Search PubMed⌕ Search

Biomedical subjects

Henrik Hjalgrim

Publications and source records attributed to Henrik Hjalgrim.

At least 19 recordsLinked to original sources

Plasma donation rates and infection risk: A multicentre observational study in Denmark.

BACKGROUND AND OBJECTIVES: The demand for plasma-derived medicinal products underscores the need to assess health effects of plasma donation. This study examines the association between plasma donation rates and infection risk in a country with voluntary, non-remunerated donation. MATERIALS AND METHODS: From 2016 to 2024, 45,615 first-time plasma donors were enrolled in a cohort study with time-varying exposure. Follow-up began 90 days after the first plasma donation, with donation rates recalculated every 90 days. Donation rates were categorized as 0, 1 (reference), 2-3, 4-5 or 6-8 donations. Infection was defined using Danish health registers. Survival models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: The median plasma donation rate was 2 (Q1, 1; Q3, 4). During follow-up, 15,498 donors experienced an infection. A trend of decreasing HRs for infection was observed with higher donation rates compared with a single donation (0 donations: HR: 0.89, 95% CI: 0.86-0.93; 2-3 donations: HR: 0.85, 95% CI: 0.81-0.89; 4-5 donations: HR: 0.65, 95% CI: 0.59-0.72; and 6-8 donations: HR: 0.48, 95% CI: 0.36-0.62). Findings were consistent across multiple regression models. CONCLUSION: In this study, higher plasma donation rates were associated with lower infection risk. Importantly, this inverse association is likely due to bias inherent to observational designs, particularly the internal healthy donor effect, which limits interpretation. Thus, no causal relationship between plasma donation rates and infection risk can be inferred. This underscores the challenges of assessing plasma donation safety using non-randomized data.

Adult↗

Hidradenitis Suppurativa and Smoking, Obesity, Psoriasis, Inflammatory Bowel Disease, and Systemic Sclerosis: Results From A 2-Sample Mendelian Randomization Study.

IMPORTANCE: Smoking and obesity are associated with risk of hidradenitis suppurativa, and both are considered important environmental risk factors. However, a causal relationship remains unproven. OBJECTIVE: To primarily investigate the relationship between body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) and smoking and HS, and secondarily to investigate potential relationships between 3 inflammatory diseases (psoriasis, inflammatory bowel disease [IBD], and systemic sclerosis [SSc]) and HS. DESIGN, SETTING, AND PARTICIPANTS: A mendelian randomization (MR) study conducted in 2024 on 5 exposure phenotypes (BMI, smoking, psoriasis, IBD, and SSc) on the outcome of phenotype HS was conducted. The MR analyses used large genetic White European cohorts from genome-wide association studies (GWAS) of each of the 6 phenotypes. Initial analyses were conducted May, 2024, and were updated in May, 2025. EXPOSURE: The 5 exposure phenotypes using predetermined genome-wide significant single-nucleotide variants as proxies for each particular exposure. RESULTS: The GWAS on HS included 4814 case patients and more than 1.2 million controls from Denmark, Iceland, Finland, the UK, and the US. The BMI GWAS involved 700&#x202f;000 individuals from the UK Biobank and GIANT consortium. Smoking data were obtained from 1.23 million participants in an international consortium. The psoriasis GWAS analyzed 39&#x202f;498 case patients and 286&#x202f;769 controls from White European populations and a DNA genetic testing company. The IBD GWAS meta-analysis included 38&#x202f;155 case patients and 48&#x202f;485 controls from the International Inflammatory Bowel Disease (IBD) Genetics Consortium. The SSc GWAS included 9095 case patients and 17&#x202f;584 controls from White European populations. Genetic correlations (rg) were found between HS and all exposure phenotypes except SSc (BMI: rg&#x2009;=&#x2009;0.36, P&#x2009;<&#x2009;.001; smoking: rg&#x2009;=&#x2009;0.33, P&#x2009;<&#x2009;.001; IBD: rg&#x2009;=&#x2009;0.25, P&#x2009;<&#x2009;.001; psoriasis: rg&#x2009;=&#x2009;0.34, P&#x2009;<&#x2009;.001; SSc: rg&#x2009;=&#x2009;0.33, P&#x2009;=&#x2009;.22). MR analyses supported an effect of BMI on HS (&#x3b2;&#x2009;=&#x2009;0.87; odds ratio [OR] per BMI unit, 1.20; 95% CI, 1.17-1.23; P&#x2009;<&#x2009;.001) without signs of pleiotropy (slope: &#x3b2;&#x2009;=&#x2009;0.91, P&#x2009;<&#x2009;.001, P for intercept&#x2009;=&#x2009;.76). Smoking showed a significant causal estimate (&#x3b2;&#x2009;=&#x2009;0.59, P&#x2009;<&#x2009;.001), but results became inconclusive in subsequent sensitivity analyses. Among IBD, psoriasis, and SSc, results supported a causal effect of IBD on HS (&#x3b2;&#x2009;=&#x2009;0.18, OR&#x2009;=&#x2009;1.20; 95% CI, 1.15-1.24; P&#x2009;<&#x2009;.001), without signs of pleiotropy. CONCLUSIONS AND RELEVANCE: These findings indicate causal effects of IBD and increased BMI on the risk of HS. This information may help physicians inform patients about disease risk contributed by modifiable lifestyle behaviors, which can be beneficial for planning lifestyle interventions.

Humans↗

Atopy and risk of non-Hodgkin lymphoma.

BACKGROUND: A possible connection between allergy and cancer has been suspected, but allergy-related conditions or atopy have been inconsistently associated with reduced risks of non-Hodgkin lymphoma. We investigated this association in a population-based case-control study and in a prospective study with prediagnostic blood specimens. METHODS: We carried out a population-based study of 3055 case patients with non-Hodgkin lymphoma and 3187 control subjects in Denmark and Sweden, including questionnaire information on allergy and blood specimens, and a nested case-control study within a prospective cohort of more than 400,000 Finnish women. In the second study, serum specimens from the 198 case patients who developed non-Hodgkin lymphoma within a median of 8.9 years after the blood was drawn were matched with serum specimens from 594 control subjects. In both studies, laboratory-based evidence of allergy (atopy) was determined in serum on the basis of specific IgE reactivity to common inhalant allergens. Dissemination of disease was classified by the Ann Arbor system. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by logistic regression. RESULTS: In the first study, ever having hay fever, but not other allergic conditions, was associated with a reduced risk of non-Hodgkin lymphoma. In particular, subjects with specific IgE reactivity in serum had a 32% (95% CI = 20% to 42%) lower risk of overall non-Hodgkin lymphoma than those without such reactivity. However, among case patients, dissemination of the disease was strongly inversely associated with specific IgE reactivity. In the second (i.e., prospective) study, no association was found between non-Hodgkin lymphoma and specific IgE reactivity, except possibly immediately before a diagnosis of non-Hodgkin lymphoma (> or = 10 years before diagnosis, OR = 1.00, 95% CI = 0.48 to 2.09; 5-9 years before, OR = 0.95, 95% CI = 0.50 to 1.84; 1-4 years before, OR = 0.33, 95% CI = 0.11 to 1.02; and < 1 year before, OR = 0.27, 95% CI = 0.03 to 2.31). CONCLUSION: Allergy may not be causally associated with the risk of non-Hodgkin lymphoma. The inverse association observed in some case-control studies may arise because non-Hodgkin lymphoma suppresses the immunologic response to allergens.

Adult↗

Multiple sclerosis after infectious mononucleosis.

BACKGROUND: Infectious mononucleosis caused by the Epstein-Barr virus has been associated with increased risk of multiple sclerosis. However, little is known about the characteristics of this association. OBJECTIVE: To assess the significance of sex, age at and time since infectious mononucleosis, and attained age to the risk of developing multiple sclerosis after infectious mononucleosis. DESIGN: Cohort study using persons tested serologically for infectious mononucleosis at Statens Serum Institut, the Danish Civil Registration System, the Danish National Hospital Discharge Register, and the Danish Multiple Sclerosis Registry. SETTING: Statens Serum Institut. PATIENTS: A cohort of 25 234 Danish patients with mononucleosis was followed up for the occurrence of multiple sclerosis beginning on April 1, 1968, or January 1 of the year after the diagnosis of mononucleosis or after a negative Paul-Bunnell test result, respectively, whichever came later and ending on the date of multiple sclerosis diagnosis, death, emigration, or December 31, 1996, whichever came first. MAIN OUTCOME MEASURE: The ratio of observed to expected multiple sclerosis cases in the cohort (standardized incidence ratio). RESULTS: A total of 104 cases of multiple sclerosis were observed during 556,703 person-years of follow-up, corresponding to a standardized incidence ratio of 2.27 (95% confidence interval, 1.87-2.75). The risk of multiple sclerosis was persistently increased for more than 30 years after infectious mononucleosis and uniformly distributed across all investigated strata of sex and age. The relative risk of multiple sclerosis did not vary by presumed severity of infectious mononucleosis. CONCLUSIONS: The risk of multiple sclerosis is increased in persons with prior infectious mononucleosis, regardless of sex, age, and time since infectious mononucleosis or severity of infection. The risk of multiple sclerosis may be increased soon after infectious mononucleosis and persists for at least 30 years after the infection.

Adult↗

Psychiatric hospitalizations in a cohort of Danish polio patients.

Although previous polio infection remains a considerable cause of long-term morbidity worldwide, few studies have examined the psychiatric consequences of poliomyelitis. The authors followed 4,660 polio patients hospitalized at the primary infectious disease hospital in Copenhagen, Denmark, between 1922 and 1954 as well as 19,017 age- and gender-matched Danes for psychiatric hospitalizations from January 1, 1977, to December 31, 1993. Incidence rates of all psychiatric disorders combined and of separate diagnostic groups of psychiatric diseases in the two cohorts were compared, yielding the incidence rate ratio, a measure of relative risk. Overall, polio patients had a 40% increased risk of being hospitalized for a psychiatric disorder (incidence rate ratio = 1.43, 95% confidence interval: 1.23, 1.66). Apparently, the overall increased risk of psychiatric hospitalizations could not be confined to specific groups of psychiatric disorders but seemed to be explained by slightly increased risks of several different disorders, especially milder psychiatric disorders. Finally, psychiatric morbidity did not differ between paralytic and nonparalytic polio patients. History of hospitalization for polio might be associated with subsequent risk of hospitalization for psychiatric disorders. The underlying mechanism for this association remains uncertain.

Adult↗

Reproductive patterns and non-Hodgkin lymphoma risk in Danish women and men.

Reproductive patterns have been inconsistently linked to risk of non-Hodgkin lymphoma (NHL) in women, and fathering patterns in relation to NHL risk have not been studied. The authors conducted a register-based cohort study of 4.1 million Danes to investigate associations of livebirths with subsequent NHL incidence (85 million person-years, 3819 NHL cases). The impact of induced abortions, ectopic pregnancies, spontaneous abortions, missed abortions, stillbirths, and hydatidiform moles on subsequent NHL incidence was studied in a subcohort of 1.2 million women. Ratios of NHL incidence rates, accompanying trend tests and two-sided p-values were calculated by log-linear Poisson regression analyses. Pregnancies, whether ending in livebirths or not, were unrelated to NHL incidence in women. The only statistically significant finding in women was that, among parous women, age at first child-birth was inversely associated with NHL incidence (p-trend = 0.001). In men, there was no overall difference in NHL incidence between fathers and non-fathers. However, in men with children, NHL risk declined with increasing number of children (p-trend = 0.02) and increased with time since birth of the most recent child (p-trend < 0.001). Pregnancies have limited impact, if any, on subsequent NHL risk in women. Our findings in men need replication, but, if verified, they may reflect lymphomagenesis-associated male subfertility prior to NHL diagnosis.

Cohort Studies↗

[Chromosome changes associated with childhood leukaemia occur prenatally].

Leukaemia is the most common cancer in childhood, yet only a few risk factors have been identified. Studies of monozygotic twins with concordant leukaemia and retrospective analyses of neonatal blood spots from children with leukaemia indicate that chromosomal translocations characteristic of childhood leukaemia often occur prenatally. The chromosomal translocations may be initiators of the leukaemia development but per se are insufficient to cause the disease. The findings provide a basic understanding of the natural history of childhood leukaemia and may make the development of preventive measures feasible.

Child, Preschool↗

Cancer risk among patients with multiple sclerosis: a population-based register study.

Cancer occurrence in patients with multiple sclerosis (MS) has been little studied, but associations with brain tumours, breast cancer, Hodgkin lymphoma and nasopharyngeal carcinoma have been suggested. We took advantage of population-based registers of MS and cancer to assess the risk of cancer following diagnosis of MS. Patients registered in the Danish Multiple Sclerosis Register were linked with the Danish Cancer Register to obtain information on cancer occurrence. The ratio of the observed to the number of expected cancers based on population-based incidence rates, i.e., the standardised incidence ratio (SIR), served as measure of the relative cancer risk. A database comprising all Danish women born after April 1, 1935, with information on all live-born children, was used in the analyses of breast cancer to adjust for reproductive factors. Overall 1,037 cancers were observed in 11,817 MS patients during 153,875 person-years of follow-up vs. an expected number of 1,098 (SIR = 0.94 [95% confidence interval CI: (0.89-1.00)]. The risk of brain tumours and Hodgkin lymphoma was not increased. A 16% overall reduced cancer risk in men with MS was explained by reduced numbers of cancers of the digestive, respiratory and genital organs. Though the overall cancer risk was not increased [SIR = 1.01(0.94-1.09), n = 676], female MS patients had an increased risk of breast cancer [SIR = 1.21 (1.05-1.39), n = 193]. Adjusting for parity and age at first child delivery did not change this risk estimate materially. In general MS patients are not at increased risk of cancer. Women with MS, however, seem to have a small excess risk of breast cancer, which cannot be attributed to reduced parity or delayed first child birth.

Adult↗

Personal and family history of autoimmune diabetes mellitus and susceptibility to young-adult-onset Hodgkin lymphoma.

Young-adult-onset (15-44 years of age) Hodgkin lymphoma (HL) is believed to arise as a consequence of late primary infection in susceptible individuals. The properties of this susceptibility remain little understood. We have previously reported an increased occurrence of HL in patients with rheumatoid arthritis and among their offspring, suggesting that susceptibility to autoimmunity might be of importance also in the pathogenesis of HL. To explore this hypothesis, we assessed the association of personal and family history of diabetes mellitus, with risk of subsequent HL in a population-based case-control study, including as cases all individuals diagnosed with HL above 15 years of age 1964-1999 (n = 6,873) in Sweden, and matched population controls (n = 12,565). First-degree relatives of cases and controls were identified through linkage with the Multi-generation Register. We identified discharges listing diabetes mellitus through linkage with the Inpatient Register (1964-2000). We used odds ratios (OR) as measures of relative risk. Cases with young-adult-onset HL were less likely to have a personal (OR =0.5, 95% CI 0.2-1.1) or family (OR =0.7, 95% CI 0.6-0.8) history of diabetes mellitus. In contrast, HL diagnosed at older ages was neither associated with a personal (OR =1.0) nor family (OR =1.0) history of diabetes mellitus. These findings suggests that characteristics of the immune system associated with conditions such as diabetes mellitus type I are of importance in the pathogenesis of young-adult-onset HL.

Adult↗

Autoimmune and chronic inflammatory disorders and risk of non-Hodgkin lymphoma by subtype.

BACKGROUND: Some autoimmune and chronic inflammatory disorders are associated with increased risks of non-Hodgkin lymphoma (NHL). Because different NHL subtypes develop at different stages of lymphocyte differentiation, associations of autoimmune and inflammatory disorders with specific NHL subtypes could lead to a better understanding of lymphomagenic mechanisms. METHODS: In a population-based case-control study in Denmark and Sweden, 3055 NHL patients and 3187 matched control subjects were asked about their history of autoimmune and chronic inflammatory disorders, markers of severity, and treatment. Logistic regression with adjustment for study matching factors was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for NHL overall and for NHL subtypes. RESULTS: Risks of all NHL were increased in association with rheumatoid arthritis (OR = 1.5, 95% CI = 1.1 to 1.9), primary Sjögren syndrome (OR = 6.1, 95% CI = 1.4 to 27), systemic lupus erythematosus (OR = 4.6, 95% CI = 1.0 to 22), and celiac disease (OR = 2.1, 95% CI = 1.0 to 4.8). All of these conditions were also associated with diffuse large B-cell lymphoma, and some were associated with marginal zone, lymphoplasmacytic, or T-cell lymphoma. Ever use of nonsteroidal anti-inflammatory drugs, systemic corticosteroids, and selected immunosuppressants was associated with risk of NHL in rheumatoid arthritis patients but not in subjects without rheumatoid arthritis. Also, multivariable adjustment for treatment had little impact on risk estimates. Psoriasis, sarcoidosis, and inflammatory bowel disorders were not associated with increased risk of NHL overall or of any NHL subtype. CONCLUSIONS: Our results confirm the associations between certain autoimmune disorders and risk of NHL and suggest that the associations may not be general but rather mediated through specific NHL subtypes. These NHL subtypes develop during postantigen exposure stages of lymphocyte differentiation, consistent with a role of antigenic drive in autoimmunity-related lymphomagenesis.

Adult↗

Reliability of self-reported family history of cancer in a large case-control study of lymphoma.

BACKGROUND: Case-control studies of familial cancer risk traditionally rely on self-reported family history of cancer, which may bias results due to differential recall between case patients and control subjects. To evaluate the reliability of self-reported data, we analyzed questionnaire and registry-based data on familial cancer from a population-based case-control study of malignant lymphoma. METHODS: All 1508 lymphoma case patients and 1229 control subjects completed a telephone interview assessing cancer in family members. Participants were linked to the Swedish Multi-Generation Register and Cancer Register to identify confirmed cancer diagnoses in first-degree relatives. The sensitivity and specificity of self-reported familial cancer were calculated among case patients and control subjects and were compared using logistic regression. All statistical tests were two-sided. RESULTS: Lymphoma case patients reported a family history of any cancer with statistically significantly higher sensitivity than control subjects (0.85, 95% confidence interval [CI] = 0.83 to 0.87 and 0.80, 95% CI = 0.77 to 0.82, respectively) but with marginally lower specificity (0.89, 95% CI = 0.87 to 0.91 and 0.92, 95% CI = 0.90 to 0.94, respectively). The sensitivity of self-reporting familial cancers by site ranged from less than 0.20 for rare malignancies to nearly 0.75 for more common types, whereas specificity was generally 0.98 or greater. For most sites, the reliability of self-report was similar in patients and control subjects. However, patients reported familial hematopoietic cancer with statistically significantly higher sensitivity (0.60, 95% CI = 0.57 to 0.62) than control subjects (0.38, 95% CI = 0.35 to 0.40). Odds ratios for the association between familial cancer and risk of non-Hodgkin lymphoma were consistently higher when based on self-reported, compared with registry data-based, family history of any cancer or of hematopoietic cancer. CONCLUSIONS: Reliability of self-reported family history of cancer varies between case patients and control subjects. Recall bias may thus produce biased results in case-control studies of familial cancer risk.

Adult↗

Type 1 diabetes and multiple sclerosis: A Danish population-based cohort study.

BACKGROUND: Type 1 diabetes mellitus (T1D) and multiple sclerosis (MS) contribute considerably to the burden of autoimmune diseases in young adults. Although HLA patterns of T1D and MS are considered mutually exclusive, individual and familial co-occurrence of the 2 diseases has been reported. OBJECTIVE: To assess the co-occurrence of T1D and MS by estimating the risk for MS in patients with T1D and the risk for T1D in first-degree relatives of patients with MS. DESIGN, SETTING, AND PARTICIPANTS: Two population-based disease registers, the Danish Hospital Discharge Register and the Danish Multiple Sclerosis Register were used to identify patients with T1D, defined as patients in whom diabetes was diagnosed before age 20 years (N = 6078), and patients with MS (N = 11 862). First-degree relatives (N = 14,771) of patients with MS were identified from family information in the Danish Civil Registration System. MAIN OUTCOME MEASURE: Patients with T1D and first-degree relatives of patients with MS were followed up for occurrence of MS and T1D, respectively, and the relative risks were expressed as standardized incidence ratios, that is, ratios of observed to expected numbers of outcomes based on national age, sex, and period-specific MS and T1D incidence rates. RESULTS: Patients with T1D were at more than 3-fold increased risk for development of MS (relative risk, 3.26; 95% confidence interval, 1.80-5.88; n = 11). First-degree relatives of patients with MS were at 63% increased risk (relative risk, 1.63; 95% confidence interval, 1.26-2.12; n = 56) for development of T1D. However, adjusting for familial relationship to patients with T1D reduced the excess risk to 44% (relative risk, 1.44; 95% confidence interval, 1.11-1.88; n = 56). CONCLUSION: The present nationwide cohort study demonstrates an intraindividual and, to a lesser degree, an intrafamilial co-occurrence of MS and T1D.

Adolescent↗

Preleukemic TEL-AML1-positive clones at cell level of 10(-3) to 10(-4) do not persist into adulthood.

The TEL-AML1 translocation, t(12;21)(p13;q22), is one of the most frequent genetic aberrations in childhood B-cell precursor acute lymphoblastic leukemia (ALL), where it occurs in 25% of all cases. In contrast, the translocation is seen in only 3% of adult ALL cases. Evidence suggests that the TEL-AML1 translocation occurs in utero in 1% of all newborn children at cell levels of 10 to 10. In this study, we explore the prevalence of TEL-AML1-positive cells in 2 cohorts of healthy blood donors by real-time and nested reverse transcription-polymerase chain reaction. Overall, TEL-AML1-positive cells were demonstrated in 10 of 2005 healthy donors, that is, a prevalence of 0.5% (95% confidence interval, 0.2-0.3%). The level of TEL-AML1-positive cells was estimated to 10 to 10. The observed prevalence of TEL-AML1-positive cells in healthy adults is of the same order of magnitude as the prevalence reported in healthy newborns, but the observed cell level of 10 to 10 is much lower. These data indicates that prenatal TEL-AML1 subclones does not persist throughout adult life at cell levels of 10 to 10. The findings are compatible with the risk of t(12;21)(p13;q22) ALL correlating with the total number of TEL-AML1-positive cells in peripheral blood in both childhood and adulthood.

Adult↗

Variation in DNA repair genes ERCC2, XRCC1, and XRCC3 and risk of follicular lymphoma.

The reasons for the positive association between skin cancer and non-Hodgkin's lymphoma are not known but may be due to common susceptibility involving suboptimal DNA repair. Therefore, we investigated selected polymorphisms and haplotypes in three DNA repair genes, previously associated with skin cancer and DNA repair capacity, in risk of follicular lymphoma, including possible gene interaction with cigarette smoking and sun exposure. We genotyped 19 single nucleotide polymorphisms (SNP) in the ERCC2, XRCC1, and XRCC3 genes in 430 follicular lymphoma patients and 605 controls within a population-based case-control study in Denmark and Sweden. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using unconditional logistic regression and haplotype associations were assessed with a global score test. We observed no associations between variation in the ERCC2 and XRCC1 genes and follicular lymphoma risk. In XRCC3, increased risk of follicular lymphoma was suggested for rare homozygotes of three SNPs [Rs3212024: OR, 1.8 (95% CI, 1.1-2.8); Rs3212038: OR, 1.5 (95% CI, 1.0-2.4); Rs3212090: OR, 1.5 (95% CI, 1.0-2.5)]. These results were strengthened in current cigarette smokers. However, evidence of differences in XRCC3 haplotype distributions between follicular lymphoma cases and controls was weak, both overall and in current smokers. We conclude that polymorphic variation in the XRCC3 gene, but not in ERCC2 or XRCC1, may be of importance for susceptibility to follicular lymphoma, perhaps primarily in current smokers. The link between skin cancer and follicular lymphoma is unlikely to be mediated through common variation in the studied DNA repair gene polymorphisms.

Adolescent↗

Incidence of non-Hodgkin's lymphoma in Sweden, Denmark, and Finland from 1960 through 2003: an epidemic that was.

BACKGROUND: Reports during the early 1990s indicated non-Hodgkin's lymphoma (NHL) as one of the most rapidly increasing malignancies. More recent trends remain poorly characterized, as do the underlying reasons for NHL time trends, in particular, the effect of changes in classification and registration of lymphoproliferative malignancies. Insights into the descriptive epidemiology of NHL may shed light upon its elusive etiology. METHODS: We used data from the Swedish, Danish, and Finnish national cancer registers to assess the incidences of NHL and other lymphoproliferative malignancies between 1960 and 2004. Using Poisson regression, we estimated the annual rate of change in NHL incidence per decade by sex, age, and country. RESULTS: In Sweden, Denmark, and Finland, the NHL incidence increased in both genders and all age categories by about 4% every year up until the early 1990s. Thereafter, the incidence increased at a slower rate (ages 60-79 years), stabilized (ages 50-59 and > or =80 years), and decreased (ages 0-49 years), respectively, similarly for males and females in the three countries. Time trends of NHL were not reciprocated and explained by trends for other lymphoproliferative malignancies nor explained by trends in NHL as secondary primaries or NHL diagnosed postmortem. CONCLUSIONS: The epidemic increase of NHL has recently subsided. Changes in the classification of lymphoproliferative malignancies, or occurrence of NHL as second primaries, only offer a marginal explanation.

Adolescent↗

Family history of hematopoietic malignancy and risk of lymphoma.

BACKGROUND: A family history of hematopoietic malignancy is associated with an increased risk of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL), although the magnitude of the relative risk is unclear. We estimated the association between familial hematopoietic cancer and risk of lymphoma using validated, registry-based family data, and we also investigated whether associations between some environmental exposures and risk of lymphoma vary between individuals with and without such a family history. METHODS: In a population-based case-control study of malignant lymphoma, 1506 case patients and 1229 control subjects were linked to the Swedish Multi-Generation Register and then to the Swedish Cancer Register to ascertain history of cancer in first-degree relatives of patients with malignant lymphoma. Multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations with the risk of lymphoma. RESULTS: A history of hematopoietic malignancy in any first-degree relative was associated with an increased risk of all NHL (OR = 1.8, 95% CI = 1.2 to 2.5), common B-cell NHL subtypes, and HL. Relative risks were generally stronger in association with sibling hematopoietic cancer (OR for all NHL = 3.2, 95% CI = 1.3 to 7.6) than with parental hematopoietic cancer (OR = 1.6, 95% CI = 1.1 to 2.3). A family history of NHL or chronic lymphocytic leukemia (CLL) was associated with an increased risk of several NHL subtypes and HL, whereas familial multiple myeloma was associated with a higher risk of follicular lymphoma. There was no statistically significant heterogeneity in NHL risk associations with environmental factors between individuals with and without familial hematopoietic malignancy. CONCLUSIONS: The increased risk of NHL and HL among individuals with a family history of hematopoietic malignancy was approximately twofold for both lymphoma types. There was no evidence that etiologic associations varied between familial NHL and nonfamilial NHL.

Adult↗

Medication use and risk of non-Hodgkin's lymphoma.

Conflicting results from previous epidemiologic studies shed little light on whether medication use is associated with risk of non-Hodgkin's lymphoma (NHL). To investigate this question, the authors conducted a population-based case-control study in Denmark and Sweden from 1999 to 2002, including 3,055 incident NHL cases and 3,187 controls. Participants reported their past use of medications and history of particular medical conditions. Unconditional logistic regression was used to estimate multivariate odds ratios and 95% confidence intervals for the associations between medication use and risk of NHL; all statistical tests were two sided. Use of antibiotics more than 10 times during adulthood was positively associated with risk of NHL and most major NHL subtypes; when users were compared with nonusers, the odds ratio for NHL was 1.8 (95% confidence interval: 1.4, 2.3); p(trend) for total antibiotic use <0.001. In addition, high cumulative use of nonsteroidal anti-inflammatory drugs was marginally associated with elevated NHL risk. Other medications evaluated were not associated with risk of NHL or its most common subtypes. Findings suggest that inflammation, infections, susceptibility to infections, and/or use of antibiotics or nonsteroidal anti-inflammatory drugs to treat these conditions may increase the risk of NHL. However, most of the medications examined were not associated with NHL risk.

Adolescent↗

Familial risk of multiple sclerosis: a nationwide cohort study.

Multiple sclerosis (MS) is known to accumulate within families. The magnitude of the familial risk, however, remains uncertain. Using a nationwide MS register and other national registers, the authors estimated relative and absolute risks of MS in a population-based cohort that included 19,615 first-degree relatives of 8,205 Danish MS patients followed from 1968 to 1997. The ratio of observed to expected numbers of MS cases served as the measure of the relative risk of MS. Lifetime risks of MS in first-degree relatives were estimated as the product of the relative risk and the national lifetime risk of MS. Overall, first-degree relatives had a sevenfold increased risk of MS (relative risk=7.1, 95% confidence interval: 5.8, 8.8) (n=90) compared with the background population. By modeling the individual incidence rate of MS as the sum of a familial component and a sporadic risk component, the familial excess lifetime risk was found to be 2.5% (95% confidence interval: 2.0, 3.2) among first-degree relatives of MS patients, irrespective of the gender of the proband and the relative. This percentage should be added to a sporadic absolute risk in the general population of 0.5% in women and 0.3% for men. Spouses of MS patients did not experience an increased risk of MS, suggesting no major role for environmental factors acting in adulthood.

Denmark↗