Vaccine-Derived Immunity in Children With Cancer-Analysis of Anti-Tetanus and Anti-Diphtheria Antibodies Changes after Completion of Antineoplastic Therapy

MMR vaccination timing and long-term immunity among childhood cancer survivors

Long-term seroprotection against the measles and mumps viruses has not been reported in childhood cancer survivor (CCS) who received two-lifetime doses of the measles, mumps, and rubella (MMR) vaccine. We performed a retrospective study of measles and mumps titers among 55 CCS who received standard chemotherapy and two MMR vaccinations at any time. Over 75% of CCS who received at least one MMR prior to their cancer diagnosis had a negative or equivocal titer to measles or mumps. In contrast, all CCS who received the MMR series following their cancer treatment demonstrated long-term seroprotection to both viruses at a mean of 8.2 years after their last vaccination.

Trojan-horse silk fibroin nanocarriers loaded with a re-call antigen to redirect immunity against cancer

BACKGROUND

The current challenge for immunotherapies is to generate effective antitumor immunity. Since tumor immune escape mechanisms do not impact pre-existing and consolidated immune responses, we tested the hypothesis of redirecting a pregenerated immunity to cancer: to recall a non-tumor antigen response against the tumor, silk fibroin nanoparticles (SFNs) have been selected as 'Trojan-horse' carriers, promoting the antigen uptake by the tumor cells.

METHODS

SFNs have been loaded with either ovalbumin (OVA) or CpG oligonucleotide (CpG) as antigen or adjuvant, respectively. In vitro uptake of SFNs by tumor (B16/F10 melanoma and MB49 bladder cancer) or dendritic cells, as well as the presence of OVA-specific T cells in splenic and tumor-infiltrating lymphocytes, were assessed by cytometric analyses. Proof-of-concept of in vivo efficacy was achieved in an OVA-hyperimmune B16/F10 murine melanoma model: SFNs-OVA or SFNs-CpG were injected, separately or in association, into the subcutaneous peritumoral area. Cancer dimensions/survival time were monitored, while, at the molecular level, system biology approaches based on graph theory and experimental proteomic data were performed.

RESULTS

SFNs were efficiently in vitro uptaken by cancer and dendritic cells. In vivo peritumor administration of SFNs-OVA redirected OVA-specific cytotoxic T cells intratumorally. Proteomics and systems biology showed that peritumoral treatment with either SFNs-OVA or SFNs-CpG dramatically modified tumor microenvironment with respect to the control (CTR), mainly involving functional modules and hubs related to angiogenesis, inflammatory mediators, immune function, T complex and serpins expression, redox homeostasis, and energetic metabolism. Both SFNs-OVA and SFNs-CpG significantly delayed melanoma growth/survival time, and their effect was additive.

CONCLUSIONS

Both SFNs-OVA and SFNs-CpG induce effective anticancer response through complementary mechanisms and show the efficacy of an innovative active immunotherapy approach based on the redirection of pre-existing immunity against cancer cells. This approach could be universally applied for solid cancer treatments if translated into the clinic using re-call antigens of childhood vaccination.

Systematic review and meta-analysis of HPV vaccination in women with systemic lupus erythematosus (SLE)

OBJECTIVE

We conducted a systematic review and meta-analysis to access HPV vaccines' safety and immunogenicity in Systemic Lupus Erythematosus (SLE) women.

METHODS

The search was conducted in the most relevant databases. Meta-analyses to evaluate seroconversion rates for each HPV vaccine type and SLE flare rates after vaccination were performed.

RESULTS

We identified 3,467 articles; six papers referring to SLE population were included. Five articles that evaluated vaccine immunogenicity at 7th month after enrollment were included in the meta-analysis. Overall seroconversion rates among SLE participants were 89.3% (95%CI, 0.76-1.00) for HPV6; 92.4% (95%CI, 0.82-1.00) for HPV11; 96.4% (95%CI, 0.93-1.00) for HPV16; and 91.8% (95%CI, 0.85-1.00) for HPV18. Five studies were included in the qualitative analysis of vaccines safety. Pain at the injection site was the most common adverse event (AE). Just one study reported serious AE not related to the vaccine. Flare rate after HPV vaccination was 12,6% (95% CI, 0.04-0.21).

CONCLUSION

Few studies, small sample size, evaluated HPV vaccines in SLE women. Seroconversion rates in SLE women were like healthy women, but anti-HPV geometric mean titers (GMT) were slightly lower in SLE women. HPV vaccines were safe in this population.

Casting a wider protective net: Anti-infective vaccine strategies for patients with hematologic malignancy and blood and marrow transplantation

Patients who have hematologic malignancies are at high risk for infections but vaccinations may be effective prophylaxis. The increased infection risk derives from immune defects secondary to malignancy, the classic example being CLL, and chemotherapies and immunotherapy used to treat the malignancies. Therapy of hematologic malignancies is being revolutionized by introduction of novel targeted agents and immunomodulatory medications, improving the survival of patients. At the same time those agents uniquely change the infection risk and response to immunizations. This review will summarize current vaccine recommendations for patients with hematologic malignancies including patients who undergo hematopoietic cell transplant.

Severe infections following treatment for childhood cancer: a report from CYP-C

Little is known about infections occurring after childhood cancer treatment. We assessed the risk of severe infection postcancer therapy in survivors of leukemia compared to other cancer types. We performed a population-based cohort study of children <15 years of age diagnosed with cancer (2001-2016), alive and relapse-free 30 days after treatment completion. The risk of severe infection in both groups was estimated using subdistribution proportional hazard regression. We identified 6148 survivors (1960 with leukemia). The cumulative incidence (95% confidence interval) of severe infections at 3 years was 0.70% (0.40-1.2%) in leukemia and 0.51% (0.32-0.79%) in other cancers. The risk of severe infection was not statistically different in leukemia survivors compared to other cancer types in univariate and multivariate analysis (adjusted hazard ratio: 1.40, 95% CI: 0.69-2.85). No significant association was found between a history of leukemia and an increased risk of severe infection after treatment, compared to other cancer types.

Infections as a potential long-term risk following childhood leukemia

Leukemia is the most common childhood cancer. While infections are a frequent and potentially severe complication while on treatment, less is known about the risk for infections following therapy completion. In this article, we propose that leukemia survivors might be at increased risk of infections following therapy completion than the general population, independently of potential confounders such as age, sex and Down syndrome. This association is conceivably due to several factors. First, therapy-induced immune dysfunction of both the humoral and cellular compartments appears to last for several years following anti-cancer therapy and after hematopoietic stem cell transplantation. Second, clinical and epidemiological research has shown leukemia survivors are disproportionally affected by comorbidities related to leukemia treatment and its complications, such as diabetes and obesity, which may induce secondary immunodeficiency and infections. Last, differences in health-related behaviors between leukemia survivors and the general population (such as re-vaccination practices) may affect the baseline risk of infections. Although under-represented in the epidemiological literature as a possible late effect of childhood leukemia and its treatment, it is plausible that leukemia survivors are at increased risk of infections for several years when compared to the general population and their siblings. Further research is needed to empirically test these hypotheses.

Long-Term Risk of Infections After Treatment of Childhood Leukemia: A Population-Based Cohort Study Using Administrative Health Data

PURPOSE

Infections are a frequent complication during childhood leukemia treatment. Little is known about the infectious risk in survivors. We compared the relative rate (RR) of infections after treatment completion between pediatric leukemia survivors and the general population.

METHODS

We performed a retrospective, population-based cohort study of children diagnosed with leukemia between 1992 and 2015 in Ontario, Canada, who were alive and relapse free 30 days after treatment completion (index date). Leukemia survivors were matched 5:1 with the general population by year of birth, sex, and rural status and stratified by initial treatment, including and excluding hematopoietic stem-cell transplantation (HSCT). The primary outcome was time to infections, as identified using validated diagnostic codes from administrative databases. Individuals were censored at the earliest of death, first relapse, loss to follow-up, or end of study.

RESULTS

A total of 2,204 leukemia survivors were included and matched with 11,020 controls. The rate of infections was elevated after treatment completion compared with controls (RR, 1.51; 95% CI, 1.45 to 1.57) and at less than 1 year (RR, 1.77; 95% CI, 1.69 to 1.86); 1 to 4.99 years (RR, 1.66; 95% CI, 1.62 to 1.71), and 5 or more years (RR, 1.29; 95% CI, 1.22 to 1.36) from the index date. Among those whose initial treatment excluded HSCT, the rate remained elevated more than 5 years from the index date (RR, 1.29; 95% CI, 1.23 to 1.35). Infection-related death was significantly increased in leukemia survivors both among the entire cohort (hazard ratio, 149.3; 95% CI, 20.4 to 1,091.9) and among those without HSCT (hazard ratio, 92.7; 95% CI, 12.4 to 690.7).

CONCLUSION

A significant association was found between a history of leukemia therapy and an increased risk of infections. Additional study is needed to establish which exposures in patients with leukemia lead to late infections.