The recombinant allergens can be used reliably to identify Can f 1 and Can f 2-sensitized individuals. However, the two allergens are insufficient as reagents for diagnosing dog allergy.

As a part of the long-term prospective follow-up study conducted for women with genital human papillomavirus (HPV) infections in Kuopio University Hospital, Finland, since 1981, a case-control study was designed to assess risk factors for genital HPV infections. The cases (n = 691) were women who had been invited to attend the follow-up program on the basis of an abnormal cervical smear consistent with HPV-induced cytopathic changes, i.e., had a clinical HPV infection. The controls (n = 706) were a randomly selected group of women who had normal smears in the screening. Both groups were asked to fill in an extensive questionnaire focusing on detailed epidemiologic data on previous gynecologic and obstetric history, sexual practices, sexual partners, and smoking habits. In the multivariate analysis, eight variables emerged as independent risk factors for prevalent HPV infection. These variables could explain over 80% of the risk for infection. The risk for the infection varied with age, being highest in the age group 20-29 years, thereafter declining in the following 10-year age groups. The strongest independent risk factor was the number of sexual partners during the past 2 years (adjusted odds ratio = 12.1; 95% confidence interval 4.3-33.8 for five or more vs. one or no partners). Among the independent risk factors that increased the risk were also current smoking (adjusted odds ratio = 2.7; 95% confidence interval 1.7-4.3), warts in sexual partner(s) (adjusted odds ratio = 3.2; 95% confidence interval 1.6-6.5), and increasing frequency of sexual intercourse per week. Independent risk factors with a protective effect included a normal result in the last Papanicolaou smear, regular use of an intrauterine device as a contraceptive method, and good personal hygiene. No significant association between oral contraceptive use and risk for HPV infection was found. Condom use did not result in protection from the infection. The results of this study support the concepts that sexual intercourse is the main form of transmission among adults and that sexual promiscuity is the most important determinant for genital HPV infections.

Major respiratory allergens of dogs, mice, rats, horses and cows belong to the lipocalin group of proteins. The sequence identity of lipocalins is often less than 20%, but they contain between one and three structurally conserved regions and their three–dimensional structures are similar. Lipocalins share common biological functions, predominantly related to the transport of small hydrophobic molecules, such as vitamins and pheromones. Immune reactivity to lipocalin allergens is not well known. In Bos d 5, the IgE–binding epitopes are spread along the molecule, whereas in Bos d 2, the C terminus appears to contain the human B cell epitopes. Bos d 5 contains several murine T cell epitopes. No information is available on human T cell epitopes. The maximal number of epitopes an allergic patient’s T cells could recognize in Bos d 2 was five. Three of the epitopes were colocalized in the structurally conserved regions of lipocalins. Interestingly, one of the epitopes was recognized by the T cells of all patients and the computer predictions suggested that there would be an epitope in the corresponding parts of human endogenous lipocalins. The proliferative responses of peripheral blood mononuclear cells of Bos d 2–allergic subjects to Bos d 2 were weak. The T cell response was Th2–dominated. To explain these observations, we have proposed that the allergenicity of lipocalins may be a consequence of molecular mimicry between lipocalin allergens and endogenous lipocalins at the T cell level.

No abstract

The immunological characteristics of an important group of animal-derived allergens, lipocalins, are poorly known. To explore the immunology of the lipocalin allergen Bos d 2, several mouse strains with different H-2 haplotypes were immunized with the allergen. Only the BALB/c mouse mounted a distinct humoral response against Bos d 2. The proliferative spleen cell responses of all mouse strains remained very weak. Further experiments with BALB/c mice confirmed that Bos d 2 is a weak inducer of both humoral and cellular responses, and that the responses were weaker than with the control antigens hen egg lysozyme (HEL) and tetanus toxoid. IgG subclass analyses showed that Bos d 2 was prone to favor the T(h)2 response. Although s.c. immunization using complete Freund's adjuvant favored the T(h)1-deviated immune response by lymph node cells, Bos d 2 was able to induce the production of IL-4 while the control antigen HEL did not. Epitope mapping revealed that BALB/c mice recognized one immunodominant epitope in Bos d 2, almost identical to that recognized by humans. The epitope was shown to be immunogenic in subsequent experiments. However, further studies are needed to clarify the significance of priming and stimulation doses of the immunodominant and other epitopes in Bos d 2 for the outcome of immune response against the allergen. The murine immune response against Bos d 2 closely resembled that observed in humans. The weak immunogenicity of Bos d 2 may be associated with its allergenicity.