagnosis and treatment of ITP, including a special interest in addressing rare causes of this disease in our daily clinical practice. The target population of this review is adult patients only and the target audience is medical professionals.

Changes in Adenosine Deaminase Activity and Endothelial Dysfunction after Mild Coronavirus Disease-2019

Endothelial cells are a preferential target for SARS-CoV-2 infection. Previously, we have reported that vascular adenosine deaminase 1 (ADA1) may serve as a biomarker of endothelial activation and vascular inflammation, while ADA2 plays a critical role in monocyte and macrophage function. In this study, we investigated the activities of circulating ADA isoenzymes in patients 8 weeks after mild COVID-19 and related them to the parameters of inflammation and microvascular/endothelial function. Post-COVID patients revealed microvascular dysfunction associated with the changes in circulating parameters of endothelial dysfunction and inflammatory activation. Interestingly, serum total ADA and ADA2 activities were diminished in post-COVID patients, while ADA1 remained unchanged in comparison to healthy controls without a prior diagnosis of SARS-CoV-2 infection. While serum ADA1 activity tended to positively correspond with the parameters of endothelial activation and inflammation, sICAM-1 and TNFα, serum ADA2 activity correlated with IL-10. Simultaneously, post-COVID patients had lower circulating levels of ADA1-anchoring protein, CD26, that may serve as an alternative receptor for virus binding. This suggests that after the infection CD26 is rather maintained in cell-attached form, enabling ADA1 complexing. This study points to the possible role of ADA isoenzymes in cardiovascular complications after mild COVID-19.

Survival implications vs. complications: unraveling the impact of vitamin D adjunctive use in critically ill patients with COVID-19-A multicenter cohort study

Background

Despite insufficient evidence, vitamin D has been used as adjunctive therapy in critically ill patients with COVID-19. This study evaluates the effectiveness and safety of vitamin D as an adjunctive therapy in critically ill COVID-19 patients.

Methods

A multicenter retrospective cohort study that included all adult COVID-19 patients admitted to the intensive care units (ICUs) between March 2020 and July 2021. Patients were categorized into two groups based on their vitamin D use throughout their ICU stay (control vs. vitamin D). The primary endpoint was in-hospital mortality. Secondary outcomes were the length of stay (LOS), mechanical ventilation (MV) duration, and ICU-acquired complications. Propensity score (PS) matching (1:1) was used based on the predefined criteria. Multivariable logistic, Cox proportional hazards, and negative binomial regression analyses were employed as appropriate.

Results

A total of 1,435 patients were included in the study. Vitamin D was initiated in 177 patients (12.3%), whereas 1,258 patients did not receive it. A total of 288 patients were matched (1:1) using PS. The in-hospital mortality showed no difference between patients who received vitamin D and the control group (HR 1.22, 95% CI 0.87-1.71; p = 0.26). However, MV duration and ICU LOS were longer in the vitamin D group (beta coefficient 0.24 (95% CI 0.00-0.47), p = 0.05 and beta coefficient 0.16 (95% CI -0.01 to 0.33), p = 0.07, respectively). As an exploratory outcome, patients who received vitamin D were more likely to develop major bleeding than those who did not [OR 3.48 (95% CI 1.10, 10.94), p = 0.03].

Conclusion

The use of vitamin D as adjunctive therapy in COVID-19 critically ill patients was not associated with survival benefits but was linked with longer MV duration, ICU LOS, and higher odds of major bleeding.

COVID-19 infection: a possible induction factor for development of autoimmune diseases?

Following the global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the importance of investigation of the pathogenesis and immunological characteristics of COVID-19 became quite clear. Currently, there are reports indicating that COVID-19 is able to induce autoimmune responses. Abnormal immune reactions are a cornerstone in the pathogenicity of both conditions. Detection of autoantibodies in COVID-19 patients may suggest a link between COVID-19 and autoimmunity. In this study, we focused on the similarities and possible differences between COVID-19 and autoimmune disorders to explore the relationship between them. Comparing the pathogenicity of SARS-CoV-2 infection with autoimmune conditions revealed significant immunological properties of COVID-19 including the presence of several autoantibodies, autoimmunity-related cytokines, and cellular activities that could be useful in future clinical studies aiming at managing this pandemic.

Comparative Analysis of De Novo Immune Thrombocytopenia Following mRNA COVID-19 Vaccine Versus Non-mRNA Vaccines and COVID-19: A Global Database Analysis

Introduction Autoimmune diseases have been linked to COVID-19 vaccines. An increasing number of cases have reported de novo immune thrombocytopenia (ITP) following mRNA COVID-19 vaccines. This study aims to investigate the incidence of de novo ITP following the mRNA COVID-19 vaccine in comparison to other non-mRNA vaccines and COVID-19. Methods Data were collected from the TriNetX global health research network, which covers over 117 million patients. Four different patient cohorts were included: those who received the mRNA COVID-19 vaccine (between 12/15/2020 - 5/1/2023), the influenza vaccine (between 01/01/2010 - 01/01/2020), tetanus, diphtheria, and pertussis/tetanus and diphtheria (Tdap/Td) vaccines (between 01/01/2010 - 01/01/2020), and those who had COVID-19 (between 01/01/2020 - 05/01/2023). A comparative analysis was conducted to examine the occurrence of de novo ITP within three weeks after receiving mRNA COVID-19 vaccine, non-mRNA vaccines, or upon diagnosis of COVID-19. Additionally, a comparative analysis was performed after 1:1 propensity score matching to balance baseline characteristics (age, sex, and race). Results The overall event rate was 0.07 per 10,000 for the mRNA COVID-19 vaccine, 0.25 per 10,000 for the influenza vaccine, and 0.28 per 10,000 for the Tdap/Td vaccines. Additionally, the incidence of de novo ITP following COVID-19 was 0.30 per 10,000. Those who received the influenza vaccine and Tdap/Td vaccines had higher rates of de novo ITP compared to the mRNA COVID-19 vaccine group, with a relative risk of 3.48 and 3.88, respectively. The occurrence of de novo ITP following COVID-19 was significantly higher compared to that following the mRNA COVID-19 vaccine, with a relative risk of 4.27. Post-propensity score matching analysis produced similar outcomes. Conclusions The findings of this study suggest that the incidence of de novo ITP is significantly lower following mRNA-based COVID-19 vaccines compared to non-mRNA vaccines and COVID-19.

Immune thrombocytopenia: a review on the pathogenetic role of immune cells

INTRODUCTION

Immune thrombocytopenia [ITP] is a common bleeding disorder with an isolated platelet count of less than 100 × 109/L.

AREAS COVERED

Relevant literature from 2003 to 2022 was retrieved and reviewed from the Google Scholar search engine and PubMed database. Antibodies produced by autoreactive B lymphocytes and the phagocytic function of macrophages are considered the most critical factors in platelet destruction. Also, macrophages present the antigen to T lymphocytes and activate them. Follicular helper T-cells [TFH] play a role in stimulating, differentiating, and activating autoreactive B cells, while cluster of differentiation [CD]-8+ T plays a role in platelet destruction through apoptosis. The classical pathway of the complement system also causes platelet destruction. By inhibiting platelet production, low levels of thrombopoietin and an immune response against megakaryocytes in the bone marrow worsen thrombocytopenia.

EXPERT OPINION

T-cell subset changes and an increase in activated autoreactive B cells, in addition to the function of components of the innate immune system [the complement system, dendritic cells, and natural killer cells], play a critical role in the pathogenesis of the ITP. Accurate detection of these changes may lead to developing new therapeutic strategies and identifying better prognostic/diagnostic factors.

Bone marrow alterations in COVID-19 infection: The root of hematological problems

INTRODUCTION

The 2019 coronavirus disease (COVID-19) is a respiratory infection caused by the SARS-CoV-2 virus with a significant impact on the hematopoietic system and homeostasis. The effect of the virus on blood cells indicates the involvement of the bone marrow (BM) as the place of production and maturation of these cells by the virus and it reminds the necessity of investigating the effect of the virus on the bone marrow.

METHOD

To investigate the effects of COVID-19 infection in BM, we reviewed literature from the Google Scholar search engine and PubMed database up to 2022 using the terms "COVID-19; SARS-CoV-2; Bone marrow; Thrombocytopenia; Hemophagocytosis; Pancytopenia and Thrombocytopenia.

RESULTS

Infection with the SARS-CoV-2 virus is accompanied by alterations such as single-line cytopenia, pancytopenia, hemophagocytosis, and BM necrosis. The presence of factors such as cytokine release syndrome, the direct effect of the virus on cells through different receptors, and the side effects of current treatments such as corticosteroids are some of the important mechanisms in the occurrence of these alterations.

CONCLUSION

To our knowledge, this review is the first study to comprehensively investigate BM alterations caused by SAR-CoV-2 virus infection. The available findings show that the significant impact of this viral infection on blood cells and the clinical consequences resulting from them are deeper than previously thought and it may be rooted in the changes that the virus causes in the BM of patients.

Immune thrombocytopenia in the setting of acute SARS-CoV-2 infection

Immune thrombocytopenia (ITP) is an immune-mediated event, characterised by the destruction of platelets by autoantibodies resulting in isolated thrombocytopaenia (platelets <100 x10⁹/L). In children, most cases are preceded by a viral infection. Cases of ITP in the setting of SARS-CoV-2 infection have been described. We describe a previously healthy boy, who presented with an extensive frontal and periorbital haematoma, petechial rash on the trunk and coryza. He had suffered a minor head trauma, 9 days before admission. Blood tests revealed a platelet count of 8000/µL. The remainder study was unremarkable, except for a positive SARS-CoV-2 PCR. Treatment comprised a single dose of intravenous immunoglobulin, with increase in platelet count and no recurrence. We made a working diagnosis of an ITP concurrent with a SARS-CoV-2 infection. Although few cases have been described, SARS-CoV-2 might be considered as a trigger for ITP.

Evaluation of potential adverse events following COVID-19 mRNA vaccination among adults aged 65 years and older: Two self-controlled studies in the U.S

BACKGROUND

Our near-real-time safety monitoring of 16 adverse events (AEs) following COVID-19 mRNA vaccination identified potential elevation in risk for six AEs following primary series and monovalent booster dose administration. The crude association with AEs does not imply causality. Accordingly, we conducted robust evaluation of potential associations.

METHODS

We conducted two self-controlled case series studies of COVID-19 mRNA vaccines (BNT162b2 and mRNA-1273) in U.S. Medicare beneficiaries aged ≥ 65 years. Adjusted incidence rate ratio (IRRs) and 95 % confidence intervals (CIs) were estimated following primary series doses for acute myocardial infarction (AMI), pulmonary embolism (PE), immune thrombocytopenia (ITP), disseminated intravascular coagulation (DIC); and following monovalent booster doses for AMI, PE, ITP, Bell's Palsy (BP) and Myocarditis/Pericarditis (Myo/Peri).

RESULTS

The primary series study included 3,360,981 individuals who received 6,388,542 primary series doses; the booster study included 6,156,100 individuals with one monovalent booster dose. The AMI IRR following BNT162b2 primary series and booster was 1.04 (95 % CI: 0.91 to 1.18) and 1.06 (95 % CI: 1.003 to 1.12), respectively; for mRNA-1273 primary series and booster, 1.01 (95 % CI: 0.82 to 1.26) and 1.05 (95 % CI: 0.998 to 1.11), respectively. The hospital inpatient PE IRR following BNT162b2 primary series and booster was 1.19 (95 % CI: 1.03 to 1.38) and 0.86 (95 % CI: 0.78 to 0.95), respectively; for mRNA-1273 primary series and booster, 1.15 (95 % CI: 0.94 to 1.41) and 0.87 (95 % CI: 0.79 to 0.96), respectively. The studies' results do not support that exposure to COVID-19 mRNA vaccines elevate the risk of ITP, DIC, Myo/Peri, and BP.

CONCLUSION

We did not find an increased risk for AMI, ITP, DIC, BP, and Myo/Peri and there was not consistent evidence for PE after exposure to COVID-19 mRNA primary series or monovalent booster vaccines. These results support the favorable safety profile of COVID-19 mRNA vaccines administered in the U.S. elderly population.

Immune Thrombocytopenia Secondary to COVID-19 in a Vitamin B12-Deficient Patient: A Diagnostic Dilemma and Therapeutic Challenge

Immune thrombocytopenia (ITP) caused by infectious and non-infectious conditions has been reported in coronavirus disease 2019 (COVID-19) patients too. Here we present a 64-year-old male patient with post-COVID-19 pneumonia who presented with a gastrointestinal bleed and was found to have severe isolated thrombocytopenia (22,000/cumm) diagnosed as ITP with extensive investigations. He was treated with pulse steroid therapy and later was also given intravenous immunoglobin in view of poor response. The addition of eltrombopag also resulted in a sub-optimal response. He was also having low vitamin B12, and his bone marrow also supported the megaloblastic picture. Hence, injectable cobalamin was added to the regimen, which resulted in a sustained rise in platelet count that reached 78,000/cumm, and the patient got discharged. This shows the possible hindrance to treatment response by concomitant B12 deficiency. Vitamin B12 deficiency is not an uncommon entity and should be tested in those who show no or slow response to thrombocytopenia.

Immune Thrombocytopenic Purpura Following COVID-19 Infection: A Case Report and Literature Review

Immune thrombocytopenic purpura (ITP) has been described following both coronavirus disease 2019 (COVID-19) infection and COVID-19 vaccination. ITP is a challenging diagnosis of exclusion, and the pathophysiology of these complications is not well understood but believed to be autoimmune in nature. We describe a severe case of ITP following COVID-19 infection in a patient without a history of hematologic or autoimmune disease and his subsequent uneventful course following COVID-19 vaccination. The current Centers for Disease Control and Prevention (CDC) advisory does not identify a history of ITP as a contraindication to COVID-19 vaccination. We compare our study, which describes an uneventful COVID-19 vaccination course with cases that have described recurrences and relapses of ITP following both COVID-19 infection and COVID-19 vaccination. These reports suggest that the placement of some patients into a unique subset among all patients with ITP may be prudent with regard to future COVID-19 vaccination. Through a literature review, we discuss a broader picture of how COVID-19 infection-associated ITP may differ from COVID-19 mRNA vaccination-associated ITP in its demographics, etiology, and outcomes.

Mixed Warm and Cold Autoimmune Hemolytic Anemia With Concomitant Immune Thrombocytopenia Following Recent SARS-CoV-2 Infection and Ongoing Rhinovirus Infection

Mixed-type autoimmune hemolytic anemia (AIHA) is a term used to describe hemolysis occurring in the context of both warm and cold reactive autoantibodies to red blood cells. Immune thrombocytopenia (ITP) is an acquired form of thrombocytopenia potentially complicated by hemorrhage due to autoantibodies reactive with platelets and megakaryocytes. Diagnosis of ITP requires exclusion of other known causes of thrombocytopenia. AIHA and ITP may be primary disorders or associated with lymphoproliferative, autoimmune, or viral infections. Here, we report a rare case of simultaneous mixed-type autoimmune hemolytic anemia with immune thrombocytopenia following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection treated with Paxlovid followed by Rhinovirus infection.

Use of thrombopoietin receptor agonists in adults with immune thrombocytopenia: a systematic review and Central European expert consensus

There are currently three thrombopoietin receptor agonists (TPO-RAs) approved in Europe for treating patients with immune thrombocytopenia (ITP): romiplostim (Nplate®), eltrombopag (Revolade®), and avatrombopag (Doptelet®). However, comparative clinical data between these TPO-RAs are limited. Therefore, the purpose of this study was to perform a literature review and seek expert opinion on the relevance and strength of the evidence concerning the use of TPO-RAs in adults with ITP. A systematic search was conducted in PubMed and Embase within the last 10 years and until June 20, 2022. A total of 478 unique articles were retrieved and reviewed for relevance. The expert consensus panel comprised ITP senior hematologists from eight countries across Central Europe. The modified Delphi method, consisting of two survey rounds, a teleconference and email correspondence, was used to reach consensus. Forty articles met the relevancy criteria and are included as supporting evidence, including five meta-analyses analyzing all three European-licensed TPO-RAs and comprising a total of 31 unique randomized controlled trials (RCTs). Consensus was reached on seven statements for the second-line use of TPO-RAs in the management of adult ITP patients. In addition, the expert panel discussed TPO-RA treatment in chronic ITP patients with mild/moderate COVID-19 and ITP patients in the first-line setting but failed to reach consensus. This work will facilitate informed decision-making for healthcare providers treating adult ITP patients with TPO-RAs. However, further studies are needed on the use of TPO-RAs in the first-line setting and specific patient populations.

Immune thrombocytopenic purpura secondary to COVID-19 vaccination: A systematic review

INTRODUCTION

This systematic review aimed to retrieve patients diagnosed with de novo immune thrombocytopenic purpura (ITP) after COVID-19 immunization to determine their epidemiological characteristics, clinical course, therapeutic strategies, and outcome.

MATERIALS AND METHODS

We conducted the review using four major databases, comprising PubMed, Scopus, Web of Science, and the Cochrane library, until April 2022. A systematic search was performed in duplicate to access eligible articles in English. Furthermore, a manual search was applied to the chosen papers' references to enhance the search sensitivity. Data were extracted and analyzed with the SPSS 20.1 software.

RESULTS

A total of 77 patients with de novo COVID-19 vaccine-associated ITP were identified from 41 studies, including 31 case reports and 10 case series. The median age of patients who developed COVID-19 vaccine-associated ITP was 54 years (IQR 36-72 years). The mRNA-based COVID-19 vaccines, including BNT16B2b2 and mRNA-1273, were most implicated (75.4%). Those were followed by the adenovirus vector-based vaccines, inclusive of ChAdOx1 nCoV-19 and vAd26.COV2.S. No report was found relating ITP to other COVID-19 vaccines. Most cases (79.2%) developed ITP after the first dose of COVID-19 vaccination. 75% of the patients developed ITP within 12 days of vaccination, indicating a shorter lag time compared to ITP after routine childhood vaccinations. Sixty-seven patients (87%) patients were hospitalized. The management pattern was similar to primary ITP, and systemic glucocorticoids, IVIg, or both were the basis of the treatment in most patients. Most patients achieved therapeutic goals; only two individuals required a secondary admission, and one patient who presented with intracranial hemorrhage died of the complication.

CONCLUSIONS

De novo ITP is a rare complication of COVID-19 vaccination, and corresponding reports belong to mRNA-based and adenovirus vector-based vaccines, in order of frequency. This frequency pattern may be related to the scale of administration of individual vaccines and their potency in inducing autoimmunity. The more the COVID-19 vaccine is potent to induce antigenic challenge, the shorter the lag time would be. Most patients had a benign course and responded to typical treatments of primary ITP.

Analysis of hematologic adverse events reported to a national surveillance system following COVID-19 bivalent booster vaccination

Hematologic complications, including vaccine-induced immune thrombotic thrombocytopenia (VITT), immune thrombocytopenia (ITP), and autoimmune hemolytic anemia (AIHA), have been associated with the original severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines. However, on August 31, 2022, new formulations of the Pfizer-BioNTech and Moderna vaccines were approved for use without clinical trial testing. Thus, any potential adverse hematologic effects with these new vaccines remain unknown. We queried the US Centers for Disease Control Vaccine Adverse Event Reporting System (VAERS), a national surveillance database, through February 3, 2023, all reported hematologic adverse events that occurred within 42 days of administration of either the Pfizer-BioNTech or Moderna Bivalent COVID-19 Booster vaccine. We included all patient ages and geographic locations and utilized 71 unique VAERS diagnostic codes pertaining to a hematologic condition as defined in the VAERS database. Fifty-five reports of hematologic events were identified (60.0% Pfizer-BioNTech, 27.3% Moderna, 7.3% Pfizer-BioNTech bivalent booster plus influenza, 5.5% Moderna bivalent booster plus influenza). The median age of patients was 66 years, and 90.9% (50/55) of reports involved a description of cytopenias or thrombosis. Notably, 3 potential cases of ITP and 1 case of VITT were identified. In one of the first safety analyses of the new SARS-CoV-2 booster vaccines, we identified few adverse hematologic events (1.05 per 1,000,000 doses), most of which could not be definitively attributed to vaccination. However, three reports of possible ITP and one report of possible VITT highlight the need for continued safety monitoring of these vaccines as their use expands and new formulations are authorized.

A Case of COVID-19-Induced Immune Thrombocytopenia (ITP) in an Adult Female: An Under-Recognized Emerging Phenomenon

Coronavirus disease 2019 (COVID-19) follows a mild course in majority of cases, but some patients may develop non-pulmonary yet life-threatening complications. A Pandora's box had been opened when multisystem hyper-inflammatory syndromes and autoimmune diseases that had been described previously in children and young adults, that are associated with COVID-19, have now emerged in adults. They need to be recognized as important sequelae of severe COVID-19 disease. Immune thrombocytopenia (ITP) or thrombocytopenic purpura is an autoantibody and T-cell-mediated autoimmune disorder characterized by isolated thrombocytopenia, which can be triggered by different infections. First-line treatment of severe ITP includes platelet transfusions in life-threatening cases, followed by corticosteroids and intravenous immunoglobulins (IVIG). Since the beginning of the pandemic, more and more cases of COVID-19-associated ITP have been reported. We report a case of acquired ITP in a young woman that could only be attributed to her COVID-19 infection and was refractory to platelet transfusion, requiring further treatments. The aim of this report is to review some of the etiologies and purposed molecular mechanisms of the autoimmune nature of the disease and to focus on diagnosis and treatment. We will review the current literature surrounding this non-pulmonary manifestation of COVID-19 and current treatment options for this uncommon presentation of ITP.

The Legacy of Infectious Disease Exposure on the Genomic Diversity of Indigenous Southern Mexicans

To characterize host risk factors for infectious disease in Mesoamerican populations, we interrogated 857,481 SNPs assayed using the Affymetrix 6.0 genotyping array for signatures of natural selection in immune response genes. We applied three statistical tests to identify signatures of natural selection: locus-specific branch length (LSBL), the cross-population extended haplotype homozygosity (XP-EHH), and the integrated haplotype score (iHS). Each of the haplotype tests (XP-EHH and iHS) were paired with LSBL and significance was determined at the 1% level. For the paired analyses, we identified 95 statistically significant windows for XP-EHH/LSBL and 63 statistically significant windows for iHS/LSBL. Among our top immune response loci, we found evidence of recent directional selection associated with the major histocompatibility complex (MHC) and the peroxisome proliferator-activated receptor gamma (PPAR-γ) signaling pathway. These findings illustrate that Mesoamerican populations' immunity has been shaped by exposure to infectious disease. As targets of selection, these variants are likely to encode phenotypes that manifest themselves physiologically and therefore may contribute to population-level variation in immune response. Our results shed light on past selective events influencing the host response to modern diseases, both pathogenic infection as well as autoimmune disorders.

Staging of COVID-19 disease; using selected laboratory profiles for prediction, prevention and management of severe SARS-CoV-2 infection in Africa-review

There are many uncertainties on the future management of the coronavirus disease 19 (COVID-19) in Africa. By July 2021, Africa had lagged behind the rest of the world in Covid-19 vaccines uptake, accounting for just 1.6% of doses administered globally. During that time COVID 19 was causing an average death rate of 2.6% in Africa, surpassing the then global average of 2.2%. There were no clear therapeutic guidelines, yet inappropriate and unnecessary treatments may have led to unwanted adverse events such as worsening of hyperglycemia and precipitating of ketoacidosis in administration of steroid therapy. in order to provide evidence-based policy guidelines, we examined peer-reviewed published articles in PubMed on COVID 19, or up-to date data, we focused our search on publications from 1st May 2020 to 15th July, 2021. For each of the studies, we extracted data on pathophysiology, selected clinical chemistry and immunological tests, clinical staging and treatment. Our review reports a gross unmet need for vaccination, inadequate laboratory capacity for immunological tests and the assessment of individual immune status, clinical staging and prediction of disease severity. We recommend selected laboratory tools in the assessment of individual immune status, prediction of disease severity and determination of the exact timing for suitable therapy, especially in individuals with co-morbidities.

Histopathological Patterns of Cutaneous Adverse Reaction to Anti-SARS-CoV-2 Vaccines: The Integrative Role of Skin Biopsy

The advent of vaccines represented a milestone to allow the slowing down and then containing of the exponential increase in ongoing infections and deaths of COVID-19. Since the first months of the vaccination campaign in various continents, there has been a certain number of reports of adverse events, including skin reactions. We conducted a systematic review, searching on PubMed, Web of Science, Scopus, and Cochrane Library for the words: COVID vaccine, dermatopathology, skin, eruptions, rash, cutaneous, BNT162b2 (Pfizer-BioNTech), ChAdOX1 (AstraZeneca), and mRNA-1273 (Moderna). A total of 28 records were initially identified in the literature search of which two were duplicates. After screening for eligibility and inclusion criteria, 18 publications were ultimately included. Various clinical cutaneous manifestations and histopathological patterns following vaccination have been described in literature. The most frequent clinical-pathological presentations were erythematous maculo-papular eruptions in different way of distribution with histopathological pictures mostly represented by interface changes and mixed peri-vascular and peri-adnexal cell infiltrate. Other presentations included new onset of pemphigoid bullous disease (n = 15), delayed T-cell-mediated hypersensitivity reaction (injection site reactions) (n = 10), purpuric skin rash (n = 13), mostly localized on the legs bilaterally and symmetrically with histological pictures characterized by extravasation of erythrocytes in the superficial and middle dermis, and other types of reactions. New studies with large case series and further literature reviews are needed to improve the clinical management of patients and optimize the timeline for carrying out histological biopsy for confirmatory, supportive, and differential diagnosis purposes.

Autoimmune complications of COVID-19 and potential consequences for long-lasting disease syndromes

The latest WHO report determined the increasing diversity within the CoV-2 omicron and its descendent lineages. Some heavily mutated offshoots of BA.5 and BA.2, such as BA.4.6, BF.7, BQ.1.1, and BA.2.75, are responsible for about 20% of infections and are spreading rapidly in multiple countries. It is a sign that Omicron subvariants are now developing a capacity to be more immune escaping and may contribute to a new wave of COVID-19. Covid-19 infections often induce many alterations in human physiological defense and the natural control systems, with exacerbated activation of the inflammatory and homeostatic response, as for any infectious diseases. Severe activation of the early phase of hemostatic components, often occurs, leading to thrombotic complications and often contributing to a lethal outcome selectively in certain populations. Development of autoimmune complications increases the disease burden and lowers its prognosis. While the true mechanism still remains unclear, it is believed to mainly be related to the host autoimmune responses as demonstrated, only in some patients suffering from the presence of autoantibodies that worsens the disease evolution. In fact in some studies the development of autoantibodies to angiotensin converting enzyme 2 (ACE2) was identified, and in other studies autoantibodies, thought to be targeting interferon or binding to annexin A1, or autoantibodies to phospholipids were seen. Moreover, the occurrence of autoimmune heparin induced thrombocytopenia has also been described in infected patients treated with heparin for controlling thrombogenicity. This commentary focuses on the presence of various autoantibodies reported so far in Covid-19 diseases, exploring their association with the disease course and the durability of some related symptoms. Attempts are also made to further analyze the potential mechanism of actions and link the presence of antibodies with pathological complications.

Treatment, outcome and re-vaccination of patients with SARS-CoV-2 vaccine-associated immune thrombocytopenia

PURPOSE

Following the emergency use authorization of BNT162b2 by the Food and Drug administration (FDA) in early December 2020, mRNA- and vector-based vaccines became an important means of reducing the spread and mortality of the COVID-19 pandemic. The European Medicines Agency labelled immune thrombocytopenia (ITP) as a rare adverse reaction of unknown frequency after vector-, but not mRNA-vaccination. Here, we report on the long-term outcome of 6 patients who were diagnosed with de-novo, vaccine-associated ITP (VA-ITP), and on the outcome of subsequent SARS-CoV-2 re-vaccinations.

METHODS

Patients were included after presenting to our emergency department. Therapy was applied according to ITP guidelines. Follow-up data were obtained from outpatient departments. Both mRNA- or vector-based vaccines were each used in 3 cases, respectively.

RESULTS

In all patients, the onset of symptoms occurred after the 1st dose of vaccine was applied. 5 patients required treatment, 3 of them 2nd line therapy. All patients showed a complete response eventually. After up to 359 days of follow-up, 2 patients were still under 2nd line therapy with thrombopoietin receptor agonists. 5 patients have been re-vaccinated with up to 3 consecutive doses of SARS-CoV-2 vaccines, 4 of them showing stable platelet counts hereafter.

CONCLUSION

Thrombocytopenia after COVID-19 vaccination should trigger a diagnostic workup to exclude vaccine-induced immune thrombotic thrombocytopenia (VITT) and, if confirmed, VA-ITP should be treated according to current ITP guidelines. Re-vaccination of patients seems feasible under close monitoring of blood counts and using a vaccine that differs from the one triggering the initial episode of VA-ITP.

Balancing benefits and potential risks of vaccination: the precautionary principle and the law of unintended consequences

Vaccination is a life-saving endeavour, yet risk and uncertainty are unavoidable in science and medicine. Vaccination remains contentious in the public mind, and vaccine hesitancy is a serious public health issue. This has recently been reignited in the discussion over potential side effects of COVID-19 vaccines, and the decision by several countries to suspend measures such as the AstraZeneca vaccine. In these instances, the precautionary principle has often been invoked as a rationale, yet such heuristics do not adequately weigh potential harms against real benefits. How we analyse, communicate and react to potential harms is absolutely paramount to ensure the best decisions and outcomes for societal health, and maintaining public confidence. While balancing benefits and risks is an essential undertaking, it cannot be achieved without due consideration of several other pertinent factors, especially in the context of vaccination, where misguided or exaggerated fears have in the past imperilled public health. While well meaning, over reactions to potential hazards of vaccination and other health interventions can have unintended consequences, and cause lingering damage to public trust. In this analysis, we explore the challenges of assessing risk and benefit, and the limitations of the precautionary principle in these endeavours. When risk is unclear, cautious vigilance might be a more pragmatic and useful policy than reactionary suspensions.

Immune Thrombocytopenia Following Booster Dose of the Moderna mRNA-1273 Vaccine

Vaccine-mediated immune thrombocytopenia, although previously reported, is considered exceedingly rare. The probability of the incidence of profound thrombocytopenia following the COVID-19 mRNA-based vaccine has been less elucidated. We present the case of an 81-year-old female patient who became profoundly thrombocytopenic with bleeding manifestations six days after the Moderna mRNA-1273 vaccine administration. Fortunately, she exhibited platelet count recovery after treatment with intravenous immunoglobulins and steroid therapy. Furthermore, we show that the inherent risk of COVID-19 infection leading to thrombocytopenia significantly outweighs the vaccine's risk.