Case reports of management of aplastic anemia after COVID-19 vaccination: a single institute experience in Taiwan

Aplastic Anemia in the light of the COVID-19 pandemic: infection, vaccination, and pathophysiologic mechanisms

Patients infected with SARS-CoV-2 and vaccinated against COVID-19 could develop aplastic anemia (AA). Comprehensive review and analysis were conducted through a selective literature search in PubMed, Scopus, EMBASE, and Web of Science. For this analysis, 26 studies were included, comprising 16 case reports, 7 case series, and 3 observational studies, totaling 53 patients. The causes of acquired or idiopathic AA are diverse; this review presents recent findings, including possible new etiologies such as SARS-CoV-2 infection and COVID-19 vaccines. This possible association is explored, addressing the existing gap, and aiming to improve daily medical practice. This article reviews the relationship between AA and SARS-CoV-2 infection, as well as COVID-19 vaccines, analyzing cases of de novo occurrence and relapses of AA. Although a definitive mechanistic link has not yet been established, possible underlying pathophysiological mechanisms are explored.

Multidisciplinary approaches to study anaemia with special mention on aplastic anaemia (Review)

Anaemia is a common health problem worldwide that disproportionately affects vulnerable groups, such as children and expectant mothers. It has a variety of underlying causes, some of which are genetic. A comprehensive strategy combining physical examination, laboratory testing (for example, a complete blood count), and molecular tools for accurate identification is required for diagnosis. With nearly 400 varieties of anaemia, accurate diagnosis remains a challenging task. Red blood cell abnormalities are largely caused by genetic factors, which means that a thorough understanding requires interpretation at the molecular level. As a result, precision medicine has become a key paradigm, utilising artificial intelligence (AI) techniques, such as deep learning and machine learning, to improve prognostic evaluation, treatment prediction, and diagnostic accuracy. Furthermore, exploring the immunomodulatory role of vitamin D along with biomarker‑based molecular techniques offers promising avenues for insight into anaemia's pathophysiology. The intricacy of aplastic anaemia makes it particularly noteworthy as a topic deserving of concentrated molecular research. Given the complexity of anaemia, an integrated strategy integrating clinical, laboratory, molecular, and AI techniques shows a great deal of promise. Such an approach holds promise for enhancing global anaemia management options in addition to advancing our understanding of the illness.

Aplastic Anemia Following COVID-19 Vaccination: A Systematic Review of Case Reports and Case Series

Background: Aplastic anemia (AA) is the prototypical bone marrow failure syndrome due to the destruction of hematopoietic stem cells by cytotoxic T cells. According to case reports, vaccines could lead to the development of AA. We conducted the present systematic review to evaluate cases of AA following vaccination against coronavirus disease (COVID-19). Materials and Methods: We searched the following databases: PubMed, Scopus, and EMBASE in English, Portuguese, and Spanish languages until April 24, 2023. Published reports and case series on AA following vaccination against COVID-19 were included. The Joanna Brigs Institute (JBI) was used to assess study quality and risk of bias. Results: Six studies were selected from 102 research studies, and data were extracted according to the inclusion criteria. All case reports and case series reported the occurrence of AA following COVID-19 vaccination. AA events were mainly observed in vaccines with messenger ribonucleic acid technology (Moderna; Pfizer-BioNTech). AA was diagnosed by bone marrow biopsy, and severity was determined by Camitta criteria. Conclusion: All cases of AA were properly diagnosed. The sample size was small; therefore, further investigations are required to demonstrate and elucidate the complete pathophysiological mechanisms of AA development after receiving COVID-19 vaccination.

New-onset aplastic anemia after SARS-CoV-2 vaccination

Aplastic anemia (AA) is a rare autoimmune disease. Drugs, viruses, and radiation are among the most common etiologic factors, and most cases have immune pathophysiology. SARS-CoV-2 vaccines have been linked with rare side effects, including cases of acquired aplastic anemia. Here we review all the reported cases of new-onset AA after SARS-CoV-2 vaccination, and discuss their clinical characteristics and management. 18 patients in these case reports had a median age of 58 years. The time from vaccination to onset of aplastic anemia ranged from 1 day to 7 months, with a median of 2.5 weeks. Seventeen patients were diagnosed with severe or very severe aplastic anemia post-vaccination and all patients received standard treatments for acquired aplastic anemia. Seventeen patients achieved a complete or partial response and only 1 patient died. Aplastic anemia can be considered a very rare SARS-CoV-2 vaccine-related adverse event, although a causative relationship has not been proven. Reporting cases of such uncommon post-vaccination events could help clinicians to consider aplastic anemia when pancytopenia is observed after vaccination. The benefits of SARS-Cov-2 vaccination are established, and reports of rare events serve only to increase awareness in daily clinical practice.

Acquired aplastic anaemia after SARS-CoV-2 infection in China: a case report

Since the coronavirus disease 2019 (COVID-19) pandemic began, several research groups in different countries have described cases of aplastic anaemia (AA) after COVID-19 or COVID-19 vaccination. Here, we present the case of a patient with new-onset AA in Changsha, China, that was presumably associated with preceding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We conducted an epidemiological assessment of the incidence rate of blood system diseases from July 1, 2022, to May 31, 2023, in the haematology department of the Second Xiangya Hospital of Central South University and Hunan Children's Hospital. The detection rates of AA and leukaemia in the first two months after the epidemic outbreak were higher than those before and during the outbreak. However, only the difference in the detection rate of leukaemia was statistically significant.

New onset of hypomegakaryocytic thrombocytopenia with the potential for progression to aplastic anemia after BNT162b2 mRNA COVID-19 vaccination

Vaccination with a coronavirus disease-2019 (COVID-19) vaccine is an effective public health measure for reducing the risk of infection and severe complications from COVID-19. However, serious hematological complications after COVID-19 vaccination have been reported. Here, we report a case of new-onset hypomegakaryocytic thrombocytopenia (HMT) with the potential for progression to aplastic anemia (AA) that developed in a 46-year-old man 4 days after the fourth mRNA COVID-19 vaccination. Platelet count rapidly decreased after vaccination and white blood cell count declined subsequently. Bone marrow examination immediately after disease onset showed severely hypocellular marrow (cellularity of almost 0%) in the absence of fibrosis, findings that were consistent with AA. Since the severity of pancytopenia did not meet the diagnostic criteria for AA, the patient was diagnosed with HMT that could progress to AA. Treatment with eltrombopag and cyclosporine was started immediately after diagnosis and cytopenia improved. Although it is difficult to determine whether the post-vaccination cytopenia was vaccine induced or accidental because the association was chronological, vaccination with an mRNA-based COVID-19 vaccine may be associated with development of HMT/AA. Therefore, physicians should be aware of this rare, but serious adverse event and promptly provide appropriate treatment.

An Unusual Case of Acquired Aplastic Anemia following SARS-CoV-2 Vaccination: A Case Report

Aplastic Anemia (AA) is a condition where the body's immune system attacks and destroys the hematopoietic stem cells, leading to pancytopenia and an empty bone marrow. AA can be effectively treated using immunosuppressive therapy or hematopoietic stem-cell transplantation. The damage to stem cells in the bone marrow can be due to several causes, such as autoimmune diseases, medication like cytotoxic drugs and antibiotics, and exposure to toxins or chemicals in the environment. In this case report, we present the diagnosis and treatment of a 61-year-old man who was diagnosed with Acquired Aplastic Anemia, which could have developed following his serial immunizations with the SARS-CoV-2 COVISHIELD viral vector vaccine. The patient received immunosuppressive therapy consisting of cyclosporine, anti-thymocyte globulin, and prednisone, resulting in a significant improvement in his condition.

Ph-Positive B-Cell Acute Lymphoblastic Leukemia Occurring after Receipt of Bivalent SARS-CoV-2 mRNA Vaccine Booster: A Case Report

The coronavirus disease 2019 (COVID-19) pandemic is a universal emergency public health issue. A large proportion of the world's population has had several spike antigen exposures to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and/or COVID-19 vaccinations in a relatively short-term period. Although sporadic hematopoietic adverse events after COVID-19 vaccine inoculation were reported, there is currently no sufficient evidence correlating anti-spike protein immune responses and hematopoietic adverse events of vaccinations. We reported the first case of Ph-positive B-cell acute lymphoblastic leukemia (ALL) occurring after a bivalent mRNA COVID-19 vaccine inoculation. The otherwise healthy 43-year-old female patient had a total of six spike antigen exposures in the past 1.5 years. Informative pre-vaccine tests and bone marrow study results were provided. Although the causal relationship between bivalent vaccinations and the subsequent development of Ph-positive B-cell ALL cannot be determined in the case report, we propose that anti-spike protein immune responses could be a trigger for leukemia. Clinicians must investigate the hematopoietic adverse events closely after COVID-19 vaccinations. Further pre-clinical studies to investigate the safety of bivalent mRNA COVID-19 vaccine are required.