Involvement of Virus-Induced Interferon Production in IgG Autoantibody-Mediated Anemia.

Infection with viruses, such as the lactate dehydrogenase-elevating virus (LDV), is known to trigger the onset of autoimmune anemia through the enhancement of the phagocytosis of autoantibody-opsonized erythrocytes by activated macrophages. Type I interferon receptor-deficient mice show enhanced anemia, which suggests a protective effect of these cytokines, partly through the control of type II interferon production. The development of anemia requires the expression of Fcγ receptors (FcγR) I, III, and IV. Whereas LDV infection decreases FcγR III expression, it enhances FcγR I and IV expression in wild-type animals. The LDV-associated increase in the expression of FcγR I and IV is largely reduced in type I interferon receptor-deficient mice, through both type II interferon-dependent and -independent mechanisms. Thus, the regulation of the expression of FcγR I and IV, but not III, by interferons may partly explain the exacerbating effect of LDV infection on anemia that results from the enhanced phagocytosis of IgG autoantibody-opsonized erythrocytes.

Prognostic significance of hemoglobin level and autoimmune hemolytic anemia in SARS-CoV-2 infection.

Higher levels of D-dimer, LDH, and ferritin, all have been associated with the poor prognosis of COVID-19. In a disease where there are acute inflammation and compromised oxygenation, we investigated the impact of initial hemoglobin (Hgb) levels at Emergency Department (ED) triage on the severity and the clinical course of COVID-19. We conducted a cross-sectional study on 601 COVID-19 patients in a COVID-19 national referral center between 13 and 27 June 2020. All adult patients presented at our hospital that required admission or hotel isolation were included in this study. Patients admitted to the intensive care unit (ICU) had a lower initial Hgb than those admitted outside the ICU (12.84 g/dL vs. 13.31 g/dL, p = 0.026) and over the course of admission; the prevalence of anemia (Hgb < 12.5 g/dL) was 65% in patients admitted to ICU, whereas it was only 43% in non-ICU patients (odds ratio of 2.464, 95% CI 1.71-3.52). Anemic ICU patients had a higher mortality compared with non-anemic ICU patients (hazard ratio = 1.88, log-rank p = 0.0104). A direct agglutination test (DAT) for all anemic patients showed that 14.7% of ICU patients and 9% of non-ICU patients had autoimmune hemolytic anemia (AIHA). AIHA patients had significantly longer length of hospital stay compared with anemic patients without AIHA (17.1 days vs. 14.08 days, p = 0.034). Lower Hgb level at hospital presentation could be a potential surrogate for COVID-19 severity.

Immune dysregulation and multisystem inflammatory syndrome in children (MIS-C) in individuals with haploinsufficiency of SOCS1.

BACKGROUND: We studied 2 unrelated patients with immune thrombocytopenia and autoimmune hemolytic anemia in the setting of acute infections. One patient developed multisystem inflammatory syndrome in children in the setting of a severe acute respiratory syndrome coronavirus 2 infection. OBJECTIVES: We sought to identify the mechanisms underlying the development of infection-driven autoimmune cytopenias. METHODS: Whole-exome sequencing was performed on both patients, and the impact of the identified variants was validated by functional assays using the patients' PBMCs. RESULTS: Each patient was found to have a unique heterozygous truncation variant in suppressor of cytokine signaling 1 (SOCS1). SOCS1 is an essential negative regulator of type I and type II IFN signaling. The patients' PBMCs showed increased levels of signal transducer and activator of transcription 1 phosphorylation and a transcriptional signature characterized by increased expression of type I and type II IFN-stimulated genes and proapoptotic genes. The enhanced IFN signature exhibited by the patients' unstimulated PBMCs parallels the hyperinflammatory state associated with multisystem inflammatory syndrome in children, suggesting the contributions of SOCS1 in regulating the inflammatory response characteristic of multisystem inflammatory syndrome in children. CONCLUSIONS: Heterozygous loss-of-function SOCS1 mutations are associated with enhanced IFN signaling and increased immune cell activation, thereby predisposing to infection-associated autoimmune cytopenias.

A Rare Presentation of Epstein-Barr Virus Infection.

BACKGROUND: Epstein-Barr virus (EBV) is a herpesvirus spread by intimate contact. It is known to cause infectious mononucleosis. Complications, including hematologic pathology and splenic rupture, are uncommon. This report is a case of EBV-induced autoimmune hemolytic anemia and biliary stasis. CASE REPORT: An 18-year-old man presented to the emergency department with abdominal pain, nausea, vomiting, and jaundice. He did not have risk factors for liver injury or hepatitis. His vital signs were notable for a fever. On examination, he was obviously jaundiced, but not in distress. Laboratory evaluation showed hemolytic anemia and biliary stasis. Ultimately, his inpatient workup yielded positive EBV serology and a positive direct agglutinin test with cold agglutinins. He made a full recovery with supportive care. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: EBV is a widely disseminated herpesvirus. Infectious mononucleosis is a common presentation of acute infection, and treatment of EBV-related diseases are largely supportive. Complications, such as splenic rupture and hematologic pathology, are uncommon. Biliary stasis and autoimmune hemolytic anemia in the form of cold agglutinin disease secondary to EBV is rare, and typically resolves with supportive care and cold avoidance. More advanced treatment methods are available in the setting of severe hemolysis. Elevated transaminases, direct hyperbilirubinemia, or evidence of hemolytic anemia in the setting of a nonspecific viral syndrome should raise suspicion for EBV infection. Rapid recognition can lead to more prompt prevention and treatment of other EBV-related complications.

EBV-related Cold Agglutinin Disease Presenting With Conjugated Hyperbilirubinemia: A Pediatric Case Report and Mini Review.

Hemolytic anemia occurs in only 1% to 3% of hospitalized patients with infectious mononucleosis. The authors describe an 8-year-old girl without cervical lymphadenopathy or splenomegaly, who presented with conjugated hyperbilirubinemia and was diagnosed with cold agglutinin disease caused by an immunoglobulin M autoantibody with anti-i specificity. Acute Epstein-Barr virus infection was confirmed by serologic and molecular methods. She recovered uneventfully after a 3-week course of methylprednisolone. Epstein-Barr virus infection should be considered in any case of hemolytic anemia associated with hepatic dysfunction, especially when direct antiglobulin test is positive for C3d. In these cases, a course of corticosteroids seems safe and may be beneficial.

[Clinical manifestations of Epstein-Barr virus infection in children and adolescents].

The most commonly known clinical manifestation of primary Epstein-Barr virus infection is infectious mononucleosis. In this review we cover the diagnostics and basic patho-physiology of Epstein-Barr virus infection and present the many clinical manifestations of the virus, including less well-known diseases such as hepatitis, auto-immune haemolytic anaemia, and neurological and immunological diseases. Our aim is to strengthen the clinicians' awareness and understanding of these conditions in order to improve diagnostics and avoid delay of treatment.

[Severe haemolytic anaemia and hepatitis in the course of Epstein-Barr virus infection].

Epstein-Barr virus (EBV) is globally prevalent and in adolescents mostly observed as infectious mononucleosis. Abnormal liver blood tests are common, whereas more serious hepatitis is less prevalent. Autoimmune haemolytic anaemia may also occur in the course of this infection. We report a case of a 15-year-old girl with cholestatic hepatitis and autoimmune haemolytic anaemia associated with EBV infection. The Donath-Landsteiner test was positive suggesting paroxysmal cold haemoglobinuria. She was treated with supportive care and discharged in recovery after three weeks.

Human Immunodeficiency Virus Infection Increases the Risk of Incident Autoimmune Hemolytic Anemia: A Population-Based Cohort Study in Taiwan.

Background: Currently, the association between human immunodeficiency virus (HIV) infection and subsequent development of autoimmune hemolytic anemia (AIHA) remains unclear. This nationwide population-based cohort study aimed to determine the association between incident AIHA and HIV infection in Taiwan. Methods: During 2000-2012, we identified people aged ≧15 years living with HIV (PLWH) from the Taiwan Centers for Disease Control HIV Surveillance System. Individuals were considered to be infected with HIV on the basis of positive results of an HIV type 1 Western blot. Age- and sex-matched controls without HIV infection were selected from the Taiwan National Health Insurance Research Database for comparison. All patients were followed until 31 December 2012 and observed for occurrence of AIHA. Results: Of 171468 subjects (19052 PLWH and 152416 controls), 30 (0.02%) had incident AIHA during a mean follow-up of 5.45 years, including 23 PLWH (0.12%) and 7 controls (0.01%). After adjustment for age, sex, and comorbidities, HIV infection was found to be an independent risk factor of incident AIHA (adjusted hazard ratio, 20.9; 95% confidence interval, 8.34-52.3). Moreover, PLWH who were receiving highly active antiretroviral therapy were more likely to develop AIHA than those who were not receiving these drugs (adjusted hazard ratio, 16.2; 95% confidence interval, 3.52-74.2). Conclusions: Our study suggests that HIV infection is an independent risk factor for incident AIHA.

Severe acute hepatitis and cold agglutinin-related hemolytic anemia secondary to prime infection with Epstein-Barr virus.

Epstein-Barr virus, a member of the Herpesviridae family, is responsible for the infectious mononucleosis clinical syndrome, which mainly includes the pharyngitis, fever, and lymphadenopathy triad after incubation for 30-50 days. The liver is involved in 80-90% of patients in a self-limiting transient manner, with jaundice being much more uncommon (5%). From a hematological standpoint it may manifest aplastic anemia, neutropenia, and thrombocytopenia. We report a case of infectious mononucleosis that included severe acute hepatitis and was associated with severe hemolytic anemia secondary to cold agglutinins. After exclusion of other etiologies, and given the clinical suspicion of the above association, which was later confirmed by lab tests, empiric therapy was initiated with antiviral agents (aciclovir + valganciclovir) and corticoids, which resulted in a progressive clinical improvement until complete remission. Therefore, we believe that this case report will reinforce the clinical evidence in support of the above combined therapy for serious infectious mononucleosis as a step prior to liver transplantation.

Follicular lymphoma in situ in the spleen of a patient with autoimmune hemolytic anemia and carrying HCV was associated with more clonal B-cells than t(14;18) positive B-cells.

Certain autoimmune conditions are associated with an increased risk of lymphoid malignancy. We report a 65-year old patient with autoimmune hemolytic anemia (AIHA) complicated by a follicular lymphoma (FL) in situ and other B-cell clones in the spleen. This diagnosis was made by immunohistochemistry, flow cytometry, and Southern blot analysis of the B-cell receptor. Chromosomal analysis revealed 46,XX,t(14;18)(q32;q21) 2/20, 46,XX,del(7)(q?),del(11)(q?) 2/20, and 46,XX 16/20. It has been speculated that these preneoplastic conditions do not progress to overt FL and other lymphomas without a second lymphomagenic insult. However, AIHA confers a 27.4-fold higher risk of such an insult leading to lymphoma compared with the normal healthy population. Without any therapy after splenectomy, our current study patient remained healthy with no lymphoma development for 28 months. Based on this case, we discuss the pathophysiology of lymphomagenesis in a spleen with AIHA and the roles of a splenectomy for preventing further lymphomagenesis in AIHA patients.

Autoimmune Hemolytic Anemia Triggered by Infection with Human Parvovirus B19 after Total Abdominal Colectomy for Ulcerative Colitis.

A 50-year-old man was admitted to our hospital for an adhesive ileus 14 years after total abdominal colectomy for ulcerative colitis (UC). The ileus decreased with conservative treatment, however, autoimmune hemolytic anemia (AIHA) was diagnosed due to worsening anemia, a positive direct Coombs test, low haptoglobin, high lactase dehydrogenase, reticulocytosis, and an increase in the erythroblastic series in a bone-marrow examination. Human parvovirus B19 (PV-B19) IgM and PV-B19 DNA were present, indicating the development of AIHA triggered by an infection with PV-B19. The patient is currently being monitored after spontaneous remission. This is the first report of UC after total abdominal colectomy complicated by AIHA triggered by PV-B19 infection.

Fatal autoimmune hemolytic anemia due to immunoglobulin g autoantibody exacerbated by epstein-barr virus.

Most cases of autoimmune hemolytic anemia (AIHA) are caused by the production of an autoantibody that targets determinants on red blood cells (RBCs). This autoantibody can be immunoglobulin (Ig) G, IgM, or IgA. Some autoantibodies react optimally at 0° to 4°C (ie, cold agglutinin) and usually are clinically insignificant. High-titer cold agglutinins are associated with IgM autoantibody and complement fixation induced by infectious agents, including the Epstein-Barr virus (EBV). This case report describes a 31-year-old man who had jaundice, a hemoglobin of 6.0 gdL, and was diagnosed with a hemolytic crisis of AIHA. He received a total of 11 RBC transfusions during a 15-hour period without sustained response and later died. The direct antiglobulin test results for this patient were positive, whereas the cold-agglutinin-testing results were negative. We detected EBV DNA in blood via polymerase chain reaction (PCR). We report a rare case of AIHA associated with an IgG autoantibody and exacerbated by EBV infection, causing a fatal hemolytic anemia.

A case of recurrent autoimmune hemolytic anemia during remission associated with acute pure red cell aplasia and hemophagocytic syndrome due to human parvovirus B19 infection successfully treated by steroid pulse therapy with a review of the literature.

The patient was a 47-year-old man diagnosed as having autoimmune hemolytic anemia (AIHA) in April 2011. He also had a congenital chromosomal abnormality, a balanced translocation. Treatment with prednisolone (PSL) 60 mg/day resulted in resolution of the AIHA, and the treatment was completed in November 2011. While the patient no longer had anemia, the direct and indirect Coombs tests remained positive. In May 2013, he developed recurrent AIHA associated with acute pure red cell aplasia (PRCA) and hemophagocytic syndrome (HPS) caused by human parvovirus B19 (HPV B19) infection. Tests for anti-erythropoietin and anti-erythropoietin receptor antibodies were positive. Steroid pulse therapy resulted in resolution of the AIHA, PRCA, as well as HPS. The serum test for anti-erythropoietin antibodies also became negative after the treatment. However, although the serum was positive for anti-HPV B19 IgG antibodies, the patient continued to have a low CD4 lymphocyte count (CD4, <300/µL) and persistent HPV B19 infection (HPV B19 DNA remained positive), suggesting the risk of recurrence and bone marrow failure.

Case of cytomegalovirus-associated direct anti-globulin test-negative autoimmune hemolytic anemia.

A 1-year-old boy developed autoimmune hemolytic anemia after a negative direct anti-globulin test. The concentration of erythrocyte membrane-associated immunoglobulin G, determined using an immunoradiometric assay, correlated with disease activity. He was positive for cytomegalovirus (CMV) both serologically and by quantitative real-time polymerase chain reaction, indicating that his autoimmune hemolytic anemia was directly caused by CMV infection. Since anti-CMV immunoglobulin G was not absorbed by the patient's erythrocytes, cross-reaction between erythrocyte antigens and CMV was not likely a causative factor for hemolysis.