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Mads Melbye

Publications and source records attributed to Mads Melbye.

At least 73 records · Page 4Linked to original sources
PubMed2003

Age- and sex-specific incidence of childhood leukemia by immunophenotype in the Nordic countries.

BACKGROUND: Studies from various countries have found an increasing incidence of childhood leukemia in recent decades. To characterize time trends in the age- and sex-specific incidence of childhood acute leukemia during the last 20 years in the Nordic countries, we analyzed a large set of population-based data from the Nordic Society of Paediatric Haematology and Oncology (NOPHO) in their acute leukemia database covering a population of approximately 5 million children aged 0-14 years. METHODS: Temporal trends in acute myeloid leukemia and acute lymphoblastic leukemia incidence rates overall and for acute lymphoblastic leukemia immunophenotypes and for specific age groups were analyzed by Poisson regression adjusting for age, sex, and country. All statistical tests were two-sided. RESULTS: We identified 1595 girls and 1859 boys diagnosed with acute lymphoblastic leukemia between January 1, 1982, and December 31, 2001, and 260 girls and 224 boys diagnosed with de novo acute myeloid leukemia between January 1, 1985, and December 31, 2001. No statistically significant change was seen in the overall incidence rate for acute lymphoblastic leukemia during the 20-year study (annual change = 0.22%, 95% confidence interval [CI] = -0.36% to 0.80%). The incidence rate of B-precursor acute lymphoblastic leukemia remained unchanged (annual change = 0.30%, 95% CI = -0.57% to 1.18%) from January 1, 1986, through December 31, 2001. A somewhat lower incidence in the first years of the study period indicated an early increasing incidence of B-precursor acute lymphoblastic leukemia that corresponded to a simultaneous decreasing incidence of unclassified acute lymphoblastic leukemia. Incidences of T-cell acute lymphoblastic leukemia (annual change = 1.55%, 95% CI = -1.14% to 4.31%) and acute myeloid leukemia (annual change = 0.58%, 95% CI = -1.24% to 2.44%) were stable during the study period. CONCLUSION: Incidences of acute myeloid leukemia overall, acute lymphoblastic leukemia overall, and specific acute lymphoblastic leukemia immunophenotypes have been stable in the Nordic countries over the past two decades.

Adolescent↗
PubMed2003

Characteristics of Hodgkin's lymphoma after infectious mononucleosis.

BACKGROUND: Infectious mononucleosis-related Epstein-Barr virus (EBV) infection has been associated with an increased risk of Hodgkin's lymphoma in young adults. Whether the association is causal remains unclear. METHODS: We compared the incidence rates of Hodgkin's lymphoma in two population-based Danish cohorts of patients who were tested for infectious mononucleosis: 17,045 with serologic evidence of having had acute EBV infection, and 24,614 with no such evidence. We combined the cohort of patients who had serologically verified infectious mononucleosis with a cohort of 21,510 Swedish patients with infectious mononucleosis (combined total, 38,555). Biopsy specimens of Hodgkin's lymphomas occurring during follow-up in this combined cohort were tested serologically for the presence of EBV. Using this information, we modeled the relative risk of EBV-negative and EBV-positive Hodgkin's lymphoma in different periods after the diagnosis of infectious mononucleosis and estimated the median incubation time for mononucleosis-related EBV-positive Hodgkin's lymphoma. RESULTS: Only serologically confirmed infectious mononucleosis was associated with a persistently increased risk of Hodgkin's lymphoma. Sixteen of 29 tumors (55 percent), obtained from patients with infectious mononucleosis, had evidence of EBV. There was no evidence of an increased risk of EBV-negative Hodgkin's lymphoma after infectious mononucleosis. In contrast, the risk of EBV-positive Hodgkin's lymphoma was significantly increased (relative risk, 4.0; 95 percent confidence interval, 3.4 to 4.5). The estimated median incubation time from mononucleosis to EBV-positive Hodgkin's lymphoma was 4.1 years (95 percent confidence interval, 1.8 to 8.3). CONCLUSIONS: A causal association between infectious mononucleosis-related EBV infection and the EBV-positive subgroup of Hodgkin's lymphomas is likely in young adults.

Adolescent↗
PubMed2003

Association between thimerosal-containing vaccine and autism.

CONTEXT: Mercuric compounds are nephrotoxic and neurotoxic at high doses. Thimerosal, a preservative used widely in vaccine formulations, contains ethylmercury. Thus it has been suggested that childhood vaccination with thimerosal-containing vaccine could be causally related to neurodevelopmental disorders such as autism. OBJECTIVE: To determine whether vaccination with a thimerosal-containing vaccine is associated with development of autism. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort study of all children born in Denmark from January 1, 1990, until December 31, 1996 (N = 467 450) comparing children vaccinated with a thimerosal-containing vaccine with children vaccinated with a thimerosal-free formulation of the same vaccine. MAIN OUTCOME MEASURES: Rate ratio (RR) for autism and other autistic-spectrum disorders, including trend with dose of ethylmercury. RESULTS: During 2 986 654 person-years, we identified 440 autism cases and 787 cases of other autistic-spectrum disorders. The risk of autism and other autistic-spectrum disorders did not differ significantly between children vaccinated with thimerosal-containing vaccine and children vaccinated with thimerosal-free vaccine (RR, 0.85 [95% confidence interval [CI], 0.60-1.20] for autism; RR, 1.12 [95% CI, 0.88-1.43] for other autistic-spectrum disorders). Furthermore, we found no evidence of a dose-response association (increase in RR per 25 microg of ethylmercury, 0.98 [95% CI, 0.90-1.06] for autism and 1.03 [95% CI, 0.98-1.09] for other autistic-spectrum disorders). CONCLUSION: The results do not support a causal relationship between childhood vaccination with thimerosal-containing vaccines and development of autistic-spectrum disorders.

Autistic Disorder↗
PubMed2003

Risk factors for acute respiratory tract infections in young Greenlandic children.

Acute respiratory infections cause considerable morbidity among Inuit children, but there is very little information on the risk factors for these infections in this population. To identify such factors, the authors performed a prospective community-based study of acute respiratory infections in an open cohort of 288 children aged 0-2 years in the town of Sisimiut, Greenland. Between July 1996 and August 1998, children were monitored weekly, and episodes of upper and lower respiratory tract infections were registered. Risk factor analyses were carried out using a multivariate Poisson regression model adjusted for age. Risk factors for upper respiratory tract infections included attending a child-care center (relative risk = 1.7 compared with home care) and sharing a bedroom with adults (relative risk = 2.5 for one adult and 3.1 for two adults). Risk factors for lower respiratory tract infections included being a boy (relative risk = 1.5), attending a child-care center (relative risk = 3.3), exposure to passive smoking (relative risk = 2.1), and sharing a bedroom with children aged 0-5 years (relative risk = 2.0 for two other children). Breastfeeding tended to be protective for lower respiratory tract infections. The population-attributable risk of lower respiratory tract infections associated with passive smoking and child-care centers was 47% and 48%, respectively. The incidence of acute respiratory infections among Inuit children may be reduced substantially through public health measures.

Acute Disease↗
PubMed2003

Influence of tumor location on breast cancer prognosis.

Our objective was to investigate the influence of primary tumor location on breast cancer prognosis. We used a population-based registry since 1977 that has collected detailed information regarding clinical and histopathological presentation, postoperative therapy and follow-up status on Danish women with breast cancer. Nodal status and relative risk of dying was estimated according to primary tumor localization in the breast. Overall, 35319 patients with primary breast cancer were included in the study. After adjustment for prognostic factors, the risk of dying increased significantly (up to 21%) with increasing distance of tumor location from the axilla. This trend was seen both among women with and without spread to the axillary lymph nodes. In conclusion, survival is significantly better for women with a tumor in the upper lateral quadrant than tumors located elsewhere in the breast. Our finding of a similar trend according to distance from the axilla among women with positive axillary lymph nodes who all are allocated to systemic therapy suggests that a better lymph node staging procedure alone is unlikely to eliminate these survival differences. Other reasons for the observed differences should be sought to help improve survival for women with breast cancer.

Aged↗
PubMed2003

A population-based register study of vaccine coverage among children in Greenland.

To assess coverage rates of standard childhood vaccinations in Greenland, a geographically isolated and sparsely populated area, and to determine risk factors for low coverage, we performed a register-based cohort study among 596 children from 1993 to 1998 in Sisimiut, Greenland. For vaccines given before the age of 2 years (pertussis 1-3, DT-IPV 1-3, and MMR 1) coverage rates in general were impressively high being on or above levels of Western countries. A risk factor for low coverage was migration. The Greenlandic vaccination model with free vaccinations administered by health workers who systematically call in children at scheduled times seems highly efficient and could be a model for other similar countries.

Child↗
PubMed2003

BCG vaccination and risk of atopy.

CONTEXT: It has been suggested that BCG vaccination may protect against development of allergic diseases, particularly when given just after birth. BCG vaccination was given routinely to all infants in Greenland until 1990, when it was withdrawn from the vaccination program. Whether this resulted in an increased prevalence of atopy in children born after the stop of BCG vaccination is unknown. OBJECTIVE: To determine whether BCG vaccination and age at BCG vaccination are associated with development of atopy. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study among schoolchildren aged 8 to 16 years in 4 towns on the northwest coast of Greenland. Participants had a blood sample drawn and information on BCG vaccination was obtained during 2 periods, November 1998 and November 2001. A total of 1686 children (79% of available children) participated, 1575 of whom had complete information on vaccination status. Atopy was defined as a positive test result in an assay that tests for IgE specific against the most common inhalant allergens in serum. MAIN OUTCOME MEASURES: Odds ratio (OR) of atopy in BCG-vaccinated compared with unvaccinated children and OR according to age at vaccination. RESULTS: The risk of atopy was the same in BCG-vaccinated compared with unvaccinated children after adjustment for confounders (OR, 1.03; 95% confidence interval, 0.72-1.48). The risk of atopy in BCG-vaccinated children was not associated with age at vaccination (P =.17). CONCLUSIONS: BCG vaccination administered to infants is not associated with reduced risk of development of atopy.

Adolescent↗
PubMed2003

Smallpox vaccination and risk of allergy and asthma.

BACKGROUND: It has been proposed that childhood vaccinations may influence the development of allergy. Atopy and allergic diseases have increased after routine smallpox vaccination was stopped in the 1970s. OBJECTIVE: We examined whether administration of smallpox vaccination during childhood was associated with a decreased risk of atopy, allergic rhinitis, and asthma. METHODS: The occurrence of atopy, allergic rhinitis, and asthma was studied in nearly 2000 women participating in a national birth cohort study. Detailed information on smallpox vaccination was available from school health records. Atopic status was assessed serologically by a specific response to 11 common inhalant allergens by using serum samples obtained from the women during the period 1997 to 2001. Information on allergic rhinitis and asthma was available from telephone interviews. RESULTS: We found no association between having been vaccinated against smallpox in childhood and risk of atopy or allergic rhinitis. Smallpox vaccination was associated with a slightly decreased risk of asthma. There was no association between age at smallpox vaccination and risk of atopy, allergic rhinitis, or asthma. Adjusting for birth cohort, sibship size, age of the woman's mother at birth, and social class in childhood did not change these results. CONCLUSION: Our findings do not suggest that childhood vaccination against smallpox, even if given early in life, influences the development of atopy or allergic rhinitis. The association with asthma should be interpreted with caution and needs further study.

Adolescent↗
PubMed2003

Mode of delivery and risk of allergic rhinitis and asthma.

BACKGROUND: It has been hypothesized that cesarean section might increase the risk of developing allergic disease by depriving the fetus and newborn of exposure to maternal microflora. Furthermore, it has been suggested that complicated modes of delivery might be associated with an increased risk of asthma. OBJECTIVE: The purpose of this investigation was to study whether cesarean section and other complicated modes of delivery are associated with an increased risk of allergic rhinitis or asthma. METHODS: Information on self-reported allergic rhinitis, asthma ever, current asthma, and occupation was obtained from 9722 singleton women born in Denmark during the period 1973-1977 who participated in a national cohort study during the period 1997-2001. For these women, information was available on mode of delivery (spontaneous delivery, cesarean section, vacuum extraction, or other complicated mode of delivery, such as rotation/traction or use of forceps), gestational age, birth weight, and length at birth from the Danish Medical Birth Register. Information on parity and maternal age was obtained from the Danish Civil Registration System. RESULTS: The odds ratios (ORs) of allergic rhinitis were 1.16 (95% CI, 0.90-1.49) for cesarean section and 1.06 (95% CI, 0.85-1.32) for other complicated modes of delivery in comparison with spontaneous delivery. The corresponding ORs of asthma ever were 1.33 (95% CI, 1.02-1.74) and 1.18 (95% CI, 0.94-1.49) for cesarean section and other complicated modes of delivery, respectively, and the ORs of current asthma were 1.22 (95% CI, 0.87-1.73) and 1.26 (95% CI, 0.94-1.68), respectively, in comparison with spontaneous delivery. CONCLUSIONS: Our findings do not support the hypothesis that cesarean section or other complicated modes of delivery are associated with the development of allergic rhinitis. However, there might be a positive association with development of asthma--in particular, for cesarean section--that was not explained by gestational age, birth weight, ponderal index, smallness for gestational age, parity, maternal age, or occupation.

Adult↗
PubMed2003

Atopic dermatitis in young children: diagnostic criteria for use in epidemiological studies based on telephone interviews.

The aim of the study was to establish diagnostic criteria for atopic dermatitis in 1.5-year-old children that could be employed in epidemiological studies of atopic dermatitis based on telephone interviews. In a Danish cohort of 100,000 pregnant women, 4 computer-assisted telephone interviews were carried out. In the last interview, conducted when the child was 1.5 years old, mothers were asked about their child's skin condition. Eighty-one women who had answered that their child suffered from either an itchy rash or atopic dermatitis were invited to participate in the study. Of these, 60 took part in the study and had their child examined by a dermatologist. Affirmative answers to 1) itchy rash or doctor-verified atopic dermatitis and 2) recurrent rash or rash for at least 4 consecutive 0.5-month periods, and 3) localization in elbow creases, behind the knees, wrists/hands, face or generalized rash resulted in the highest sensitivity and specificity for atopic dermatitis as diagnosed by the dermatologist, who found 37 of 60 children (62%) suffering from atopic dermatitis. Using this algorithm, telephone interviews can be used to diagnose atopic dermatitis in young children in large-scale epidemiological investigations.

Adult↗
PubMed2003

Does pregnancy induce the shedding of premalignant ovarian cells?

BACKGROUND: High parity is associated with reduced risk of ovarian cancer. One hypothesis is that pregnancy is associated with clearance of a fraction of the genetically modified (premalignant) cells from the ovaries. METHODS: We evaluated this hypothesis using a model that estimates the cell clearance fraction at first and second pregnancy according to age at pregnancy. The model was fitted using reproductive history data from a cohort of 1.5 million Danish women born between 1935 and 1978 and followed for 28.7 million person-years. During this follow-up period, 2,035 developed invasive ovarian cancer. RESULTS: We found the model to have a satisfactory fit despite the very few parameters involved. The model estimated similar cell clearance fractions for the first and second pregnancy and decreasing clearance with later age at pregnancy. CONCLUSION: The relation of pregnancy history to risk of ovarian cancer can be well described by a cell clearance model that allows the cell clearance fraction to decrease with age at pregnancy.

Adult↗
PubMed2002

[Epstein-Barr virus and Hodgkin's lymphoma].

The suspicion that Hodgkin's lymphoma, previously known as Hodgkin's disease, may have an infectious etiology has existed for many years. The assumption rests on epidemiological characteristics, in particular a strong correlation between socio-economic status and risk of Hodgkin's lymphoma in young adults, as well as both serological and molecular biological evidence that the Epstein-Barr virus is involved in the development of up to 50% of all cases of Hodgkin's lymphoma. We present the current epidemiological, serological and molecular biological evidence for an infectious etiology to Hodgkin's lymphoma with emphasis on the association with Epstein-Barr virus.

Adult↗
PubMed2002

[Infectious causes of non-Hodgkin lymphomas].

The etiology to non-Hodgkin's lymphoma remains incompletely understood. Chronic infection with certain viruses and bacteria has attracted interest in recent years because of the association with lymphoma development. In this article we present an overview of the current evidence of infectious causes to non-Hodgkin's lymphomas.

Borrelia burgdorferi↗
PubMed2002

[Human papillomavirus and the risk of anogenital cancer].

Strong evidence suggests that virtually all cases of cervical cancer are caused by infection with oncognenic types of human papillomavirus (HPV). HPV is also found frequently in neighbouring anogenital epithelia and their neoplastic lesions. This review describes the general aspects of the natural history of anogenital HPV infections and summarises the evidence for an association between HPV and cancers of the uterine cervix, vulva, anus and penis.

Anus Neoplasms↗
PubMed2002

[MMR vaccination and autism--a population-based follow-up study].

INTRODUCTION: It has been suggested that the measles-mumps-rubella (MMR) vaccination causes autism. MATERIAL AND METHODS: We conducted a retrospective cohort study of all children born in Denmark from January 1991 through December 1998. The cohort was established based on data from the Danish Civil Registration System. A unique person identifiable number given to all subjects enabled linkage with other national registries. MMR vaccination status was obtained from the Danish National Board of Health. Information on the children's autism status was obtained from the Danish Psychiatric Central Register which contains information on all diagnoses received from psychiatric hospitals, psychiatric wards, and outpatient clinics in Denmark. We obtained information on potential confounders from the Danish Medical Birth Registry, the National Hospital Registry, and Statistics Denmark. RESULTS: In the cohort of 537,303 children (2,129,864 person-years), 440,655 children had been MMR vaccinated. We identified 316 children with a diagnosis of autistic disorder and 442 with a diagnosis of other spectrum disorders. After adjusting for potential confounders, the risk for autistic disorder and other spectrum disorders was not increased in vaccinated compared with unvaccinated children (relative risk 0.92; 95 percent confidence interval, 0.68 to 1.24 and relative risk 0.83; 95 percent confidence interval, 0.65 to 1.07). There was no association between age at vaccination, time since vaccination or calendar period at time of vaccination and development of autistic disorder. DISCUSSION: This study provides strong evidence against the hypothesis that MMR vaccination causes autism.

Autistic Disorder↗
PubMed2002

[Acute respiratory tract infections and mannose-binding lectin insufficiency in small children].

INTRODUCTION: According to hospital-based studies, increased susceptibility to certain infections is associated with genotypes that cause low serum levels of the protein mannose-binding lectin (MBL). However, the contribution of MBL insufficiency to the incidence of common childhood infections on a population basis is unknown. To investigate the effect of MBL insufficiency on the risk of acute respiratory infections (ARI) in unselected children, we performed a prospective population-based study of ARI in young children in Sisimiut, Greenland. MATERIAL AND METHODS: An open cohort of children aged 0-2 years was formed in 1996, and followed up with weekly morbidity surveillance visits for a two-year period. Episodes of ARI were diagnosed on medical history and clinical examinations. MBL genotypes were determined from blood samples according to the presence of structural alleles and promoter alleles. RESULTS: Altogether 294 children participated and 44 refused. Blood samples were taken from 252 participants. A 2.1-fold (95% confidence interval 1.4-3.1) increased risk of ARI was found in MBL-insufficient children compared with MBL-sufficient children (p < 0.001). The risk association was largely restricted to the period 6 to 17 months of age, whereas less or no effect could be shown in younger and older children. DISCUSSION: These population-based data suggest that genetic factors such as MBL insufficiency play an important role in host defence, particularly during the vulnerable period of infancy between 6 and 17 months of age, when the adaptive immune system is immature.

Acute Disease↗
PubMed2002

Fever in pregnancy and risk of fetal death: a cohort study.

BACKGROUND: Hyperthermia acts as a teratogen in some animals where it can induce resorption of the fetus and fetal death. Fever during pregnancy, especially in the period of embryogenesis, is also suspected as being a risk factor for fetal death in human beings. We did a large cohort study in Denmark to investigate this possibility. METHODS: We interviewed 24040 women who were recruited in the first half of pregnancy to the Danish National Birth Cohort Study, and obtained information on the number of fever incidents during the first 16 weeks of pregnancy. For each fever episode, the highest measured body temperature, duration of incident, and gestational age were recorded. Outcomes of pregnancies were identified through linkage with the Civil Registration System and the National Discharge Registry. Cox's regression with time-dependent variables was used to estimate the relative risk of fetal death, taking delayed entry into account. FINDINGS: 1145 pregnancies resulted in a miscarriage or stillbirth (4.8%). During the first 16 pregnancy weeks 18.5% of the women experienced at least one episode of fever. However, we found no association between fever in pregnancy and fetal death before or after adjustment for known risk factors of fetal death (relative risk 0.95 [95% CI 0.80-1.13]). This finding was consistent irrespective of measured maximum temperature, duration and number of fever incidents, or the gestational time of the fever incident, and was observed for fetal death in all three trimesters of pregnancy. INTERPRETATION: We found no evidence that fever in the first 16 weeks of pregnancy is associated with the risk of fetal death in clinically recognised pregnancies.

Abortion, Spontaneous↗