Acute respiratory distress syndrome in a child with human parvovirus B19 infection

A 6-year-old girl developed shock and multiple organ dysfunction including acute respiratory distress syndrome in association with parvovirus B19 infection. The diagnosis was based on positive antibodies and the detection of parvovirus 19 DNA in serum, bronchial secretions and skin biopsy. It seems likely, but it was not proved, that the parvovirus infection caused acute respiratory distress syndrome.

Clinical heterogeneity of human parvovirus B19 infection following adult liver transplantation

Severe aplastic anemia and its secondary comorbidities associated with human parvovirus B19 infection is a rare and sometimes refractory complication following liver transplantation.We retrospectively reviewed data for 217 adult liver transplant recipients from donations after death in China March 2013 through May 2017, 5 patients with human parvovirus B19 infectious diseases were teased out, and diagnoses were made from positive serological marker, bone marrow aspiration, and genome assay, other hemolytic causes were excluded. Severe aplastic anemia and its comorbidities were confirmed, combination of immunoglobulin and blood transfusion as well as immunosuppressant switch was employed for 5 recipients.Four male and 1 female recipients were diagnosed with human parvovirus B19 infections based on clinical presentations, bone marrow aspiration, and nested PCR, age ranged from 47 to 62 years, the onset time from liver transplantation varied from 29 to 415 days, anemia improved in 5 patients, 2 deaths occurred due to parvovirus-related morbidities, 1 patient died from de novo carcinoma of the tongue 2 years later and unrelated to parvovirus, 2 other recipients are still alive.Human parvovirus B19 infectious disease is a rare but clinically significant infection whose comorbidities will bring about more attentions.

The N-terminal 5-68 amino acids domain of the minor capsid protein VP1 of human parvovirus B19 enters human erythroid progenitors and inhibits B19 infection

Parvovirus B19 (B19V) infection causes diseases in humans ranging from the mild erythema infectiosum to severe hematological disorders. The unique region of the minor structural protein VP1 (VP1u) of 227 amino acids harbors strong neutralizing epitopes which elicit dominant immune responses in patients. Recent studies have shown that the VP1u selectively binds to and enters B19V permissive cells through an unknown cellular proteinaceous receptor. In the present study, we demonstrated that purified recombinant VP1u effectively inhibits B19V infection of ex vivo expanded primary human erythroid progenitors. Furthermore, we identified the amino acid sequence 5-68 of the VP1 (VP1u^5-68aa) is sufficient to confer the inhibition of B19V infection at a level similar to that of the full-length VP1u. In silico structure prediction suggests that the VP1u^5-68aa contains three α-helices. Importantly, we found that the inhibition capability of the minimal domain VP1u^5-68aa is independent of its dimerization but is likely dependent on the structure of the three predicated α-helices. As VP1u^5-68aa outcompetes the full-length VP1u in entering cells, we believe that VP1u^5-68aa functions as a receptor-binding ligand during virus entry. Finally, we determined the effective inhibition potency of VP1u^5-68aa in B19V infection of human erythroid progenitors, which has a half maximal effective concentration (EC₅₀) of 67 nM, suggesting an anti-viral peptide candidate to combat B19V infection.IMPORTANCEHuman parvovirus B19 infection causes severe hematological disorders, including transient aplastic crisis, pure red cell aplasia, and hydrops fetalis. A productive B19 infection is highly restricted to human erythroid progenitors in human bone marrow and fetal liver. In the current study, we identified that the N-terminal 5-68 amino acids domain of the minor viral capsid protein VP1 enters ex vivo expanded human erythroid progenitors, which is nearly 5 times more efficient than the full-length VP1 unique region (1-227aa). Importantly, purified recombinant 5-68aa of the VP1 has a high efficiency in inhibition of parvovirus B19 infection of human erythroid progenitors, which has a half maximal effective concentration (EC₅₀) of 67 nM and a low cytotoxicity. The N-terminal 5-68 amino acids holds the potential as an effective antiviral of parvovirus B19 caused hematological disorders, as well as a carrier to deliver proteins to human erythroid progenitors.

Overall prevalence of human parvovirus B19 among blood donors in mainland China: A PRISMA-compliant meta-analysis

BACKGROUND

Human parvovirus B19 (B19V) infection exhibits a broad range of clinical outcomes. Blood transfusion is a common route of B19V transmission. However, information about the overall prevalence of B19V infection and B19V genotypes among blood donors in mainland China is lacking.

METHODS

This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search for studies reporting the B19V prevalence among blood donors in mainland China from 2000 to 2018 was performed. The prevalence of B19V was estimated through a meta-analysis of the relevant literature. A comprehensive meta-analysis program was used for data processing and statistical analysis.

RESULTS

Twenty-one eligible articles were included, involving 48,923 participants assessed for B19V-DNA, 12,948 participants assessed for anti-B19V immunoglobulin M (IgM), and 8244 participants assessed for anti-B19V immunoglobulin G (IgG). The analysis revealed the pooled estimates of the prevalence rates of B19V-DNA, anti-B19V IgM, and anti-B19V IgG among blood donors to be 0.7% (95% confidence interval [CI] 0.2-2.4%), 2.7% (95% CI 1.7-4.3%), and 33.6% (95% CI 28.2-39.4%), respectively. Moreover, phylogenetic analyses indicated that 142 of 169 (84.0%) B19V isolates belonged to Genotype 1.

CONCLUSIONS

The overall prevalence of B19V among blood donors is not high in mainland China, and most isolates belong to Genotype 1.

GABAA receptor encephalitis associated with human parvovirus B19 virus infection: Case report

RATIONALE

Human parvovirus B19 (B19) infection can produce a spectrum of clinical syndromes, including neurological manifestations, most notably encephalitis. Although symptoms suggestive of autoimmune disease in patients with B19 infection have been previously described, a clear association of autoimmune encephalitis with B19 infection has yet to be established.

PATIENT CONCERNS

We describe the case of a 6-year-old boy who was hospitalized due to status epilepticus, which evolved to super-refractory status epilepticus that was only mildly responsive to anticonvulsant drugs.

DIAGNOSIS

A cerebrospinal fluid study identified slight pleocytosis and B19 positivity. A subsequent autoimmunity cerebrospinal fluid study revealed the presence of anti-γ-aminobutyric acid type A (GABAA) receptor antibodies.

INTERVENTIONS

After pulse therapy with methylprednisolone and continuous therapy with prednisolone with cyclosporine, the patient experiencing seizure persistence with disordered motor function manifestations and only minor improvement in consciousness, and so, plasmapheresis was performed. With continued immunosuppressive treatments with cyclosporine and prednisolone, the patient's clinical picture showed progressive improvement, with good control of seizures. Although the patient tolerated withdrawal of the anticonvulsant drugs well, he developed seizures when corticosteroid therapy withdrawal was attempted, so was started on azathioprine.

OUTCOMES

After immunosuppressive therapy, the patient evolved with complete remission of symptoms, normal neurological examination and age-appropriate neuropsychomotor development.

LESSONS

The present case characteristics, together with previous findings, support the hypothesis that autoimmunity may be triggered by extensive antigen release due to degeneration of infected neurons. This case highlights the importance of early clinical suspicion and treatment.

[Seroprevalence and infection by human parvovirus B19 in pregnant women from Córdoba, Argentina, 2021-2022]

Introduction

parvovirus B19 (B19V) infection during pregnancy can be transmitted to the fetus and cause serious complications such as fetal hydrops and stillbirth. The preexistence of specific IgG prevents vertical transmission. Seroprevalence in fertile age is variable (50-70%) and depends on the region/viral circulation, in addition to factors such as maternal age and frequent exposure to children.

Objectives

to determine seroprevalence for B19V in pregnant women at Hospital Universitario de Maternidad y Neonatología (HUMN), analyze its association with predictive factors and describe cases of B19V infection.

Methods

observational, cross-sectional study. Patients treated at HUMN during 2021-2022 were included and compatible demographic and clinical data were recorded. Specific IgG was quantified and its association with predictive factors was analyzed by bivariate analysis (p<0.05). In cases with signs/symptoms associated with B19V, specific IgM and viral DNA were also determined. Results: 317 cases were studied and anti-B19V IgG was detected in 214/317 (67.5%). No association was found between seroprevalence and maternal age, multiparity, cohabitation with children under 15 years of age, or presence of maternal/fetal signs/symptoms. Ten cases (10.4%) of B19V infection were identified, all of them with anemia and one with fetal hydrops and VDRL+.

Conclusion

in the population studied, B19V seroprevalence for was 67.5% and independent of the predictive factors, leaving 32.5% without evidence of exposure to the virus (susceptible to contracting the infection in the future). The detection of infection in symptomatic cases indicates the importance of investigating B19V in this group.