Common Immune-Related Exposures/Conditions and Risk of Non-Hodgkin Lymphoma: A Case-Control Study of Disease-Discordant Twin Pairs

Abstract

We evaluated the association between common immune system-altering experiences and non-Hodgkin lymphoma (NHL) risk using a case-control study of 162 like-sex twin pairs discordant for NHL, identified from the International Twin Study. Information on medical history and evidence of childhood exposure to microbes was obtained by questionnaire from 1998 to 2002. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. Intra-twin-pair agreement between twins on individual exposures was high (76%-97%). A negative association between NHL and seasonal hay fever (odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.10, 0.75) and certain allergies (OR = 0.29, 95% CI: 0.13, 0.68) was observed. The number of atopic diseases was negatively associated with NHL (P for trend = 0.0003). A history of infectious mononucleosis was negatively associated with NHL risk (OR = 0.35, 95% CI: 0.14, 0.90). NHL risk was associated with more frequent childhood exposure to microbes during early life (P for trend = 0.04). No differences in association by NHL subtype were observed, although statistical power for these comparisons was low. These observations support the hypothesis that immune-related exposures, especially atopy, are associated with decreased NHL risk. Use of the within-twin-pair study design mitigates confounding by genome, family structure, and unmeasured characteristics of early childhood factors.

Allergic conditions are not associated with the risk of non-Hodgkin’s lymphoma or Hodgkin’s lymphoma: a systematic review and meta-analysis

“…Among these articles, 40 were excluded for the following reasons: did not report the association between allergic conditions and the risk of lymphoma (n=24), not original articles (n=5), insufficient data (n=6), and duplicate reports from the same study population (n=5). A total of 41 articles were finally included in the present meta-analysis, 2 , 4 , 6 – 8 , 10 – 12 , 15 – 47 as shown in Figure 1 .…”

“…The characteristics of the included studies are presented in Table S1 . Among the included studies, 37 studies reported the association between allergic conditions and the risk of NHL, 2 , 4 , 6 – 8 , 10 – 12 , 16 – 18 , 20 – 23 , 25 , 27 – 47 while 12 studies investigated the risk of HL (several studies reported both NHL and HL). 2 , 7 , 10 , 15 , 19 , 24 , 26 , 27 , 29 , 32 , 33 , 39 …”

“…Several case– control studies have indicated that people with a history of allergic conditions might have a lower risk of NHL 6–8. In a meta-analysis of 13 case–control studies, allergic conditions, such as hay fever and asthma, were observed to be modestly associated with the risk of NHL 9.…”

“…Several case– control studies have indicated that people with a history of allergic conditions might have a lower risk of NHL. 6 – 8 In a meta-analysis of 13 case–control studies, allergic conditions, such as hay fever and asthma, were observed to be modestly associated with the risk of NHL. 9 However, results from cohort studies are inconsistent, 10 – 12 as evidence from cohort studies is generally considered to be stronger than that from retrospective studies; a meta-analysis including both case–control studies and cohort studies might be warranted.…”

Conjunctival lymphomas in Japanese monozygotic twins: A case report

“…Studies of monozygotic twins, who share a common genome, provide an effective way of assessing the potential contribution of environmental factors to NHL development. According to a questionnaire survey on medical history (e.g., infections and atopic disease) and microbial exposure history (e.g., sucking on a pacifier) in 162 twin pairs with discordant development of NHL, the risk of NHL was higher in the twin who had been more frequently exposed to microbes than their co-twin (18). Conjunctival lymphoma is believed to be caused by prolonged antigen stimulation resulting from chronic conjunctival infection with Chlamydia psittaci and other organisms, causing loss of B-lymphocyte control and 80% of ocular adnexal lymphoma samples carried C. psittaci DNA (19).…”