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

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.

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.

Post-Transplantation Anemia and Risk of Death Following Lung Transplantation

BACKGROUND

Post-transplantation anemia (PTA) is frequent among solid organ transplant recipients and has been associated with increased morbidity and mortality. However, the prevalence and impact of PTA in lung transplant recipients is still not elucidated.

METHODS

We performed a retrospective cohort study of adult Danish lung transplant recipients between January 2010 and December 2019. The prevalence and severity of PTA were determined during the first three years post-transplantation. Associations between PTA and selected risk factors were established using uni- and multivariate logistic regression models.

RESULTS

A total of 278 patients were included. At one and three years post-lung transplantation the prevalence of PTA was 75% and 52%, respectively. Male sex was associated with increased odds of PTA at all time points (aOR ranging from 2.3, 95% CI 1.1-4.6, P = 0.02 to 5.9, 95% CI 2.6-14, P < .001). Cystic fibrosis was also associated with anemia at one-year post-transplantation (aOR 4.3, 95% CI 1.2-17, P = 0.03). We found no strong associations between PTA and renal function or viral infections. Excess mortality in recipients with moderate or severe anemia compared to patients with mild or no anemia was borderline statistically significant at one-year post-lung transplantation (aHR 2.0, 95% CI 0.9-4.4, P = 0.07).

DISCUSSION

Post-transplantation anemia is very common in Danish lung transplant recipients. Male sex and cystic fibrosis are independent risk factors for development of anemia. Further investigation on PTA, the underlying mechanisms, and its clinical impact is needed.