Received Jan 12, 2026
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| RSV | RSV (NO BRAND NAME) | UNKNOWN MANUFACTURER | UNK | — | — |
Evans syndrome; This is a literature report for the following literature source(s). Case Presentation: A 66-year-old female with a past medical history of hypertension, generalized anxiety disorder, hyperlipidemia, gastroesophageal reflux disease, and obstructive sleep apnea presented to the Emergency Department with an urgent care referral for a new-onset petechial rash involving her arms, legs, and face. The initial laboratory investigation showed a platelet count of 2x109/L, urging immediate transfer to the ED. Her previous laboratory tests showed normal platelet levels. The patient denied any history of recent infections, fever, recent travel, sick contacts, prior history of platelet disorders, known autoimmune disease, or family history of platelet or bleeding disorders. Her home medications included amlodipine, losartan, hydrochlorothiazide, and escitalopram. She reported receiving the RSV vaccine one week before admission. On presentation, her vital signs were stable. Laboratory workup showed a white blood cell (WBC) count of 5.4x109/L, a hemoglobin level of 14.3 g/dL, and a severely reduced platelet count of 1x109/L, with a normal chemistry panel. HIV and hepatitis panels were all negative. Initially, the patient was started on expectant treatment for presumed ITP with highdose dexamethasone 40 mg daily for 4 days (days 1-4) and a 1 g/kg dose of intravenous immunoglobulin (IVIG) on days 2-3. On hospital day 4, her hemoglobin declined from 14.3 g/dL on admission to 11.6 g/dL, prompting the initiation of hemolysis testing, including lactate dehydrogenase (LDH), haptoglobin, direct antiglobulin (Coombs) test, and a peripheral smear, all of which had not been obtained on admission, given the initially normal hemoglobin. These day-4 studies revealed a sudden rise in total bilirubin, low haptoglobin, elevated LDH, and a positive direct antiglobulin test for IgG (C3d negative), consistent with hemolytic anemia. A detailed timeline of the patient's clinical course is summarized. Further serologic testing showed an ANA titer of 1:80 with a cytoplasmic pattern and 1:40 with a nuclear homogenous pattern, findings considered low-level and nonspecific, but suggestive of underlying immune dysregulation consistent with Evans syndrome. No additional autoimmune workup was pursued. CMV IgG positive, positive EBV IgG, and negative IgM. Cardiolipin IgG<2.0, Cardiolipin IgM<2.0. The hematopathology study did not provide definitive immunophenotypic evidence of a hematolymphoid neoplasm. The bone marrow biopsy revealed a hypercellular marrow with 65% cellularity, an increased immature megakaryocyte fraction without clustering, a myeloid-to-erythroid ratio of approximately 2:1 with 34% erythroid precursors showing full maturation, ~14% red blood cell precursors by flow cytometry, preserved granulocytic maturation, absence of increased blasts, dysplasia, or clonal lymphoid populations, and a normal karyotype findings most consistent with normal to mildly increased erythropoiesis. CT scans from 2021 to 2025 consistently demonstrated stable, scattered, and tiny pulmonary nodules without any interval change. Most recently, these nodules were characterized as benign, with no suspicious features and no evidence of lymphadenopathy. Due to refractory thrombocytopenia, the patient initially received one dose of rituximab, followed by one dose of romiplostim. Afterward, she continued on rituximab infusions every week at a rate of 375 mg/m2 for four doses, along with prednisone at 1 mg/kg/day. Within five weeks, her blood count returned to normal. She had required IVIG only once on admission and did not undergo blood type or crossmatch, as no transfusion was ever needed. Notably, there was no recurrence of hemolysis during the remainder of her clinical course. Figures illustrate the temporal trends in hematologic parameters and hemolytic markers, respectively, during the clinical course and response to immunosuppressive therapy. Discussion and Conclusions: To the best of the authors knowledge, this is the first case documented of Evans syndrome secondary to RSV vaccination. The clinical hospital course, lack of alternative etiologies, and temporal association are consistent with cases of vaccine-associated Evans syndrome reported after receiving other vaccinations, such as influenza and COVID-19. The elevated prevalence of damaging variation in immune-regulatory genes in pediatric cohorts supports the pathophysiological mechanism, which is thought to involve aberrant activation of autoreactive lymphocytes in genetically or immunologically susceptible individuals. Furthermore, Evans syndrome is increasingly understood as a clinical manifestation of underlying immune dysregulation, characterized by aberrant T- and B-cell responses, expansion of circulating T-follicular helper cells, chronic T-cell activation, and reduced naive CD4+ T cells, regardless of whether a genetic defect is identified. RSV infection and vaccination can further trigger Th2/Th17 polarization, excessive cytokine production, and impaired interferon signaling, contributing to immunopathology and potentially precipitating autoimmune cytopenia in genetically or immunologically susceptible individuals. Host genetic variation plays a decisive role in modulating immune responses and disease severity in RSV infection and related complications. In pediatric Evans syndrome, up to 65% of cases harbor damaging variants in immuneregulatory genes, including LRBA, CTLA4, and STAT3, which are associated with more severe, treatment-refractory disease and increased risk of additional immunopathologic manifestations. Systematic genetic testing is recommended in pediatric patients with Evans syndrome to guide prognosis and enable targeted therapy. In contrast, in adults, testing should be considered selectively based on early onset, family history, or atypical features. Autoantibody panels and immunophenotyping should be considered in patients with Evans syndrome secondary to RSV vaccination, particularly in cases that are severe or refractory. These investigations can identify underlying immune dysregulation, with common findings including hypogammaglobulinemia, lymphoproliferation, and abnormal lymphocyte subsets. Early identification of immune dysregulation is critical for prognosis and management, as patients with definable immune dysregulation are more likely to require multiple lines of immunomodulatory therapy and have a more severe disease course. However, the utility of these investigations in adult-onset Evans syndrome and specifically in the context of RSV vaccination requires further research. Rarely, autoimmune cytopenia can develop as a result of the immune system's reaction to vaccination, especially when adjuvanted protein subunit vaccines are used. In the literature, seven cases of Evans syndrome have been identified following vaccination. Despite widespread vaccination, the sporadic occurrence of Evans syndrome - while biologically plausible - underscores the overall safety of RSV vaccines. In a cohort of more than 4.7 million older adults, a slight increase in Guillain-Barre syndrome was observed; however, no association with Evans syndrome was identified, and no excess risk of ITP was reported. Evans syndrome has not been recognized as a vaccine-related adverse event in early safety data from clinical trials and post-licensure analyses. Knowing the risk-benefit of the vaccine, the risk of immune-mediated hematologic complications remains very low compared with the benefits of vaccination in preventing severe RSV disease in high-risk populations.; Sender's Comments: considering immune system's reaction to vaccination and plausible temporal association reported event Evans syndrome considered related. The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.
Medical History/Concurrent Conditions: Gastroesophageal reflux disease; Generalized anxiety disorder; Hyperlipidemia; Hypertension; Obstructive sleep apnea
Test Name: bone marrow biopsy; Result Unstructured Data: Test Result:revealed a hypercellular marrow; Comments: with 65% cellularity, an increased immature megakaryocyte fraction without clustering, a myeloid-to-erythroid ratio of approximately2:1 with 34% erythroid precursors showing full maturation, ~14% red blood cell precursors by flow cytometry, preserved granulocytic maturation, absence of increased blasts, dysplasia, or clonal lymphoid populations, and a normal karyotype findings most consistent with normal to mildly increased erythropoiesis; Test Name: bilirubin; Result Unstructured Data: Test Result:Sudden rise; Comments: day-4; Test Name: EBV IgG; Test Result: Positive ; Test Name: IgM; Test Result: Negative ; Test Name: lactate dehydrogenase; Result Unstructured Data: Test Result:Normal; Test Name: Cardiolipin IgG; Result Unstructured Data: Test Result:2.0; Test Name: Cardiolipin IgM; Result Unstructured Data: Test Result:2.0; Test Name: CT scans; Result Unstructured Data: Test Result:from 2021 to 2025 consistently demonstrated stable; Comments: scattered, and tiny pulmonary nodules without any interval change.; Test Name: Coombs; Test Result: Positive ; Comments: for IgG (C3d negative); Test Name: CMV IgG; Test Result: Positive ; Test Name: hemoglobin; Result Unstructured Data: Test Result:14.3 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:11.6 g/dl; Comments: On hospital day 4, Declined; Test Name: hemoglobin; Result Unstructured Data: Test Result:14 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:16 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:11.6 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:9 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:9.8 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:7.9 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:7.7 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:11.2 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:12.3 g/dl; Test Name: hemoglobin; Result Unstructured Data: Test Result:12.5 g/dl; Test Name: haptoglobin; Result Unstructured Data: Test Result:Low; Test Name: hepatitis; Test Result: Negative ; Test Name: HIV; Test Result: Negative ; Test Name: chemistry panel; Result Unstructured Data: Test Result:Normal; Test Name: hematopathology; Result Unstructured Data: Test Result:did not provide definitive immunophenotypic; Comments: evidence of a hematolymphoid neoplasm; Test Name: platelet count; Result Unstructured Data: Test Result:Normal; Test Name: platelet count; Result Unstructured Data: Test Result:2; Comments: Unit- 10*9/L; Test Name: platelet count; Result Unstructured Data: Test Result:1; Comments: severely reduced; Test Name: platelet count; Result Unstructured Data: Test Result:4; Test Name: platelet count; Result Unstructured Data: Test Result:2; Test Name: platelet count; Result Unstructured Data: Test Result:16; Test Name: platelet count; Result Unstructured Data: Test Result:31; Test Name: platelet count; Result Unstructured Data: Test Result:9; Test Name: platelet count; Result Unstructured Data: Test Result:35; Test Name: platelet count; Result Unstructured Data: Test Result:208; Test Name: serologic testing; Result Unstructured Data: Test Result:showed an ANA titer of; Comments: 1:80 with a cytoplasmic pattern and 1:40 with a nuclear homogenous pattern, findings considered low-level and nonspecific, but suggestive of underlying immune dysregulation consistent with Evans syndrome; Test Name: peripheral smear; Result Unstructured Data: Test Result:Normal; Test Name: vital sign; Result Unstructured Data: Test Result:Stable; Test Name: white blood cell; Result Unstructured Data: Test Result:5.4; Comments: Unit- 10*9/L; Test Name: white blood cell; Result Unstructured Data: Test Result:22.6; Test Name: white blood cell; Result Unstructured Data: Test Result:10.5; Test Name: white blood cell; Result Unstructured Data: Test Result:8; Test Name: white blood cell; Result Unstructured Data: Test Result:9.2