Impact of pre-graft serology on risk of BKPyV infection post-renal transplantation.

OBJECTIVES: BK polyomavirus-associated nephropathy is a troublesome disease caused by BK polyomavirus (BKPyV) infection in immunocompromised renal graft recipients. There are no effective treatments available, making immunosuppression reduction the only management option. Thus, pre-graft predictive BKPyV replication markers are needed for identification of patients at high risk of viraemia. METHODS: We conducted a retrospective study to assess the correlation between pre-transplantation BKPyV serostatus and post-transplantation incidence of BKPyV infection. Sera from 329 recipients and 222 matched donors were tested for anti-BKPyV antibodies against BKPyV serotypes I and IV by using a virus-like particle-based immunoglobulin G enzyme-linked immunosorbent assay, and BKPyV DNA load was monitored for at least 1 year post-transplantation. RESULTS: Eighty recipients were viruric and 59 recipients were viraemic post-transplantation. In the post-transplantation period, the probability of developing viraemia for serotype I increased from 4.3% for the D-/R+ group to 12.1% for the D+/R+ group, climbing to 37.5% for the D+/R- group (P < 0.05). When calculating recipient mean titres for serotypes I and IV, we observed a clear difference in the proportions of viraemia, decreasing from 50% for mean titres <400 to 13.5% for titres ≥400 (P < 0.001), as well as a higher proportion of presumptive nephropathy (50% versus 23.1%, respectively; P < 0.05). In univariate analysis, this parameter had an odds ratio of 6.41 for the risk of developing post-transplantation BKPyV viraemia (95% confidence interval 3.16-13.07; P < 0.0001). CONCLUSIONS: Determination of both donor and recipient BKPyV seropositivity before transplantation and antibody titre measurements may serve as a predictive tool to manage clinical BKPyV infection by identification of patients at high risk.

SARS-CoV-2 infection long time after full vaccination is related to a lack of neutralizing antibodies.

SARS-CoV-2 infections after COVID-19 vaccination are not unexpected, but those occurring more than 14 days after second vaccine dose need to be investigated. We describe a well-characterized infection which occurred almost 2 months after full vaccination, and provide the evidence of a link with a lack of anti-SARS-CoV-2 neutralizing antibodies.

Assessment of intra-sample variability in HIV-1 DNA drug resistance genotyping.

BACKGROUND AND OBJECTIVES: HIV-1 drug resistance testing can be performed in proviral DNA. The non-homogenous distribution of viral variants in cells can impact the performance of this method. We assessed the variability of HIV-1 DNA genotyping results in the same blood sample using a next-generation sequencing (NGS) method. METHODS: For each included patient, a blood sample from a single venipuncture was split into five 1 mL aliquots, which were independently tested in the same run. HIV-1 DNA was quantified in blood samples using real-time PCR, and NGS was performed with the Sentosa platform combined with the Sentosa SQ HIV genotyping Assay. RESULTS: A total of 60 aliquots from 12 samples (12 patients) were tested. The median age was 45.50 years old, and all patients were treated with antiretrovirals. A significant variability can sometimes be observed in HIV-1 DNA quantification between aliquots from the same sample, with a coefficient of variation ranging from 23% to 89%. The analysis of resistance-associated mutations (RAMs) with a 20% cut-off found some discordances in RAMs profile between aliquots from the same sample for 5, 3 and 3 patients in the reverse transcriptase, protease and integrase genes, respectively. The analysis with a lower cut-off (10%) showed additional mutations, but did not improve the intra-sample concordance. CONCLUSIONS: There is an intra-sample variability in HIV-1 DNA resistance test results, and repetition may sometimes bring additional information, but the extent of its clinical impact still requires further investigation.

Spatial and Temporal Virus Load Dynamics of SARS-CoV-2: A Single-Center Cohort Study.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused an ongoing pandemic. Reverse transcription polymerase chain reaction (RT-PCR) is the gold standard for the detection of SARS-CoV-2 and has been applied to different specimen types. Understanding the virus load and virus detection frequency in different specimen types is important to improve diagnosis and estimate the duration of potential infectivity. We conducted a retrospective single-center cohort study on hospitalized and outpatients with SARS-CoV-2 infection. We analyzed the frequency of virus detection, virus load, and duration of the virus excretion in upper and lower respiratory specimens as well as stool and plasma. We found that the frequency of SARS-CoV-2 detection, the virus load, and duration of virus excretion was higher in lower respiratory tract (LRT) than in upper respiratory tract (URT) specimens. The duration of virus excretion was longer in patients requiring intensive care unit (ICU) admission. In conclusion, LRT specimens are the most appropriate specimen type for the detection and follow-up of SARS-CoV-2 infection. Duration of virus excretion is longer in severe cases of SARS-CoV-2 infection.

Panton-Valentine Leukocidin-Secreting Staphylococcus aureus Pneumonia Complicating COVID-19.

Necrotizing pneumonia induced by Panton-Valentine leukocidin-secreting Staphylococcus aureus is a rare but life-threatening infection that has been described in patients after they had influenza. We report a fatal case of this superinfection in a young adult who had coronavirus disease.

Risk factors for BK virus viremia and nephropathy after kidney transplantation: A systematic review.

In the last 20 years, the management of BK polyomavirus (BKPyV) reactivation in kidney transplant patients has become a true challenge for the transplant community. The only treatment option is based on the early identification of at-risk patients. The number of reported risk factors for BKPyV reactivation has increased markedly in the literature last years, although they are sometimes in an unclear or contradictory manner. Our purpose is to provide a systematic review and meta-analysis of risk factors for BKPyV viremia and nephropathy described in multivariate analyses. The PubMed database was searched for prospective or prospectively-based observational studies on risk factors for BKPyV viremia and/or nephropathy. Our qualitative assessment of risk factors was based on the odds ratios and hazard ratios calculated in multivariate regression analyses. Of the 241 publications screened, 34 were included in the qualitative analysis. In all, 144 and 19 distinct factors were analyzed for BKPyV viremia and for BKPyV nephropathy, respectively. Our evaluation highlighted eight risk factors for BKPyV viremia: a tacrolimus regimen, a deceased donor, a male recipient, a history of previous transplant, age at transplantation, ureteral stent use, delayed graft function, and acute rejection episodes increased the risk of BKV viremia to varying extents. Tacrolimus and acute rejection episodes were also associated with a higher incidence of BKPyV nephropathy. BKPyV reactivation is a serious complication after renal transplantation. With a view to combating this problem, existing data should be published in full, and new prospective international multicenter studies should be performed.