Morbimortality of pandemic influenza A H1N1 infection in kidney transplant recipients requiring hospitalization: a comparative analysis with nonimmunocompromised patients

Effect of COVID-19 on Kidney Graft Function One Year after Onset

Background and Objectives: Kidney transplant recipients (KTRs) are at a higher risk of severe COVID-19 development. The course of the infection may vary. Long-term consequences for graft function are still being studied. We investigate whether the clinical course of SARS-CoV-2 infection among KTRs had a long-term effect on graft function. Patients and method: 128 KTRs with confirmed SARS-CoV-2 infection were included in the study. They were divided into two groups: mild (without the need for oxygen therapy; n = 91) and severe (with the need for oxygen therapy; n = 21). Baseline characteristics and medical data, especially creatinine level, estimated glomerular filtration rate (eGFR) CKD-EPI, and proteinuria, were analyzed. The main outcomes were the absolute and relative change in eGFR during the one-year follow-up after COVID-19. In the final models, sex, age, smoking, presence of diabetes mellitus (DM), and cardiovascular disease (CVD) were included. Results: KTRs with severe COVID-19 were older, more likely to smoke, and had DM and CVD more frequently. Our analysis reveals that COVID-19 severity was associated with a significantly more pronounced relative eGFR decline one year after recovery only in males [-13.94 (95% CI: -25.13 to -2.76, p = 0.015) percentage points]. One year after the disease onset, males with a severe course of the infection had a higher eGFR decline than those with a mild one. The COVID-19 severity did not affect eGFR loss in females. Conclusions: In KTRs suffering from COVID-19, deterioration of graft function was noticed. The eGFR decline was associated with disease severity and sex. It indicates a need for further research, observation, and preventive actions for KTRs, especially males.

Epidemiology of laboratory-confirmed influenza among kidney transplant recipients compared to the general population-A nationwide cohort study

Seasonal influenza causes morbidity and mortality after organ transplantation. We quantified the detection of laboratory-confirmed influenza among kidney transplant recipients compared to the general population in a nationwide cohort. All laboratory-confirmed cases of influenza and hospitalizations due to influenza among all kidney transplant recipients in our country between 1995 and 2017 were captured with database linkage from statutory national registries. Data from the general population of Finland, population 5.5 million, were used for comparisons. Annual incidences of influenza and hospitalizations due to influenza, and standardized incidence ratios (SIR) were calculated. Altogether 3904 kidney transplant recipients with a total follow-up of 37 175 patient-years were included. Incidence of laboratory-confirmed influenza was 9.0 per 1000 patient years in 2003-2019, and 18.0 per 1000 patient years during 2015-2019. The risk of laboratory-confirmed influenza was significantly higher among kidney transplant recipients compared to the general population (SIR 5.1, 95% CI 4.5-5.7). SIR for hospitalization due to influenza was 4.4 (95% CI 3.4-4.7). Mortality of the hospitalized patients was 9%, and 5% of the patients with laboratory-confirmed influenza. Detection of laboratory-confirmed influenza is increased fivefold and risk of hospitalization due to influenza more than fourfold among kidney transplant recipients compared to the general population.

Vaccination With Live Attenuated Vaccines in Four Children With Chronic Myeloid Leukemia While on Imatinib Treatment

Chronic myeloid leukemia (CML) in childhood and adolescence is a rare malignancy that can successfully be treated with the tyrosine kinase inhibitor (TKI) imatinib. According to the current experience, treatment is necessary for years and, in the majority of cases, a lifelong approach is required to control the malignant disease. To what extent imatinib causes immunosuppression in different age cohorts is a controversial discussion. According to general medical recommendations, live vaccines are contraindicated in individuals treated with imatinib. However, a recent increase in the number of globally reported cases of measles has been observed and continues to rise. Due to the high contagiousness of the virus, near-perfect vaccination coverage (herd immunity of 93 to 95%) is required to effectively protect against measles resurgence-a scenario that is not realistic in many countries. When four teenagers with CML (median age 13 years, range 12-15) who were enrolled into pediatric trial CML-paed II while on imatinib treatment (median treatment duration 36 months, range 11-84) were identified without protective measles and/or varicella titers, we carefully balanced the risks of a live vaccination under immunosuppressive TKI medication against the benefit of being protected. The patients underwent live vaccination with the live attenuated vaccines M-M-RVAX Pro® and Varivax® simultaneously (Patient #1), Priorix® and Varilix® consecutively (Patient #2), and Priorix® (Patients #3 and #4). While the first three patients were vaccinated while receiving TKI therapy, treatment with imatinib was interrupted in patient #4 for 1 week prior and 2 weeks after vaccination. Patients #1 and #3 reacted with stable long-term seroconversion. In Patient #2, serum titer conversion against measles and varicella could not be demonstrated and thus revaccination with Priorix® and Varilix® was performed 3 years later. However, protective titers did not develop or were lost again. Patient #4 also lost protective titers against measles when assessed 10 months after vaccination, but revaccination resulted in stable seroprotective titers over 12 months after the last vaccination during ongoing imatinib treatment. We conclude that in all patients, the safety of live vaccines could be documented, as no acute or late adverse events were observed. However, in line with observations that memory B-cells are lost under exposure to imatinib, revaccination may become necessary (two out of four patients in this small series lost their seroprotection). Considering that the number of cases is very small, we also suggest some criteria for decision-making regarding live vaccinations of CML patients treated with imatinib.

[Database linkage for surveillance of the influenza A(H1N1)pdm09 pandemic in Brazil, 2009-2010]

Based on database linkage, the objective of this study was to describe the epidemiological profile of notified cases and deaths from the new viral subtype of influenza during the influenza pandemic. Secondary data were used from the SINAN (Information System for Notifiable Diseases) and SIM (Mortality Information System) for the years 2009 and 2010. Linkage identified 5,973 deaths of cases notified as pandemic influenza. Of these, 2,170 (36.33%) had been classified in the SINAN as confirmed pandemic influenza, 215 (3.6%) as due to other infectious agents, and 3,340 (55.92%) as ruled out. After linkage, some cases in the SINAN database that were closed as death from influenza (n = 658) or death from other causes (n = 847) could not be located in the SIM database. Database linkage can improve the surveillance system and monitoring of morbidity and mortality. We recommend strengthening influenza surveillance in Brazil using linkage of Ministry of Health databases.

Human Influenza Virus Infections

Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection.

Clinical aspects of influenza A(H1N1)pdm09 cases reported during the pandemic in Brazil, 2009-2010

OBJECTIVE

To describe the clinical aspects of cases of influenza A(H1N1)pdm09 in Brazil.

METHODS

A descriptive study of cases reported in Sistema de Informação de Agravos de Notificação (SINAN), 2009-2010.

RESULTS

As the final classification, we obtained 53,797 (56.79%) reported cases confirmed as a new influenza virus subtype, and 40,926 (43.21%) cases discarded. Fever was the most common sign, recorded in 99.74% of the confirmed and 98.92% of the discarded cases. Among the confirmed cases, the presence of comorbidities was reported in 32.53%, and in 38.29% of the discarded cases. The case fatality rate was 4.04%; 3,267 pregnant women were confirmed positive for influenza A new viral subtype and 2,730 of them were cured. The case fatality rate of pregnant women was 6.88%.

CONCLUSION

The findings suggested concern of the health system with pregnant women, and patients with comorbidities and quality of care may have favored a lower mortality. We recommend that, when caring for patients with severe respiratory symptoms, with comorbidities, or pregnant women, health professionals should consider the need for hospital care, as these factors make up a worse prognosis of infection by the pandemic influenza virus.

Differential influenza H1N1-specific humoral and cellular response kinetics in kidney transplant patients

Renal transplant recipients (RTR) are considered at high risk for influenza-associated complications due to immunosuppression. The efficacy of standard influenza vaccination in RTRs is unclear. Hence, we evaluated activation of the adaptive immunity by the pandemic influenza A(H1N1) 2009 (A(H1N1)pdm09) vaccine in RTRs as compared to healthy controls. To determine cross-reactivity and/or bystander activation, seasonal trivalent influenza vaccine and tetanus/diphteria toxoid (TT/DT) vaccine-specific T cells along with allospecific T cells were quantified before and after A(H1N1)pdm09 vaccination. Vaccination-induced alloimmunity was additionally determined by quantifying serum creatinine and proinflammatory protein IP-10. Contrary to healthy controls, RTRs required a booster vaccination to achieve seroconversion (13.3 % day 21; 90 % day 90). In contrast to humoral immunity, sufficient A(H1N1)pdm09-specific T-cell responses were mounted in RTRs already after the first immunization with a magnitude comparable with healthy controls. Interestingly, vaccination simultaneously boosted T cells reacting to seasonal flu but not to TT/DT, suggesting cross-activation. No alloimmune effects were recorded. In conclusion, protective antibody responses required booster vaccination. However, sufficient cellular immunity is established already after the first vaccination, demonstrating differential kinetics of humoral and cellular immunity.

Rare and emerging viral infections in transplant recipients

Emerging viral pathogens include newly discovered viruses as well as previously known viruses that are either increasing, or threatening to increase in incidence. While often first identified in the general population, they may affect transplant recipients, in whom their manifestations may be atypical or more severe. Enhanced molecular methods have increased the rate of viral discovery but have not overcome the problem of demonstrating pathogenicity. At the same time, improved clinical diagnostic methods have increased the detection of reemerging viruses in immunocompromised patients. In this review, we first discuss viral diagnostics and the developing field of viral discovery and then focus on rare and emerging viruses in the transplant population: human T-cell leukemia virus type 1; hepatitis E virus; bocavirus; KI and WU polyomaviruses; coronaviruses HKU1 and NL63; influenza, H1N1; measles; dengue; rabies; and lymphocytic choriomeningitis virus. Detection and reporting of such rare pathogens in transplant recipients is critical to patient care and improving our understanding of posttransplant infections.

Emerging viral diseases in kidney transplant recipients

Viruses are the most important cause of infections and a major source of mortality in Kidney Transplant Recipients (KTRs). These patients may acquire viral infections through exogenous routes including community exposure, donor organs, and blood products or by endogenous reactivation of latent viruses. Beside major opportunistic infections due to CMV and EBV and viral hepatitis B and C, several viral diseases have recently emerged in KTRs. New medical practices or technologies, implementation of new diagnostic tools, and improved medical information have contributed to the emergence of these viral diseases in this special population. The purpose of this review is to summarize the current knowledge on emerging viral diseases and newly discovered viruses in KTRs over the last two decades. We identified viruses in the field of KT that had shown the greatest increase in numbers of citations in the NCBI PubMed database. BKV was the most cited in the literature and linked to an emerging disease that represents a great clinical concern in KTRs. HHV-8, PVB19, WNV, JCV, H1N1 influenza virus A, HEV, and GB virus were the main other emerging viruses. Excluding HHV8, newly discovered viruses have been infrequently linked to clinical diseases in KTRs. Nonetheless, pathogenicity can emerge long after the discovery of the causative agent, as has been the case for BKV. Overall, antiviral treatments are very limited, and reducing immunosuppressive therapy remains the cornerstone of management.