Immunologic monitoring of cytomegalovirus (CMV) enzyme-linked immune absorbent spot (ELISPOT) for controlling clinically significant CMV infection in pediatric allogeneic hematopoietic stem cell transplant recipients

The dynamics of recovery of cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) and its impact on controlling clinically significant CMV infections following hematopoietic stem cell transplant (HSCT) are rarely reported in pediatric HSCT recipients. In this study, dynamics of recovery of CMV-specific CMI and its clinical significance in controlling CMV viremia and clinically significant CMV infections were assessed in pediatric allogeneic HSCT recipients. All subjects underwent CMV pp65- and IE1-specific enzyme-linked immune absorbent spot (ELISPOT) assays just before transplantation and then monthly until the detection of CMV-specific CMI with ≥ 5 spot-forming cells (SFC) / 2.0 × 105 cells. Clinically significant CMV infections were defined as CMV diseases, prolonged CMV infections, recurrent CMV infections or late onset CMV infections. Among 52 recipients, 88.5% of recipients recovered CMV-specific CMI with ≥ 5 SFC/ 2.0 × 105 cells at a median of 34 days (interquartile range [IQR]: 29–95 days) following HSCT, 55.8% at 30 days following HSCT, and 73.1% at 90 days following HSCT. The presence of CMV-specific CMI before HSCT was the significant factors for the reconstitution of CMV specific CMI after HSCT (adjusted odds ratio [aOR] = 13.33; 95% confidence interval [CI] = 1.21–142.86). After HSCT, 30 recipients experienced CMV viremia, of which 20 were clinically significant CMV infections. The full recovery of CMV-specific CMI with ≥ 50 SFC / 2.0 × 105 cells after HSCT was the protective factor for the development of clinically significant CMV infections (aOR = 0.13; 95% CI = 0.22–0.71). In the haploidentical HSCT recipients, 82.1% recovered CMV-specific CMI at a median of 65 days after HSCT (IQR: 34–118 days) with a tendency to recover their CMV-specific CMI later than did those from non-haploidentical donors (65 days vs. 30 days; P = 0.001). Clinically significant CMV infections tended to occur more frequently in the haploidentical HSCT recipients compared to those with matched donor HSCT (46.4% vs. 29.2%; P = 0.205). The full recovery of CMV-specific CMI with ≥ 50 SFC/2.0 × 105 cells after HSCT also lowered the risk of development of clinically significant CMV infections (aOR = 0.08; 95% CI = 0.01–0.90). However, transplantation from haploidentical donors was a significant risk factor hampering recovery of CMV-specific CMI (aOR = 0.08; 95% CI = 0.01–0.86) and full recovery of CMV-specific CMI (aOR = 0.05; 95% CI = 0.01–0.50). Pre-transplant CMV-specific CMI influenced the recovery of CMV-specific CMI, and the full recovery of CMV-specific CMI could be a surrogate marker for preventing clinically significant CMV infections in pediatric HSCT recipients. Immunologic monitoring using ELISPOT assay before and after HSCT helps in identifying patients with a high risk of CMV infection and in controlling CMV infection.

Immunologic monitoring over people vaccinated against plague in caspian sand natural focus in order to assess and manage health risks

To provide better opportunities for managing both risks caused by vaccination and risks of epidemiological complications, immunologic monitoring over people vaccinated with live dried plague vaccine (LPV) due to epidemiologic indications was performed. Our research goal was to assess whether immunologic monitoring over people vaccinated against plague yielded informative results; it was done to substantiate activities aimed at improving procedures for LPV application. Immunologic monitoring was performed from 2016 to 2019 in the Caspian sand natural plague focus according to conventional procedures for assessing humoral and cellular components in immunity. We determined immunologic parameters in 217 volunteers vaccinated with LPV and 130 healthy donors (the reference group) prior to and 1 and 12 months after vaccination. We suggested a methodical approach based on aggregated analysis of the summated immune response predictors chosen for estimation in volunteers vaccinated with LPV and giving score values to them; it allows revealing people who react to plague microbe antigens predominantly as per cellular, humoral, or mixed type. Immunologic monitoring results proved that it was safe to apply LPV; they allowed characterizing trends occurring in immunological restructuring in vaccinated volunteers, determining limits of fluctuation in individual parameters of an immune response to the vaccine, and revealing people with both normal and changed (reduced or increased) immunologic reactivity to LPV. If monitoring data are taken into account, it provides an opportunity to predict vaccination results as per epidemiological parameters, to reveal groups with normal, high, or low immune reactivity to plague microbe antigens in order to determine people in them who need an individual approach when it comes down to anti-plague vaccination.

Immunologic monitoring over people vaccinated against plague in caspian sand natural focus in order to assess and manage health risks

To provide better opportunities for managing both risks caused by vaccination and risks of epidemiological complications, immunologic monitoring over people vaccinated with live dried plague vaccine (LPV) due to epidemiologic indications was performed. Our research goal was to assess whether immunologic monitoring over people vaccinated against plague yielded informative results; it was done to substantiate activities aimed at improving procedures for LPV application. Immunologic monitoring was performed from 2016 to 2019 in the Caspian sand natural plague focus according to conventional procedures for assessing humoral and cellular components in immunity. We determined immunologic parameters in 217 volunteers vaccinated with LPV and 130 healthy donors (the reference group) prior to and 1 and 12 months after vaccination. We suggested a methodical approach based on aggregated analysis of the summated immune response predictors chosen for estimation in volunteers vaccinated with LPV and giving score values to them; it allows revealing people who react to plague microbe antigens predominantly as per cellular, humoral, or mixed type. Immunologic monitoring results proved that it was safe to apply LPV; they allowed characterizing trends occurring in immunological restructuring in vaccinated volunteers, determining limits of fluctuation in individual parameters of an immune response to the vaccine, and revealing people with both normal and changed (reduced or increased) immunologic reactivity to LPV. If monitoring data are taken into account, it provides an opportunity to predict vaccination results as per epidemiological parameters, to reveal groups with normal, high, or low immune reactivity to plague microbe antigens in order to determine people in them who need an individual approach when it comes down to anti-plague vaccination.