Emerging viral diseases in kidney transplant recipients

Risk factors associated with Hepatitis E virus infection in kidney transplant recipients in a single tertiary Center in the United States

BACKGROUND

Hepatitis E virus (HEV), the causative agent of hepatitis E, is a common but self-limiting disease. However, in immunosuppressed kidney transplant 47 recipients (KTRs), HEV infection can become chronic. We investigated risk factors associated with HEV infection among 271 KTRs at the Johns Hopkins Hospital transplanted between 1988 and 2012.

METHODS

HEV infection was defined as having positive anti-HEV IgM, anti-HEV IgG, or HEV RNA. The risk factors included: age at transplant, sex, hemodialysis/peritoneal dialysis, plasmapheresis, transfusions, community urbanization, and other socioeconomic factors. Logistic regression was used to determine independent risk factors associated with HEV infection.

RESULTS

Out of 271 KTRs, 43 (16%) had HEV infection though not active disease. HEV infection in KTRs was associated with older age (≥45 years; OR = 4.04; 95% CI = 1.81-57 10.03; p = 0.001) and living in communities with low proportions of minorities (OR = 0.22; 95% 58 CI = 0.04-0.90; p = 0.046).

CONCLUSION

KTRs who had HEV infection may be at an increased risk of developing chronic HEV.

Correlation between CYP3A5 gene polymorphism and BK virus infection in kidney transplant recipients

BACKGROUND

Cytochrome P450 3A5 (CYP3A5) includes two active genotypes, namely CYP3A5*1/*1 or *1/*3 with the fast metabolic activity and CYP3A5*3/*3 with slow metabolic. We retrospectively analyzed the correlation between CYP3A5 gene polymorphism and the susceptibility to the BK virus (BKV) infection in renal transplant recipients.

METHODS

According to the inclusion/ exclusion criteria, we selected 134 recipients who received kidney transplantation at the Renmin Hospital of Wuhan University from January 2019 to December 2019. Based on the pre-operative CYP3A5 sequencing results, 134 recipients were divided into two groups: those expressing the fast metabolic CYP3A5*1/*1 or *1/*3 genotype; and, those expressing slow metabolic CYP3A5*3/*3 genotype. These two recipient groups were then analyzed for the BKV infection rate with different metabolic types to establish the potential relationship between CYP3A5 gene polymorphism and BKV infection.

RESULTS

The overall incidence of BKV viruria was 37.3%, whereas BKV viremia was 4.5% among all 134 recipients. The fast metabolism group had 9.1% incidence of BKV viremia and 49.1% incidence of BKV viruria. In contrast, the slow metabolism group had only 1.3%incidence of BKV viremia (P = 0.031) with only 29.1% BKV viruria (P = 0.011). The incidence of low levels of urinary BKV in the fast metabolism group was higher than that in the slow metabolism group (P = 0.005), while no significant statistical difference in the incidence of high levels of urinary BKV and high and low levels of blood BKV.

CONCLUSION

After kidney transplantation, CYP3A5 gene polymorphism of recipients present a certain relationship with the occurrence of BKV infection, which may be of value for the prediction and prevention of BKV infection.

Hepatitis E virus infection and rejection in kidney transplant recipients

BACKGROUND

Hepatitis E virus (HEV) infection has been associated with immune-mediated kidney diseases in developing countries. However, its relationship with kidney transplant outcomes has never been studied. We investigated the association between HEV infection and kidney graft rejection among kidney transplant recipients (KTRs).

METHODS

We conducted a matched cohort and longitudinal study utilizing banked sera following kidney transplantation during 1988-2012. Studies with evidence of post-transplantation HEV infection were identified by positive ELISA tests (anti-HEV IgM or anti-HEV IgG seroconversion) or positive HEV PCR and matched to KTR controls with negative HEV ELISA and PCR tests in a 1:5 ratio by age, sex, crossmatch status, immunosuppression era, and time of HEV testing. Outcome data collected included time to first kidney graft rejection, transaminases, and glomerular filtration rates. Log-ranked test was used to analyze survival.

RESULTS

Of 271 KTRs, 9 (3%) had evidence of post-transplantation HEV infection and were compared to 45 negative, matched controls. Median age at transplantation was 46 years. Kidney graft rejection was reported in 8 (89%) of cases and 21 (47%) of controls. Median time to first episode of kidney graft rejection was 17.4 months in cases and 30.8 months in controls (p = 0.029), with a higher hazard of developing kidney graft rejection in cases (HR = 3.23, 95% CI: 1.19-8.79). Lower mean glomerular filtration rates over time were observed in cases (35 mL/min/1.73m²) versus controls (42.4 mL/min/1.73m²) but did not reach significance (p = 0.24).

CONCLUSION

Subjects with evidence of post-transplantation HEV infection demonstrated earlier kidney graft rejection compared to controls.

The Magnitude and Functionality of SARS-CoV-2 Reactive Cellular and Humoral Immunity in Transplant Population Is Similar to the General Population Despite Immunosuppression

BACKGROUND

The ability of transplant (Tx) patients to generate a protective antiviral response under immunosuppression is pivotal in COVID-19 infection. However, analysis of immunity against SARS-CoV-2 is currently lacking.

METHODS

Here, we analyzed T cell immunity directed against SARS-CoV-2 spike-, membrane-, and nucleocapsid-protein by flow cytometry and spike-specific neutralizing antibodies in 10 Tx in comparison to 26 nonimmunosuppressed (non-Tx) COVID-19 patients.

RESULTS

Tx patients (7 renal, 1 lung, and 2 combined pancreas-kidney Txs) were recruited in this study during the acute phase of COVID-19 with a median time after SARS-CoV-2-positivity of 3 and 4 d for non-Tx and Tx patients, respectively. Despite immunosuppression, we detected antiviral CD4+ T cell-response in 90% of Tx patients. SARS-CoV-2-reactive CD4+ T cells produced multiple proinflammatory cytokines, indicating their potential protective capacity. Neutralizing antibody titers did not differ between groups. SARS-CoV-2-reactive CD8+ T cells targeting membrane- and spike-protein were lower in Tx patients, albeit without statistical significance. However, frequencies of anti-nucleocapsid-protein-reactive, and anti-SARS-CoV-2 polyfunctional CD8+ T cells, were similar between patient cohorts. Tx patients showed features of a prematurely aged adaptive immune system, but equal frequencies of SARS-CoV-2-reactive memory T cells.

CONCLUSIONS

In conclusion, a polyfunctional T cell immunity directed against SARS-CoV-2 proteins as well as neutralizing antibodies can be generated in Tx patients despite immunosuppression. In comparison to nonimmunosuppressed patients, no differences in humoral and cellular antiviral-immunity were found. Our data presenting the ability to generate SARS-CoV-2-specific immunity in immunosuppressed patients have implications for the handling of SARS-CoV-2-infected Tx patients and raise hopes for effective vaccination in this cohort.

Isolation of Viable SARS-CoV-2 Virus from Feces of an Immunocompromised Patient Suggesting a Possible Fecal Mode of Transmission

(1) Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) excretion in stools is well documented by RT-PCR, but evidences that stools contain infectious particles are scarce. (2) Methods: After observing a Corona Virus 2019 Disease (COVID-19) epidemic cluster associated with a ruptured sewage pipe, we search for such a viable SARS-CoV-2 particle in stool by inoculating 106 samples from 46 patients. (3) Results: We successfully obtained two isolates from a unique patient with kidney transplantation under immunosuppressive therapy who was admitted for severe diarrhea. (4) Conclusions: This report emphasizes that SARS-CoV-2 is an enteric virus, and infectious virus particles can be isolated from the stool of immune-compromised patients like, in our case, kidney transplant recipient. Immune-compromised patients are likely to have massive multiplication of the virus in the gastrointestinal tract and this report suggests possible fecal transmission of SARS-CoV-2.

Isolation of Viable SARS-CoV-2 Virus from Feces of an Immunocompromised Patient Suggesting a Possible Fecal Mode of Transmission

(1) Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) excretion in stools is well documented by RT-PCR, but evidences that stools contain infectious particles are scarce. (2) Methods: After observing a Corona Virus 2019 Disease (COVID-19) epidemic cluster associated with a ruptured sewage pipe, we search for such a viable SARS-CoV-2 particle in stool by inoculating 106 samples from 46 patients. (3) Results: We successfully obtained two isolates from a unique patient with kidney transplantation under immunosuppressive therapy who was admitted for severe diarrhea. (4) Conclusions: This report emphasizes that SARS-CoV-2 is an enteric virus, and infectious virus particles can be isolated from the stool of immune-compromised patients like, in our case, kidney transplant recipient. Immune-compromised patients are likely to have massive multiplication of the virus in the gastrointestinal tract and this report suggests possible fecal transmission of SARS-CoV-2.

Human Cytomegalovirus Inhibits Autophagy of Renal Tubular Epithelial Cells and Promotes Cellular Enlargement

Human Cytomegalovirus (HCMV) is a frequent opportunistic pathogen in immunosuppressed patients, which can be involved in kidney allograft dysfunction and rejection. In order to study the pathophysiology of HCMV renal diseases, we concentrated on the impact of HCMV infection on human renal tubular epithelial HK-2 cells. Our aim was to develop a model of infection of HK-2 cells by using the viral strain TB40/E, that contains the extended cell tropism of clinical isolates and the efficient viral multiplication in cell culture of laboratory-adapted strains. We observed that HK-2 cells can be infected by HCMV and expressed viral antigens, but they do not produce extracellular viral particles. We then studied the interplay of HCMV with ciliogenesis and autophagy. Primary cilium (PC) is a stress sensor important to maintain renal tissue homeostasis that projects from the apical side into the lumen of tubule cells. PC formation and length were not modified by HCMV infection. Autophagy, another stress response process critically required for normal kidney functions, was inhibited by HCMV in HK-2 cells with a reduction in the autophagic flux. HCMV classically induces an enlargement of infected cells in vivo and in vitro, and we observed that HCMV infection led to an enlargement of the HK-2 cell volume. Our results constitute therefore an excellent starting point to further explore the role of these mechanisms in renal cells dysfunction.

Impact assessment and investigation of factors associated with herpesviruses viremia in the first year of renal transplantation

The increased risk for opportunistic infections after a renal transplant requires monitoring of viral infections to avoid future complications. Our goal was to investigate the impact and factors associated with Epstein-Barr virus (EBV), human cytomegalovirus (HCMV) and human herpesvirus type 6 (HHV-6) viremia in renal transplant recipients. Whole blood samples were collected monthly from 82 patients during the first semester and then quarterly up to 1 year after transplantation. EBV, HCMV, and HHV-6 were detected and quantified by TaqMan real-time polymerase chain reaction. The results showed that EBV and HCMV viremia were detected in 32 patients (39% each), while HHV-6 viremia in only 3 patients (3.7%). EBV was significantly associated with age (P = .050), thymoglobuline induction (P = .019), mTOR inhibitor-based therapy (P = .003), and female gender (P = .044). HCMV was significantly associated with basiliximab induction (P = .015), mycophenolate mofetil (MMF)-based therapy (P = .003) and allograft acute rejection (P = .033). Moreover, HCMV-disease was correlated with MMF-based therapy (P = .021) and female gender (P = .003). In conclusion, EBV and HCMV viremia were associated with different immunosuppressive induction and maintenance strategies. Additionally, higher HCMV viremia (> 10 ⁴ copies/mL) was related to acute allograft rejection.

Practical Applications in Immunohistochemistry: Evaluation of Rejection and Infection in Organ Transplantation

CONTEXT

-Immunohistochemical analysis of tissue biopsy specimens is a crucial tool in diagnosis of both rejection and infection in patients with solid organ transplants. In the past 15 years, the concept of antibody-mediated rejection has been refined, and diagnostic criteria have been codified in renal, heart, pancreas, and lung allografts (with studies ongoing in liver, small intestine, and composite grafts), all of which include immunoanalysis for the complement split product C4d.

OBJECTIVES

-To review the general concepts of C4d biology and immunoanalysis, followed by organ-allograft-specific data, and interpretative nuances for kidney, pancreas, and heart, with discussion of early literature for lung and liver biopsies. Additionally, practical applications and limitations of immunostains for infectious organisms (Polyomavirus, Adenoviridae [adenovirus], and the herpes virus family, including Herpes simplex virus, Cytomegalovirus, Human herpes virus 8, and Epstein-Barr virus) are reviewed in the context of transplant recipients.

DATA SOURCES

-Our experience and published primary and review literature.

CONCLUSIONS

-Immunohistochemistry continues to have an important role in transplant pathology, most notably C4d staining in assessment of antibody-mediated rejection and assessment of viral pathogens in tissue. In all facets of transplant pathology, correlation of morphology with special studies and clinical data is critical, as is close communication with the transplant team.

Epidemiology and management of chronic hepatitis E infection in solid organ transplantation: a comprehensive literature review

Hepatitis E virus (HEV) infection has emerged as a global public health issue. Although it often causes an acute and self-limiting infection with low mortality rates in the western world, it bears a high risk of developing chronic hepatitis in immunocompromised patients with substantial mortality rates. Organ transplant recipients who receive immunosuppressive medication to prevent rejection are thought to be the main population at risk for chronic hepatitis E. Therefore, there is an urgent need to properly evaluate the clinical impact of HEV in these patients. This article aims to review the prevalence, infection course, and management of HEV infection after solid organ transplantation by performing a comprehensive literature review. In addition, an in-depth emphasis of this clinical issue and a discussion of future development are also presented.