Parvovirus B19 infection reminiscent of myelodysplastic syndrome in three children with chronic hemolytic anemia

How I investigate dysgranulopoiesis

Dysgranulopoiesis is a condition in which granulocytic production is defective and is most often described in neoplastic conditions. However, it can also be frequently seen in non-neoplastic conditions. Early suspicion and detection of these non-neoplastic causes may prevent further invasive and expensive interventions. In this review, we take a look at the various causes of dysgranulopoiesis with an emphasis on non-neoplastic etiologies, followed by a detailed outline of the laboratory approach for determining its many causes.

Leukoerythroblastosis as an Unusual Presentation of Parvovirus B19 Infection in a Sickle Cell Patient

Parvovirus B19 infection in pediatrics most commonly causes fifth disease, a mild viral illness. Hematologic manifestations include severe anemia, especially in patients with chronic hemolytic anemias or who are immunocompromised. Because of the shortened life span of erythrocytes in patients with sickle cell disease, parvovirus infection can cause transient aplastic crisis which can be life-threatening. However, leukocytosis and thrombocytosis are rarely seen. We report leukoerythroblastosis as an unusual presentation of acute parvovirus B19 infection in a previously splenectomized 12-year-old boy with sickle cell disease.

[Application of systematic etiological analysis in final and differential diagnosis of hereditary hemolytic anemia]

目的

探讨溶血病因系统分析策略在遗传性溶血性贫血病因诊断和鉴别诊断中的应用。

方法

以溶血病因系统分析方法对疑诊溶血性贫血的1 506例患者进行分析。

结果

①1 506例疑诊溶血性贫血患者中，男799例，女707例，中位年龄22岁（4 d~86岁）。涉及三大遗传性溶血病因的患者共1 413例（94%），其中单一病因溶血1 044例（74%），复合型溶血369例（26%）。②在涉及三大遗传性溶血病因的患者中，单一病因血红蛋白病、红细胞膜病及红细胞酶病分别为235例（22%）、656例（63%）及153例（15%）。单一溶血病因与复合溶血病因合并统计，涉及血红蛋白病、红细胞膜病及红细胞酶病分别为489例（29%）、948例（57%）及239例（14%）。上述两种基数统计的三大遗传性溶血病因构成比差异均无统计学意义（P值均>0.05）。③369例（26%）复合型溶血中，不同类型遗传缺陷以血红蛋白病合并红细胞膜病最常见（50%，184/369），亦见于红细胞酶病合并红细胞膜病（18%，66/369），血红蛋白病合并红细胞酶病（4%，13/369）。相同类型遗传缺陷复合型血红蛋白病、复合型膜病、复合型酶病分别为29例（8%）、57例（15%）、9例（2%）。其他复合型溶血、贫血、黄疸占3%（11例），见于合并后天因素、继发因素及其他系统异常。

结论

三大遗传性溶血病因同期检查能对94％的患者进行分类，常见的遗传性溶血病因依次为红细胞膜病、血红蛋白病和红细胞酶病。复合型溶血并非少见，仅单一因素分析不足以提供充分确诊依据。

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.

Research on the human virome: where are we and what is next

The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health convened a Working Group on the Microbiome in Cardiovascular, Pulmonary and Hematologic Health and Diseases from June 25, 2014, to June 26, 2014. The Working Group's central goal was to define what major microbiome research areas warranted additional study in the context of heart, lung, and blood (HLB) diseases. The Working Group identified studies of the human virome a key priority.

A review of blood diseases and cytopenias associated with human parvovirus B19 infection

Parvovirus B19 is a single-stranded DNA virus which preferentially targets the erythroblast resulting in red cell aplasia, which is temporary in immunocompetent persons. Since the discovery of B19 virus in 1975, a wide variety of blood diseases and cytopenias affecting several blood cell lineages have been documented during or following B19 infection. These include cytopenias affecting the erythroid, megakaryoblastoid, myeloid and lymphoid lineages, as well as a variety of bicytopenias, pancytopenia, bone marrow necrosis / fat embolism syndrome, myelodysplastic syndrome, leucoerythroblastopenia, and hemophagocytic lymphohistiocytosis. B19 infection may also complicate and precede the course of acute leukemia, the significance of which remains to be determined. This review describes the current state of knowledge of the abnormalities of individual blood cell lineages encountered during parvovirus B19 infection, over the almost 40 years since its discovery, and reveals some very interesting themes, which improve our understanding of the pathogenesis of B19 infection with particular reference to the bone marrow.

Update on Myelodysplastic Syndromes Classification and Prognosis

Myelodysplastic syndromes (MDS) are a collection of cytogenetically heterogeneous clonal bone marrow (BM) failure disorders derived from aberrant hematopoietic stem cells in the setting of an aberrant hematopoietic stem cell niche. Patients suffer from variably progressive and symptomatic bone marrow failure with a risk of leukemic transformation. Diagnosis of MDS has long been based on morphologic assessment and blast percentage as in the original French-American-British classification. The recently developed Revised International Prognostic Scoring System provides improved prognostication using more refined cytogenetic, marrow blast, and cytopenia parameters. With the advent of deep sequencing technologies, dozens of molecular abnormalities have been identified in MDS.

Infections in myelodysplastic syndromes

Myelodysplastic syndromes are associated with a risk of severe infections. While neutropenia is likely to be the main predisposing factor, several other immune defects have been reported, including impaired neutrophil function, B-, T- and NK-cell defects and the possible consequences of iron overload due to red blood cell transfusions. The advanced age of most patients, their frequent comorbidities, and the fact that drugs such as hypomethylating agents and lenalidomide, which are effective in myelodysplastic syndromes but can transiently worsen neutropenia, may increase the risk of infection and their severity in this context. The majority of infections in myelodysplastic syndromes are bacterial, while the incidence of fungal infections is not well known and viral infections seem to be rare. No prophylactic measures against infections have demonstrated efficacy in myelodysplastic syndromes. However, pending more data, we propose here some recommendations for the management of patients with myelodysplastic syndromes. In the future, an important contribution can be made by prospective trials testing the efficacy of prophylactic and therapeutic approaches to infection in these patients, especially in the context of the new drugs available for myelodysplastic syndromes.

The spectrum of parvovirus b19 infection in a pediatric hemato-oncologic ward

Of 1059 children, 35 children with various hemato-oncologic diseases were diagnosed with parvovirus B19 infection. The clinical spectrum included 11 immunocompromised patients presenting with prolonged pancytopenia, 7 patients with delayed hematologic recovery after stem cell transplantation, 5 patients with parvovirus B19 as possible cause of severe aplastic anemia or myelodysplastic syndrome, and 12 children with hemolytic anemia and transient aplastic crisis.

Transient myeloproliferation mimicking JMML associated with parvovirus infection of infancy

We report a 2-month-old infant with Parvovirus B19 infection presenting as transient myeloproliferation resembling juvenile myelomonocytic leukemia (JMML). Patient history, physical examination, and laboratory findings were suggestive of JMML. On viral serology, raised IgM and IgG titers for Parvovirus B19 infection were found in the absence of giant proerythroblasts and viral inclusions in the erythroid precursors. Follow-up showing a decrease in viral titers suggested parvovirus infection as an etiological factor for the development of myeloproliferative features. This case highlights the importance of viral serology in work-up myeloproliferative disorders of infancy and childhood.

Reversible bone marrow dysplasia in patients with systemic lupus erythematosus

OBJECTIVE

Several reports of bone marrow dysplasia in patients with systemic lupus erythematosus (SLE) have been published. However, the reports are restricted primarily to descriptions of the erythroid lineage; no follow-up studies have been reported, and the clinical significance of the dysplasias is unknown. Therefore, in the present study, the dysplasias noted in bone marrow aspirates obtained from SLE patients were characterized.

PATIENTS AND METHODS

The smears of bone marrow aspirates obtained from 17 SLE patients who had bone marrow aspiration due to cytopenia (WBC < 1,500/microl, or Hb < 10.5 g/dl, or platelet count < 10 x 10(4)/microl) were examined retrospectively. Of the 17 patients, 4 had a repeat bone marrow aspiration during follow-up. Clinical and laboratory data were obtained from the medical records.

RESULTS

Of the 17 SLE patients, 12 had dysplasias, including: erythroid cell multinuclearity (trinuclear or more) (5 patients), megaloblastoid changes (4), pseudo-Pelger abnormalities (6), annular nuclear myeloid cells (2), separated nuclear megakaryocytes (4), and micromegakaryocytes (5). In the 4 patients who had follow-up bone marrow aspiration, these dysplasias were correlated with disease activity; some abnormalities disappeared with remission of SLE. Diffuse proliferative glomerulonephritis (3 patients) and cerebral lupus/neuropsychiatric lupus (4 patients) were seen only in patients with dysplasia.

CONCLUSION

This study found that bone marrow dysplasia can be observed in all lineage cells of SLE patients, and that the dysplasia is reversible during the course of the disease. The presence of dysplasias appears to be associated with disease severity.

Comparison of two new classifications for pediatric myelodysplastic and myeloproliferative disorders

BACKGROUND

The category, cytology, cytogenetics (CCC) system for myelodysplastic syndrome (MDS) and the pediatric WHO system for MDS/myeloproliferative disorder (MPD) have recently been proposed to characterize these diseases in pediatrics.

OBJECTIVE

We compare the CCC and pediatric WHO systems against each other and against the French, American, British (FAB) and adult WHO classifications in order to determine which more accurately classifies these diseases and predicts outcome.

METHODS

An 18-year retrospective review identified patients less than 18 years of age meeting CCC and/or pediatric WHO criteria for the diagnosis of MDS or MPD. Resolution, stability, progression, and death in the subcategories of each system were compared.

RESULTS

Twenty-eight patients were included in the study. Pediatric WHO: 17 patients met criteria, 10 died. Eight developed acute myelogenous leukemia (AML) (seven died), one juvenile myelomonocytic leukemia (JMML) (died), one chronic myelomonocytic leukemia (CMML) (currently in relapse), two died of complications, two responded to BMT, three have stable disease, one resolved. Eleven patients were not classifiable by the pediatric WHO system, one of which progressed to AML and died. CCC: 26 patients met criteria, 9 died. Nine developed AML (8 died), 1 died of complications, 10 responded to treatment (BMT and/or chemotherapy). Four are stable without treatment, two resolved. Two patients with MPD were not classifiable by the CCC system.

CONCLUSIONS

Both the pediatric WHO and CCC systems are better able to classify MDS in children than the adult WHO and FAB classifications. The pediatric WHO system is more exclusive. Children meeting these criteria are more likely to progress to AML or death. The restrictive nature of the pediatric WHO system was unable to classify one case of fatal MDS. The CCC system is more inclusive and can stratify patients into a neutral or poor prognosis based upon outcome. However, the CCC system ignores those diseases with a myeloprolifferative component. This resulted in two cases of MPD that were unclassifiable by the CCC system. One of these patients died, the other is currently in relapse.

Acute parvovirus B19 infection mimicking congenital dyserythropoietic anemia

Infection with human parvovirus B19 is known to cause transient erythroid aplasia in children with hemolytic anemia but has also been associated with bone marrow necrosis and morphologic changes suggesting myelodysplasia. The authors describe a previously healthy child who presented with severe hypoplastic anemia. Initial bone marrow aspiration revealed erythroid hyperplasia, dyserythropoiesis, and multinucleated erythroid cells with nuclear budding and bridging, consistent with the diagnosis of congenital dyserythropoietic anemia. Serologic testing documented acute parvovirus infection, and on recovery the correct diagnosis of unsuspected congenital spherocytosis was established. This case expands the spectrum of hematologic disease associated with acute parvovirus infection.

Myelodysplastic features in visceral leishmaniasis

We have detected trilineage myelodysplasia in two children recently diagnosed to have visceral leishmaniasis (V.L.), which led us to investigate retrospectively available peripheral blood and bone marrow aspirate smears of 5 children previously diagnosed as V.L. We saw that they also had trilineage myelodysplasia. We postulate that elevated levels of tumor necrosis factor-alpha (TNFalpha) may cause trilineage myelodysplasia in the patients with V.L. This nonclonal myelodysplasia may be responsible for pancytopenia along with hypersplenism, hemolysis and reticuloendothelial hyperplasia causing abnormal retention of iron in V.L.