The role of immunoglobulin prophylaxis for prevention of cytomegalovirus infection in pediatric hematopoietic stem cell transplantation recipients

Application of CMV-IVIg as prophylaxis against cytomegalovirus reactivation in allogeneic hematopoietic stem cell transplantation patients

Cytomegalovirus (CMV) reactivation remains one of the major and life-threatening complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Yet, there is still a lack of safe and effective ways to prevent CMV reactivation in allo-HSCT patients. Here, we retrospectively analyzed a cohort of patients who underwent HSCT at our transplant center between 2018 and 2022 to evaluate the efficacy of prophylactic CMV-specific intravenous immunoglobulin (CMV-IVIg) against CMV reactivation. After Propensity Score Matching, the CMV reactivation rate was significantly decreased in the CMV-IVIg group (HR, 2.952; 95% CI,1.492-5.841; P = .002) compared with the control group. Additionally, the time duration of CMV reactivation (P = .001) and bacterial infection rate (P = .013) were significantly lower in the CMV-IVIg group. Moreover, prophylactic CMV-IVIg was more effective in CMV seropositive patients who received ATG as part of GVHD prevention (HR, 8.225; 95% CI,1.809-37.39; P = .006). In conclusion, CMV-IVIg is considered an effective and safe way to prevent CMV reactivation in HSCT recipients, which may be related to the acceleration of immune reconstitution in the early stage after transplantation.

Efficacy of Cytomegalovirus Specific Immunoglobulins to Reduce CMV Reactivation in Pediatric Hematopoietic Stem Cell Transplant Recipients

Cytomegalovirus (CMV) infection is a serious complication of pediatric hematopoietic stem cell transplant (HSCT). To date, antiviral therapy has been the mainstay of prophylaxis, with conflicting results regarding the benefits of CMV-specific immunoglobulins (CMV-Ig). After introducing prophylactic CMV-Ig to HSCT recipients at risk (seropositive recipient and/or donor), we conducted a single-center retrospective study comparing the incidence and severity of CMV infection with and without CMV-Ig. We identified 49 'at risk' recipients from 76 consecutive HSCTs over 3.5 years, in addition to standard antiviral prophylaxis, 10 patients received CMV-Ig and 39 did not. There was no significant difference in donor type, cell source, conditioning, or CMV status between the groups. We observed a potential trend toward reduction of incidence of CMV reactivation in patients exposed to CMV-Ig (30%) compared with those who weren't (38.4%). Besides, no symptomatic or lethal infection was observed in the CMV-Ig group, and time to recovery seemed shorter (21 [±7] vs 51.4 [±55] days) and peak titers lower (4578 [±4788] vs 24131 [±49257]) with CMV-Ig. No adverse events were noted. The statistical significance of the results was limited by the small sample size. These data raise interest in prophylactic CMV-Ig as a safe way of potentially reducing the severity and duration of CMV reactivation in HSCT.

Diagnosis and treatment for the early stage of cytomegalovirus infection during hematopoietic stem cell transplantation

Cytomegalovirus (CMV) infection remains a frequent complication after hematopoietic stem cell transplantation (HSCT) and causes significant morbidity and mortality in transplantation recipients. In this review, we highlight the role of major risk factors that are associated with the incidence of CMV infection. Advances in immunosurveillance may predict CMV infection, allowing early interventions to prevent severe infection. Furthermore, numerous therapeutic strategies against CMV infection after HSCT are summarized. A comprehensive understanding of the current situation of CMV treatment may provide a hint for clinical practice and even promote the development of novel strategies for precision medicine.

Prevention and management of human cytomegalovirus in pediatric HSCT recipients: A review

Cytomegalovirus (CMV), like other herpesviruses, has the unique ability to establish latent infection with subsequent reactivation during periods of stress and immunosuppression. Herpesviruses cause potentially devastating disease, particularly in hematopoietic stem cell transplant (HSCT) recipients. CMV is especially of concern in HSCT recipients given the high community seroprevalence, high risk of reactivation and high risk of transmission from HSCT donors to recipients causing primary infection after transplantation. The risk of CMV infection and severity of CMV disease varies depending on the underlying disease of the HSCT recipient, donor and recipient CMV status prior to HSCT, type of conditioning therapy in preparation for HSCT, allogeneic versus autologous HSCT, donor graft source, timing of infection in relation to HSCT, and other patient comorbidities. Different strategies exist for prevention (e.g., preemptive therapy vs. universal prophylaxis) as well as management of CMV disease (e.g., antiviral therapy, augmenting immune reconstitution, cytotoxic T-cell therapy). The purpose of this narrative review is to discuss diagnosis, prevention, and management of CMV infection and disease at different stages of HSCT, including key points illustrated through presentations of complex cases and difficult clinical scenarios. Traditional and novel strategies for CMV management will be discussed in the context of these unique clinical cases.

Immune Prophylaxis and Therapy for Human Cytomegalovirus Infection

Human Cytomegalovirus (HCMV) infection is widespread and can result in severe sequelae in susceptible populations. Primary HCMV infection of naïve individuals results in life-long latency characterized by frequent and sporadic reactivations. HCMV infection elicits a robust antibody response, including neutralizing antibodies that can block the infection of susceptible cells in vitro and in vivo. Thus, antibody products and vaccines hold great promise for the prevention and treatment of HCMV, but to date, most attempts to demonstrate their safety and efficacy in clinical trials have been unsuccessful. In this review we summarize publicly available data on these products and highlight new developments and approaches that could assist in successful translation of HCMV immunotherapies.

Detection of Antibodies Against Human Leukocyte Antigen Class II in the Sera of Patients Receiving Intravenous Immunoglobulin

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IVIG is occasionally used for preventing and treating severe infections of patients who are to undergo transplantation. Administration of IVIG, which includes high-titer antibodies (Abs) against HLA class I and II, might have a substantial influence on the HLA Ab test results of these patients. However, this issue has remained unreported.

Advances in the Development of Therapeutics for Cytomegalovirus Infections

The development of therapeutics for cytomegalovirus (CMV) infections, while progressing, has not matched the pace of new treatments of human immunodeficiency virus (HIV) infections; nevertheless, recent developments in the treatment of CMV infections have resulted in improved human health and perhaps will encourage the development of new therapeutic approaches. First, the deployment of ganciclovir and valganciclovir for both the prevention and treatment of CMV infections and disease in transplant recipients has been further improved with the licensure of the efficacious and less toxic letermovir. Regardless, late-onset CMV disease, specifically pneumonia, remains problematic. Second, the treatment of congenital CMV infections with valganciclovir has beneficially improved both hearing and neurologic outcomes, both fundamental advances for these children. In these pediatric studies, viral load was decreased but not eliminated. Thus, an important lesson learned from studies in both populations is the need for new antiviral agents and the necessity for combination therapies as has been shown to be beneficial in the treatment of HIV infections, among others. The development of monoclonal antibodies, sirtuins, and cyclopropovir may provide new treatment options.

Role of Neutralizing Antibodies in CMV Infection: Implications for New Therapeutic Approaches

Cytomegalovirus (CMV) infection elicits a potent immune response that includes the stimulation of antibodies with neutralizing activity. Recent studies have focused on elucidating the role of neutralizing antibodies in protecting against CMV infection and disease and characterizing viral antigens against which neutralizing antibodies are directed. Here, we provide a synthesis of recent data regarding the role of neutralizing antibodies in protection against CMV infection/disease. We consider the role of humoral immunity in the context of the global CMV-specific immune response, and the implications that recent findings have for vaccine and antibody-based therapy design.

The Current Status of Cytomegalovirus (CMV) Prevalence in the MENA Region: A Systematic Review

Human cytomegalovirus (CMV) is a highly prevalent herpesvirus worldwide. According to the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO), CMV infects people of all ages, and by the age of five, approximately one-third of children in the United States are infected. Although the infection is generally asymptomatic, it can cause severe disease in immunocompromised patients, transplant and transfusion recipients, as well as newborn neonates. The objective of this study is to systematically review published literature on CMV in the MENA region to estimate its incidence in the region and describe its epidemiological and clinical significance. The literature was searched through four scientific databases: PubMed, Scopus, Science Direct, and Web of Science. A total of 72 studies from 11 countries satisfied the inclusion criteria, covering a period from 1988-2019. The CMV IgG seroprevalence ranged from 8.7%-99.2% (SD = 38.95%). CMV incidence in these countries ranged between 1.22% and 77% in transplant and transfusion recipients, with an increase in incidence with advanced age. However, the incidence rate was unclear for congenital CMV due to the variability of the reporting. This review highlights the need for more robust and well-designed studies to better estimate CMV incidence in the MENA region, standardize diagnostic criteria, and consider prophylactic and pre-emptive treatments to limit the morbidity and mortality of the disease.

CMV Management with Specific Immunoglobulins: A Multicentric Retrospective Analysis on 92 Allotransplanted Patients

CMV represents one of the most severe life-threatening complications of allogeneic stem cell transplantation (allo-SCT). Pre-emptive treatment is highly effective, but toxicity and repetitive reactivation of CMV represent a significant challenge in the clinical practice. The use of anti-CMV specific immunoglobulins (Megalotect) is controversial. We retrospectively collected data on 92 patients submitted to allo-SCT for hematological malignancies, in whom Megalotect was used either for prophylaxis (n=14) or with pre-emptive therapy, together with an anti-CMV specific drug (n=78). All the patients were considered at high-risk, due to the presence of at least one risk factor for CMV reactivation. The treatment was well tolerated, with no reported infusion reactions, nor other adverse events, none of the 14 cases treated with Megalotect as prophylaxis developed CMV reactivation. 51/78 (65%) patients who received Megalotect during pre-emptive treatment achieved complete clearance of CMV viremia, and 14/51 patients (29%) developed a breakthrough CMV infection. 7/78 patients (9%) developed CMV disease. The projected 1-year OS, 1-year TRM, and 1-year RR is 74%, 15%, and 19%, respectively. No differences were observed in terms of OS, TRM, and RR by comparing patients who achieved a complete response after treatment versus those who did not. These retrospective data suggest that Megalotect is safe and well-tolerated. When used as prophylaxis, no CMV reactivation was recorded. Further prospective trials are warranted to identify the best set of patients who can benefit from Megalotect alone or in addition to anti-CMV specific drugs.

New Developments in the Management of Cytomegalovirus Infection After Transplantation

Cytomegalovirus (CMV) continues to be one of the most important pathogens that universally affect solid organ and allogeneic hematopoietic stem cell transplant recipients. Lack of effective CMV-specific immunity is the common factor that predisposes to the risk of CMV reactivation and clinical disease after transplantation. Antiviral drugs are the cornerstone for prevention and treatment of CMV infection and disease. Over the years, the CMV DNA polymerase inhibitor, ganciclovir (and valganciclovir), have served as the backbone for management, while foscarnet and cidofovir are reserved for the management of CMV infection that is refractory or resistant to ganciclovir treatment. In this review, we highlight the role of the newly approved drug, letermovir, a viral terminase inhibitor, for CMV prevention after allogeneic hematopoietic stem cell transplantation. Advances in immunologic monitoring may allow for an individualized approach to management of CMV after transplantation. Specifically, the potential role of CMV-specific T-cell measurements in guiding the need for the treatment of asymptomatic CMV infection and the duration of treatment of CMV disease is discussed. The role of adoptive immunotherapy, using ex vivo-generated CMV-specific T cells, is highlighted. This article provides a review of novel drugs, tests, and strategies in optimizing our current approaches to prevention and treatment of CMV in transplant recipients.

A Native Human Monoclonal Antibody Targeting HCMV gB (AD-2 Site I)

Hyperimmune globulin (HIG) has shown efficacy against human cytomegalovirus (HCMV) for both transplant and congenital transmission indications. Replicating that activity with a monoclonal antibody (mAb) offers the potential for improved consistency in manufacturing, lower infusion volume, and improved pharmacokinetics, as well as reduced risk of off-target reactivity leading to toxicity. HCMV pathology is linked to its broad cell tropism. The glycoprotein B (gB) envelope protein is important for infections in all cell types. Within gB, the antigenic determinant (AD)-2 Site I is qualitatively more highly-conserved than any other region of the virus. TRL345, a high affinity (Kd = 50 pM) native human mAb to this site, has shown efficacy in neutralizing the infection of fibroblasts, endothelial and epithelial cells, as well as specialized placental cells including trophoblast progenitor cells. It has also been shown to block the infection of placental fragments grown ex vivo, and to reduce syncytial spread in fibroblasts in vitro. Manufacturing and toxicology preparation for filing an IND (investigational new drug) application with the US Food and Drug Administration (FDA) are expected to be completed in mid-2019.

Clinical indications for intravenous immunoglobulin utilization in a tertiary medical center: a 9-year retrospective study

BACKGROUND

Intravenous immunoglobulins (IVIG) are a biologic product originally developed to treat immunocompromised patients. In the past decades, there has been increased utilization of IVIG in autoimmune conditions. The objectives were to evaluate the clinical use of IVIG in the largest tertiary medical center in Israel and to determine top uses, estimate off-label usage, and assess consumption of this blood product.

STUDY DESIGN AND METHODS

We conducted an observational, retrospective study involving all patients who received IVIG from 2007 through 2015. Subjects were classified into five groups according to the indication for treatment.

RESULTS

A total of 1117 patients were identified. The mean (±SD) ages of adults and children were 55 ± 17 and 8 ± 7 years, respectively. Most common indication for treatment were immune-mediated conditions (54%), followed by secondary immunodeficiency (28%), primary immunodeficiency (10%), infections (4%), and miscellaneous (4%). The main immune-mediated conditions treated were hematologic disorders (305 patients, 27%), neurologic disorders (219 patients, 20%), and rheumatologic conditions (79 patients, 7%). Overall, a significant change in study period was observed in the number of patients (p < 0.001), consumption of IVIG (p < 0.01), and amount of IVIG administered per patient (p < 0.01). Fifty-six percent of the IVIG infusions were given for off-label Food and Drug Administration (FDA) indications.

CONCLUSION

In this study, we demonstrated that immune-mediated conditions represent the majority of indications for treatment with IVIG. We observed a 417% increase in IVIG administration (g) over time, attributed mainly to autoimmune diseases. Many indications are still off-label according to FDA recommendations.

Interaction of Immunoglobulin with Cytomegalovirus-Infected Cells

Intravenous immunoglobulin (IVIG) is used to treat or prevent severe viral infection, especially cytomegalovirus (CMV) infections. IVIG was characterized to understand its interaction with CMV-infected cells. IVIG retarded CMV spread and reduced virus yields depending on the neutralizing (NT) antibody titer. Immediate early protein synthesis was reduced by IVIG in 3 to 15 h, and IVIG specifically reduced the ratio of 66/68k protein synthesis among immediate early proteins in an NT antibody-dependent manner between 4 and 8 h after infection, indicating that antigenic modulation of CMV-infected cells by IVIG reduced viral protein synthesis and virus production. The half-life of antibody bound to CMV-infected cells was 3.8 h. NT antibody titers to varicella-zoster virus (VZV) and CMV in IVIG were dose dependently absorbed by cells infected with VZV and CMV, respectively, but the antibody titers to CMV and VZV, respectively, were not affected. NT antibody in 0.3 mL of IVIG (15 mg) was specifically absorbed by 10⁸ CMV-infected cells and 10⁷ VZV-infected cells, suggesting that the NT antibody in IVIG might be inactivated by one-tenth of a similar volume of CMV-infected or VZV-infected cells. Various antiviral activities of IVIG may contribute to control and alleviation of CMV infection.