Serologic study on parvovirus b19 infection in childhood acute lymphoblastic leukemia during chemotherapy: clinical and hematologic implications

Parvoviral disease in childhood cancer: Clinical outcomes and impact on therapy at a tertiary cancer center in India

BACKGROUND AND AIM

Parvovirus-B19 disease in immunocompromised children can cause myelosuppression and therapeutic delays. We studied the clinical profiles of children having symptoms suggestive of parvoviral disease at our institution, a large tertiary cancer center.

METHODS

Children below age 15 years undergoing treatment for malignancies with clinical features suggestive of parvoviral infection, and/or unexplained drop in hemoglobin, and/or prolonged cytopenia were screened for parvovirus infection using DNA-PCR for parvovirus-B19 (PB19) in the peripheral blood. Patients testing positive from September 2014 till February 2017 were studied.

RESULTS

Of the 59 patients (36 patients with hematolymphoid malignancies, 23 with solid tumors) screened for suspected parvoviral infections, 27 tested positive. Median age was 9.6 years (2.25-15 years), 18 (66%) had hematolymphoid malignancies, while 7 (33%) had solid tumors. Six patients (26%) were on intensive phases, 16 (60%) patients developed the symptoms during maintenance chemotherapy, and 4 (15%) after completion of therapy. Isolated anemia was the commonest feature seen in 10 patients (37%) while bicytopenia and pancytopenia were noticed in 8 (30%) and 9 (33%) patients respectively. Fifty percent of patients those who received rituximab (3/6) developed persistent parvoviremia (>4 weeks) as compared with 24% (5/21) of those who did not. Two patients (7%) developed hemophagocytic lymphohistiocytosis (HLH). Treatment delay by more than 14 days was encountered in a majority (62%), with 5 patients requiring treatment modification or even suspension.

CONCLUSIONS

Parvoviral infection in children who are on or have recently completed chemotherapy can lead to multiple cytopenias and significant treatment delays. Rituximab exposure may lead to persistent parvoviral disease (p < 0.05). HLH, though occasional, can be a serious complication.

Induction Failure in Acute Leukemia or Parvovirus B19 Infection?

Parvovirus B19 infection may be seen in acute leukemia patients and clinical findings and cytopenia caused by the viral infection may complicate the evaluation of the remission status. Herein we present a standard risk pediatric acute lymphobiastic leukemia patient who developed myalgia, bone pain, bone marrow aplasia and sinusoidal obstruction syndrome at the end of the induction treatment and was diagnosed as having parvovirus B19 infection.

In utero cytomegalovirus infection and development of childhood acute lymphoblastic leukemia

It is widely suspected, yet controversial, that infection plays an etiologic role in the development of acute lymphoblastic leukemia (ALL), the most common childhood cancer and a disease with a confirmed prenatal origin in most cases. We investigated infections at diagnosis and then assessed the timing of infection at birth in children with ALL and age, gender, and ethnicity matched controls to identify potential causal initiating infections. Comprehensive untargeted virome and bacterial analyses of pretreatment bone marrow specimens (n = 127 ALL in comparison with 38 acute myeloid leukemia cases in a comparison group) revealed prevalent cytomegalovirus (CMV) infection at diagnosis in childhood ALL, demonstrating active viral transcription in leukemia blasts as well as intact virions in serum. Screening of newborn blood samples revealed a significantly higher prevalence of in utero CMV infection in ALL cases (n = 268) than healthy controls (n = 270) (odds ratio [OR], 3.71, confidence interval [CI], 1.56-7.92, P = .0016). Risk was more pronounced in Hispanics (OR=5.90, CI=1.89-25.96) than in non-Hispanic whites (OR=2.10 CI= 0.69-7.13). This is the first study to suggest that congenital CMV infection is a risk factor for childhood ALL and is more prominent in Hispanic children. Further investigation of CMV as an etiologic agent for ALL is warranted.

Study on clinical characteristics and follow-up visit of acquired aplastic anemia associated with parvovirus B19 infection

OBJECTIVE

To investigate clinical characteristics of parvovirus (B19) related aplastic anemia (AA).

METHODS

Of the 28 children with AA included in this study, 24 were treated routinely and received planned follow-up; 15 were subject to B19-DNA re-examination during the treatment and 8 underwent examination for B19-IgM and B19-IgG. Another 39 initially identified AA children were enrolled as the controls and received the treatment same as the above-mentioned group.

RESULTS

There were more patients aged 5-8 y in the B19 infection group than the control group (P < 0.05). The course of AA in the B19 infection group was less than 2 mo and the serious aplastic anemia (SAA) and very serious aplastic anemia (VSAA) were more frequently observed in this group than the controls (P < 0.05). The overall efficacy of the treatments in the B19 infection group was more dismal than that in the controls (P < 0.05). Among 15 patients who were subjected to B19-DNA re-examination, negative findings were found in 6 patients with chronic aplastic anemia (CAA); the B19-DNA was persistently positive in 2 of the SAA and 5 VSAA patients. IgM and IgG were respectively detected in 3 and 2 patients out of the 8 children who received antibody examination.

CONCLUSIONS

Parvovirus B19 infection contributes to the generation of AA, particularly in children aged 5-8 y. The AA induced may be mainly classified as serious and very serious type, with a course of disease less than 2 mo. Patients can be saved if B19-DNA is eliminated and the antibody is produced.

Parvovirus B19-associated hemophagocytic lymphohistiocytosis in a child with precursor B-cell acute lymphoblastic leukemia under maintenance chemotherapy

Development of hemophagocytic lymphohistiocytosis (HLH) is quite rare among acute lymphoblastic leukemia (ALL) patients. We present a 3-year-old boy with precursor B-cell ALL, who was complicated by HLH because of parvovirus B19 infection during maintenance chemotherapy. Remarkable erythroid hypoplasia, giant normoblasts, and hemophagocytosed macrophages in bone marrow were important clues for the diagnosis. The patient was successfully treated with high-dose steroids and intravenous immunoglobulins. To our knowledge, this is the first report describing parvovirus B19-associated HLH in ALL. Our case highlights that parvovirus B19 can cause HLH, a potentially fatal disorder, and prolonged unexpected cytopenia in childhood ALL.

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.

Parvovirus B19 infection in pediatric oncology patients: diagnostic value of clinical and serologic parameters compared with nested PCR

BACKGROUND

Oncology patients are at particular risk for parvovirus B19 infection, which may cause severe, persistent, usually nonspecific illness in this group.

AIM

This study was designed to assess the prevalence and impact of parvovirus B19 in pediatric oncology patients receiving chemotherapy, and to define the optimal diagnostic tests in such patients.

SUBJECTS AND METHODS

Fifty-nine children under chemotherapy (39 with acute lymphocytic leukemia and 20 with solid tumors) with mean age of 4.96+/-1.94 years, in addition to 30 healthy children of matched age and sex, were enrolled in this study. Clinical and laboratory data were collected by examination and from patients' records. Specific parvovirus B19 immunoglobulin (Ig) M and IgG antibodies were assessed by enzyme-linked immunosorbent assay, and parvovirus DNA was detected by nested polymerase chain reaction (PCR) for all patients and controls.

RESULTS

Parvovirus DNA was detected in 16 (27.1%), IgM in 3 (5.1%), and IgG in 36 (61%) patients. IgM had sensitivity, specificity, and accuracy of 18.75%, 100%, and 77.9%, respectively, whereas those of IgG were 81.25%, 53.4%, and 61%, respectively. PCR-positive patients had significantly higher frequency of unexplained anemia, red blood cell transfusions, and longer hospital stay than PCR-negative patients (P<0.001). Multiple linear regression analysis showed that unexplained anemia and multiple red blood cell transfusions were the most important variables that can predict PCR positivity.

CONCLUSIONS

Parvovirus B19 is not an uncommon problem in pediatric oncology patients who exhibited weak antibody response and nonspecific clinical features. Screening of these patients with PCR rather than serology is recommended when infection is suspected.

Tracking of peptide-specific CD4+ T-cell responses after an acute resolving viral infection: a study of parvovirus B19

The evolution of peptide-specific CD4(+) T-cell responses to acute viral infections of humans is poorly understood. We analyzed the response to parvovirus B19 (B19), a ubiquitous and clinically significant pathogen with a compact and conserved genome. The magnitude and breadth of the CD4(+) T-cell response to the two B19 capsid proteins were investigated using a set of overlapping peptides and gamma interferon-specific enzyme-linked immunospot assays of peripheral blood mononuclear cells (PBMCs) from a cohort of acutely infected individuals who presented with acute arthropathy. These were compared to those for a cohort of B19-specific immunoglobulin M-negative (IgM(-)), IgG(+) remotely infected individuals. Both cohorts of individuals were found to make broad CD4(+) responses. However, while the responses following acute infection were detectable ex vivo, responses in remotely infected individuals were only detected after culture. One epitope (LASEESAFYVLEHSSFQLLG) was consistently targeted by both acutely (10/12) and remotely (6/7) infected individuals. This epitope was DRB1*1501 restricted, and a major histocompatibility complex peptide tetramer stained PBMCs from acutely infected individuals in the range of 0.003 to 0.042% of CD4(+) T cells. Tetramer-positive populations were initially CD62L(lo); unlike the case for B19-specific CD8(+) T-cell responses, however, CD62L was reexpressed at later times, as responses remained stable or declined slowly. This first identification of B19 CD4(+) T-cell epitopes, including a key immunodominant peptide, provides the tools to investigate the breadth, frequency, and functions of cellular responses to this virus in a range of specific clinical settings and gives an important reference point for analysis of peptide-specific CD4(+) T cells during acute and persistent virus infections of humans.

Establishment of functional B cell memory against parvovirus B19 capsid proteins may be associated with resolution of persistent infection

Parvovirus B19 (B19) infection can occur during acute lymphoblastic leukemia and persistent viral infection can occur despite intravenous immunoglobulin administration. Here, evidence is presented that resolution of persistent B19 infection in an acute lymphoblastic leukemia patient may be associated with the simultaneous strengthening of antigen-specific B cell memory against the B19 capsid protein VP2 and diminution in the memory response against the B19 non-structural protein 1 (NS1). Determination of antigen-specific B cell memory status may enhance the serological and molecular analyses of persistent B19 infection.

Persistent human parvovirus B19 infection in children under maintenance chemotherapy for acute lymphocytic leukemia

OBJECTIVE

To report on B19 infection management and chemotherapy schedule consequences in five children treated for acute lymphocytic leukemia (ALL).

PATIENTS AND METHODS

Between May 2001 and February 2002, five patients between 4 and 12 years of age, receiving maintenance chemotherapy for ALL, presented with symptoms suggesting B19 infection (pallor, fatigue, petechiae and pancytopenia in four patients; generalized rash in two patients; acute hepatitis in one patient). Qualitative polymerase chain reaction (PCR) on peripheral blood was used for diagnosis and follow-up of infection; quantitative PCR was used for viral load measurement. Intravenous nonspecific high-dose immunoglobulin therapy was administered until PCR was negative.

RESULTS

Qualitative B19 DNA was found in the peripheral blood of all patients, confirming the infection. Viral load at diagnosis ranged from 10 to 10 particles/mL blood. B19 DNA was detectable in four patients at 45, 21, 40, and 44 weeks, respectively. Chemotherapy was delayed in all patients. No clear benefit of intravenous immunoglobulin was noted.

CONCLUSIONS

Infection with B19 is rarely reported in patients with ALL, but it should be suspected when unexplained pancytopenia occurs during chemotherapy. Persistent B19 infection remains a challenge in the management of patients receiving maintenance chemotherapy for ALL, as no specific therapy such as a specific immunoglobulin or vaccine exists. The role of viral load measurement needs to be established in terms of its use in follow-up and evaluation of the therapeutic response.

Parvovirus B19 infection as a cause of anemia in pediatric acute lymphoblastic leukemia patients during maintenance chemotherapy

PURPOSE

Persistent parvovirus B19 tends to occur in immunocom-promised patients and manifests as pure red cell aplasia and chronic anemia. This study aimed to detect the contribution of parvovirus B19 infection to anemia in children with acute lymphoblastic leukemia (ALL) receiving chemotherapy.

PATIENTS AND METHODS

Two groups of ALL patients were studied during maintenance chemotherapy: 50 patients with persistent anemia (ie, extending for >2 weeks) and 34 patients without anemia (controls). Serum parvovirus B19 IgG and IgM were investigated by an enzyme-linked immunosorbent assay, and the virus DNA was sought in bone marrow cells by a nested polymerase chain reaction assay.

RESULTS

Parvovirus B19 DNA was detected in 11 of the 50 (22%) ALL children with anemia, 4 of whom were also IgM positive. In addition, IgM positivity was observed in nine (18%) other children who were negative for parvovirus B19 DNA. The children without anemia were found to be significantly different than those with anemia in terms of parvovirus B19 DNA positivity and DNA + IgM positivity (P = 0.03 and 0.01, respectively). IgG was found to be positive in a total of 19 (38%) cases, with B19 DNA present in 6 of them.

CONCLUSIONS

These findings indicate the high frequency of parvovirus B19 in anemia in children with ALL and the importance of testing for its DNA in the bone marrow cells together with IgG and IgM antibodies in the serum of immunocompromised patients. It is important to consider parvovirus B19 infections as a cause of anemia and suppressed erythropoiesis in children with ALL who are receiving ongoing treatment.

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.