A Low Incidence of Cytomegalo Virus Infection Following Allogeneic Hematopoietic Stem Cell Transplantation Despite a High Seroprevalence

Cytomegalovirus Reactivation as a Risk Factor for All-Cause Mortality in Children Undergoing Hematopoietic Stem Cell Transplantation: Experience Over Two Decades from a Tertiary Referral Center in India

The aim of the study was to analyse the burden of cytomegalovirus (CMV) disease in children undergoing hematopoietic stem cell transplantation (HSCT) and its correlation with all-cause mortality. We performed a retrospective study in children up to 18 years of age who underwent allogeneic HSCT between February 2002 to December 2021 in the pediatric blood and marrow transplantation unit. A total of 1035 patients were included where five hundred forty-three (52.4%) patients underwent matched family donor (MFD) HSCT, 213 (20.5%) underwent matched unrelated donor (MUD) HSCT; 279 (26.9%) underwent haploidentical HSCT (T cell replete in 213 and T cell depleted in 66 patients). CMV reactivation was documented in 258 (24.9% patients). CMV was seen in 39 (7.2%) MFD, 77 (36.1%) MUD, 106 T cell replete (49.7%) and 36 T cell depleted (54.5%) transplants. CMV reactivation was predominantly documented in those where donor and recipient were positive (D + /R +) for CMV serostatus (77%)) prior to HSCT. Overall mortality rate was significantly higher in the CMV positive group (103/258, 39.9%), as compared to the CMV negative group (152/777, 19.6%) (p value = 0.0001). CMV was the direct cause of death in 13/1035 children (1.2%). GvHD as a cause of death was found to be significantly higher among those with CMV (n = 32) as compared to those without CMV (n = 14) (35.6 versus 9%, p value = 0.0001). The incidence of CMV reactivation was noted in 25% of HSCT recipients, and predominantly in haploidentical HSCTs. CMV reactivation was shown to significantly impact all-cause mortality and there was a significantly increased risk of mortality due to GvHD among those with CMV reactivation.

Time-dependent analysis of the impact on early cytomegalovirus reactivation of HLA mismatch and acute graft-versus-host disease after allogeneic hematopoietic cell transplantation from related donors in acquired aplastic anemia

Cytomegalovirus (CMV) reactivation is an important issue in allogeneic hematopoietic cell transplantation (HCT). The incidence of early CMV reactivation is notably high in HLA-mismatched HCT. However, the interactions between HLA mismatch and acute graft-versus-host disease (aGvHD), a time-dependent event, make it methodologically challenging to evaluate the independent impact on CMV reactivation of the two variables. We retrospectively analyzed 355 patients with acquired aplastic anemia who received related donor transplants using a unified antithymocyte globulin-based platform. Patients were divided into group 1 (6/6 HLA match), group 2 (1-2/6 HLA allelic mismatch), and group 3 (3/6 HLA allelic mismatch). The impact of covariates was analyzed through two models: (1) time-dependent Cox and (2) dynamic landmarking analysis. The time-dependent Cox model showed that the HLA mismatch of 3/6 alleles (hazard ratio (HR) =1.852, P = .004) and aGvHD (HR = 1.009, P = .019) were independent risk factors for CMV reactivation. With the dynamic landmarking analysis, a higher HLA disparity correlated to increased early CMV reactivation (HR = 1.606, P = .001) at all time points. Developing aGvHD following HCT was generally associated with a higher incidence of CMV reactivation (HR = 1.623, P = .013), though its impact decreased with successive later landmark time points. In conclusion, our data suggest that the higher HLA disparity and aGvHD increases susceptibility to early CMV reactivation. In particular, the dynamic landmarking analysis demonstrated the time-varying effect of aGvHD on CMV reactivation, and HLA mismatch showed a profound impact over time following HCT.

Cytomegalovirus infection may be oncoprotective against neoplasms of B-lymphocyte lineage: single-institution experience and survey of global evidence

Background

Although cytomegalovirus (CMV) is not considered tumorigenic, there is evidence for its oncomodulatory effects and association with hematological neoplasms. Conversely, a number of experimental and clinical studies suggest its putative anti-tumour effect. We investigated the potential connection between chronic CMV infection in patients with B-lymphocyte (B-cell) malignancies in a retrospective single-center study and extracted relevant data on CMV prevalences and the incidences of B-cell cancers the world over.

Methods

In the clinical single-center study, prevalence of chronic CMV infection was compared between patients with B-cell leukemia/lymphoma and the healthy controls. Also, global data on CMV seroprevalences and the corresponding country-specific incidences of B- lineage neoplasms worldwide were investigated for potential correlations.

Results

Significantly higher CMV seropositivity was observed in control subjects than in patients with B-cell malignancies (p = 0.035). Moreover, an unexpected seroepidemiological evidence of highly significant inverse relationship between country-specific CMV prevalence and the annual incidence of B-cell neoplasms was noted across the populations worldwide (ρ = −0.625, p < 0.001).

Conclusions

We try to draw attention to an unreported interplay between CMV infection and B-cell lymphomagenesis in adults. A large-scale survey across > 70 countries disclosed a link between CMV and B-cell neoplasms. Our evidence hints at an antagonistic effect of chronic CMV infection against B-lymphoproliferation.

Highlights of Abstracts on Hematopoietic Stem Cell Transplant in Annual Conference of ISHBT 2018

Stem cell transplant in India has been seeing a steady progressive growth over the last decade. Thirty abstracts related to various aspects of bone marrow transplant were presented in the annual conference of Indian Society of Hematology and Transfusion medicine in 2018. All abstracts which were published were reviewed. They were categorized into autologous transplants, allogeneic transplants, lab aspects and supportive care. They have been summarized to provide a snapshot of the data presented. These data are likely to encourage to start or enhance transplant activity at other centers.