Comparative analysis of a double primer PCR assay with plasma, leukocytes and antigenemia for diagnosis of active human cytomegalovirus infection in bone marrow transplant patients

Altered Signatures of Plasma Inflammatory Proteins and Phonotypic Markers of NK Cells in Kidney Transplant Patients upon CMV Reactivation

Cytomegalovirus (CMV) reactivation remains a common opportunistic infection with a prominent role in immune reconstitution in organ transplant recipients. CMVs as important drivers of natural killer (NK) cell differentiation has been indicated to prompt several phenotypic and functional alteration in these cells. We aimed to monitor the reconstitution of NK cells and change the signature of inflammatory proteins at the critical phase of CMV reactivation over six months after kidney transplantation. The present study indicated that CMV reactivation is associated with the development of IL-6, IL-10, and cytotoxic granules, including granzyme-B and granulysin, and the drop in the frequency of CD16 + NKG2A-CD57 + NK cell subset in kidney transplant recipients (KTRs) with reactivation versus non- reactivated ones. Our findings describe distinct immune signatures that emerged with CMV reactivation after kidney transplantation, which may be helpful in the timely management of CMV infection in KTRs.

Tissue presentation of human pegivirus infection in liver transplanted recipients

Human pegivirus-1 (HPgV-1) is known for its protective role in HIV co-infected individuals. This immunomodulatory effect raised questions concerning the possible role of HPgV-1 infection and the risk of rejection in liver transplanted patients. We aimed to evaluate the possible protective effect of HPgV-1 on graft outcome of liver transplanted patients. A total of 283 patients were recruited. Formalin-fixed paraffin-embedded tissue samples were collected from the explanted liver. HBV-DNA, HCV-RNA, and HPgV-1-RNA were determined using PCR and multiplex RT-PCR assays. The clinical course of patients including the occurrence of acute cellular rejection was compared between HPgV-1-infected vs. uninfected patients. HBV-DNA, HCV-RNA and HPgV-1-RNA were detected in 42.6%, 4.9%, and 7.8% of samples, respectively. None of the HPgV-1-infected patients experienced graft rejection. Group LASSO logistic regression revealed that HPgV-1 infection was the only factor which significantly reduced the odds of graft rejection (OR = 0.5, 95% CI = 0.29-0.89). No significant association was found between the presence of HPgV-1 with HBV and HCV infections. The lack of graft rejection in HPgV-1-infected liver transplanted patients might indicate a possible role of this virus for graft surveillance. Since these are still preliminary findings, prospective studies should further elucidate the role of HPgV-1 in liver transplantation outcomes.

Harnessing Memory NK Cell to Protect Against COVID-19

The worldwide struggle against the coronavirus disease 2019 (COVID-19) as a public health crisis continues to sweep across the globe. Up to now, effective antiviral treatment against COVID-19 is not available. Therefore, throughout virus infections, a thorough clarification of the virus-host immune system interactions will be most probably helpful to encounter these challenges. Emerging evidence suggests that just like SARS and MERS, COVID-19 primarily suppresses the innate immune system, enabling its stable propagation during the early stage of infection. Consequently, proinflammatory cytokines and chemokines have been increasing during infection progression associated with severe lung pathology. It is imperative to consider hyper inflammation in vaccine designing, as vaccine-induced immune responses must have a protective role against infection without leading to immunopathology. Among the front-line responders to viral infections, Natural Killer (NK) cells have immense therapeutic potential, forming a bridge between innate and adaptive responses. A subset of NK cells exhibits putatively increased effector functions against viruses following pathogen-specific and immunization. Memory NK cells have higher cytotoxicity and effector activity, compared with the conventional NK cells. As a pioneering strategy, prompt accumulation and long-term maintenance of these memory NK cells could be an efficacious viral treatment. According to the high prevalence of human cytomegalovirus (HCMV) infection in the world, it remains to be determined whether HCMV adaptive NK cells could play a protective role against this new emerging virus. In addition, the new adaptive-like KIR+NKG2C+ NK cell subset (the adaptive-like lung tissue residue [tr]NK cell) in the context of the respiratory infection at this site could specifically exhibit the expansion upon COVID-19. Another aspect of NK cells we should note, utilizing modified NK cells such as allogeneic off-the-shelf CAR-NK cells as a state-of-the-art strategy for the treatment of COVID-19. In this line, we speculate introducing NKG2C into chimeric antigen receptors in NK cells might be a potential approach in future viral immunotherapy for emerging viruses. In this contribution, we will briefly discuss the current status and future perspective of NK cells, which provide to successfully exploit NK cell-mediated antiviral activity that may offer important new tools in COVID-19 treatment.

Association of the costimulatory molecule gene polymorphisms and active cytomegalovirus infection in hematopoietic stem cell transplant patients

Determinative associations may exist between costimulatory molecule gene polymorphisms with a variety of post hematopoietic stem cell transplantation (HSCT) viral related clinical outcomes especially acute graft versus host disease (aGVHD). Therefore in this study the associations between costimulatory molecule gene polymorphisms including: cytotoxic T-lymphocyte antigen-4 (CTLA4), programmed cell death-1 (PD-1), inducible T cell costimulator (ICOS), and cluster differentiation 28 (CD28) with active cytomegalovirus (CMV) infection were evaluated in HSCT patients. The 72 allogeneic HSCT patients with and without aGVHD were enrolled in this cross sectional study between years: 2004-2011. The single nucleotide polymorphisms in loci of the costimulatory molecules including: CTLA4 gene (-318 C/T, 1722 T/C, 1661 A/G, +49 A/G), PD-1 gene (PD-1.3 A/G, PD-1.9 C/T), ICOS gene (1720 C/T), and CD28 gene (+17 C/T) were analyzed in studied HSCT patients by PCR-RFLP methods. The active CMV infection was evaluated in fresh EDTA-treated blood samples of each allogeneic HSCT patients by CMV antigenemia kit according to manufacturer's instruction. Active CMV infection was found in 11 of 72 (15.27 %) of allogeneic HSCT patients. The T allele and TT genotype of the CD28 +17 C/T were significantly higher frequency in active CMV infected allogeneic HSCT patients experienced aGVHD. The G allele and GG genotype of the CTLA4 -1661 A/G were significantly higher frequent in active CMV infected allogeneic HSCT patients experienced low grade of aGVHD. Finally, finding of significant associations between CD28 +17 C/T and CTLA4 -1661 A/G genotypes with CMV active infection in allogeneic HSCT patients experienced aGVHD emphasize on the importance of the genetic pattern of costimulatory genes in outcomes of active CMV infection in HSCT patients needs completed studies.

Association of the costimulatory molecule gene polymorphisms and active cytomegalovirus infection in hematopoietic stem cell transplant patients

Determinative associations may exist between costimulatory molecule gene polymorphisms with a variety of post hematopoietic stem cell transplantation (HSCT) viral related clinical outcomes especially acute graft versus host disease (aGVHD). Therefore in this study the associations between costimulatory molecule gene polymorphisms including: cytotoxic T-lymphocyte antigen-4 (CTLA4), programmed cell death-1 (PD-1), inducible T cell costimulator (ICOS), and cluster differentiation 28 (CD28) with active cytomegalovirus (CMV) infection were evaluated in HSCT patients. The 72 allogeneic HSCT patients with and without aGVHD were enrolled in this cross sectional study between years: 2004-2011. The single nucleotide polymorphisms in loci of the costimulatory molecules including: CTLA4 gene (-318 C/T, 1722 T/C, 1661 A/G, +49 A/G), PD-1 gene (PD-1.3 A/G, PD-1.9 C/T), ICOS gene (1720 C/T), and CD28 gene (+17 C/T) were analyzed in studied HSCT patients by PCR-RFLP methods. The active CMV infection was evaluated in fresh EDTA-treated blood samples of each allogeneic HSCT patients by CMV antigenemia kit according to manufacturer's instruction. Active CMV infection was found in 11 of 72 (15.27 %) of allogeneic HSCT patients. The T allele and TT genotype of the CD28 +17 C/T were significantly higher frequency in active CMV infected allogeneic HSCT patients experienced aGVHD. The G allele and GG genotype of the CTLA4 -1661 A/G were significantly higher frequent in active CMV infected allogeneic HSCT patients experienced low grade of aGVHD. Finally, finding of significant associations between CD28 +17 C/T and CTLA4 -1661 A/G genotypes with CMV active infection in allogeneic HSCT patients experienced aGVHD emphasize on the importance of the genetic pattern of costimulatory genes in outcomes of active CMV infection in HSCT patients needs completed studies.

The prevalence of molecular and immunologic infective markers of hepatitis viruses in patients with hematological malignancies

Acute and chronic viral hepatitis infections are corresponding to increase the risk of different types of hematological malignancies especially with leukemia. In this study the serological and molecular markers of hepatitis viruses were evaluated in patients with different types of leukemia in comparing with control group. In this cross sectional study, 100 EDTA-treated blood samples were collected from leukemia patients and also from healthy control group, respectively. Serological and molecular markers of HBV, HCV and HDV viruses were analyzed for determination of the role of these hepatitis viruses in clinical outcomes of leukemia disorders. Increasing risk factors of leukemia were evaluated statistically in two studied groups by SPSS software. One of molecular and immunological markers of HBV, HDV and HCV was found in 24 of 100 (24%), 22 of 100 (22%), and 1 of 100 (1%) patients with leukemia and in 12 of 100 (12%), 6 of 100 (6%), and 2 of 100 (2%) control patients. Significant differences were detected in detection of HBsAg (P = 0.02), HBeAb (P = 0.009), and HCV-RNA (P = 0.05) between leukemia patients and control group, respectively. The high prevalence of HBV and HCV infective markers were detected in ALL and AML patients. Identification of high prevalence of HBV and HCV infective markers in leukemia patients proposed strong association between hepatitis viral infections and leukemia. Therefore, evaluation of the prevalence of viral hepatitis infections in larger groups of patients with long lasting follow up is suggesting.

Active human cytomegalovirus infection and glycoprotein b genotypes in brazilian pediatric renal or hematopoietic stem cell transplantation patients

A prospective analysis of active Human Cytomegalovirus infection (HCMV) was conducted on 33 pediatric renal or hematopoietic stem cell post-transplant patients. The HCMV-DNA positive samples were evaluated for the prevalence of different gB subtypes and their subsequent correlation with clinical signs. The surveillance of HCMV active infection was based on the monitoring of antigenemia (AGM) and on a nested polymerase chain reaction (N-PCR) for the detection of HCMV in the patients studied. Using restriction analysis of the gB gene sequence by PCR-RFLP (Restriction Fragment Length Polymorphism), different HCMV strains could be detected and classified in at least four HCMV genotypes. Thirty-three pediatric recipients of renal or bone marrow transplantation were monitored. Twenty out of thirty-three (60.6%) patients demonstrated active HCMV infection. gB1 and gB2 genotypes were more frequent in this population. In this study, we observed that gB2 had correlation with reactivation of HCMV infection and that patients with mixture of genotypes did not show any symptoms of HCMV disease. Future studies has been made to confirm this.

Laboratory diagnosis of cytomegalovirus infection and disease in immunocompromised patients

PURPOSE OF REVIEW

To review new developments in PCR technology as they apply to detecting cytomegalovirus viremia and pneumonia, recent advances in detecting CMV resistance to antivirals and assays of specific CMV lymphocyte function.

RECENT FINDINGS

This review summarizes the attempts to use real time PCR for cytomegalovirus deoxyribonucleic acidemia and to compare it to conventional PCR and antigenemia, it also reviews the use of quantitative PCR on bronchoalveolar lavage to assist in the diagnosis of CMV pneumonia. Phenotypic assays of susceptibility in tissue culture are much too slow to assist clinical decisions, taking weeks for completion. Genotypic assays may be performed directly on clinical samples such as blood, and cerebrospinal fluid and can be done by sequencing in a very few days.Finally, assays of lymphocytic functional responsiveness to cytomegalovirus can be used to identify transplant recipients at continuing risk for cytomegalovirus disease.

SUMMARY

Assays for CMV DNA or antigen in blood are superior to culture for documenting viremia and pneumonia. Genotypic assays have largely replaced phenotypic assays for CMV resistance to antivirals. Lymphocyte responses to CMV antigen(s) may identify patients at risk for CMV disease.