A cluster of parvovirus B19 infections in renal transplant recipients: a prospective case series and review of the literature

Determinants of Time-to-Death of Chronic Lymphocytic Leukemia Patients at Felege Hiwot Referral Hospital, Bahir Dar, Ethiopia

Background

Leukemia is a group of cancers that usually begin in the bone marrow and results in a large number of abnormal white blood cells. Chronic Lymphocytic Leukemia is the most prevalent leukemia in Western countries, with an estimated incidence rate of less than 1 to 5.5 per 100 000 people, and average age at diagnosis of 64 to 72 years. It is more common in men among Chronic Lymphocytic Leukemia patients in Ethiopia's hospitals at Felege Hiwot Referal Hospital.

Methods

A retrospective cohort research design was employed to acquire critical information from patients' medical records in order to achieve the study's purpose. The study comprised the medical records of 312 Chronic Lymphocytic Leukemia who were followed from January 1, 2018 to December 31, 2020. A Cox proportional hazard model was used to determine the risk factors for time to death in Chronic Lymphocytic Leukemia patients.

Results

Accordingly the Cox proportional hazard model, age (Hazard Ratio = 11.36; P < .001), sex of male (Hazard Ratio = 1.04; P = .004), married status (Hazard Ratio = 0.03; P = .003), medium stages of Chronic Lymphocytic Leukemia (Hazard Ratio = 1.29; P = .024), high stages of Chronic Lymphocytic Leukemia (Hazard Ratio = 1.99; P < .001), presence of anemia (Hazard Ratio =0.09; P = .005), platelets (Hazard Ratio = 2.11; P = .007), hemoglobin (Hazard Ratio = 0.02; P < .001), lymphocytes (Hazard Ratio = 0.29; P = .006), red blood cell (Hazard Ratio = 0.02; P < .001), which patients with Chronic Lymphocytic Leukemia had a significant relationship with time to death.

Conclusions

Age, sex, Chronic Lymphocytic Leukemia stage, anemia, platelets, hemoglobin, lymphocytes, and red blood cells were all statistically significant determinants in the time to death of Chronic Lymphocytic Leukemia patients, according to the data. As a result, healthcare providers should pay particular attention to and emphasize the identified characteristics, as well as provide frequent counseling on how to enhance the health of Chronic Lymphocytic Leukemia patients.

A Systematic Review and Meta-Analysis of Posttransplant Anemia With Overall Mortality and Cardiovascular Outcomes Among Kidney Transplant Recipients

Introduction: Posttransplant anemia is a common finding after kidney transplantation. A previous meta-analysis reported an association between anemia and graft loss. However, data on cardiovascular outcomes have not yet been reported. Objective: We conducted an updated meta-analysis to examine the association between posttransplant anemia and outcomes after transplantation including cardiovascular mortality in adult kidney transplant recipients. Methods: We comprehensively searched the databases of MEDLINE and EMBASE from inception to November 2021. Data from each study were combined using the random-effects model. Generic inverse variance method of DerSimonian and Laird was employed to calculate the risk ratios and 95% CIs. Results: Seventeen studies from August 2006 to April 2019 were included (16 463 kidney transplantation recipients). Posttransplant anemia was associated with overall mortality (pooled risk ratio = 1.72 [1.39, 2.13], I² = 56%), graft loss (pooled risk ratio = 2.28 [1.77, 2.93], I² = 94%), cardiovascular death (pooled risk ratio = 2.06 [1.35, 3.16], I² = 0%), and cardiovascular events (pooled risk ratio = 1.33 [1.10, 1.61], I² = 0%). Early anemia (≤6 months), compared with late anemia (>6 months), has higher risk of overall mortality and graft loss with a pooled risk ratio of 2.63 (95% CI 1.79-3.86; I² = 0%) and 2.96 (95% CI 2.29-3.82; I² = 0%), respectively. Discussion: In addition to increased risk of graft loss, our updated meta-analysis demonstrated that posttransplant anemia was significantly associated with poor outcomes after kidney transplantation including overall mortality, graft loss, cardiovascular death, and cardiovascular events. Future studies are required to assess the effects of treatment strategies for posttransplant anemia on posttransplant outcomes including cardiovascular mortality.

The current therapeutic approach for anaemia after kidney transplant

PURPOSE OF REVIEW

Anaemia after kidney transplantation is a common finding with no uniform management guideline. Most approaches are derived from the chronic kidney disease (CKD) population. Recent advances for the treatment of anaemia in patients with CKD/End stage renal disease include hypoxia-inducible factor-prolyl hydroxylase inhibitor (HIF-PHi), a novel class of oral erythropoietin-stimulating agents (ESAs). We present relevant studies of HIF-PHi in the transplant population and its implications on the management of posttransplant anaemia.

RECENT FINDINGS

Data on HIF-PHi use in the kidney transplant population are promising. Limited data demonstrate a significant increase in haemoglobin, with a comparable safety profile to epoetin. Reported adverse effects include overcorrection and low iron stores.

SUMMARY

Current therapeutic approaches to anaemia in the kidney transplant population is mostly derived from the CKD population. More studies are needed on HIF-Phi, a novel class of ESAs that has thus far demonstrated promise in the kidney transplant population.

Parvovirus B19 status in liver, kidney and pancreas transplant candidates: A single center experience

BACKGROUND

Parvovirus B19 (B19V) is associated with a wide range of clinical manifestations. The major presentation is erythema infectiosum. However, a persistent infection may cause pure red cell aplasia and chronic anemia in immunocompromized patients. The B19V seroprevalence varies with age and geographical location.

AIM

To determine the B19V serological status and DNAemia in kidney, liver, and pancreas transplant candidates.

METHODS

Patients who underwent kidney, liver, or simultaneous kidney and pancreas/liver transplantation between January 2021 and May 2022 were included in the study. The serum samples were collected before transplantation. For detection of B19V DNA, a LightMix Kit B19V EC (TIB MOLBIOL, Berlin, Germany) was used. B19V IgM and IgG antibodies were detected using a commercial ELISA test (Euroimmun, Lübeck, Germany).

RESULTS

One hundred and thirty-one transplant candidates were included in the study, 71.0% male, with an average age of 53.27 years ± 12.71 years. There were 68.7% liver, 27.5% kidney, 3.0% simultaneous pancreas/kidney transplant (SPKT), and 0.8% simultaneous liver/kidney transplant recipients. No patients had detectable B19V DNA. B19V IgG seroprevalence was 77.1%. No acute or recent infections were detected (IgM antibodies). There was no difference in the mean age of seronegative and seropositive patients (51.8 years ± 12.9 years vs 53.7 years ± 12.7 years, t = -0.603; P = 0.548). Although seropositivity was lower in patients aged less than 30 years (66.6%) compared to the patients aged 30-59 years and > 60 years (80.4% and 78.1%, respectively), this difference was not significant. In addition, there was no difference in seropositivity between male and female transplant candidates, 76.3% and 78.9% (χ² = 0.104; P = 0.748). The seroprevalence did not differ among organ recipients, with 77.8%, 80.6%, and 50.0% for liver, kidney, and SPKT, respectively, (χ² = 5.297; P = 0.151). No significant difference was found in the seroprevalence in kidney transplant patients according to dialysis modality. Seroprevalence was 71.1% in hemodialysis patients, and 100% in peritoneal dialysis patients (χ² = 0.799; P = 0.372).

CONCLUSION

The B19V seroprevalence is expectedly high among kidney, liver, and pancreas transplant candidates, but there are still 22.9% of seronegative individuals who remain at risk for primary disease and severe manifestations. Further research should elucidate the necessity of B19V screening in peri-transplant management.

Clinical utility of immune function based on IFN-γ monitoring of lymphocyte subsets for parvovirus B19 infection in renal recipients

BACKGROUND

There should be a heightened index of suspicion for Parvovirus B19 (PVB19)-related anemia in organ transplant recipients. Thus far, there is no consensus or recommendation for clinical routine monitoring methods of PVB19 recipients to allow tailoring of immunosuppression.

METHODS

We conducted a retrospective study to evaluate the utility of the function (represented by the abilities to secrete IFN-γ) and numbers of lymphocyte subsets in monitoring PVB19 infections in renal recipients posttransplant. The enrolled 109 patients were split into 2 groups according to whether the recipients had an occurrence of PVB19 infection: 37 (33.94%) recipients developed PVB19 infection and 72 (66.06%) immune-stable recipients.

RESULTS

The PVB19 infected group had significantly lower absolute counts and functions of different lymphocyte subsets compared with immune-stable recipients. We showed that the frequencies of IFN-γ + CD4 + T cells, IFN-γ + CD8 + T cells, and IFN-γ + NK cells increased markedly after treatment when compared to the occurrence in patients with timepoint before therapy, especially the percentages of IFN-γ + CD4 + T cells were significantly higher. Receiver operating characteristic (ROC) analysis showed that the optimal infection indicator was IFN-γ + NK cells frequency, with an auROC curve of 0.925. Concomitantly, Cox regression analysis indicated that the post-therapy increasing level of IFN-γ secreting function was significantly predictive of recurrent infections (P < 0.001).

CONCLUSIONS

We recommend prospective risk stratification for the high-risk population at risk of early-onset PVB19 infection and its recurrence involves screening strategies of immune-based surveillance with the sensitive IFN-γ + secreting monitoring for antiviral prophylaxis and preemptive therapy goal. Clinical Trial Notation: clinical trial registration number: chiCTR-ROC-17010756.

Parvovirus B19 infection in kidney transplant recipients: A prospective study in a teaching hospital in Shanghai, China

BACKGROUND

There is a lack of epidemiological studies on the course and clinical characteristics of Parvovirus B19 (B19V) infections in kidney transplant (KT) recipients. This study was undertaken to provide recommendations for clinical B19V infection diagnosis and treatment.

METHODS

Serum samples of KT recipients were regularly collected and tested for B19V-DNA copies, B19V-IgG/IgM levels, as well as hematological parameters and functions of kidney and liver. The course of B19V infection was described according to the results of serology and DNA testing, and the clinical and epidemiological data were combined for analysis.

RESULTS

75% B19V infections occurred within 2 weeks after KT(n = 9). The infection rate of B19V in KT recipients was high, namely 10.17% (n = 12). The number of 10 patients IgM antibodies against B19V (IgM+) and theDNA B19V (DNA+), whereas 2 patients were IgM negative (IgM-) but DNA+. The B19V infected KT patients showed several symptoms, including anemia (100%), reduction of platelets (8.33%), and damage to liver (75%) and kidney function (16.67%) Patients with progressive anemia in the first two weeks after KT, which combined with the decrease of reticulocytes, are more likely to have B19V infection. Associations of four main therapeutic risk factors for B19V infections in KT patients have been analyzed. B19V infection was associated with use of basiliximab (OR = 1.19; 95%- CI: 1.08-1.32; P = 0.003) and use of thymoglobulins (OR = 0.84; 95%-CI: 0.76-0.93; P = 0.003).

CONCLUSIONS

Doctors should be alert to B19V infection, especially in the immunodeficient patients within the first two weeks after transplantation.

Metagenomic Next-Generation Sequencing Reveals the Profile of Viral Infections in Kidney Transplant Recipients During the COVID-19 Pandemic

Background

To study the clinical application of metagenomic next-generation sequencing (mNGS) in the detection of viral infections in kidney transplant recipients (KTRs) during the COVID-19 pandemic.

Methods

Using mNGS technology, 50 human fluid samples of KTRs were detected, including 20 bronchoalveolar lavage fluid (BALF) samples, 21 urine samples and 9 blood samples. The detected nucleic acid sequences were compared and analyzed with the existing viral nucleic acid sequences in the database, and the virus infection spectrum of KTRs was drawn.

Results

The viral nucleic acids of 15 types of viruses were detected in 96.00% (48/50) of the samples, of which 11 types of viruses were in BALF (95.00%, 19/20), and the dominant viruses were torque teno virus (TTV) (65.00%; 13/20), cytomegalovirus (CMV) (45.00%; 9/20) and human alphaherpesvirus 1 (25.00%; 5/20). 12 viruses (95.24%, 20/21) were detected in the urine, and the dominant viruses were TTV (52.38%; 11/21), JC polyomavirus (52.38%; 11/21), BK polyomavirus (42.86%; 9/21), CMV (33.33%; 7/21) and human betaherpesvirus 6B (28.57%; 6/21). 7 viruses were detected in the blood (100.00%, 9/9), and the dominant virus was TTV (100.00%; 9/9). Four rare viruses were detected in BALF and urine, including WU polyomavirus, primate bocaparvovirus 1, simian virus 12, and volepox virus. Further analysis showed that TTV infection with high reads indicated a higher risk of acute rejection (P < 0.05).

Conclusions

mNGS detection reveals the rich virus spectrum of infected KTRs, and improves the detection rate of rare viruses. TTV may be a new biomarker for predicting rejection.

Multisystem Involvement Induced by Human Parvovirus B19 Infection in a Non-immunosuppressed Adult: A Case Report

Background

Human parvovirus B19 (B19V) infection is usually symptomless and occurs in the childhood. While in immunocompromised adults, B19V infection also presents various clinical symptoms due to the host's immune status. The classic symptoms include erythema, anemia, arthropathy, and edema, but neurological involvement is rare.

Case Presentation

In this report, we present a case of B19V infection caused multiple organ dysfunction in a non-immunosuppressed adult. Metagenomic next-generation sequencing (mNGS) was used and successfully detected the pathogen in multiple types of samples, including blood, cerebrospinal fluid (CSF), and bronchoalveolar lavage fluid (BALF). The diagnosis was subsequently confirmed by polymerase chain reaction (PCR). He was treated with intravenous gamma globulin, resulting in a significant resolution of symptoms after 1 month.

Conclusion

Multisystem involvement induced by B19V infection was found in this case report. mNGS performed great advantages in rapidly and accurately diagnosing B19V infection in multiple types of samples, which helps the timely adjustment of treatment and improves the prognosis.

Environmental Monitoring of Parvovirus B19 in the Kidney Transplantation Ward of a Chinese Teaching Hospital

Purpose

Parvovirus B19 (B19V) infection is a viral threat after kidney transplantation. It is mainly transmitted by close-contact inhalation of aerosolized viral particles. The risk of nosocomial spread of B19V in the transplantation ward is quite high. This study aimed to evaluate the quality of routine disinfection and the effectiveness of isolation measures in the wards of B19V-infected kidney transplant recipients.

Patients and Methods

Throat swab samples of 19 kidney transplant recipients admitted to the isolation ward and three healthcare workers (HCWs) were collected for viral DNA detection. Routine disinfection procedures were performed twice a day in general and B19V isolation wards. Environmental surface and air samples were collected for viral DNA detection before and after disinfection.

Results

A total of four patients were diagnosed with B19V infection and transferred to the B19V isolation ward, of which only two had positive throat swab samples. The other 15 patients and all HCWs tested negative for B19V. A total of 88 environmental surface and air samples were collected. Eight of the environmental samples collected in the B19V isolation ward before disinfection tested positive for B19V, while one sample tested positive after disinfection. In the general wards, all environmental samples collected before disinfection tested negative for B19V. All 24 samples collected from ambient air, whether in B19V isolation or general wards, before or after disinfection, tested negative for B19V.

Conclusion

Existing methods of routine or terminal disinfection for air and object surfaces were effective in eliminating B19V from object surfaces and ambient air in the isolation and general wards. Material surfaces that are exposed to high frequency and easily contaminated by blood, body fluids, and indoor air were the focus of cleaning and disinfection. Nosocomial cross-infection of other immunocompromised patients and HCWs can be avoided if appropriate prevention and control measures are taken.

The detection, treatment of parvovirus B19 infection induced anemia in solid organ transplants: a case series and literature review of 194 patients

BACKGROUND

There are no optimal diagnostic, treatment and post-infection surveillance strategies for parvovirus B19 infection in solid organ transplantation (SOT) recipients.

METHODS

We conducted a retrospective review of all PVB19 infected cases confirmed by qPCR among SOT recipients at our institution over a 3-year period and reviewed the literature from 1990 to 2021.

RESULTS

Eight kidney and two heart transplant patients with refractory anemia had PVB19 infection. The viral DNA load in peripheral blood ranged from 2.62 × 10² to 8.31 × 10⁶ copies/mL. Two patients with the lowest PVB19 DNA load only reduced the use of immunosuppressants and anemia was relieved. Eight received intravenous immunoglobulin (IVIG) (ranging from 0.25 to 0.5 g/kg/day). The median time to anemia improvement (hemoglobulin>100g/L) was 16 days (8-70 days) after treatment. One patient had a PVB19 relapse and viral DNA load > 1.00 × 10⁸ copies/mL at diagnosis. A total of 86 studies involving 194 SOTs were screened from the literature, and the most common symptom was anemia and low reticulocyte count. PVB19 DNA was detected in all cases. Of that, 91.4% of cases received IVIG, 53.8% received IVIG and immunosuppression reduction, 6.5% of cases showed reduced immunosuppression without IVIG, and 2.1% did not receive any special treatment. The recurrence rate was 17.5%.

CONCLUSION

PVB19 infection is a cause of anemia after SOT, and treatment mainly relies on IVIG and/or immunosuppression reduction.

Parvovirus B19 Infection due to over Immunosuppression in Kidney Transplant Recipients: Case Reports and Literature Review

Parvovirus B19 (PB19) is a single-stranded DNA virus that belongs to the Erythrovirus genus within the Parvoviridae family. Clinical presentations associated with PB19 infection vary greatly, depending on the infected individual's age and hematologic and immunologic status. The limited data available regarding consensus on screening algorithms and indications in donors and recipients prior to kidney transplantation makes diagnosis and management challenging. We presented 3 cases of pure red cell aplasia due to parvovirus B19 after kidney transplant. These patients were diagnosed with severe normocytic, normochromic anemia (hemoglobin below 60 g/L) in the 1^st 6 months posttransplant. A complete anemia work-up revealed low reticulocyte count and was otherwise inconclusive. All patients were diagnosed with pure red cell aplasia due to parvovirus B19. Two patients improved after receiving intravenous immunoglobulin 2 gm/kg given over 4 doses. Unfortunately, they relapse after few weeks and required additional doses of intravenous immunoglobulin in conjugation with reduction of their immunosuppressive medication. The third patient improved after holding mycophenolate mofetil (MMF) and did not require intravenous immunoglobulin. Whereas PB19 infection is typically self-limiting and associated with positive IgM serology in immunocompetent hosts, these cases highlight the importance of considering PB19 infection in the differential diagnosis of persistent anemia in immunocompromised patients and the challenges in confirming the diagnosis. Intravenous immunoglobulin (IVIG) can be an effective treatment in immunocompromised patients with primary or relapsed PB19 infection in conjunction with minimizing immunosuppressive medication. Further research and consideration are required to determine appropriate and targeted screening in donors and recipients in the peritransplantation period.

Donor-Derived Human Parvovirus B19 Infection in Kidney Transplantation

Background

Donor-derived human parvovirus B19 (B19V) infections are rarely reported. Thus, its incidence in kidney transplantation is still unknown due to lack of surveillance studies. Similarly, whether the donor needs to be routinely screened for B19V and whether the kidneys from those with B19V DNAemia could be accepted also remain unknown.

Methods

This retrospective study aims to evaluate the donor-derived B19V infections occurring in 823 living and 1,225 deceased donor kidney transplantations from January 2016 to December 2020. The serum viral load of living donors and their corresponding recipients was evaluated before and after transplantation. Meanwhile, for the deceased donor kidney transplantation, the serum viral load of recipients was only tested after transplantation; if recipients of a deceased donor subsequently developed B19V infection, the serum viral load of recipients and their corresponding donors before transplantation would then be further traced.

Results

A total of 15 living donors were B19V DNAemia positive before the donation, of which B19V DNAemia occurred in three corresponding recipients. In deceased donor kidney transplantation, DNAemia occurred simultaneously in 18 recipients and their corresponding nine donors. A progressive decline in hemoglobin and reticulocyte count could be observed in one living donor recipient and other 11 deceased donor recipients, which were all well controlled by treatment eventually.

Conclusion

The incidence of donor-derived B19V infection was 0.4% and 1.5% in living and deceased kidney transplantations, respectively. B19V was seemingly unnecessary to be routinely screened for the donor. Moreover, kidneys of the donors with B19V infection were acceptable.

Epidemiology of parvovirus B19 and anemia among kidney transplant recipients: A meta-analysis

Background

Persistent anemia has been described in kidney transplant (KTx) recipients with parvovirus B19 virus infection. However, the epidemiology of parvovirus B19 and parvovirus B19-related anemia after KTx remains unclear. We conducted this systematic review (1) to investigate the incidence of parvovirus B19 infection after KTx and (2) to assess the incidence of parvovirus B19 among KTx patients with anemia.

Materials and Methods

A systematic review was conducted in EMBASE, MEDLINE, and Cochrane databases from inception to March 2019 to identify studies that reported the incidence rate of parvovirus B19 infection and/or seroprevalence of parvovirus B19 in KTx recipients. Effect estimates from the individual studies were extracted and combined using random-effects, generic inverse variance method of DerSimonian and Laird. The protocol for this systematic review is registered with PROSPERO (no. CRD42019125716).

Results

Nineteen observational studies with a total of 2108 KTx patients were enrolled. Overall, the pooled estimated seroprevalence of parvovirus B19 immunoglobulin G was 62.2% (95% confidence interval [CI]: 45.8%-76.1%). The pooled estimated incidence rate of positive parvovirus B19 DNA in the 1^st year after KTx was 10.3% (95% CI: 5.5%-18.4%). After sensitivity analysis excluded a study that solely included KTx patients with anemia, the pooled estimated incidence rate of positive parvovirus B19 DNA after KTx was 7.6% (95% CI: 3.7%-15.0%). Among KTx with anemia, the pooled estimated incidence rate of positive parvovirus B19 DNA was 27.4% (95% CI: 16.6%-41.7%). Meta-regression analysis demonstrated no significant correlations between the year of study and the incidence rate of positive parvovirus B19 DNA (P = 0.33). Egger's regression asymmetry test was performed and demonstrated no publication bias in all analyses.

Conclusion

The overall estimated incidence of positive parvovirus B19 DNA after KTX is 10.3%. Among KTx with anemia, the incidence rate of positive parvovirus B19 DNA is 27.4%. The incidence of positive parvovirus B19 DNA does not seem to decrease overtime.

Recurrence of Pure Red Cell Aplasia in a Kidney Transplant Recipient Due to Reactivation of Parvovirus B19 Infection Despite Two Cycles of Intravenous Immunoglobulin Therapy

Parvovirus B19 is a single-stranded DNA virus that typically has an affinity for erythroid progenitor cells in bone marrow and leads to pure red cell aplasia. This is a common pathogen in humans, and the expression of the infection depends on the host's hematologic and immunologic status. Here, we report a female patient who developed severe and persistent anemia after kidney transplant while being on immunosuppressive therapy. The parvovirus B19 immunoglobulin M test was positive, and the virus was detected by polymerase chain reaction as parvovirus B19 (23.5 million copies/mL) in the blood sample. Bone marrow examination revealed giant pronormoblasts. She responded well to intravenous immunoglobulin without adverse event. Hemoglobin levels gradually increased, and normal levels were achieved at 3 months posttreatment. Although her renal function did not deteriorate, severe anemia (with hemoglobin level 5 g/dL) recurred 3 times during 12 months posttransplant.

Endonuclease Activity Inhibition of the NS1 Protein of Parvovirus B19 as a Novel Target for Antiviral Drug Development

Human parvovirus B19 (B19V), a member of the genus Erythroparvovirus of the family Parvoviridae, is a small nonenveloped virus that has a single-stranded DNA (ssDNA) genome of 5.6 kb with two inverted terminal repeats (ITRs). B19V infection often results in severe hematological disorders and fetal death in humans. B19V replication follows a model of rolling hairpin-dependent DNA replication, in which the large nonstructural protein NS1 introduces a site-specific single-strand nick in the viral DNA replication origins, which locate at the ITRs. NS1 executes endonuclease activity through the N-terminal origin-binding domain. Nicking of the viral replication origin is a pivotal step in rolling hairpin-dependent viral DNA replication. Here, we developed a fluorophore-based in vitro nicking assay of the replication origin using the origin-binding domain of NS1 and compared it with the radioactive in vitro nicking assay. We used both assays to screen a set of small-molecule compounds (n = 96) that have potential antinuclease activity. We found that the fluorophore-based in vitro nicking assay demonstrates sensitivity and specificity values as high as those of the radioactive assay. Among the 96 compounds, we identified 8 which have an inhibition of >80% at 10 µM in both the fluorophore-based and radioactive in vitro nicking assays. We further tested 3 compounds that have a flavonoid-like structure and an in vitro 50% inhibitory concentration that fell in the range of 1 to 3 µM. Importantly, they also exhibited inhibition of B19V DNA replication in UT7/Epo-S1 cells and ex vivo-expanded human erythroid progenitor cells.

Risk factors and long-term outcomes of parvovirus B19 infection in kidney transplant patients

BACKGROUND

Parvovirus B19 is a small, non-enveloped, single-stranded DNA virus with a special affinity for the erythroid progenitor cells of the bone marrow. The first case of parvovirus B19 infection in a kidney transplant recipient (KTR) was reported in 1986. Data on the risk factors and specific clinical characteristics of parvovirus B19 infection remain insufficient.

METHODS

We screened 602 KTRs for parvovirus B19 infection using parvovirus B19 polymerase chain reaction (PCR) from January 1990 to April 2016, and the clinical characteristics of patients with positive results were compared to those of age- and gender-matched patients with negative PCR results.

RESULTS

A total of 39 KTRs tested positive for parvovirus B19, and they were compared to 78 age- and gender-matched patients among 563 KTRs who had negative PCR results. In all, 89.7% of positive cases were reported within the first year after kidney transplantation. In multivariate analyses, deceased-donor kidney transplantation (odds ratio [OR] 9.067, 95% confidence interval [CI] 1.668-49.275, P = .011), use of tacrolimus (OR 3.607, 95% CI 1.024-12.706, P = .046), PCR test within 1 year of kidney transplantation (OR 12.456, 95% CI 2.674-58.036, P = .001), and hemoglobin levels (OR 0.559, 95% CI 0.351-0.889, P = .014) showed significant correlations with parvovirus B19 infection. Graft survival did not differ between the two groups during the follow-up period of 111.68 ± 54.54 months (P = .685 by log-rank test).

CONCLUSION

The identification of factors related to positive parvovirus B19 PCR results may promote the early detection of parvovirus B19 infection. Further studies are needed to elucidate the characteristics of parvovirus B19 infection in kidney transplantation.

A Case Report of Parvovirus B19 Infection in a Renal Allograft

Parvovirus B19 infection is undiagnosed in recipients undergoing solid organ transplantation. It is usually responsible for unexplained acute and chronic red blood cell aplasia that does not respond to erythropoietin therapy. Cases of parvovirus B19 infection associated with pancytopenia, solid organ dysfunction, and allograft rejection have been described in the literature. The deterioration of the immune system as a result of severe immunotherapy favors the reactivation of a previous infection or the acquisition of a new one. We present a case of a 32-year-old woman with a 1-year history of renal allograft transplant and previous cytomegalovirus (CMV) infection who presented with chest pain, polyarthritis, pancytopenia, and renal dysfunction. A serum sample using polymerase chain reaction showed a parvovirus titer of 13.8 trillion IU/mL and a CMV titer of 800 IU/mL. The renal biopsy revealed nucleomegaly with focal viral inclusions, along with changes associated with immunotherapy toxicity. Electron microscopy demonstrated capillary and tubular epithelial cells with "viral factories," thereby confirming the diagnosis. Thus, screening for parvovirus B19 is advised in high-risk patients who present with refractory anemia to avoid the complications of a chronic infection associated with the fatal rejection of the transplanted organ.

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.

Effects of Parvovirus B19 Infection in Renal Transplant Recipients: A Retrospective Review of Three Cases

Parvovirus B19 (PVB19) is a DNA virus which causes clinically relevant infection in renal transplant recipients (RTR) leading to significant morbidity. Manifestations include erythropoietin resistant anemia, proteinuria, and glomerulosclerosis in the allograft. Severe infection may require administration of intravenous immunoglobulin, reduction in immunosuppression and transfusions. The major challenge in managing and preventing the infection in RTR involves the act of balancing the decreased level of immunosuppression and the risk of rejection. The objective of this article is to understand the importance of PVB19 infection and its outcome in RTR. We reviewed the medical records of three RTR with confirmed PVB19 infection and recorded patient information including demographics, clinical and laboratory data, management, and outcome. The average time of occurrence of PVB19 infection as transplant was 8.6 weeks and they presented with symptomatic anemia. Elevated creatinine values were noted in two of them. Following treatment, anemia improved and creatinine values returned to baseline. One of them developed an early relapse and had to be treated once again similarly. We emphasize the importance of maintaining a high index of suspicion for PVB19 infection in patients with anemia in the posttransplant phase, especially in patients on higher doses of immunosuppressants. Early and proper treatment can prevent worsening clinical condition and possible effects on the allograft.

American society of Nephrology Quiz and Questionnaire 2014: transplantation

The Nephrology Quiz and Questionnaire remains an extremely popular session for attendees of the Annual Kidney Week Meeting of the American Society of Nephrology. Once again, the conference hall was overflowing with audience members and eager quiz participants. Topics covered by the expert discussants included electrolyte and acid-base disorders, glomerular disease, ESRD/dialysis, and transplantation. Complex cases representing each of these categories along with single best answer questions were prepared and submitted by the panel of experts. Before the meeting, program directors of United States nephrology training programs and nephrology fellows answered the questions through an internet-based questionnaire. During the live session, members of the audience tested their knowledge and judgment on a series of case-oriented questions prepared and discussed by experts. They compared their answers in real time using audience response devices with the answers of the nephrology fellows and training program directors. The correct and incorrect answers were then discussed after the audience responses and the results of the questionnaire were displayed. As always, the audience, lecturers, and moderators enjoyed this educational session. This article recapitulates the session and reproduces its educational value for the readers of CJASN. Enjoy the clinical cases and expert discussions.

Resistance of dialyzed patients to erythropoietin

Resistance to recombinant human erythropoietin is a common condition in dialyzed patients with chronic kidney disease and is associated with more hospitalizations, increased mortality and frequent blood transfusions. The main cause of hyporesponsiveness to recombinant human erythropoietin in these patients is iron deficiency. However, a high proportion of patients does not respond to treatment, even to the use of intravenous iron, which indicates the presence of other important causes of resistance. In addition to the iron deficiency, the most common causes of resistance include inflammation, infection, malnutrition, inadequate dialysis, and hyperparathyroidism, although other factors may be associated. In the presence of adequate iron stores, other causes should be investigated and treated appropriately.

Blood disorders typically associated with renal transplantation

Renal transplantation has become one of the most common surgical procedures performed to replace a diseased kidney with a healthy kidney from a donor. It can help patients with kidney failure live decades longer. However, renal transplantation also faces a risk of developing various blood disorders. The blood disorders typically associated with renal transplantation can be divided into two main categories: (1) Common disorders including post-transplant anemia (PTA), post-transplant lymphoproliferative disorder (PTLD), post-transplant erythrocytosis (PTE), and post-transplant cytopenias (PTC, leukopenia/neutropenia, thrombocytopenia, and pancytopenia); and (2) Uncommon but serious disorders including hemophagocytic syndrome (HPS), thrombotic microangiopathy (TMA), therapy-related myelodysplasia (t-MDS), and therapy-related acute myeloid leukemia (t-AML). Although many etiological factors involve the development of post-transplant blood disorders, immunosuppressive agents, and viral infections could be the two major contributors to most blood disorders and cause hematological abnormalities and immunodeficiency by suppressing hematopoietic function of bone marrow. Hematological abnormalities and immunodeficiency will result in severe clinical outcomes in renal transplant recipients. Understanding how blood disorders develop will help cure these life-threatening complications. A potential therapeutic strategy against post-transplant blood disorders should focus on tapering immunosuppression or replacing myelotoxic immunosuppressive drugs with lower toxic alternatives, recognizing and treating promptly the etiological virus, bacteria, or protozoan, restoring both hematopoietic function of bone marrow and normal blood counts, and improving kidney graft survival.

Parvovirus B19 (B19) and cytomegalovirus (CMV) infections and anti-erythropoietin (anti-EPO) antibodies in patients on dialysis hyporesponsive to erythropoietin therapy

BACKGROUND

Approximately 10% of patients receiving recombinant human erythropoietin (rHuEPO) do not respond to the treatment. We evaluated parvovirus B19 (B19) and cytomegalovirus (CMV) infections and antierythropoietin (anti-EPO) antibodies as potential causes of anemia in dialyzed patients, hyporesponsive to rHuEPO.

METHODS

Data from 120 dialyzed patients, receiving rHuEPO alfa, were collected: demographic characteristics, rHuEPO dose, duration of rHuEPO treatment and time on dialysis, etiology of chronic kidney disease and transfusion history. Serology and PCR were performed to address B19 and CMV infection status. An ELISA was developed to detect anti-EPO antibodies.

RESULTS

rHuEPO resistance correlated with high ferritin levels (p = 0.001) and short time on dialysis (p = 0.012). B19 DNA was found in 10 (8.3%) dialyzed patients and CMV DNA was detected in 33 (27.5%). There was no significant correlation between B19 infection and anemia,while a tendency of correlation between active CMV infection and hemoglobin levels or hematocrit value (p= 0.069 and p= 0.070, respectively) has been observed. Anti-EPO antibodies were not detected in any patient.

CONCLUSIONS

B19 infection is a rare complication in dialyzed patients and should be investigated after exclusion of other common causes, while CMV infection is rather common. The role of CMV infection in the hyporesponsiveness in dialyzed patients should be further evaluated in other studies. Our data suggest that anti-EPO antibodies are not involved in rHuEPO resistance in this population.

Clinical investigation of human parvovirus B19 infection after renal transplantation in China

OBJECTIVE

We investigated the incidence of human parvovirus B19 (HPV B19) infection after renal transplantation as well as the risk of anemia and renal allograft damage among infected transplant recipients in China.

METHODS

We selected 114 patients at 1-18 months after renal transplantation for detection of HPV B19 DNA copies compared with a control population. Renal function and hematopoiesis were compared between infected and noninfected groups.

RESULTS

Twenty-seven patients diagnosed with HPV B19 infection during follow-up (18.75%),which was a significantly higher number than among the general population over the same period. Infected versus nonaffected patients exhibited a significantly higher incidence of anemia and urinary abnormalities in addition to significantly lower values of hemoglobin, higher serum creatinine concentrations, and lower glomerular filtration rates. The 2 groups did not differ in the types or doses of calcineurin inhibitor (CNI) immunosuppressants. Two cases of pure red cell aplasia (PRCA) as confirmed using bone marrow biopsy, were observed in the infected group. They displayed HPV B19 DNA copy numbers >10(7)/mL and segmental mesangial cell proliferation on renal biopsy. The PRCA cases were cured with immunomodulatory therapy.

CONCLUSIONS

The HPV B19 infection rate was significantly higher among renal transplant recipients than normal controls. Infections correlated with damage to the renal allograft, which may in turn cause PRCA. Immunomodulation therapy was effective to treat this complication of HPV B19 infection.

Human parvovirus B19 infection in a renal transplant recipient: a case report

Background

Parvovirus B19 presents tropism for human erythroid progenitor cells, causing chronic anemia in organ transplant recipients, due to their suppressed humoral and cellular responses. Diagnosis may be achieved through serological tests for detection of anti-B19 antibodies. However, renal transplant recipients are not routinely tested for parvovirus B19 infection, since there is scanty data or consensus on screening for B19 infection, as well as for treatment or preventive management of transplanted patients.

Case presentation

Herein we report a kidney transplant recipient, who was unresponsive to treatment of severe anemia, and presented hypocellular hematopoietic marrow, megaloblastosis and hypoplasia of erythroid lineage with larger cells with clear nuclei chromatin and eosinophilic nuclear inclusions. This patient was seropositive for Epstein-Barr and Cytomegalovirus infections and negative for anti-parvovirus B19 IgM and IgG antibodies, although symptoms were suggestive of parvoviruses infection. A qualitative polymerase chain reaction testing for B19 in serum sample revealed positive results for B19 virus DNA.

Conclusion

This case report suggests that the diagnostic process for parvovirus B19 in renal transplant recipients should include a polymerase chain reaction assay to detect B19-DNA, since specific serological tests may be unreliable given their impaired humoral responses. These results also indicate the importance of considering parvovirus B19 infection in the differential diagnosis of persistent anemia in transplanted patients.

Effect of maintenance immunosuppressive drugs on virus pathobiology: evidence and potential mechanisms

Recent evidence suggesting a potential anti-CMV effect of mTORis is of great interest to the transplant community. However, the concept of an immunosuppressant with antiviral properties is not new, with many accounts of the antiviral properties of several agents over the years. Despite these reports, to date, there has been little effort to collate the evidence into a fuller picture. This manuscript was developed to gather the evidence of antiviral activity of the agents that comprise a typical immunosuppressive regimen against viruses that commonly reactivate following transplant (HHV1 and 2, VZV, EBV, CMV and HHV6, 7, and 8, HCV, HBV, BKV, HIV, HPV, and parvovirus). Appropriate immunosuppressive regimens posttransplant that avoid acute rejection while reducing risk of viral reactivation are also reviewed. The existing literature was disparate in nature, although indicating a possible stimulatory effect of tacrolimus on BKV, potentiation of viral reactivation by steroids, and a potential advantage of mammalian target of rapamycin (mTOR) inhibition in several viral infections, including BKV, HPV, and several herpesviruses.

Pure red cell aplasia in a simultaneous pancreas-kidney transplantation patient: inside the erythroblast

A case of pure red cell aplasia in a simultaneous kidney-pancreas transplant recipient on immunosuppressive therapy is reported here. The patient presented with anemia unresponsive to erythropoietin treatment. Bone marrow cytomorphology was highly suggestive of parvovirus pure red cell aplasia, which was confirmed with serology and polymerase chain reaction positive for parvovirus B19 DNA in peripheral blood. After the administration of intravenous immunoglobulin the anemia improved with a rising number of the reticulocytes.

Anemia and erythrocytosis in patients after kidney transplantation

Anemia is a highly prevalent disorder in recipients of renal allografts. Despite its frequent occurrence, there is still uncertainty with regard to treatment targets and treatment options. This includes questions on appropriate iron management, the choice and dosage of erythropoietin stimulating agents, criteria for the timing of treatment initiation and the targeted hemoglobin values. The review summarizes available data on recent therapeutic strategies for post transplant anemia, as well as for post transplant erythrocytosis, another hematological disorder, that has decreased in recent years.

Parvovirus B19 infection and severe anemia in renal transplant recipients

Kidney transplant (KT) recipients can develop symptomatic Parvovirus (PV) B19 infections, frequently associated with persistent anemia. The aim of this study was to evaluate the prevalence and clinical significance of PV B19 infection in anemic and non-anemic KT patients. Overall, out of 64 patients monitored for the presence of PV B19 by real-time PCR, 2 (3.12%) had an active PV B19 infection, in absence of other viral coinfections. The 2 cases occurred in nonanemic kidney transplant patients group (2/50, 4%), while none of the anemic transplant patients (0/14) was found to suffer from this infection. Moreover, patients affected by active PV B19 infection showed viral loads not exceeding 1 × 10⁵ genome copies/reaction. In conclusion, in this study, PV B19 infection was not common in renal transplant population and wasn't associated with severe anemia.

[Parvovirus B19 infection after kidney transplantation]

Prevalence for human parvovirus B19 infection is estimated to be between 2% and 30% in renal transplant recipients. In post-transplant settings, parvovirus B19 infection may occur either as a primary infection or a reactivation. Parvovirus transmission most commonly occurs through respiratory tract but may also result from graft or blood packs contamination. Co-infections with HHV-6 and CMV viruses are frequent. The hallmark symptom is anemia, more rarely pancytopenia and hemophagocytic syndrome. In respect to renal involvement, parvovirus B19 infection has been associated with graft dysfunction in 10% of cases. Both thrombotic microangiopathies and collapsing glomerulopathies have been reported concomitantly with parvovirus B19 infection but the causal link remains unclear. Other complications are seldomly reported, including hepatitis, encephalitis, and myocarditis. Diagnosis is based on pre and post-transplant serological status. In addition, the management of parvovirus B19 infection in immunocompromised patients requires quantitative assessment of blood viral load by PCR. The treatment relies primarily on reduction of immunosuppression combined with intravenous immunoglobulin infusions. Relapses occur in 30% of cases.

The possible role of early post-transplant inflammation in later anemia in kidney transplant recipients

Delayed kidney graft function and acute rejection in the early post-transplant period affect both short and long-term allograft survival. Allograft rejection, as an inflammatory state, results in increased erythropoietin resistance, which leads to decreased haemoglobin (Hb) level. We conducted this study to evaluate whether inflammation in the early post-transplant period could predict later anemia.This is a retrospective cohort study based on the analysis of 64 existing clinical records.

PREDICTOR

White blood cells (WBC) count obtained by the end of the first week post-transplant (W1). Covariates: Donor's age, recipient's age and sex.

OUTCOME

Anemia identified at 12 months (M12) post engraftment. Median WBC count at W1 was 9,5 x103/microL (5th - 95th percentile 5,2 x103/microL -17,8 x103/microL). Mean Hb values at M12 were 129,9 +/- 20,3 g/L, in males 136,2 +/- 20,1 g/L and in females 119,4 +/- 16,2 g/L. The significant correlation was found between WBC at W1 and Hb at M12. Pearson coefficient of correlation r was -0,26, and 95% confidence interval (CI) for r was -0,47 to -0,015 (p=0,03). Univariate logistic regression showed significant association between WBC at W1 and Hb at M12 (OR 1,20; 95% CI 1,04 to 1,39, p=0,01). After the adjustment for donor's and recipient's age by transplantation and recipient's sex, multiple regression showed that WBC count remained predictive of anemia at M12 (OR 1,17; 95% CI 1,01 to 1,36, p=0,03). Early post-transplant inflammatory response predicts later anemia in kidney transplant recipients. An increase in WBC count in the first week post-transplant by 109/L increases the risk for anemia after twelve months by 17%.

Successful renal re-transplantation in the presence of pre-existing anti-DQ5 antibodies when there was zero mismatch at class I human leukocyte antigen A, B, & C: a case report

Introduction

Hyperacute rejection may be prevented by avoiding the transplantation of kidneys into patients with pre-existing anti-donor Class I human leukocyte antigen antibodies. However, the role of anti-donor-Class II-human leukocyte antigen-DQ antibodies is not established. The question is ever more relevant as more sensitive cross-matching techniques detect many additional antibodies during the final crossmatch. We now report successful renal transplantation of a patient who had pre-existing antibodies against his donor's human leukocyte antigen-DQ5.

Case presentation

Our patient, a Caucasian man, was 34 years of age when he received his first deceased donor renal transplant. After 8 years, his first transplant failed from chronic allograft dysfunction and an earlier bout of Banff 1A cellular rejection. The second deceased donor kidney transplant was initially allocated to the patient due to a 0 out of 6 mismatch. The B cell crossmatch was mildly positive, while the T Cell crossmatch was negative. Subsequent assays showed that the patient had preformed antibodies for human leukocyte antigen DQ5 against his second donor. Despite having preformed antibodies against the donor, the patient continues to have excellent allograft function two years after his second renal transplant.

Conclusion

The presence of pre-existing antibodies against human leukocyte antigen DQ5 does not preclude transplantation. The relevance of having other antibodies against class II human leukocyte antigens prior to transplantation remains to be studied.

Postrenal transplant hemophagocytic lymphohistiocytosis and thrombotic microangiopathy associated with parvovirus b19 infection

Persistent anemia is a known consequence of Parvovirus B19 (B19) infection following renal transplantation. However, to date, no description of B19-related hemophagocytic lymphohistiocytosis (HLH) exists in renal transplant recipients. We report a 24-year-old male kidney recipient, who presented with fever, severe anemia and allograft dysfunction two years following transplantation. Hyperferritinemia, hypertriglyceridemia, elevated serum lactate dehydrogenase, pancytopenia and fragmented red blood cells on the peripheral blood were also noted. Bone marrow examination revealed giant pronormoblasts and frequent histiocytes with intracellular hematopoietic elements, consistent with HLH. Renal allograft biopsy revealed closure of the lumen of glomerular capillaries and thickening of the capillary walls compatible with thrombotic microangiopathy. The presence of anti-B19 IgM antibody and viral DNA in the patient's serum (detected by real-time PCR) confirmed an acute B19 infection. Following high-dose intravenous immunoglobulin therapy, the anemia gradually resolved and renal function improved. As far as we know, this is the first report of B19-associated HLH and thrombotic microangiopathy in a renal transplant recipient.

Pottransplantation anemia: management and rationale

In recent years, there has been an increasing interest in studying the anemia that occurs after kidney transplantation. Although many of the guidelines for the treatment of kidney transplant patients, including those for anemia, are extrapolated from recommendations for patients with chronic kidney disease, there are important differences in the cause of and response to anemia in kidney transplant recipients. In addition to the correlation of anemia with kidney function as in native renal disease, many other factors are associated with the development of anemia after transplantation, including the use of medications and the inflammation/immune response. Given the lack of large, well-designed, prospective studies, the consequences of anemia, the response to treatment, and the cost-effectiveness of treatment in the posttransplantation setting are also poorly understood.

Persistent parvovirus B19-induced anemia in an HIV-infected patient under HAART. Case report and review of literature

Recent reports document resolution of human parvovirus B19-related pure red blood cell aplasia (PB19-PRCA) in HIV-infected patients upon commencement of highly active antiretroviral therapy (HAART). This article describes a patient with PB19-PRCA who, despite fully suppressive HAART, required cyclic administration of intravenous human immunoglobulin over a period of 17 months before PB19 seroconversion and subsequent resolution of relapsing severe anemia. All reports in the English literature describing PB19-related hematologic abnormalities in the post-HAART era are also described herein.

Parvovirus-B19-associated complications in renal transplant recipients

Parvovirus B19 is a common human pathogen, causing erythema infectiosum in children, hydrops fetalis in pregnant women, and transient aplastic crisis in patients with chronic hemolytic anemia. Immunosuppressed patients can fail to mount an effective immune response to B19, resulting in prolonged or persistent viremia. Renal transplant recipients can develop symptomatic B19 infections as a result of primary infection acquired via the usual respiratory route or via the transplanted organ, or because of reactivation of latent or persistent viral infection. The most common manifestations of B19 infection in immunosuppressed patients are pure red cell aplasia and other cytopenias. Thus, this diagnosis should be considered in transplant recipients with unexplained anemia and reticulocytopenia or pancytopenia. Collapsing glomerulopathy and thrombotic microangiopathy have been reported in association with B19 infection in renal transplant recipients, but a causal relationship has not been definitively established. Prompt diagnosis of B19 infection in the renal transplant recipient requires a high index of suspicion and careful selection of diagnostic tests, which include serologies and polymerase chain reaction. Most patients benefit from intravenous immunoglobulin therapy and/or alteration or reduction of immunosuppressive therapy. Conservative therapy might be sufficient in some cases.

Parvovirus B19 and the kidney

Infection with parvovirus B19 causes several clinical syndromes (fifth disease, transient aplastic crisis, pure red cell aplasia, and hydrops fetalis) and may contribute to other illnesses. B19 has been linked to renal disease in three settings: As a cause of acute glomerulopathy and as a cause of anemia in ESRD and kidney transplantation. Case reports implicate parvovirus in the pathogenesis of proliferative glomerulonephritis and collapsing glomerulopathy, but a causal relationship has not been established. A proposed role for B19 infection is based on the temporal association of renal findings with viral infection, positive serology, and identification of the viral genome in the glomerulus. Mechanisms may include cytopathic effects on glomerular epithelial cells and/or endothelial cells and glomerular deposition of immune complexes. Patients who require dialysis may have increased susceptibility to acute and chronic anemia after parvoviral infection. Factors that predispose this population to complications of B19 infection include impaired immune response, deficient erythropoietin production, and possibly decreased erythrocyte survival. The clinical burden of parvovirus B19 infection in renal transplant recipients may be underestimated; these individuals may develop persistent viremia as a result of a dysfunctional immune response. Chronic anemia and pure red blood cell aplasia are the most common complications of parvovirus infection in this population; the diagnosis should be considered in transplant recipients with unexplained anemia or pancytopenia. Allograft rejection and dysfunction have been reported in association with infection, but a cause-effect relationship has not been proved. Further investigation of the relationship between B19 and kidney disease is warranted.

Clinical aspects of parvovirus B19 infection

Parvovirus B19 is a significant human pathogen that causes a wide spectrum of clinical complications ranging from mild, self-limiting erythema infectiosum in immunocompetent children to lethal cytopenias in immunocompromised patients and intrauterine foetal death in primary infected pregnant women. The infection may also be persistent and can mimic or trigger autoimmune inflammatory disorders. Another important clinical aspect to consider is the risk of infection through B19-contaminated blood products. Recent advances in diagnosis and pathogenesis, new insights in the cellular immune response and newly discovered genotypes of human parvoviruses form a platform for the development of modern therapeutic and prophylactic alternatives.