Human parvovirus B19 in solid organ transplantation: Guidelines from the American society of transplantation infectious diseases community of practice

Pure Red Cell Aplasia Secondary to Parvovirus B19 Infection as a Rare Cause of Anemia in a Dialysis Patient

Parvovirus B19 infection can cause chronic pure red cell aplasia in immunosuppressed hosts or acute and transient aplastic crisis in immunocompetent hosts. In dialysis patients, only transient aplastic crisis induced by parvovirus B19 infection has been reported. We herein report the first case of an adult dialysis patient who developed chronic pure red cell aplasia associated with parvovirus B19 infection. Repeated pneumonia and heart failure may contribute to an immunocompromised status, making the patient more vulnerable to parvovirus B19 infection. This case expands on the differential diagnosis of chronic anemia in patients undergoing dialysis.

Human herpesvirus-6, HHV-8 and parvovirus B19 after allogeneic hematopoietic cell transplant: the lesser-known viral complications

PURPOSE OF REVIEW

Viral infections continue to burden allogeneic hematopoietic cell transplant (HCT) recipients. We review the epidemiology, diagnosis, and management of human herpesvirus (HHV)-6, HHV-8 and parvovirus B19 following HCT.

RECENT FINDINGS

Advances in HCT practices significantly improved outcomes but impact viral epidemiology: post-transplant cyclophosphamide for graft-versus-host disease prevention increases HHV-6 reactivation risk while the impact of letermovir for CMV prophylaxis - and resulting decrease in broad-spectrum antivirals - is more complex. Beyond the well established HHV-6 encephalitis, recent evidence implicates HHV-6 in pneumonitis. Novel less toxic therapeutic approaches (brincidofovir, virus-specific T-cells) may enable preventive strategies in the future. HHV-8 is the causal agent of Kaposi's sarcoma, which is only sporadically reported after HCT, but other manifestations are possible and not well elucidated. Parvovirus B19 can cause severe disease post-HCT, frequently manifesting with anemia, but can also be easily overlooked due to lack of routine screening and ambiguity of manifestations.

SUMMARY

Studies should establish the contemporary epidemiology of HHV-6, and other more insidious viruses, such as HHV-8 and parvovirus B19 following HCT and should encompass novel cellular therapies. Standardized and readily available diagnostic methods are key to elucidate epidemiology and optimize preventive and therapeutic strategies to mitigate the burden of infection.

Infections After Liver Transplant -Timeline, Management and Prevention

Liver transplantation (LT) is the standard treatment for end- stage liver disease. Patient and graft survival have improved significantly in the last three decades owing to improvement in surgical technique, better perioperative management and better immunosuppressive regimens. However, LT recipients are at increased risk of infections, particularly in the first year after transplantation. The risk of infection is directly proportional to immunosuppressive regimen and graft function. In this review, we will briefly discuss the timeline of infections after liver transplant, preventive strategies and management of infectious complications.

Epidemiology and Management of Infections in Liver Transplant Recipients

Background: Improvements in liver transplant (LT) outcomes are attributed to advances in surgical techniques, use of potent immunosuppressants, and rigorous pre-LT testing. Despite these improvements, post-LT infections remain the most common complication in this population. Bacteria constitute the most common infectious agents, while fungal and viral infections are also frequently encountered. Multi-drug-resistant bacterial infections develop because of polymicrobial overuse and prolonged hospital stays. Immediate post-LT infections are commonly caused by viruses. Conclusions: Appropriate vaccination, screening of both donor and recipients before LT and antiviral prophylaxis in high-risk individuals are recommended. Antimicrobial drug resistance is common in high-risk LT and associated with poor outcomes; epidemiology and management of these cases is discussed. Additionally, we also discuss the effect of coronavirus disease 2019 (COVID-19) infection and monkeypox in the LT population.

A Multiplex Fluorescence of Loop Primer Upon Self-Dequenching Loop-Mediated Isothermal Amplification Assay for the Detection of Epstein-Barr Virus and Human Parvovirus B19 in Clinical Transplant Samples

Viral infections are major causes of mortality in solid-organ and hematopoietic stem cell transplant recipients. Epstein-Barr virus (EBV) and Parvovirus B19 (B19V) are among the common viral infections after transplantation and were recommended for increased screening in relevant guidelines. Therefore, the development of rapid, specific, and cost-effective diagnostic methods for EBV and B19V is of paramount importance. We applied Fluorescence of Loop Primer Upon Self-Dequenching Loop-mediated Isothermal Amplification (FLOS-LAMP) for the first time to develop a novel multiplex assay for the detection of EBV and B19V; the fluorophore attached to the probe are self-quenched in unbound state. After binding to the dumbbell-shaped DNA target, the fluorophore is dequenched, resulting in fluorescence development. The novel multiplex FLOS-LAMP assay was optimized by testing various ratios of primer sets. This novel assay, with great specificity, did not cross-react with the common virus. For the detection of EBV and B19V, the limits of detection could reach 969 and 798 copies/μL, respectively, and the assay could be completed within 25 min. Applying this novel assay to detect 200 clinical transplant individuals indicated that the novel assay had high specificity and good sensitivity. We developed multiplex FLOS-LAMP assay for the detection of EBV and B19V, which has the potential to become an important tool for clinical transplant patient screening.

Intravenous immunoglobulin in kidney transplantation: Mechanisms of action, clinical applications, adverse effects, and hyperimmune globulin

Intravenous immunoglobulin (IVIG) has been developed for over 40 years. The mechanisms of action of IVIG are complex and diverse, and there may be multiple mechanisms that combine to influence it. IVIG has been used in kidney transplantation for desensitization, treatment of antibody-mediated rejection, and ABO-incompatible transplantation. and treatment or prevention of some infectious diseases. Hyperimmune globulins such as cytomegalovirus hyperimmune globulin (CMV-IG) and hepatitis B hyperimmune globulin (HBIG) have also been used to protect against cytomegalovirus and hepatitis B virus, respectively. However, IVIG is also associated with some rare but serious adverse effects and some application risks, and clinicians need to weigh the pros and cons and develop individualized treatment programs to benefit more patients. This review will provide an overview of the multiple mechanisms of action, clinical applications, adverse effects, and prophylactic measures of IVIG, and hyperimmune globulin will also be introduced in it.

Parvovirus in Kidney Transplant Recipients: A Single-Center Experience

OBJECTIVES

Parvovirus testing is not done in routine clinical practice; thus, it is possible that reported parvovirus cases are just the tip of the iceberg of total prevalence. We present a single-center retrospective analysis of 22 events of parvovirus B19 anemia in 20 renal transplant recipients, among which 2 patients had recurrence.

MATERIALS AND METHODS

For this descriptive analytical study, parvovirus B19 disease was defined as parvovirus infection (detection by real-time polymerase chain reaction) in the presence of anemia with clinical symptoms or bone marrow biopsy findings consistent with the diagnosis. Study duration was 18 months, from June 2021 through December 2022, and patients were enrolled from a single center.

RESULTS

All patients detected with the virus had received induction with thymocyte globulin and were on standard triple drug immunosuppression. Mean age was 32 ± 12 years with median time to diagnosis of 2 months after transplant. Anemia was observed in all patients with mean hemoglobin level at presentation of 6.02 ± 1.28 g/dL. Creatinine at presentation was 1.49 mg/dL (interquartile range, 0.92-2.69 mg/dL). The most common presentation was asymptomatic patient with evaluation for anemia. During therapy, the highest median creatinine level was 2.0 mg/dL (interquartile range, 1.38-3.2 mg/dL), which was significantly higher than that at presentation (P < .018). After therapy, median creatinine level was 1.3 mg/dL, which was not significantly higher than the baseline level, demonstrating a mostly transient graft dysfunction.

CONCLUSIONS

Parvovirus B19 is a relatively underreported disease in renal transplant recipients, with patients presenting with anemia and the disease causing transient graft dysfunction. Parvovirus B19 infection responds well to a decrease in immunosuppression and intravenous immunoglobulin therapy.

Pre-Existing Intrarenal Parvovirus B19 Infection May Relate to Antibody-Mediated Rejection in Pediatric Kidney Transplant Patients

Viral infections can lead to transplant dysfunction, and their possible role in rejection is described. In total, 218 protocol biopsies performed in 106 children at 6, 12 and 24 months after transplantation were analyzed according to Banff '15. RT-PCR for cytomegalovirus, Epstein-Barr virus, BK virus and Parvovirus B19 was performed on blood and bioptic samples at the time of transplant and each protocol biopsy. The prevalence of intrarenal viral infection increases between 6 and 12 months after transplantation (24% vs. 44%, p = 0.007). Intrarenal Parvovirus B19 infection is also associated with antibody-mediated rejection (ABMR) (50% ABMR vs. 19% T-cell-mediated rejection, p = 0.04). Moreover, Parvovirus infection is higher at 12 months of follow-up and it decreases at 48 months (40.4% vs. 14%, p = 0.02), while in 24% of grafts, Parvovirus is already detectable at the moment of transplantation. Intrarenal Parvovirus B19 infection seems to be related to ABMR in pediatric kidney recipients. The graft itself may be the way of transmission for Parvovirus, so performance of a PCR test for Parvovirus B19 should be considered to identify high-risk patients. Intrarenal Parvovirus infection presents mainly during the first-year post-transplantation; thus, we recommend an active surveillance of donor-specific antibodies (DSA) in patients with intrarenal Parvovirus B19 infection during this period. Indeed, it should be considered a treatment with intravenous immunoglobulins in patients with intrarenal Parvovirus B19 infection and DSA positivity, even in the absence of ABMR criteria for kidney biopsy.

Case Report: Parvovirus B19 infection complicated by hemophagocytic lymphohistiocytosis in a heart-lung transplant patient

Immunosuppressed patients can contract parvovirus B19, and some may experience hemophagocytic lymphohistiocytosis (HLH). Herein, we describe the first report of hemophagocytic lymphohistiocytosis in a heart-lung transplant patient with concomitant parvovirus B19 infection. The patient was treated with intravenous immune globulin (IVIG) and the features of HLH were remission. This instance emphasizes the significance of parvovirus B19 monitoring in transplant patients with anemia; if HLH complicates the situation, IVIG may be an adequate remedy. Finally, a summary of the development in diagnosing and managing parvovirus B19 infection complicated by HLH is provided.

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.

Parvovirus B19-Associated Severe Anemia in Adult Liver Transplant Recipients: A Case Series and Review of the Literature

Background: Parvovirus B19 (B19V) infection is a rare cause of severe anemia in liver transplant recipients. However, few studies have systematically reviewed reported cases and summarized experience in managing this disease. Objective: We described a retrospective case series of eight adult liver transplant recipients with B19V-associated severe anemia and performed a literature review of epidemiology, etiology, clinical courses, diagnosis, treatment options available, and outcomes of B19V-associated anemia in adult liver transplant recipients. Patients and Methods: We systematically reviewed articles describing adult liver transplant recipients with B19V-associated anemia from PubMed and ScienceDirect databases from database inception to May 2022. Results: Eight articles containing 23 cases were identified in addition to eight cases from our center for a total of 31 patients (mean age, 45.7 ± 9.7 years; 74.2% male). Eighty-seven percent developed transfusion-dependent anemia within two months after liver transplantation (LT). Fever and progressive anemia are among the major manifestations. Intravenous immunoglobulin (IVIG)-based therapy was given to all patients and the treatment protocols varied among different centers. Except for two cases who died of comorbidities, 17 patients obtained long-term recovery from anemia after one course of treatment and six (19%) experienced relapses that were reversed by repeated courses of IVIG therapy. Two recipients presented with IVIG-associated side effects and two developed acute cellular rejection (ACR) after reduction of immunosuppression. Conclusions: B19V infection should be suspected early as a cause of severe anemia of unknown etiology in adult liver transplant recipients. The clearance of B19V typically lags behind recovery of anemia, and inadequate clearance of virus after cessation of IVIG appears to be a potential risk of anemia recurrence. Moreover, more attention should be paid to the side effects of high-dose IVIG infusion and ACR because of reduction of immunosuppression.

Forty Years of Molecular Diagnostics for Infectious Diseases

Nearly 40 years have elapsed since the invention of the PCR, with its extremely sensitive and specific ability to detect nucleic acids via in vitro enzyme-mediated amplification. In turn, more than 2 years have passed since the onset of the coronavirus disease 2019 (COVID-19) pandemic, during which time molecular diagnostics for infectious diseases have assumed a larger global role than ever before. In this context, we review broadly the progression of molecular techniques in clinical microbiology, to their current prominence. Notably, these methods now entail both the detection and quantification of microbial nucleic acids, along with their sequence-based characterization. Overall, we seek to provide a combined perspective on the techniques themselves, as well as how they have come to shape health care at the intersection of technologic innovation, pathophysiologic knowledge, clinical/laboratory logistics, and even financial/regulatory factors.

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.

High-grade myelodysplastic syndrome in a pediatric multi-organ transplant recipient: A case report and literature review

BACKGROUND

Pediatric myelodysplastic syndrome is a rare but life-threatening condition requiring prompt recognition and management.

METHODS

We herein present the only reported case of a pediatric multi-organ transplant recipient developing myelodysplastic syndrome.

RESULTS

The patient was a 14-year-old girl on chronic calcineurin inhibitor therapy who presented with peri-rectal pain approximately 13 years after liver, small bowel, and pancreas transplant. The initial workup revealed pancytopenia and parvovirus B19 viremia. Her definitive diagnosis was complicated by a lack of adequate bone marrow biopsy specimens and expert consultation that resulted in treatment for hemophagocytic lymphohistiocytosis. She was later diagnosed with high-grade myelodysplastic syndrome. Although curative treatment with chemotherapy and hematopoietic stem cell transplantation was strongly considered, it was not performed due to the child's rapid clinical progression, ventilator status, and active infections. The patient died approximately 6 months following symptom onset.

CONCLUSIONS

This case emphasizes the importance of early recognition of myelodysplastic syndrome in multi-organ transplant recipients on chronic immunosuppression. Pancytopenia is a common presentation in the post-transplant period that requires thorough investigation. Multiple confounding considerations such as infection, immunosuppression, and systemic inflammation can delay the diagnosis of underlying hematological malignancies. Transplant care providers should be aware of myelodysplastic syndrome and advocate for a comprehensive evaluation, given early recognition and intervention can significantly improve outcomes.

Viral infections in lung transplantation

Viral infections account for up to 30% of all infectious complications in lung transplant recipients, remaining a significant cause of morbidity and even mortality. Impact of viral infections is not only due to the direct effects of viral replication, but also to immunologically-mediated lung injury that may lead to acute rejection and chronic lung allograft dysfunction. This has particularly been seen in infections caused by herpesviruses and respiratory viruses. The implementation of universal preventive measures against cytomegalovirus (CMV) and influenza (by means of antiviral prophylaxis and vaccination, respectively) and administration of early antiviral treatment have reduced the burden of these diseases and potentially their role in affecting allograft outcomes. New antivirals against CMV for prophylaxis and for treatment of antiviral-resistant CMV infection are currently being evaluated in transplant recipients, and may continue to improve the management of CMV in lung transplant recipients. However, new therapeutic and preventive strategies are highly needed for other viruses such as respiratory syncytial virus (RSV) or parainfluenza virus (PIV), including new antivirals and vaccines. This is particularly important in the advent of the COVID-19 pandemic, for which several unanswered questions remain, in particular on the best antiviral and immunomodulatory regimen for decreasing mortality specifically in lung transplant recipients. In conclusion, the appropriate management of viral complications after transplantation remain an essential step to continue improving survival and quality of life of lung transplant recipients.

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.

Prevention of viral infections in solid organ transplant recipients in the era of COVID-19: a narrative review

INTRODUCTION

In solid organ transplant (SOT) recipients, viral infections are associated with direct morbidity and mortality and may influence long-term allograft outcomes. Prevention of viral infections by vaccination, antiviral prophylaxis, and behavioral measures is therefore of paramount importance.

AREAS COVERED

We searched Pubmed to select publications to review current preventive strategies against the most important viral infections in SOT recipients, including SARS-CoV-2, influenza, CMV, and other herpesvirus, viral hepatitis, measles, mumps, rubella, and BK virus.

EXPERT OPINION

The clinical significance of the reduced humoral response following mRNA SARS-CoV-2 vaccines in SOT recipients still needs to be better clarified, in particular with regard to the vaccines' efficacy in preventing severe disease. Although a third dose improves immunogenicity and is already integrated into routine practice in several countries, further research is still needed to explore additional interventions. In the upcoming years, further data are expected to better delineate the role of virus-specific cell mediated immune monitoring for the prevention of CMV and potentially other viral diseases, and the role of the letermovir in the prevention of CMV in SOT recipients. Future studies including clinical endpoints will hopefully facilitate the integration of successful new influenza vaccination strategies into clinical practice.

Association of Parvovirus B19 with Rheumatic Diseases

Human parvovirus B19 infections are well reported to be associated with different autoimmune disorders. They can either mimic or trigger autoimmune diseases, such as systemic lupus erythematous (SLE), rheumatoid arthritis (RA), and vasculitis. A lack of awareness about this infection can result in delays in diagnosis and poor care. In this review, the basic biology and clinical aspects of the parvovirus, human immune response, and the pathogenesis in the rheumatic diseases are discussed.

[The hematological diversity of human parvovirus B19 infection after allo-hematopoietic stem cell transplantation in pediatric patients]

目的

探讨异基因造血干细胞移植（allo-HSCT）患儿造血重建后人类细小病毒B19（HPV-B19）感染的血液学表现。

方法

对9例allo-HSCT后合并HPV-B19感染的患儿进行回顾性分析。

结果

9例患儿占同期接受allo-HSCT患儿的8.04％（9/112），男8例，女1例，中位年龄9（3～13）岁，均采取清髓性预处理方案。HPV-B19感染中位时间为移植后61（36～114）d。allo-HSCT并发HPV-B19感染患儿血液学表现具有异质性，9例患儿以血红蛋白伴网织红细胞下降为主要特点，7 d内网织红细胞比例、绝对值下降幅度中位数分别为90.4％（24.7％～98.7％）、90.7％（18.6％～99.0％）。除常见红系造血停滞表现外，allo-HSCT后合并HPV-B19感染的患儿还具有非红系的血象及骨髓变化：5例患儿外周血出现中性粒细胞下降，但骨髓涂片未见粒系增生受抑；6例患儿骨髓涂片查见巨核系增生减低，其中5例患儿外周血血小板下降。同时，allo-HSCT造血重建后合并HPV-B19感染的患儿骨髓红系受抑并非必要表现，9例患儿虽然均出现血红蛋白下降，但仅5例患儿骨髓红系增生减低。

结论

血液病患儿allo-HSCT造血重建后合并HPV-B19感染的血液学表现具有异质性，血红蛋白伴网织红细胞下降对HPV-B19感染早期诊断可能具有重要意义。

Human parvovirus B19-associated early postoperative acquired pure red cell aplasia in simultaneous pancreas-kidney transplantation: A case report

BACKGROUND

Acquired pure red cell aplasia (aPRCA) related to human parvovirus B19 (HPV B19) is rarely reported in simultaneous pancreas-kidney transplantation (SPKT) recipients; there has yet to be a case report of early postoperative infection. In this current study, we report the case of a Chinese patient who experienced the disease in the early postoperative period.

CASE SUMMARY

A 63-year-old man, with type 2 diabetes and end-stage renal disease, received a brain dead donor-derived SPKT. Immunosuppression treatment consisted of tacrolimus, prednisone, enteric-coated mycophenolate sodium (EC-MPS), and thymoglobulin combined with methylprednisolone as induction. The hemoglobin (Hb) level declined due to melena at postoperative day (POD) 3, erythropoietin-resistant anemia persisted, and reticulocytopenia was diagnosed at POD 20. The bone marrow aspirate showed decreased erythropoiesis and the presence of giant pronormoblasts at POD 43. Metagenomic next-generation sequencing (mNGS) of a blood sample identified HPV B19 infection at POD 66. EC-MPS was withdrawn; three cycles of intravenous immunoglobulin (IVIG) infusion therapy were administered; and tacrolimus was switched to cyclosporine. The HPV B19-associated aPRCA resolved completely and did not relapse within the 1-year follow-up period. The diminution in mNGS reads was correlated with Hb and reticulocyte count improvements.

CONCLUSION

HPV B19-associated aPRCA can occur at an early period after SPKT. An effective therapy regimen includes IVIG infusion and adjustment of the immuno-suppressive regimen. Moreover, mNGS can be used for the diagnosis and to reflect disease progression.

[Treatment-refractory anaemia in a 35-year-old heart transplant recipient on chronic hemodialysis]

Es wird über einen 35-jährigen Dialysepatienten nach Herztransplantation berichtet, der eine „pure red cell aplasia“ aufwies. Serologisch fand sich ein positiver Parvovirus-B19-Immunglobulin-M-Titer, im Direktnachweis mittels Polymerase-Kettenreaktion zeigten sich 80 Mrd. IU/ml. In der zytologischen Untersuchung des Knochenmarks gelang der Nachweis von Riesenproerythroblasten, pathognomonisch für eine Parvovirus-B19-Infektion. Zur Therapie erfolgte die hoch dosierte Gabe von Immunglobulinen über 5 Tage. Bei Wiedervorstellung nach vier Wochen zeigte sich die Anämie deutlich gebessert. Bei Patienten nach Organtransplantation mit hyporegenerativer Anämie sollte eine Parvovirus-B19-Infektion stets ausgeschlossen werden.

Incidence and impact of parvovirus B19 infection in seronegative solid organ transplant recipients

Routine monitoring of Parvovirus B19 (B19V) the first six months post-transplantation was performed in 241 seronegative solid organ transplant (SOT) recipients. Incidence rates (IR) during the 1st month and the 2nd to 6th months post-transplantation were 1.2 (95% CI, 0.33-3.2) and 0.21 (95% CI, 0.06-0.57) per 100 recipients per-month, respectively. Of the 6 SOT recipients with positive B19V PCR, 3 (50%) were admitted to hospital and 2 (33%) were treated with intravenous immunoglobulin. Thus, routine monitoring of B19V in seronegative SOT recipients may not be necessary. Targeted screening one-month post-transplantation and screening upon clinical suspicion could be an alternative strategy.

Enhanced Cell-Based Detection of Parvovirus B19V Infectious Units According to Cell Cycle Status

Human parvovirus B19 (B19V) causes various human diseases, ranging from childhood benign infection to arthropathies, severe anemia and fetal hydrops, depending on the health state and hematological status of the patient. To counteract B19V blood-borne contamination, evaluation of B19 DNA in plasma pools and viral inactivation/removal steps are performed, but nucleic acid testing does not correctly reflect B19V infectivity. There is currently no appropriate cellular model for detection of infectious units of B19V. We describe here an improved cell-based method for detecting B19V infectious units by evaluating its host transcription. We evaluated the ability of various cell lines to support B19V infection. Of all tested, UT7/Epo cell line, UT7/Epo-STI, showed the greatest sensitivity to B19 infection combined with ease of performance. We generated stable clones by limiting dilution on the UT7/Epo-STI cell line with graduated permissiveness for B19V and demonstrated a direct correlation between infectivity and S/G2/M cell cycle stage. Two of the clones tested, B12 and E2, reached sensitivity levels higher than those of UT7/Epo-S1 and CD36⁺ erythroid progenitor cells. These findings highlight the importance of cell cycle status for sensitivity to B19V, and we propose a promising new straightforward cell-based method for quantifying B19V infectious units.

[Persistent anemia after kidney transplantation in a 36-year-old male patient-an unusual cause]

An allogeneic kidney transplantation (match 1‑1‑0, cytomegalovirus, CMV, donor, D, +/recipient, R, - high risk) was performed in a 36-year-old patient. The patient was on dialysis due to a tubulointerstitial nephritis confirmed by biopsy 11 years previously. Posttransplantation there was a gradual decrease in the hemoglobin (Hb) level from 11.4 g/dl to 7.3 g/dl during the initial hospitalization period. Initially this was explained by the kidney transplantation and chronic fibrosing antral gastritis with erosions. Despite repeated transfusion of red cell concentrates, a refractory anemia persisted, which is why the patient presented several times at our clinic for further diagnosis and treatment. The presence of giant erythroblasts in the bone marrow and quantitative detection of parvovirus B19 (>900 million IU/ml DNA replications) was consistent with a virus-associated red cell aplasia. Intravenous immunoglobulin administration was established and showed long-term therapeutic success.

Severe Refractory Anaemia and Fever of Unknow Origin: Human Parvovirus B19 Reactivation

Reactivation of human parvovirus B19 is exceptional and characteristic of immunosuppression, with anaemia being the predominant manifestation although pancytopenia and thrombotic microangiopathy may also occur. We describe a patient with a history of diffuse large B-cell lymphoma with pure erythrocyte aplasia due to reactivation of parvovirus B19, who was treated with corticosteroids and immunoglobulins.

LEARNING POINTS

Infection with human parvovirus B19 is identified by polymerase chain reaction (PCR) testing of blood and the presence of typical giant proerythroblasts in the bone marrow.Cytomegalovirus infection should be considered in immunosuppressed patients with fever and non-specific symptoms with haematological changes.The treatment of persistent infection in immunosuppressed patients is based on the administration of IV immunoglobulins at high doses.

Development of pure red cell aplasia by transmission and persistent infection of parvovirus B19 through a kidney allograft

We report a case of pure red cell aplasia (PRCA) caused by parvovirus B19 (PVB19) infection, which was transmitted through a kidney allograft. The patient underwent a living-donor kidney transplant from his wife at the age of 60. Despite successful engraftment with a normal creatinine level, he developed severe anemia that required frequent blood transfusions 2 months after transplantation. Renal anemia was unlikely as his serum erythropoietin level was extremely high. A bone marrow aspiration test demonstrated the existence of large proerythroblasts. Although anti-PVB19 IgM antibody levels were not increased, polymerase chain reaction (PCR) detected PVB19 DNA in his serum. Thus, he was diagnosed as having PRCA induced by PVB19 infection. PCR analysis of total DNA isolated from 0-hour biopsy sections showed the existence of PVB19 DNA. Furthermore, PVB19 proteins was detected on renal tubules of 0-hour allograft by immunoperoxidase staining. Thus, transmission of PVB19 through the allograft was confirmed. A single course of intravenous immunoglobulin (IVIG) therapy resulted in substantial improvement; however, the effect was limited, and severe anemia relapsed after 5-6 months. Several courses of IVIG with adjustment of immunosuppressive drugs resulted in long-term remission. Our case demonstrates that donor-transmitted PVB19 infection should be suspected in kidney transplant recipients who develop refractory anemia during the early post-operative phase.

Beyond Cytomegalovirus and Epstein-Barr Virus: a Review of Viruses Composing the Blood Virome of Solid Organ Transplant and Hematopoietic Stem Cell Transplant Recipients

Viral primary infections and reactivations are common complications in patients after solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) and are associated with high morbidity and mortality. Among these patients, viral infections are frequently associated with viremia. Beyond the usual well-known viruses that are part of the routine clinical management of transplant recipients, numerous other viral signatures or genomes can be identified in the blood of these patients. The identification of novel viral species and variants by metagenomic next-generation sequencing has opened up a new field of investigation and new paradigms. Thus, there is a need to thoroughly describe the state of knowledge in this field with a review of all viral infections that should be scrutinized in high-risk populations. Here, we review the eukaryotic DNA and RNA viruses identified in blood, plasma, or serum samples of pediatric and adult SOT/HSCT recipients and the prevalence of their detection, with a particular focus on recently identified viruses and those for which their potential association with disease remains to be investigated, such as members of the Polyomaviridae, Anelloviridae, Flaviviridae, and Astroviridae families. Current knowledge of the clinical significance of these viral infections with associated viremia among transplant recipients is also discussed. To ensure a comprehensive description in these two populations, individuals described as healthy (mostly blood donors) are considered for comparative purposes. The list of viruses that should be on the clinicians' radar is certainly incomplete and will expand, but the challenge is to identify those of possible clinical significance.

Parvovirus-Induced Transient Aplastic Crisis in a Patient With Newly Diagnosed Hereditary Spherocytosis

Parvovirus B19 infections are prevalent in children and commonly present as slapped cheek fever, also known as the fifth disease. They are seen frequently in daycares and professions that require close contact with children. The most common presentation is a rash that is prominent on the cheeks; less common symptoms include painful or swollen joints (polyarthopathy syndrome). The infection is self-limited and resolves within one to two weeks. The virus has an affinity to the red blood cell (RBC) precursors and can rarely cause temporary cessation of the bone marrow's RBC production, leading to aplastic anemia. This is especially of significance in patients predisposed to increased RBC destruction, such as hereditary spherocytosis, sickle cell anemia, and other morphological abnormalities of the RBC. The overlapping arrest of RBC production and excessive destruction leads to a transient aplastic crisis (TAC), leading to severe life-threatening anemia, requiring blood urgent blood transfusions. There have been many studies reporting the incidence of TAC in patients with sickle cell crisis. Only a few cases have been reported in patients with hereditary spherocytosis.

Pure Red Cell Aplasia Related to Parvovirus B19 Infection in Simultaneous Pancreas and Kidney Recipient: A Case Report

A 42-year-old woman received a simultaneous pancreas and kidney transplantation (SPK). Immunosuppression consisted of tacrolimus modified release, prednisone, mycophenolate mofetil (MMF), and thymoglobulin as induction. The function of both grafts was good. Eight months after SPK, the patient suffered from weakness and arthralgia. Normocytic anemia with reticulocytopenia was revealed. In a bone marrow examination, giant pronormoblasts were found. Immunohistochemical staining of bone marrow and serum examination were positive for Parvovirus B19 (Parvo B19) confirming diagnosis of pure red cell aplasia (PRCA).The treatment consisted of MMF withdrawal, red-cell transfusions, immunoglobulins subcutaneously (SCIg) and immunosuppression reduction. Rapid improvement was observed with the rise of reticulocyte count and hemoglobin. Two months after the achievement of remission, the low dose of everolimus was added considering the high risk of rejection and antiviral potential of mTOR inhibitors. Three months later, PRCA relapsed. Retherapy with SCIg was still effective. Subsequent SCIg was supplemented due to low reticulocyte count and recurrent herpes zoster. The replication of Parvo B19 was persistent (serum qualitative test). Everolimus was withdrawn after 9 months of therapy due to the recurrence of PRCA and serious infections. The observation period after PRCA diagnosis lasts for 15 months. The patient is in good condition with no anemia and excellent grafts function. In conclusion, pure red cell aplasia related to Parvo B19 infection should be considered in transplant recipients with normocytic anemia and reticulocytopenia. The treatment with immunoglobulin G and immunosuppression reduction is an effective therapy. The role of everolimus in Parvo B19 infection requires future studies.

Transfusion-Dependent Anemia in a Simultaneous Pancreas and Kidney Transplant Recipient

A case of transfusion-dependent anemia in a simultaneous pancreas and kidney (SPK) transplant recipient that masqueraded as gastrointestinal bleeding (GIB) is described. The anemia was attributed to bleeding from the donor duodenal cuff based on balloon enteroscopy findings. The patient underwent multiple contrast-enhanced computed tomography scans and multiple endoscopies with confounding features until, eventually, the diagnosis was established. We discuss the diagnostic difficulties and the therapeutic dilemma, along with the pitfalls in ascertaining the final diagnosis.