Comparison of a partially hydrolyzed infant formula with two extensively hydrolyzed formulas for allergy prevention: a prospective, randomized study

The aim of this study was to compare the allergy-preventive effect of a partially hydrolyzed formula with two extensively hydrolyzed formulas, in infants with a high risk for development of allergic disease. High-risk infants from four Danish centres were included in the period from June 1994 to July 1995. Five-hundred and ninety-five high-risk infants were identified. High-risk infants were defined as having biparental atopy, or a single atopic first-degree relative combined with cord blood immunoglobulin E (IgE)> or =0.3 kU/l. At birth all infants were randomized to one of three different blinded formulas. All mothers had unrestricted diets during pregnancy and lactation and were encouraged to breast-feed exclusively. If breast-feeding was insufficient, one of the three formulas, according to randomization, was given during the first 4 months. It was recommended not to introduce cow's milk, cow's milk products. and solid foods until the age of 4 months. After the age of 4 months a normal unrestricted diet and conventional cow's milk-based formula were given when needed. All infants were followed-up prospectively with interview and physical examination at the age of 6, 12, and 18 months, and if any possible atopic symptoms were reported. If food allergy was suspected, controlled elimination/challenge procedures were performed in a hospital setting. Of 550 infants included in the study, 514 were seen at all visits and 36 were excluded owing to noncompliance. Of 478 infants who completed the study, 232 were exclusively breast-fed, 79 received an extensively hydrolyzed casein formula (Nutramigen), 82 an extensively hydrolyzed whey formula (Profylac), and 85 a partially hydrolyzed whey formula (Nan HA), during the first 4 months of life. These four groups were identical in regard to atopic predisposition, cord blood IgE, birthplace, and gender. Exclusively breast-fed children were exposed less to tobacco smoke and pets at home and belonged to higher social classes, whereas the three formula groups were identical concerning environmental factors. The frequency of breast-feeding was high; only eight (2%) children were not breast-fed at all. The three formula groups were identical in regard to duration of breast-feeding and age at introduction of formula and solid foods. No significant differences were found in the three groups of infants receiving formula milk regarding the cumulative incidence of atopic dermatitis or respiratory symptoms. The cumulative incidence of parental-reported cow's milk allergy was significantly higher in children fed partially hydrolyzed formula (Nan HA) compared with extensively hydrolyzed formula (Nutramigen or Profylac) at 12 and 18 months (NanHA, 7.1%; Nutramigen, 2.5%; Profylac, 0%; p=0.033). The cumulative incidence of confirmed cow's milk allergy was 1.3% (three of 232) in exclusively breast-fed infants, 0.6% (one of 161) in infants fed extensively hydrolyzed formula (Nutramigen or Profylac), and 4.7%(four of 85) in infants fed partially hydrolyzed formula (Nan HA). Partially hydrolyzed formula was found to be less effective than extensively hydrolyzed formula in preventing cow's milk allergy, 0.6% vs. 4.7% (p=0.05), but because of the small number of cases the results should be interpreted with caution. Compared with other similar studies the frequency ofatopic symptoms was low, even though the dietetic intervention did not include either maternal diet during lactation or dietary restrictions to the children after the age of 4 months.

Hazelnut allergy: a double-blind, placebo-controlled food challenge multicenter study

BACKGROUND

Tree nuts are a common cause of food allergy in Europe. However, few studies deal with real food allergy to hazelnuts in subjects believed to be allergic to this food.

OBJECTIVE

We sought to select subjects with a history of allergic reactions on ingestion of hazelnut and determine how many of these have true allergy by means of the double-blind, placebo-controlled food challenge (DBPCFC).

METHODS

Eighty-six subjects with a history of symptoms after hazelnut ingestion were recruited from 3 allergy centers (Milan, Zurich, and Copenhagen). All subjects underwent skin prick tests (SPTs) with aeroallergens and hazelnut, as well as having their specific hazelnut IgE levels determined. Diagnosis of clinical relevant food allergy was made on the basis of the DBPCFC.

RESULTS

Sixty-seven (77.9%) of 86 subjects had a positive DBPCFC result; 8 were placebo responders, and 11 were nonresponders. Of the 11 nonresponders, 4 had positive open-challenge test results. Of the DBPCFC-positive subjects, 87% also had positive skin test responses to birch pollen extract. Specific IgE determination for hazelnut (positive CAP response >/=0.7 kU/L [ie, class 2]) showed a sensitivity of 0.75, a positive predictive value (PPV) of 0.92, a specificity of 0.16, and a negative predictive value (NPV) of 0.05. Skin tests with commercial hazelnut extract produced a sensitivity of 0.89, a PPV of 0.92, a specificity of 0.05, and an NPV of 0.05. Skin tests with natural food produced a sensitivity of 0.88, a PPV of 0.94, a specificity of 0.27, and an NPV of 0.15.

CONCLUSION

This study shows that hazelnut is an allergenic source that can cause real food allergy, as confirmed by DBPCFC. Skin and IgE tests demonstrated reasonable sensitivity and PPV but a very low specificity and NPV, thus implying that these should not be used to validate the diagnosis of food allergy to hazelnut.

Regression of oral leukoplakia with alpha-tocopherol: a community clinical oncology program chemoprevention study

BACKGROUND

Oral leukoplakia is an important model for developing chemoprevention approaches for lesions in the upper aerodigestive tract. These lesions most often result from exposure to carcinogens such as tobacco and alcohol and may precede development of invasive cancer. The potent antioxidant alpha-tocopherol (vitamin E) has prevented the development of cancers of the oral cavities in animal models.

PURPOSE

The objectives of this study were to evaluate the toxicity and efficacy of alpha-tocopherol in patients with oral leukoplakia and to assess the feasibility of performing chemoprevention trials through the network of the Community Clinical Oncology Program (CCOP).

METHODS

A single-arm phase II study using the nontoxic agent alpha-tocopherol to treat oral premalignant leukoplakia was performed at seven institutions affiliated with the CCOP through The University of Texas M. D. Anderson Cancer Center. Patients with symptomatic leukoplakia or dysplasia were treated orally with alpha-tocopherol (400 IU) twice daily for 24 weeks. Follow-up was performed at 6, 12, and 24 weeks after the start of treatment to assess toxicity and response, and serum alpha-tocopherol levels were determined at baseline and at 6 and 24 weeks.

RESULTS

Of the 43 patients who have completed 24 weeks of treatment, 20 (46%) had clinical responses and nine (21%) had histologic responses. Mean serum alpha-tocopherol levels were 16.1 micrograms/mL at baseline and increased to 34.29 micrograms/mL after 24 weeks of treatment. Patient-recorded drug calendars, as well as serum drug levels, indicated excellent patient compliance; an average of 95% of the prescribed pills were taken. Treatment was extremely well tolerated; no grade 3 or 4 toxic effects were reported.

CONCLUSIONS

Administration of alpha-tocopherol resulted in both clinical and histologic responses in premalignant leukoplakia lesions. The study also demonstrated that chemoprevention trials can be performed through the CCOP. The major problems were that a high percentage of patients were not assessable for response, some patients withdrew because expenses were not reimbursable, and there was limited participation within the CCOP network. These problems may reflect difficulties inherent in the implementation of multi-institutional chemoprevention trials.

IMPLICATIONS

The efficacy of alpha-tocopherol alone and in combination with other chemopreventive agents for carcinogenesis in the upper aerodigestive tract should be explored in future trials.

Severity of respiratory syncytial virus disease related to type and genotype of virus and to cytokine values in nasopharyngeal secretions

BACKGROUND

Investigations concerning the severity of respiratory syncytial virus (RSV) disease as related to (1) RSV type and genotype determined respectively by PCR and restriction enzyme analysis and (2) interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) values in samples of nasopharyngeal secretion (NPS) have not been previously reported.

METHODS

We prospectively studied 105 RSV infections in the lower respiratory tract of infants and young children admitted to a pediatric department in Copenhagen during three winter seasons, 1993, 1994 and 1995. RSV strains were typed and genotyped, respectively, by PCR and nucleic acid restriction analysis and correlated to the severity of the disease. The ratio IL-6:TNF-alpha, determined from IL-6- and TNF-alpha values in samples of NPS, was related to the severity of the disease. Concentrations of IL-6 and of TNF-alpha were determined in serum samples taken during 5 weeks after the onset of illness.

RESULTS

Type B infections produced more severe disease than did type A infections, as assessed on the length of the hospital stay, use of respiratory support and the presence of an infiltrate on a chest radiograph. This difference was age-related. It was observed in infants 0 to 5 months old, but not in older age groups. Type B genotype B1122 produced more severe disease than type A genotype A2311 in infants 0 to 11 months old. Increased serum concentrations of IL-6 and TNF-alpha were detected in samples taken 1 to 2 days after the onset of illness. Whereas TNF-alpha serum concentrations remained high, IL-6 serum concentrations decreased during the following 3 to 4 weeks. The IL-6:TNF-alpha ratio in samples of NPS was related to the severity of the disease. A high ratio was related to a low severity.

CONCLUSIONS

The severity of disease in patients admitted with acute RSV infections can be correlated to the RSV type as determined by PCR, to the RSV genotype as determined by nucleic acid restriction analysis and to the ratio IL-6:TNF-alpha in NPS.

Occupational dermatoses in hospital cleaning women

In an investigation of 541 members of a hospital cleaning department, a prevalence rate of occupational skin diseases of 15.3% was found. During their hospital employment, 39.1% had a skin disease. Higher prevalence in the younger age groups can be explained by the selection of those with skin diseases for work away from the cleaning department. A large number developed their disease shortly after employment began. This was an indication that the observed prevalent conditions were irritant diseases. The distribution by diagnosis confirms this conclusion in as much as 75% of the occupational skin diseases were irritant dermatitis, 21% allergic contact dermatitis, and 4% monilia of the finger webs. The causes of allergic contact dermatitis were found to be formaldehyde, glutaraldehyde and chloramine in addition to nickel and rubber. Among the causes of irritant dermatitis were detergents, alkaline substances, acids and sodium perborate as well as hypochlorite and hypobromite combinations. In order to reduce occupational skin diseases among cleaning personnel, it is necessary to extend both local and more general prophylactic measures.

Exposure to stainless steel welding fumes and lung cancer: a meta-analysis

Stainless steel welding is associated with exposure to metals including hexavalent chromium and nickel. This study is a meta-analysis of five studies of stainless steel welders and the occurrence of lung cancer. Asbestos exposure and smoking habits have been taken into account. The calculated pooled relative risk estimate was 1.94 with a 95% confidence interval of 1.28-2.93. This result suggests a causal relation between exposure to stainless steel welding and lung cancer.

Cancer incidence among mild steel and stainless steel welders and other metal workers

The cancer incidence in a historical cohort of 10,059 metal workers employed during the period 1964-1984 was investigated. Standardized incidence ratios (SIR) were calculated based on registry extracts from the Danish Cancer registry. Lifetime exposure data (occupational and other) were obtained by a postal questionnaire in living cohort members and interviews by proxy for deceased and emigrated subjects. The incidence of lung cancer was increased among workers ever "employed as welders" (SIR = 1.38, 95% C.I. 1.03-1.81). There was a significant excess risk of lung cancer among "mild steel (MS) only welders" (SIR = 1.61, 95% C.I. 1.07-2.33) and "nonwelders" (SIR = 1.69, 95% C.I. 1.23-2.26) (indicating carcinogenic exposures other than welding), a borderline significant lung cancer excess among "MS ever welders" (SIR = 1.32, 95% C.I. 0.97-1.76), and a nonsignificant excess risk of lung cancer among "stainless steel (SS) only welders" (SIR = 2.38, 95% C.I. 0.77-5.55). In spite of signs of inconsistency in the risk estimation by duration and latency, we find the results support the conclusions of other studies: employment as a welder is associated with an increased lung cancer risk.

Protein contact dermatitis in slaughterhouse workers

Protein contact dermatitis, described as "gut eczema" or "fat eczema" by slaughterhouse workers, was first described a decade ago and presents as an itching, vescular eczema on the hands and fingers, a few hours after contact with animal material, especially gut material. In a cross-sectional study of 144 slaughterhouse workers, a cumulative prevalence of current and anamnestic cases of protein contact dermatitis of 22% was found, with the highest prevalence in workers eviscerating and cleansing gut. The scratch patch test was the only skin test showing positive results in workers with protein contact dermatitis, positive reactions being found, however, in less than half the cases.

Fertility among Danish male welders

Welding may be detrimental to the male reproductive system. Fertility was examined in a Danish cohort of 3702 male metalworkers over a follow-up of 47 674 person-years. Occupational histories were gathered by postal questionnaires. Information on births was obtained by record linkage to the Danish Central Population Register. Among persons who had ever worked as welders, the probability of having a child was slightly reduced the year after a year of welding exposure, even after control for differences in age, birth cohort, paternal parity, birth of a child in the preceding five years, smoking, and consumption of alcoholic beverages (odds ratio 0.89, 95% confidence interval 0.83-0.97). The reduction in fertility was associated with the welding of mild steel, but not with the welding of stainless steel. These findings are consistent with results of previous studies of time to conception and semen quality in welders.

Treatment of MRI-Diagnosed Trigeminal Peripheral Nerve Sheath Tumors by Stereotactic Radiotherapy in Dogs

Background

Stereotactic radiotherapy (SRT) is an emerging technique for treating tumors in animals.

Objectives

To assess the outcome of dogs with suspected intracranial trigeminal nerve peripheral nerve sheath tumors (PNST) treated with SRT.

Animals

Eight dogs with presumptive PNST.

Methods

This was a retrospective study of dogs identified by searching UC Davis Veterinary Medical Teaching Hospital medical records for dogs treated with SRT for a presumed PNST. Presumptive diagnosis was based on magnetic resonance imaging. SRT was delivered in 3 dose fractions of 8 Gray (Gy) on consecutive days or every other day to a total dose of 24 Gy.

Results

Median disease‐specific survival was 745 days (range: 99–1375 days, n = 6). No signs of acute adverse effects of radiation treatment were recorded. Late radiation effects versus tumor progression could not be confirmed histopathologically because of few animals undergoing necropsy.

Conclusions and Clinical Importance

This study provides preliminary evidence that dogs with PNST benefit from SRT in terms of long‐term survival. The treatment appears to be well tolerated and requires fewer anesthetic events for animals compared to full‐course radiation.

A historical prospective study of European stainless steel, mild steel, and shipyard welders

A multicentre cohort of 11,092 male welders from 135 companies located in nine European countries has been assembled with the aim of investigating the relation of potential cancer risk, lung cancer in particular, with occupational exposure. The observation period and the criteria for inclusion of welders varied from country to country. Follow up was successful for 96.9% of the cohort and observed numbers of deaths (and for some countries incident cancer cases) were compared with expected numbers calculated from national reference rates. Mortality and cancer incidence ratios were analysed by cause category, time since first exposure, duration of employment, and estimated cumulative dose to total fumes, chromium (Cr), Cr VI, and nickel (Ni). Overall a statistically significant excess was reported for mortality from lung cancer (116 observed v 86.81 expected deaths, SMR = 134). When analysed by type of welding an increasing pattern with time since first exposure was present for both mild steel and stainless steel welders, which was more noticeable for the subcohort of predominantly stainless steel welders. No clear relation was apparent between mortality from lung cancer and duration of exposure to or estimated cumulative dose of Ni or Cr. Whereas the patterns of lung cancer mortality in these results suggest that the risk of lung cancer is higher for stainless steel than mild steel welders the different level of risk for these two categories of welding exposure cannot be quantified with precision. The report of five deaths from pleural mesothelioma unrelated to the type of welding draws attention to the risk of exposure to asbestos in welding activities.

Epidemiology of Severely and Fatally Injured Patients in Western Part of Norway

Background and Aims:

Analysis of the injury mechanism and characteristics of severely and fatally injured patients in the western part of Norway.

Material and Methods:

We did a prospective registration of all severely injured patients hospitalized during a three-year period. The files of severely injured patients that died at scene or during transport were retrospectively retrieved from the Forensic Department. A total of 558 patients with an Injury Severity Score > 15 were included.

Results:

Four-hundred-forty-four men (79.6 %) and 114 women (20.4 %) with a median age of 36 and 51.5 years respectively were included. The proportion of female patients older than 80 years were 19.3 % compared to 5.6 % for men. A total of 215 (38.5 %) patients died and 149 (69.3 %) of these patients died on scene or during transport. The incidence of severely injured patients in Hordaland County was 30 per 100 000 inhabitants per year. The incidence was lowest among children below 5 years (7/100 000/year) and highest among persons older than 80 years (95/100 000/year). Men had a 3.8 times greater risk of getting seriously injured compared to women. Road traffic accidents were the cause of the injuries in 235 (42.1%) patients and 35.8% of these patients died. A total of 215 (38.5 %) patients were injured due to falls and 30.2 % of these patients died. Patients who had sustained falls were significantly older than patents with other injury mechanisms (p < 0.001, CI = 13.0–20.2). The proportion of patients with penetrating injuries was 7.3 %.

Conclusion:

The incidence of severely injured patients was 30/100000/year. Men and elderly people had a higher risk of getting severely injured. Falls were the dominating injury mechanism among elderly.

A novel tumor-derived mediator that sensitizes cytokine-resistant tumors to tumor necrosis factor

Therapeutic successes following treatment of murine tumors with tumor necrosis factor-alpha (TNF) have not been easily applied to clinical oncology because the concentrations of TNF required in humans induces systemic toxicity. This has led us to identify mediators which could sensitize tumors to the effects of TNF, permitting administration of lower doses and possible realization of the therapeutic potential of this cytokine. Our study reports the ability of a novel cytokine, endothelial-monocyte-activating polypeptide II (EMAP II), to sensitize initially resistant murine and human tumors to TNF-induced regression employing a murine model. Recombinant (r) EMAP II was purified from Escherichia coli transformed with a plasmid expressing mature EMAP II. The B16 melanoma, raised in C57BL/6 mice, or a human fibrosarcoma (HT-1080), grown in immunocompromised mice, was injected intratumorally with either vehicle or rEMAP II/heat-treated EMAP II (50-100 micrograms) followed by systemic TNF/heat-treated TNF (5 micrograms) and assessed for tumor volume, hemorrhage, and histologic appearance. Both the B16 melanoma and the HT-1080 human fibrosarcoma underwent thrombohemorrhagic and acute inflammatory changes concomitant with regression or significantly slowed growth after administration of intratumor EMAP II followed by systemic TNF. Omission or inactivation of either cytokine abrogated this effect. These results demonstrate that local treatment of certain tumors with EMAP II results in enhanced susceptibility to TNF-mediated induction of thrombohemorrhage and regression.

Intermittent preventive treatment of malaria in pregnancy: the incremental cost-effectiveness of a new delivery system in Uganda

The main objective of this study was to assess whether traditional birth attendants, drug-shop vendors, community reproductive health workers and adolescent peer mobilisers could administer intermittent preventive treatment (IPTp) with sulfadoxine-pyrimethamine (SP) to pregnant women. The study was implemented in 21 community clusters (intervention) and four clusters where health centres provided routine IPTp (control). The primary outcome measures were the proportion of women who completed two doses of SP; the effect on anaemia, parasitaemia and low birth weight; and the incremental cost-effectiveness of the intervention. The study enrolled 2785 pregnant women. The majority, 1404/2081 (67.5%) receiving community-based care, received SP early and adhered to the two recommended doses compared with 281/704 (39.9%) at health centres (P<0.001). In addition, women receiving community-based care had fewer episodes of anaemia or severe anaemia and fewer low birth weight babies. The cost per woman receiving the full course of IPTp was, however, higher when delivered via community care at US$2.60 compared with US$2.30 at health centres, due to the additional training costs. The incremental cost-effectiveness ratio of the community delivery system was Uganda shillings 1869 (US$1.10) per lost disability-adjusted life-year (DALY) averted. In conclusion, community-based delivery increased access and adherence to IPTp and was cost-effective.

Lung cancer mortality in stainless steel and mild steel welders: a nested case-referent study

The association between welding and lung cancer has been studied in a nested case-referent study within a cohort of 8,372 metal workers. Lifetime exposure data on welding and other occupational exposures, as well as alcohol and smoking habits, were obtained by interviews of spouses and colleagues. Analysis was based on 439 deceased referents and 94 deceased cases. There was a 70% excess of lung cancer associated with "welding exposure ever" (OR +/- 95% C.I.: 1.68, 1.02-2.78). Overall OR for "mild steel (MS) welding ever" was 1.64, 0.99-2.72. The risk estimates for welding exposures showed an increasing tendency up to 15 years of exposure. The pattern of stainless steel (SS) welding resembles that of mild steel with an estimated OR of 1.65, 0.88-3.0. The general conclusion is that MS welding as well as SS welding seems to be associated with an increased risk of lung cancer. Further followup of the cohort will enhance precision of the estimates.

Adverse pregnancy outcome and childhood malignancy with reference to paternal welding exposure

Welding may deteriorate spermatogenesis and increase reproductive failures. This study examines reproductive end points in a Danish cohort of 10,059 metalworkers who fathered 3,569 children in 1973 through 1986. Occupational histories were gathered by postal questionnaires. Information on pregnancy outcomes and offspring was obtained by record linkage to medical registers. The occurrence of reduced birthweight, preterm delivery, infant mortality, and congenital malformation was not increased among children at risk from paternal welding exposure in comparison with children not at risk. The overall incidence of childhood malignancies among 23,264 children born in 1968 through 1986 with a total of 259,113 person-years of follow-up was equal to national rates (relative risk 0.97, 95% confidence interval 0.63-1.42). However, pregnancies preceding a birth at risk from paternal exposure to stainless steel welding were more often terminated by spontaneous abortion (odds ratio 1.9, 95% confidence interval 1.1-3.2). This finding needs cautious interpretation and should be further investigated in future studies.

Differentiation of cell surface receptors on normal human bone marrow myeloid precursors

Receptors for IgG and complement are present on the plasma membrane of functionally mature blood neutrophils. Neutrophilic precursors lack these membrane receptors, which may account for their diminished phagocytic capability. In this study, myeloid precursors from human bone marrow were examined for the presence and activity of membrane receptors for IgG and activated complement. Morphologic identification by light microscopy of neutrophilic cells are made by rosetting techniques and chloroacetate esterase cytochemical staining and at the ultrastructural level by peroxidase reactivity. This study showed the Fc receptor was the only membrane marker on the myeloblasts and that the number of cells with the receptor increased with maturation. Functional investigation of the Fc receptor indicated that its presence on early myeloid cells was insufficient to induce IgG-mediated ingestion. Phagocytosis via the Fc receptor was not acquired until the metamyelocyte stage. Complement receptors, C3d and C3b, appeared later than the Fc receptor. The C3d receptor, detected first on the promyelocyte, remained relatively constant throughout maturation, whereas the C3b receptor acquired acquired at the myelocyte stage increased with maturation. These data provide evidence that distinct membrane changes occur during normal myeloid cell maturation and that the presence of these membrane receptors is not sufficient for Fc-mediated ingestion to occur.

Restriction pattern variability of respiratory syncytial virus during three consecutive epidemics in Denmark

A PCR-based assay was used to distinguish between respiratory syncytial virus (RSV) group A and B in order to analyze their prevalence in Denmark in three consecutive epidemics during the winters of 1992/93, 1993/94 and 1994/95. A total of 96 RSV strains isolated from hospitalized children were examined, showing alternation of group prevalence. Furthermore, the genetic variability of the RSV isolates was illustrated by restriction enzyme analysis of PCR products originating from a part of the F and G proteins that has been reported to be highly variable. We found that, in general, different genome types predominated each year, some types being present in consecutive epidemics, indicating a contribution of strains circulating unattended between outbreak seasons, while others seemed to disappear or became undetectable, being replaced by emerging types. Some of the genome types found seemed related to strains isolated up to more than two decades ago in other parts of the world. This indicates that the temporal fluctuation in predominance of genome types presumably caused by selective pressure exerted by host immunity is due to the favoring of strains from a pool of globally circulating, genetically relatively stable genome types, rather than a molecular evolution in strains induced or directed by immunoselective pressure.

Disseminated intravascular coagulation (DIC) in a kidney donor associated with transient recipient DIC

It has been controversial whether or not to accept kidneys for transplantation from donors with disseminated intravascular coagulation (DIC). We report two recipients who received the kidneys from a donor with DIC following traumatic head injury. Despite evidence of donor kidney glomerular fibrin deposits and ongoing low-grade DIC in the recipients, which resolved after 5-7 days; both recipients did well suggesting that donors with DIC can be successfully used for renal transplantation.

Validity of occupational exposure and smoking data obtained from surviving spouses and colleagues

The accuracy of exposure data from surrogate sources such as spouses and colleagues was estimated in an historical cohort of 10,059 metal workers. In a 2 year period from 1986 to 1988, 118 subjects who, in 1986, answered a questionnaire on occupational exposures and smoking habits had died. In 1988 spouses and long-term colleagues were interviewed on the same items. Separate contingency tables were developed comparing case and spouse/colleague responses. Percentage of concordance, sensitivity, specificity, the kappa measure of agreement, and a bias factor (exposed to nonexposed ratio between surrogates and cohort members) were calculated. Compared with the index subjects indications, the colleagues' and spouses' reports represented a moderately high level of concordance on occupational exposures, primarily for exposures with a moderate prevalence. There was a considerable under-reporting on both occupational exposures and smoking habits expressed in low values of sensitivity and bias factor values below one. The described misclassification of exposure data by using surrogate information might seriously influence the risk estimation and introduce bias.