Hematologic Consequences of Viral Infections

COVID-19: Risks, Complications, and Monitoring in Patients on Clozapine

The Dutch Clozapine Collaboration Group is frequently asked for advice about the management of clozapine-treated patients when infected with or vaccinated against SARS-CoV-2. We provide state of the art information about the risks of SARS-CoV-2 infection for patients on clozapine and we give advice on measures to be taken, especially in regard to the monitoring of clozapine plasma levels, WBC count and differentiation during COVID-19 and after vaccination. We present an overview of relevant editorials, observational studies, and case studies, in which COVID-19 was reported in patients on clozapine. Patients using clozapine may have a higher risk of infection than patients with schizophrenia spectrum disorders (SSD) using other antipsychotics. SARS-CoV-2 infection can result in a dangerous increase of clozapine plasma levels, and granulocytopenia and lymphocytopenia (generally mild and short-term) may also occur, usually not as a result of clozapine treatment. Clozapine intoxication, pneumonia and delirium are the main complications of COVID-19 in patients on clozapine. In order to prevent clozapine intoxication, reduction of the original dose by half is generally recommended in clozapine users who contract COVID-19. When a cytokine storm is suspected in an advanced stage of COVID-19, reduction by three quarters seems more appropriate. If COVID-19 patients on clozapine develop granulocytopenia, SARS-CoV-2, rather than clozapine, should be considered as the cause. Schizophrenia patients in general and clozapine users in particular belong to a high-risk group that warrants early vaccination on a medical indication.

Prolonged Self-Resolving Neutropenia Following Asymptomatic COVID-19 Infection

Multiple hematologic complications have been reported as a result of the novel coronavirus disease 2019 (COVID-19) infection. These include leukopenia, lymphopenia, thrombocytopenia as well as increased risk of venous thromboembolism. Neutropenia is a relatively uncommon finding, especially in asymptomatic patients with no other evidence of systemic infection. A young, healthy male undergoing training for the Navy was admitted with rhabdomyolysis following intense physical activity. He was incidentally noted to have severe neutropenia with the white blood cell (WBC) count of 2.1 × 10⁹/L and an absolute neutrophil count (ANC) of 355 cells/μL one month following prior asymptomatic COVID-19 infection. Further evaluation was negative for other infectious processes, nutritional deficiency, or underlying malignancy. Given young age without comorbidities and lack of febrile illness, watchful waiting was recommended in lieu of bone marrow biopsy which resulted in spontaneous resolution of neutropenia and normalization of WBC. The authors argue that although most hematologic complications of COVID-19 are reported in symptomatic patients, asymptomatic patients also appear to have a risk of developing hematologic complications including bone marrow suppression. Watchful waiting may be an appropriate diagnostic approach in such young, healthy individuals.

Delayed, transient and self-resolving neutropenia following COVID-19 pneumonia

A novel coronaravirus, identified as SARS-CoV-2, spread throughout the world in 2020. The COVID-19 pandemic has led to many discoveries and clinical manifestations. A young patient is presented with new, self-resolving neutropenia presenting weeks after a prolonged hospital stay for COVID-19 pneumonia. Workup included analysis for underlying infection, nutritional abnormalities, malignancy, medication and toxin exposure, all of which were negative. From 2020 to the present, few reports have described neutropenia associated with a recent COVID-19 infection. In particular, no reports have described a delayed presentation of neutropenia. The authors would like to propose that the significant inflammatory response associated with COVID-19 is likely what led to this patient's postviral neutropenia. Furthermore, in young healthy patients, bone marrow biopsy may be deferred and a watchful-waiting approach may be taken to assess for neutropenia resolution.

Anxiety and depression symptoms in patients with dengue fever and their correlation with symptom severity

OBJECTIVE

To study the prevalence of anxiety and depression symptoms in patients with dengue and to examine their correlation with symptom severity.

METHODS

In this cross sectional study, 531 consecutive patients who met the World Health Organization criteria for dengue fever admitted to Mayo Hospital, Lahore between September and November 2011 were administered the Hospital Anxiety and Depression Scale (HADS). In addition to the HADS, the severity of their symptoms, like headache, myalgias/arthralgias, fever, and retro/periorbital pain, was assessed on a 3-point scale (mild, moderate, and severe).

RESULTS

About 60% of the patients in our study met the criteria for anxiety and 62.2% of the patients met criteria for depression. Severity of fever, headache, myalgias and arthralgias, and retro/periorbital pain was positively correlated with both anxiety (Correlation coefficients: 0.148, 0.247, 0.184, 0.184 respectively and P < 0.01 for all) and depression scores (Correlation coefficients: 0.098, 0.154, 0.131, 0.125 respectively and P value < 0.01 for all). The strongest correlation was found between severity of headache and scores for both anxiety and depression. Both mean anxiety and depression scores were significantly higher in patients with platelet count below median (30,000/mm3) than in patients with platelet count above median (9.1 +/- 4.7 vs 8.2 +/- 4.7, P < 0.03, and 9.5 +/- 4.5 vs 8.5 +/- 4.5, P < 0.01, respectively).

CONCLUSION

A majority of patients with dengue have anxiety and depression symptoms. Psychiatric evaluation should be done in all Dengue patients so timely treatment can be initiated.

Early-onset autoimmune hemolytic anemia after cladribine therapy for Waldenström's macroglobulinemia

BACKGROUND

Purine nucleoside analogs are a class of antineoplastic drugs with potent lymphotoxicity against T and B lymphocytes, causing prolonged lymphopenia and linked to delayed immune complications such as opportunistic infections and more recently autoimmune hemolytic anemia (AIHA), seen mostly in patients with chronic lymphocytic leukemia (CLL). A characteristic temporal relation between fludarabine therapy and the appearance of a warm-reactive immunoglobulin G (IgG)-mediated AIHA in patients with CLL has been observed and, in some, the AIHA has been fatal. Whether both fludarabine and cladribine cause AIHA is uncertain because AIHA is commonly seen in patients with CLL without the use of these drugs. In contrast, AIHA is encountered in Waldenström's macroglobulinemia (WM) much less frequently, and the autoantibody is usually cold-reactive and IgM-mediated. In a few reported cases of AIHA arising in patients with WM after cladribine therapy, there was a latency of 24 to 60 months between therapy and the onset of AIHA, three of which were warm-reactive and IgG-mediated.

CASE REPORT

A warm-reacting IgG red cell autoantibody and evidence of hemolysis detected 1 month after completing cladribine therapy for WM, with warm antibody AIHA developing 4 months later, are described.

CONCLUSIONS

Cladribine, like fludarabine, is possibly able to produce this complication during or early after therapy. Because the use of purine analogs is becoming increasingly common, it is important to have an awareness of the complications that can arise during and after treatment. Further observations of warm AIHA during cladribine therapy are needed to establish it as a distinct complication.

Dengue Virus-Associated Hemophagocytic Syndrome and Dyserythropoiesis: A Case Report

A 33-year-old man had dengue hemorrhagic fever with initial presentation of fever, leukocytosis, and thrombocytopenia. The cause of the subsequent rapid decline in red cell counts without evidence of intravascular hemolysis or massive bleeding was confirmed as hemophagocytosis and dyserythropoiesis by bone marrow study. The patient recovered with supportive care and the bone marrow pattern was normal on repeated bone marrow study. To our knowledge, this is the first reported case of dengue virus-associated hemophagocytosis and dyserythropoiesis in Taiwan. Clinicians should consider that the occurrence of hemophagocytosis and dyserythropoiesis could be due to dengue virus infection. That this dengue virus infection was confirmed by a positive serology result at the convalescent stage but not at the acute symptomatic stage underlines the need for a second dengue serology study, as dengue infection can be missed due to an initial negative serology result.

Human parvovirus B19

Parvovirus B19 (B19) was discovered in 1974 and is the only member of the family Parvoviridae known to be pathogenic in humans. Despite the inability to propagate the virus in cell cultures, much has been learned about the pathophysiology of this virus, including the identification of the cellular receptor (P antigen), and the control of the virus by the immune system. B19 is widespread, and manifestations of infection vary with the immunologic and hematologic status of the host. In healthy immunocompetent individuals B19 is the cause of erythema infectiosum and, particularly in adults, acute symmetric polyarthropathy. Due to the tropism of B19 to erythroid progenitor cells, infection in individuals with an underlying hemolytic disorder causes transient aplastic crisis. In the immunocompromised host persistent B19 infection is manifested as pure red cell aplasia and chronic anemia. Likewise, the immature immune response of the fetus may render it susceptible to infection, leading to fetal death in utero, hydrops fetalis, or development of congenital anemia. B19 has also been suggested as the causative agent in a variety of clinical syndromes, but given the common nature, causality is often difficult to infer. Diagnosis is primarily based on detection of specific antibodies by enzyme-linked immunosorbent assay or detection of viral DNA by dot blot hybridization or PCR. Treatment of persistent infection with immunoglobulin reduces the viral load and results in a marked resolution of anemia. Vaccine phase I trials show promising results.

Successful treatment of severe aplastic anemia associated with human parvovirus B19 and Epstein-Barr virus in a healthy subject with allo-BMT

Several reports have noted pancytopenia associated with Human parvovirus B19 (PVB19) or Ebstein-Barr virus (EBV) infections in patients who have no history of immunodeficiency. To our knowledge, we report the first case of severe aplastic anemia associated with both EBV and PVB19 infections in a previously healthy 22-year-old man. He was admitted to our hematology service due to anemia and thrombocytopenia. He had no symptoms or signs of infections of these viruses. His bone marrow biopsy revealed a hypocellular marrow. Specific IgM and IgG antibodies to EBV and PVB19 were elevated. EBV and PVB19 virus genomes were detected by PCR in the bone marrow nucleated cells and the peripheral blood lymphocytes. Two months after treatment with prednisone, acyclovir, and intravenous immune globulin (IVIg), the genomes of both these viruses disappeared. However, his transfusion requirement for platelet suspensions and packed red blood cells persisted. The patient underwent allogeneic bone marrow transplant (allo-BMT) and has had an enduring complete hematological response for 8 months.

Systemic delivery of an adenoviral vector encoding canine factor VIII results in short-term phenotypic correction, inhibitor development, and biphasic liver toxicity in hemophilia A dogs

Canine hemophilia A closely mimics the human disease and has been used previously in the development of factor VIII (FVIII) protein replacement products. FVIII-deficient dogs were studied to evaluate an in vivo gene therapy approach using an E1/E2a/E3-deficient adenoviral vector encoding canine FVIII. Results demonstrated a high level of expression of the canine protein and complete phenotypic correction of the coagulation defect in all 4 treated animals. However, FVIII expression was short-term, lasting 5 to 10 days following vector infusion. All 4 dogs displayed a biphasic liver toxicity, a transient drop in platelets, and development of anticanine FVIII antibody. Canine FVIII inhibitor development was transient in 2 of the 4 treated animals. These data demonstrate that systemic delivery of attenuated adenoviral vectors resulted in liver toxicity and hematologic changes. Therefore, the development of further attenuated adenoviral vectors encoding canine FVIII will be required to improve vector safety and reduce the risk of immunologic sequelae, and may allow achievement of sustained phenotypic correction of canine hemophilia A.

Intravenous administration of recombinant adenoviruses causes thrombocytopenia, anemia and erythroblastosis in rabbits

BACKGROUND

Recombinant adenoviruses are highly efficient gene transfer vehicles but their administration to mammals is accompanied by a strong inflammatory response. The present study reports additional side effects observed during adenoviral gene transfer studies in rabbits.

METHODS

Hematological and serological parameters, the course of viremia and the organ distribution were analyzed after in vivo administration of E1-deleted adenoviruses in rabbits.

RESULTS

The systemic administration of a therapeutic dose of 5 x 10(11) infectious particles/kg (infusion time 20 min) led to an average reduction of 80-90% in the platelet count within 48 h. Full recovery took 10-14 days. Virus administration induced a strong but transient erythroblastosis (peaking 24 h after administration) which settled 48 h later. Normochromic anemia occurred over the next 10 days with hemoglobin levels dropping by about 40% to reach the lowest level 10 days after administration and taking two months for full recovery. Dose-dependent thrombocytopenia was also found in mice, but neither erythroblastosis nor anemia was observed (in equivalent doses). The hematological findings did not improve after local injection via the portal vein. Local and systemic administration led to a comparable course of viremia. Only minor differences were found in the biodistribution of viruses between local and systemic administration. Large amounts of viral DNA and transgene expression were found in the lungs, the kidneys and the ovaries, even after local administration via the portal vein.

CONCLUSIONS

Local intravenous injection via the portal vein does not prevent systemic spread of viral vectors and the occurrence of vector-related side effects. The hematological changes observed in rabbits suggest the need for careful monitoring of hematological and rheological parameters in clinical trials.

Management of the hematological manifestations of HIV infection and AIDS

Hematological abnormalities, characterized by cytopenias, are a problem commonly encountered by persons with HIV or AIDS. Cytopenias can be multifactorial in their causation and potentially life threatening to this population. An understanding of the various causes of these cytopenias and the appropriate nursing care are tantamount to nursing practice and to ensure quality of life. Goals of medical and nursing care are directed at assessment, interventions, and patient education to prevent or minimize the complications of hematological abnormalities. This article reviews current knowledge regarding the causes, pathophysiology, treatments, and nursing care of HIV/AIDS-related hematological abnormalities.

The association of thrombocytopaenia and Lyme disease

The association of asymptomatic thrombocytopaenia in six patients with acute Lyme disease is described. Recovery from thrombocytopaenia occurred shortly following antibiotic therapy. Patients residing in endemic areas for Lyme disease who present with flu-like symptoms and laboratory findings of thrombocytopaenia should prompt suspicion of acute Lyme disease. Appropriate clinical studies should be undertaken to confirm the diagnosis.

Haematologic consequences of viral infections including serum iron status

Twenty-seven children with mumps or chickenpox were taken as a model to evaluate the haematological consequences of viral infections including serum iron status. Blood samples were obtained from all patients at presentation and on the 21st day of the disease. While haemoglobin, haematocrit, and mean corpuscular volume levels were similar in two measurements (P > 0.05), the mean leucocyte, absolute lymphocyte and thrombocyte counts, mean serum iron, serum iron binding capacity and transferrin saturation levels were lower at presentation than on the 21st day of the disease. The serum iron levels were below 30 micrograms/dl in 16 (59.2%) patients at presentation while only 4 (14.8%) had low values on 21st day. Twenty-four (88.9%) patients had an increment in the serum iron binding capacity levels and 2 (7.6%) reached values above the normal range on the 21st day. In 21 (77.8%) patients, the transferrin saturation levels were below the expected ranges at presentation but 26 (96.3%) showed an increment on the 21st day. However, the mean ferritin level was higher at presentation. Therefore, during the evaluation of patients for anaemia, the presence of a recent acute viral infection should be documented so as to avoid unnecessary iron medication.

Chronic neutropenia of childhood: frequent association with parvovirus infection and correlations with bone marrow culture studies

Children with neutropenia of more than 3 months duration often have evidence of immune-mediated destruction of mature neutrophils and variable abnormalities of myeloid precursors in their bone marrow. These patients often have anti-neutrophil antibodies which persist for several months. To further investigate the aetiology of neutropenia in such patients, bone marrow cells were evaluated for the presence of common viruses. Fifteen of 19 patients tested had evidence for parvovirus infection by PCR amplification of bone marrow DNA with parvovirus specific primers. Of these 15, six also had serologic evidence of parvovirus infection. Anti-neutrophil antibodies were identified in nine of 12 patients with parvovirus infection. Bone marrow culture studies done on six patients revealed varying degrees of myeloid and erythroid inhibition by patient plasma. These studies indicate that parvovirus may be a common cause of immune-mediated neutropenia in children.

Red cell aplasia responsive to immunoglobulin therapy as initial manifestation of human immunodeficiency virus infection

A patient who presented with pure red cell aplasia as the initial manifestation of human immunodeficiency infection is described. The patient had no signs of other autoimmune processes or immunologic or histologic evidence of parvovirus B19 infection, although we detected parvovirus B19 DNA in his serum. This patient had a complete, although temporary, response to a single course of immunoglobulin therapy and is currently responding to a second treatment.

Thrombocytopenic purpura during the incubation of hepatitis B

A 6-year-old girl presented with acute thrombocytopenic purpura. Hepatitis B surface antigenaemia was present at the time of this illness, and 8 weeks later she developed acute icteric hepatitis B. Screening for hepatitis B virus should be considered in children with apparently idiopathic thrombocytopenic purpura.

Intravenous gammaglobulin treatment for immune thrombocytopenia associated with infectious mononucleosis

Severe thrombocytopenia is an uncommon (incidence less than 1%) but serious complication of infectious mononucleosis. Corticosteroids have been used for therapy with variable responses reported. Five consecutive patients with infectious mononucleosis-related severe thrombocytopenia were treated with intravenous gammaglobulin (IVIG) at a dose of 400 mg/kg/day for 2-5 days. All patients appear to have had an immunologic or consumptive etiology for their thrombocytopenia as determined by increased marrow megakaryocytes. All patients were initially treated with oral prednisone 1 mg/kg/day. Due to the relatively slow response to prednisone (platelet count less than 20,000/microliters on the 8th to 13th hospital day) or increased bleeding symptoms, IVIG was initiated. Four of the five patients rapidly developed significant increases in their platelet counts (range 44,000/microliters to 97,000/microliters). Two of these responses were sustained and two relapses occurred (while on continued steroid therapy) which again responded to booster doses of IVIG at similar doses. IVIG has been previously shown to be effective in treating patients with idiopathic thrombocytopenia purpura. Historically, patients with infectious mononucleosis-related severe thrombocytopenia often are refractory to corticosteroid therapy and our limited experience suggests that IVIG may also be effective in infectious mononucleosis-related severe thrombocytopenia.

Changes in populations of immune effector cells during the course of haemorrhagic fever with renal syndrome

To characterize the immune response in haemorrhagic fever with renal syndrome, serial changes in immune effector cells were measured in 14 patients. Significant findings included initial elevations of all major leucocyte populations, increases in suppressor T cells and B cells, decreases in helper/suppressor cell ratios, and a dramatic increase in activated T cells. These changes were most marked in severely ill patients. Changes reverted to normal over approximately one week.

Viruses and bone marrow failure

Some generalizations can be drawn from a review of virus-associated bone marrow failure. The story of B19 parvovirus illustrates that viral infection may be an occult cause of marrow failure. Although the epidemiology of transient aplastic crisis suggested a viral aetiology, the implication of a single virus was surprising; the sporadic appearance of chronic bone marrow failure in immunosuppressed persons has had none of the features of a viral illness. The incrimination of parvovirus in these cases required development of specific immunological and molecular assays. Human and animal retrovirus studies have shown that small changes in the virus genome can have dramatic effects on the biology of the infectious agent and its pathogenicity in infected hosts. In Epstein-Barr virus infection, the host's immune response may play a more important role in mediating disease than virus cytotoxicity. Finally, the association of aplastic anaemia with hepatitis may be underestimated because of the inability to diagnose virus infection without obvious liver disease. The true spectrum of bone marrow disease due to virus infection is not known.