Factors associated with cytomegalovirus reactivation following allogeneic hematopoietic stem cell transplantation: human leukocyte antigens might be among the risk factors

Epidemiology, treatment patterns, and disease burden of cytomegalovirus in hematopoietic cell transplant recipients in selected countries outside of Europe and North America: A systematic review

BACKGROUND

Cytomegalovirus (CMV) disease impacts morbidity and mortality in hematopoietic cell transplant (HCT) recipients. This systematic review summarized data on the epidemiology, management, and burden of CMV post-HCT outside of Europe and North America.

METHODS

The MEDLINE, Embase, and Cochrane databases were searched for observational studies and treatment guidelines in HCT recipients across 15 selected countries from Asia-Pacific, Latin America, and Middle East (search period: 1 January 2011-17 September 2021). Outcomes included incidence of CMV infection/disease, recurrence, risk factors, CMV-related mortality, treatments, refractory, resistant CMV, and burden.

RESULTS

Of 2708 references identified, 68 were eligible (67 studies and one guideline; 45/67 studies specific to adult allogeneic HCT recipients). The rates of CMV infection and disease within 1 year of allogeneic HCT were 24.9%-61.2% (23 studies) and 2.9%-15.7% (10 studies), respectively. Recurrence occurred in 19.8%-37.9% of cases (11 studies). Up to 10% of HCT recipients died of CMV-related causes. In all countries, first-line treatment for CMV infection/disease involved intravenous ganciclovir or valganciclovir. Conventional treatments were associated with serious adverse events such as myelosuppression (10.0%) or neutropenia only (30.0%, 39.8%) and nephrotoxicity (11.0%) (three studies), frequently leading to treatment discontinuation (up to 13.6%). Refractory CMV was reported in 2.9%, 13.0%, and 28.9% of treated patients (three studies) with resistant CMV diagnosed in 0%-10% of recipients (five studies). Patient-reported outcomes and economic data were scarce.

CONCLUSION

The incidence of CMV infection and disease post-HCT is high outside of North America and Europe. CMV resistance and toxicity highlight a major unmet need with current conventional treatments.

Adoptive Immunotherapy for Prophylaxis and Treatment of Cytomegalovirus Infection

Cytomegalovirus (CMV), a member of the Herpesviridae family, is frequent among hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients in absence of antiviral prophylaxis, and is a major cause of morbidity and mortality in these vulnerable populations. Antivirals such ganciclovir, valganciclovir, and foscarnet are the backbone therapies, however drug toxicity and antiviral resistance may render these agents suboptimal in treatment. Newer therapies such as letermovir and maribavir have offered additional approaches for antiviral prophylaxis as well as treatment of drug resistant CMV infection, though may be limited by cost, drug intolerance, or toxicity. Adoptive immunotherapy, the transfer of viral specific T-cells (VSTs), offers a new approach in treatment of drug-resistant or refractory viral infections, with early clinical trials showing promise with respect to efficacy and safety. In this review, we will discuss some of the encouraging results and challenges of widespread adoption of VSTs in care of immunocompromised patients, with an emphasis on the clinical outcomes for treatment and prophylaxis of CMV infection among high-risk patient populations.

Interplay of Environmental, Individual and Genetic Factors in Rheumatoid Arthritis Provocation

In this review, we explore systemization of knowledge about the triggering effects of non-genetic factors in pathogenic mechanisms that contribute to the development of rheumatoid arthritis (RA). Possible mechanisms involving environmental and individual factors in RA pathogenesis were analyzed, namely, infections, mental stress, sleep deprivation ecology, age, perinatal and gender factors, eating habits, obesity and smoking. The non-genetic factors modulate basic processes in the body with the impact of these factors being non-specific, but these common challenges may be decisive for advancement of the disease in the predisposed body at risk for RA. The provocation of this particular disease is associated with the presence of congenital loci minoris resistentia. The more frequent non-genetic factors form tangles of interdependent relationships and, thereby, several interdependent external factors hit one vulnerable basic process at once, either provoking or reinforcing each other. Understanding the specific mechanisms by which environmental and individual factors impact an individual under RA risk in the preclinical stages can contribute to early disease diagnosis and, if the factor is modifiable, might be useful for the prevention or delay of its development.

Revisiting Role of Vaccinations in Donors, Transplant Recipients, Immunocompromised Hosts, Travelers, and Household Contacts of Stem Cell Transplant Recipients

Vaccination is an effective strategy to prevent infections in immunocompromised hematopoietic stem cell transplant recipients. Pretransplant vaccination of influenza, pneumococcus, Haemophilus influenza type b, diphtheria, tetanus, and hepatitis B, both in donors and transplant recipients, produces high antibody titers in patients compared with recipient vaccination only. Because transplant recipients are immunocompromised, live vaccines should be avoided with few exceptions. Transplant recipients should get inactive vaccinations when possible to prevent infection. This includes vaccination against influenza, pneumococcus, H. influenza type b, diphtheria, tetanus, pertussis, meningococcus, measles, mumps, rubella, polio, hepatitis A, human papillomavirus, and hepatitis B. Close contacts of transplant recipients can safely get vaccinations (inactive and few live vaccines) as per their need and schedule. Transplant recipients who wish to travel may need to get vaccinated against endemic diseases that are prevalent in such areas. There is paucity of data on the role of vaccinations for patients receiving novel immunotherapy such as bispecific antibodies and chimeric antigen receptor T cells despite data on prolonged B cell depletion and higher risk of opportunistic infections.

The clinical and economic impact of cytomegalovirus infection in recipients of hematopoietic stem cell transplantation

BACKGROUND

CMV infection (CMV-I) remains an important complication of hematopoietic stem cell transplantation (HSCT).

METHODS

This was a retrospective, single-center cohort study in HSCT recipients. Primary outcomes were adjusted cost and all-cause mortality. Secondary analyses investigated CMV risk factors and the effect of serostatus.

RESULTS

Overall, 690 transplant episodes were included (allogeneic [n = 310]; autologous [n = 380]). All received preemptive CMV antiviral therapy at first detectable DNAemia. CMV-I occurred in 34.8% of allogeneic and 2.1% of autologous transplants; median time to onset was 45 days. In allogeneic HSCT recipients, the primary risk factor for CMV-I was CMV donor/recipient (D/R) serostatus. In a Markov multi-state model for allogeneic HSCT recipients, the hazard ratio for CMV-I and relapse was 1.5 (95% CI 0.8-2.8) and for CMV-I and mortality 2.4 (95% CI 0.9-6.5). In a multivariable model for all patients, CMV-I was associated with increased total cost (coefficient = 0.21, estimated incremental daily cost USD $500; P = 0.02). Cost was attenuated in allogeneic HSCT recipients (coefficient = 0.13, USD $699 vs $613, or $24 892 per transplant episode; P = 0.23). CMV disease (CMV-D) complicated 29.6% of CMV-I events in allogeneic HSCT recipients, but was not associated with an incrementally increased adjusted risk of mortality compared with CMV-I alone. CMV-I (56.4%) and CMV-D (19.8%) were significantly overrepresented in D-/R+ serostatus HSCT recipients, and mortality was higher in R+ HSCT recipients.

CONCLUSIONS

Despite early preemptive antiviral treatment, CMV-I impacts clinical outcomes and cost after HSCT, but the impact on cost is less pronounced in allogeneic HSCT recipients compared with autologous HSCT recipients.

Cytomegalovirus reactivation and disease amongst patients with allogeneic haematopoietic stem cell transplantation in Eastern India: Epidemiology, outcome and healthcare cost

Purpose

Data from developing countries about incidence, prognosis and healthcare cost of cytomegalovirus (CMV) reactivation amongst patients with allogeneic hematopoietic stem cell transplantation (AHSCT) remain scarce. The purpose of the study was to describe the epidemiology, outcome and cost implications of CMV reactivation and CMV disease amongst patients with AHSCT in cancer hospital in Eastern India.

Materials and Methods

The study design was a retrospective audit of clinical records.

Results

Ninety-nine per cent of patients and 94% of the donors were found to be CMV seropositive. CMV reactivation rate was 43.8% amongst patients with AHSCT (n = 130 patients). CMV reactivation occurred 118 days after AHSCT (median; range: 28-943 days). Patients with any grade of graft-versus-host disease (GVHD) had higher CMV reactivation rate than patients without GVHD. Patients with CMV reactivation had more frequent GVHD than patients without CMV reactivation. Use of steroids was associated with CMV reactivation. We found no differences in overall survival of patients with or without CMV reactivation. The cost of in-house CMV-polymerase chain reaction at our centre was USD $57 (Rs. 3650), cost for intravenous ganciclovir was USD $26 (Rs. 1665) per infusion and oral valganciclovir USD $8 (Rs. 512)/900 mg tablet. The median duration of anti-CMV therapy was 14 days (interquartile range: 14-28 days) and the average cost per patient per month directed towards CMV management ranged between USD $800 and USD $1,300 (Rs. 51,238-Rs. 83,264). Three patients (2.3%) in this series had CMV disease, all of whom died.

Conclusion

In an increasingly globalised world, where medical tourism is common, data from developing countries regarding cost and outcome of CMV infections in AHSCT patients are of relevance.

Maternal and child human leukocyte antigens in congenital cytomegalovirus infection

Congenital Cytomegalovirus infection (cCMV) is the most common cause of congenital infections worldwide causing permanent long-term impairment (LTI). cCMV immunopathogenesis remains largely unknown due to the complex interplay between viral, maternal, placental and child factors. The aim of this study was to determine the possible role of particular HLA antigens, of the number of HLA mismatches (mm) and non-inherited maternal antigens (NIMAs) in a large retrospective nation-wide cohort of children with cCMV and their mothers. HLA Class I (HLA-A, HLA-B and HLA-C) and HLA Class II (HLA-DR and HLA-DQ) were assessed in 96 mother-child pairs in relation to a control group of 5604 Dutch blood donors, but no significant differences were observed. Next, although these HLA antigens could not be assessed in relation to symptoms at birth, nor to LTI, due to the low number of cases, they could be evaluated in relation to CMV viral load. HLA-DRB1*04, and potentially HLA-B*51, was shown to have a protective role in the children as its frequency was increased in the low viral load group compared to the high viral load group, and this remained significant after correction. The number of HLA mm and of NIMAs were not associated to symptoms at birth nor to LTI or viral load. In conclusion, although none of the HLA alleles could be put forward as prognostic marker for long-term outcome, our findings give useful insights into cCMV pathogenesis, and identify potential HLAs that correlate with a better viral control.

Sex-specific survival difference in association with HLA-DRB1∗04 following allogeneic haematopoietic stem cell transplantation for lymphoid malignancies

The role of HLA system in allogeneic haematopoietic stem cell transplantation (allo-HSCT) outcome is unarguable. In this study we investigated association of HLA-A,-B and-DRB1 alleles with overall survival (OS) in 186 patients undergoing allo-HSCT for lymphoid malignancies. Analyses confirmed significantly better OS for HLA-DRB1∗04 carriers compared with non-carriers (p = 0.01). Survival benefit was confined to male patients (in multivariate analyses p = 0.034, hazard ratio 0.35, 95% confidence interval 0.13-0.92), whereas in females no difference was noted (p = 0.82). Furthermore, donor gender also affected outcome and transplantation from female HLA-DRB1∗04 carrier donors resulted in superior survival compared with female non-carrier donors (p = 0.01). Combined analyses including recipient/donor gender and HLA-DRB1∗04 showed that survival of male patients varied significantly according to donor gender and HLA-DRB1∗04 carriership (p = 0.04) with best survival among HLA-DRB1∗04 carriers transplanted from female donors. Of relevance to our results, HLA-DRB1∗04 has been documented as risk allele group for lymphoid malignancies, and studies described a male-specific risk. We believe that our findings provide further supporting evidence for sex-specific alterations secondary to HLA-DRB1∗04 or related genes. Further studies are warranted to evaluate whether in contrast to general favour of male donors HLA-DRB1∗04 carrier patients with lymphoid malignancies could benefit from transplantation from female donors.

Lymphocyte expansion after unrelated cord blood allogeneic stem cell transplantation in adults

Limited information is available regarding the incidence and features of lymphocyte expansions after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Large granular lymphocytes (LGL) expansions have been reported after bone marrow or peripheral blood, but not after unrelated cord blood (UCB) allo-HSCT, associated with indolent clinical courses and favorable outcomes. Here, we considered 85 recipients of UCB allo-HSCT to more broadly define the impact of lymphocytosis, not limited to LGL. Sustained lymphocytosis was observed in 21 (25%) patients at a median onset of 12.6 months and with a median duration of 12 months. Immunophenotypic analysis showed predominantly CD8⁺ T and/or polyclonal B-cell expansions. Three patients only had monoclonal T-cell expansion. CMV reactivation was significantly more frequent in the group of patients with lymphocytosis (76% vs 28%, P=0.0001), but was not associated with survival. Conversely, 2-year disease-free survival and overall survival were significantly higher for lymphocytosis patients (85% vs 55%, P=0.01 and 85% vs 63%, P=0.03, respectively). In conclusion, expansion of T or B lymphocytes after UCB allo-HSCT in adults is not a rare event. Although occurring relatively late after transplant, this feature is predictive of a better outcome for the patients.

How Rheumatoid Arthritis Can Result from Provocation of the Immune System by Microorganisms and Viruses

The pathogenesis of rheumatoid arthritis (RA), similar to development of a majority of inflammatory and autoimmune disorders, is largely due to an inappropriate or inadequate immune response to environmental challenges. Among these challenges, infectious agents are the undisputed leaders. Since the 1870s, an impressive list of microorganisms suspected of provoking RA has formed, and the list is still growing. Although a definite causative link between a specific infectious agent and the disease has not been established, several arguments support such a possibility. First, in the absence of a defined pathogen, the spectrum of triggering agents may include polymicrobial communities or the cumulative effect of several bacterial/viral factors. Second, the range of infectious episodes (i.e., clinical manifestations caused by pathogens) may vary in the process of RA development from preclinical to late-stage disease. Third, infectious agents might not trigger RA in all cases, but trigger it in a certain subset of the cases, or the disease onset may arise from an unfortunate combination of infections along with, for example, psychological stress and/or chronic joint tissue microtrauma. Fourth, genetic differences may have a role in the disease onset. In this review, two aspects of the problem of “microorganisms and RA” are debated. First, is there an acquired immune deficiency and, in turn, susceptibility to infections in RA patients due to the too frequent and too lengthy infections, which at last break the tolerance of self antigens? Or, second, is there a congenital deficiency in tolerance and inflammation control, which may occur even with ordinary infection frequency and duration?