Allergy and risk of childhood acute lymphoblastic leukemia: a population-based and record-based study

Shared genetic architecture between autoimmune disorders and B-cell acute lymphoblastic leukemia: insights from large-scale genome-wide cross-trait analysis

BACKGROUND

To study the shared genetic structure between autoimmune diseases and B-cell acute lymphoblastic leukemia (B-ALL) and identify the shared risk loci and genes and genetic mechanisms involved.

METHODS

Based on large-scale genome-wide association study (GWAS) summary-level data sets, we observed genetic overlaps between autoimmune diseases and B-ALL, and cross-trait pleiotropic analysis was performed to detect shared pleiotropic loci and genes. A series of functional annotation and tissue-specific analysis were performed to determine the influence of pleiotropic genes. The heritability enrichment analysis was used to detect crucial immune cells and tissues. Finally, bidirectional Mendelian randomization (MR) methods were utilized to investigate the casual associations.

RESULTS

Our research highlighted shared genetic mechanisms between seven autoimmune disorders and B-ALL. A total of 73 pleiotropic loci were identified at the genome-wide significance level (P < 5 × 10-8), 16 of which had strong evidence of colocalization. We demonstrated that several loci have been previously reported (e.g., 17q21) and discovered some novel loci (e.g., 10p12, 5p13). Further gene-level identified 194 unique pleiotropic genes, for example IKZF1, GATA3, IKZF3, GSDMB, and ORMDL3. Pathway analysis determined the key role of cellular response to cytokine stimulus, B cell activation, and JAK-STAT signaling pathways. SNP-level and gene-level tissue enrichment suggested that crucial role pleiotropic mechanisms involved in the spleen, whole blood, and EBV-transformed lymphocytes. Also, hyprcoloc and stratified LD score regression analyses revealed that B cells at different developmental stages may be involved in mechanisms shared between two different diseases. Finally, two-sample MR analysis determined causal effects of asthma and rheumatoid arthritis on B-ALL.

CONCLUSIONS

Our research proved shared genetic architecture between autoimmune disorders and B-ALL and shed light on the potential mechanism that might involve in.

Natural killer cells contribute to 'hot' tumor regression in the allergic inflammatory environment

Systemic immune status influences the elimination of tumor cells. However, it remains unclear how chronic inflammation in allergic diseases affects the tumor microenvironment and tumorigenesis. To investigate tumor progression in a state of heightened allergic inflammation, we established a mouse model of allergic inflammation. We used house dust mite extract to induce a hyper-reactive systemic immune response. Additionally, we subcutaneously inoculated two types of cancer cells (CT26 and 4T1 tumors). We conducted immune profiling of the ex-vivo tumor mass using multicolor flow cytometry staining and performed dynamic analysis of peripheral cytokines to explore the significant relationship between the development of allergic inflammation and tumorigenesis. We found that mice in a state of allergic inflammation were more susceptible to developing tumors. Interestingly, the growth of T cell-inflamed was inhibited in the allergic state, while growth of non-T cell-inflamed was promoted. Further research revealed that natural killer (NK) cells with enhanced tumor-killing or immune-regulating abilities were more active in " hot " tumors. Inhibiting NK cell activity can partially alleviate the impact of allergic inflammation on tumor growth. In summary, our results suggest that NK cells play significant role in suppressing tumor growth in an allergic inflammation mouse model. This phenomenon seems to be closely linked to both the inherent characteristics of the tumor and its interaction with the immune system. The innate immune system can be mobilized to synergize with the adaptive immune system to inhibit tumor growth, which opens a new way for a tumor immunotherapy.

Allergies, genetic polymorphisms of Th2 interleukins, and childhood acute lymphoblastic leukemia: The ESTELLE study

CONTEXT

A negative association between a history of allergy and childhood acute lymphoblastic leukemia (ALL) has been reported in previous studies, but remains debated. This work aimed to investigate this association accounting for genetic polymorphisms of the Th2 pathway cytokines (IL4, IL10, IL13, and IL4R).

METHODS

Analyses were based on the French case-control study ESTELLE (2010-2011). The complete sample included 629 ALL cases and 1421 population-based controls frequency-matched on age and gender. The child's medical history was collected through standardized maternal interview. Biological samples were collected, and genotyping data were available for 411 cases and 704 controls of European origin. Odds ratios (OR) were estimated using unconditional regression models adjusted for potential confounders.

RESULTS

In the complete sample, a significant inverse association was observed between ALL and reported history of allergic rhinitis or sinusitis (OR = 0.65 [0.42-0.98]; P = 0.04), but there was no obvious association with allergies overall. There was an interaction between genetic polymorphisms in IL4 and IL4R (P_{interaction =} 0.003), as well as a gene-environment interaction between IL4R-rs1801275 and a reported history of asthma (IOR = 0.23; P_int  = 0.008) and eczema (IOR = 0.47; P_int  = 0.06). We observed no interaction with the candidate polymorphisms in IL4 and IL13.

CONCLUSION

These results suggest that the association between allergic symptoms and childhood ALL could be modified by IL4R-rs1801275, and that this variant could also interact with a functional variant in IL4 gene. Although they warrant confirmation, these results could help understand the pathological mechanisms under the reported inverse association between allergy and childhood ALL.

Acute lymphoid leukemia etiopathogenesis

Acute lymphoid leukemia (ALL) is a type of hematological neoplasm that affects the precursor cells of strains B, T  and NK, with a higher incidence in the pediatric range. The pathophysiology of ALL is characterized by chromosomal abnormalities and genetic alterations involved in the differentiation and proliferation of lymphoid precursor cells. Despite the lack of information in the literature, it is believed that leukemogenesis originates from a complex interaction between environmental and genetic factors, which combined lead to cellular modifications. Environmental factors have been evaluated as possible predisposing factors in the development of ALL but there are still conflicting results in the world literature. In this context, the aim of the present review is to discuss the major exogenous factors regarding ALL.

Current status and perspectives regarding the association between allergic disorders and cancer

While activation of immune system may lead to a lower risk of some diseases, it has been shown that a history of atopic allergic disorders such as asthma, hay fever, eczema, and food allergies could be related to several types of cancer. However, the evidence is not entirely conclusive. Two proposals suggest a possible mechanism for the association between allergic disorders and cancers: immune surveillance and the antigenic stimulation. The association of allergy and cancer may vary by cancer site and the type of exposure. The aim of current review was to summarize the current knowledge of the association between allergic diseases and the risk of cancers with particular emphasis on case-controls and cohort studies to estimate the cancer risk associated with allergy.

Incidence of cancer after asthma development: 2 independent population-based cohort studies

BACKGROUND

Evidence regarding the risk of cancer development after asthma diagnosis is controversial and inconclusive.

OBJECTIVE

This study sought to determine whether asthma is associated with an increased risk for incident cancer.

METHODS

Two independent, population-based, longitudinal cohorts were examined, and estimated hazard ratios were determined using Cox regression. One group consisted of an unmatched cohort of 475,197 participants and a propensity score-matched cohort of 75,307 participants from the National Health Insurance Service-National Sample Cohort (NHIS-NSC; claims-based data from 2003 to 2015). The other group consisted of 5,440 participants from the Ansan-Ansung cohort (interview-based data from 2001 to 2014).

RESULTS

The NHIS-NSC matched cohort had 572,740 person-years of follow-up, 6,885 people with new asthma diagnoses, and 68,422 people without asthma diagnoses. Adults with asthma had a 75% greater risk of incident cancer overall. The excess risk for incident cancer was greatest during the first 2 years after asthma diagnosis, and this risk remained elevated throughout follow-up. Patients with nonatopic asthma had a greater risk of overall cancer than those with atopic asthma. A high cumulative dose of inhaled corticosteroids among asthma patients was associated with a 56% reduced risk of lung cancer, but had no effect on the risk of overall cancer. The results from the NHIS-NSC unmatched cohort and the Ansan-Ansung cohort were similar to the primary results from the NHIS-NSC matched cohort.

CONCLUSIONS

Asthma development was associated with an increased risk of subsequent cancer in 2 different Korean cohorts. Our findings provide an improved understanding of the pathogenesis of asthma and its relationship with carcinogenesis and suggest that clinicians should be aware of the higher risk of incident cancer among patients with asthma.

Allergies and Childhood Acute Lymphoblastic Leukemia: A Case-Control Study and Meta-analysis

Background: Allergic disease is suspected to play a role in the development of childhood acute lymphoblastic leukemia (ALL). Studies conducted over the last several decades have yielded mixed results.Methods: We examined the association between allergy, a common immune-mediated disorder, and ALL in the California Childhood Leukemia Study (CCLS), a case-control study of 977 children diagnosed with ALL and 1,037 matched controls (1995-2015). History of allergies in the first year of life was obtained from interviews, mainly reported by mothers. Logistic regression analyses were conducted to estimate ORs and 95% confidence intervals (CIs), controlling for birth order, daycare attendance, and mode of delivery. In addition, we conducted meta-analyses with data from the CCLS and 12 published studies and employed a new method to estimate between-study heterogeneity (R_b).Results: Overall, no associations were observed between childhood ALL risk and specific allergy phenotypes or any allergy, as a group. However, having any allergy was associated with an increased risk of ALL among the youngest study participants. In the meta-analysis random-effects models, reduced odds of ALL were associated with hay fever (metaOR = 0.65; 95% CI, 0.47-0.90); however, restricting the analysis to studies that used medical records for assessment of allergy or recently published studies led to null or attenuated results.Conclusions: Overall, our findings do not support a clear association between allergy and childhood ALL.Impact: The degree to which epidemiologic studies can inform the relationship between allergies and risk of childhood ALL is limited by R_b. Cancer Epidemiol Biomarkers Prev; 27(10); 1142-50. ©2018 AACR.

Genetic polymorphisms of Th2 interleukins, history of asthma or eczema and childhood acute lymphoid leukaemia: Findings from the ESCALE study (SFCE)

BACKGROUND

Previous studies on the putative role of allergy in the aetiology of childhood leukaemia have reported contradictory results. The present study aimed to analyse the relation between a medical history of asthma or eczema and childhood acute lymphoid leukaemia (ALL) in light of potential candidate gene-environment interactions.

METHODS

Analyses were based on a subset of 434 cases of ALL and 442 controls successfully genotyped and of European ancestry children enrolled in a French population-based case-control study conducted in 2003-2004. Information about medical history was obtained during a standardized interview with the mothers. Candidate polymorphisms in genes of the Th2 cytokines IL4, IL10, IL13 and IL4-receptor, were genotyped or imputed.

RESULTS

None of the variant alleles were directly associated with childhood acute lymphoid leukaemia. A medical history of asthma or eczema was reported more often in the control group (OR = 0.7 [0.5-1.0]). This association was mostly seen in the group of children not carrying the IL13-rs20541 variant allele (Interaction Odds Ratio IOR 1.9, p-interaction = 0.07) and in those carrying the IL10 triple variant haplotype (IOR 0.5, p-interaction = 0.04). No interaction was observed with the candidate polymorphisms in IL4 and IL4R.

CONCLUSION

This study provides a new insight into the relationship between allergic symptoms and childhood acute lymphoid leukaemia, by suggesting this inverse association could be limited to children carrying certain genetic polymorphisms. If confirmed, these results could help better understand the biological mechanisms involved in the development of childhood acute lymphoid leukaemia.

Agents in Development for Childhood Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is the most common cancer in childhood. Standard chemotherapy has afforded outstanding outcomes for many patients; however, there remain some sub-groups with high-risk features, refractory disease, and patients that  relapse who have a poor prognosis with conventional treatments. Over the past decade, there have been significant advances in newer treatment options, including improved monoclonal antibody therapies, T cell engagers, and chimeric antigen T-cell receptor products, all of which have changed the landscape for patients who relapse. These are now being introduced more frequently and at earlier stages of therapy. We present a brief overview of the biology and etiology of childhood ALL, treatment strategies currently in use, and discuss some newer strategies and their possible role in the future of ALL therapy for children.

Atopy and Specific Cancer Sites: a Review of Epidemiological Studies

Mounting evidence appears to link asthma and atopy to cancer susceptibility. This review presents and discusses published epidemiological studies on the association between site-specific cancers and atopy. PubMed was searched electronically for publications between 1995 and 2015, and cited references were researched manually. Quantitative studies relating to atopy, allergy, or asthma and cancer were identified and tabulated. Despite many exposure-related limitations, patterns in the studies were observed. Asthma, specifically, has been observed to be a risk factor for lung cancer. A protective effect of atopic diseases against pancreatic cancer has been shown consistently in case-control studies but not in cohort studies. Allergy of any type appears to be protective against glioma and adult acute lymphoblastic leukemia. Most studies on atopic diseases and non-Hodgkin lymphoma or colorectal cancer reported an inverse association. The other sites identified had varying and non-significant outcomes. Further research should be dedicated to carefully defined exposure assessments of "atopy" as well as the biological plausibility in the association between atopic diseases and cancer.

Association of atopic diseases and parvovirus B19 with acute lymphoblastic leukemia in childhood and adolescence in the northeast of Brazil

BACKGROUND

Several factors related to the immune system, such as a history of allergies and virus infections, may be associated with acute lymphoblastic leukemia (ALL). The purpose of this study was to analyze whether the presence of atopic diseases and previous infection with parvovirus B19 and Epstein-Barr virus (EBV) are associated with the development of ALL.

METHODS

This case-control study was performed in two tertiary hospitals located in northeastern Brazil. The study population included 60 patients who were diagnosed with non-T-cell ALL using myelogram and immunophenotyping and 120 patients in the control group. Atopy was evaluated via a parent questionnaire and medical records. Total immunoglobulin (Ig)E and IgG levels of parvovirus B19 and EBV were measured in the serum. Logistic regression was performed to assess the association between variables and odds of ALL.

RESULTS

We identified a significant inverse association between rhinitis, urticaria and elevated IgE serum levels with ALL. A history of parvovirus B19 infection showed a significant association with this type of cancer [OR (95 % CI) 2.00 (1.94-4.26); P = 0.050]. In logistic regression, the presence of atopy was a protective factor [OR (95 % CI) 0.57 (0.38-0.83); P = 0.004], and the presence of IgG for parvovirus B19 was an important risk factor for ALL [OR (95 % CI) 2.20 (1.02-4.76); P = 0.043].

CONCLUSIONS

These results suggest that atopic diseases and elevated total IgE levels are associated with a potential protective effect on the development of ALL. Previous infection with parvovirus B19 contributed to ALL susceptibility.

Reported associations between asthma and acute lymphoblastic leukemia: insights from a hybrid simulation study

Numerous studies have reported a protective association between asthma and acute lymphoblastic leukemia (ALL), but the causal structure of this association remains unclear. We present a hybrid simulation to examine the compatibility of this association with uncontrolled confounding by infection or another unmeasured factor. We generated a synthetic cohort using inputs on the interrelations of asthma, ALL, infections, and other suggested risk factors from the literature and the Danish National Birth Cohort. We computed odds ratios (ORs) between asthma and ALL in the synthetic cohort with and without adjustment for infections and other (including unmeasured) confounders. Only if infection was an extremely strong risk factor for asthma (OR of 10) and an extremely strong protective factor against ALL (OR of 0.1) was the asthma-ALL association compatible with the literature (OR of 0.78). Similarly, strong uncontrolled confounding by an unmeasured factor could downwardly bias the asthma-ALL association, but not enough to replicate findings in the literature. This investigation illustrates that the reported protective association between asthma and ALL is unlikely to be entirely due to uncontrolled confounding by infections or an unmeasured confounder alone. Simulation can be used to advance our understanding of risk factors for rare outcomes as demonstrated by this study.

Association of asthma with the risk of acute leukemia and non-Hodgkin lymphoma

An increasing incidence of hematological malignancies has been observed in children and adults worldwide over the last few decades. Asthma is a common chronic inflammatory disease. The aim of the present meta-analysis was to evaluate the potential association between a history of asthma and the risk of acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) and non-Hodgkin lymphoma (NHL). A literature search was performed through PubMed and the Cochrane Database of Systematic Reviews and the Newcastle-Ottawa Scale was used to evaluate the quality of the selected studies. The I² index was used to evaluate heterogeneity and the outcome was measured as the odds ratio (OR) by the random-effects model. A total of 16 case-control studies were included. All the studies were of high quality. The OR for ALL was 0.90 [95% confidence interval (CI): 0.68-1.19; P=0.45; I²=79%]. The OR for AML was 0.85 (95% CI: 0.67-1.08; P=0.19; I²=8%). The OR for NHL was 0.91 (95% CI: 0.83-1.00; P=0.05; I²=0%). Asthma was found to be inversely associated with the risk of NHL. A negative trend of association of asthma with ALL and AML was also observed. However, additional large prospective studies are required to confirm these findings.

Immune-related conditions and acute leukemia in children with Down syndrome: a Children's Oncology Group report

BACKGROUND

Children with Down syndrome have unique immune profiles and increased leukemia susceptibility.

METHODS

Mothers of 158 children with Down syndrome diagnosed with acute leukemia at 0 to 19 years in 1997 to 2002 and 173 children with Down syndrome but no leukemia were interviewed. Associations were evaluated via multivariable unconditional logistic regression.

RESULTS

No associations were detected for asthma, eczema, allergies, or hypothyroidism. Diabetes mellitus associated with leukemia (OR = 9.23; 95% confidence interval 2.33-36.59); however, most instances occurred concurrent with or after the leukemia diagnosis.

CONCLUSIONS AND IMPACT

Children with Down syndrome who develop leukemia have increased diabetes risk, likely due to treatment and underlying susceptibility factors.

Allergy and risk of hematologic malignancies: associations and mechanisms

Increasing evidence indicates that a dysregulated immune system, as the one found in allergic disorders, can affect survival of tumor cells. A possible association between allergies and risk of hematologic malignancies has been examined in several epidemiological studies; however, results were not always consistent. The aim of this review is to report the preclinical and clinical data, which support a correlation between allergy and hematologic neoplasms. Immune system modulation could represent a powerful tool in the prevention and treatment of hematologic malignancies.

Allergic diseases and risk of hematopoietic malignancies in a cohort of postmenopausal women: a report from the Iowa Women's Health Study

BACKGROUND

Allergic diseases signify immune dysregulation attributable to underlying genetics and environmental exposures. Associations between various allergies and hematopoietic cancers have been observed, albeit inconsistently; however, few prospective studies have examined the risk, and even fewer among older adults.

METHODS

We examined risk of incident hematopoietic cancers in those reporting allergic diseases in a population-based cohort of 22,601 older women (Iowa Women's Health Study). Self-reported allergic status, including asthma, hay fever, eczema, and/or other allergies, was determined via questionnaire in 1997 (mean age, 72 years; range, 63-81 years). Incident cancers were ascertained by linkage with the Iowa Cancer Registry from 1997 to 2011. Cox proportional hazards regression was performed to estimate multivariate-adjusted HR and 95% confidence intervals (CI) for myeloid (N = 177) and lymphoid (N = 437) malignancies, respectively.

RESULTS

Allergic diseases were not associated with risk of myeloid (HR, 1.00; 95% CI, 0.72-1.37) or lymphoid (HR, 0.99; 95% CI, 0.81-1.22) malignancies overall, or for most allergic and malignant subtypes examined. Self-reported asthma was positively associated with development of myelodysplastic syndrome (MDS; HR, 2.00; 95% CI, 0.93-4.32). In addition, there was a 30% to 40% decrease in risk of both lymphoid and myeloid cancers in those reporting rural residences but no association in those reporting urban residences; the interaction between residence and allergy was statistically significant for lymphoid malignancies (Pinteraction = 0.05).

CONCLUSIONS AND IMPACT

These results suggest that asthma may contribute to the pathogenesis of MDS, a finding consistent with the chronic antigen stimulation hypothesis. Susceptibility differences by location of residence are concordant with the hygiene hypothesis and merit additional exploration.

Associations between allergies and risk of hematologic malignancies: results from the VITamins and lifestyle cohort study

Immune dysregulations associated with allergies may affect cancer cell biology but studies on the relationship between allergies and risk of hematologic malignancies (HM) yielded inconsistent results. Herein, we used the vitamins and Lifestyle (VITAL) cohort to examine this association. From 2000 to 2002, 66,212 participants, aged 50-76, completed a baseline questionnaire on cancer risk factors, medical conditions, allergies, and asthma. Through 2009, incident HMs (n = 681) were identified via linkage to the surveillance, epidemiology, and end results cancer registry. After adjustment for factors possibly associated with HMs, a history of airborne allergy was associated with increased risk of HMs (hazard ratio [HR] = 1.19 [95% confidence interval: 1.01-1.41], P = 0.039) in Cox proportional hazards models. This association was limited to allergies to plants/grass/trees (HR = 1.26 [1.05-1.50], P = 0.011) and was strongest for some mature B-cell lymphomas (HR = 1.50 [1.14-2.00], P = 0.005). Gender-stratified analyses revealed that the associations between airborne allergies overall and those to plants, grass, and trees were only seen in women (HR = 1.47 [1.14-1.91], P = 0.004; and HR = 1.73 [1.32-2.25], P < 0.001) but not men (HR = 1.03 [0.82-1.29], P = 0.782; and HR = 0.99 [0.77-1.27], P = 0.960). Together, our study indicates a moderately increased risk of HMs in women but not men with a history of allergies to airborne allergens, especially to plant, grass, or trees.

Allergy and acute leukaemia in children with Down syndrome: a population study. Report from the Mexican inter-institutional group for the identification of the causes of childhood leukaemia

BACKGROUND

Allergies have been described as protective factors against the development of childhood acute leukaemia (AL). Our objective was to investigate the associations between allergy history and the development of AL and acute lymphoblastic leukaemia (ALL) in children with Down syndrome (DS).

METHODS

A case-control study was performed in Mexico City. The cases (n=97) were diagnosed at nine public hospitals, and the controls (n=222) were recruited at institutions for children with DS. Odds ratios (OR) were calculated.

RESULTS

Asthma was positively associated with AL development (OR=4.18; 95% confidence interval (CI): 1.47-11.87), whereas skin allergies were negatively associated (OR=0.42; 95% CI: 0.20-0.91).

CONCLUSION

Our findings suggest that allergies and AL in children with DS share biological and immune mechanisms. To our knowledge, this is the first study reporting associations between allergies and AL in children with DS.

Invited commentary: childhood acute lymphoblastic leukemia and allergies: biology or bias?

Previous epidemiologic studies have shown an inverse association between a personal history of atopy/allergies, both overall and among asthma, eczema, and hay fever investigated separately, and childhood acute lymphoblastic leukemia (ALL) with some consistency; however, in most of these studies, exposure data were collected by maternal interview. Now, in a population-based and records-based study in this issue of the Journal (Am J Epidemiol. 2012;176(11):970-978), Chang et al. report an increased risk for allergic conditions across different etiologic time periods, calling the former paradigm into doubt. A review of the basic biology literature shows that proposed mechanisms support either a positive or an inverse association. In light of this ambiguity, it is epidemiology's turn to determine the direction of association.

Perspectives on the causes of childhood leukemia

Acute leukemia is the most common cancer in children but the causes of the disease in the majority of cases are not known. About 80% are precursor-B cell in origin (CD19+, CD10+), and this immunophenotype has increased in incidence over the past several decades in the Western world. Part of this increase may be due to the introduction of new chemical exposures into the child's environment including parental smoking, pesticides, traffic fumes, paint and household chemicals. However, much of the increase in leukemia rates is likely linked to altered patterns of infection during early childhood development, mirroring causal pathways responsible for a similarly increased incidence of other childhood-diagnosed immune-related illnesses including allergy, asthma, and type 1 diabetes. Factors linked to childhood leukemia that are likely surrogates for immune stimulation include exposure to childcare settings, parity status and birth order, vaccination history, and population mixing. In case-control studies, acute lymphoblastic leukemia (ALL) is consistently inversely associated with greater exposure to infections, via daycare and later birth order. New evidence suggests also that children who contract leukemia may harbor a congenital defect in immune responder status, as indicated by lower levels of the immunosuppressive cytokine IL-10 at birth in children who grow up to contract leukemia, as well as higher need for clinical care for infections within the first year of life despite having lower levels of exposure to infections. One manifestation of this phenomenon may be leukemia clusters which tend to appear as a leukemia "outbreak" among populations with low herd immunity to a new infection. Critical answers to the etiology of childhood leukemia will require incorporating new tools into traditional epidemiologic approaches - including the classification of leukemia at a molecular scale, better exposure assessments at all points in a child's life, a comprehensive understanding of genetic risk factors, and an appraisal of the interplay between infectious exposures and the status of immune response in individuals.