Objective To investigate the importance of sensitisation and exposure to allergens and viral infection in precipitating acute asthma in adults resulting in admission to hospital.

The NACManchester Asthma and Allergy Study is a prospective study of the development of asthma and allergies in childhood. The subjects (995 children at age 3 years) were recruited in utero by screening parents in the antenatal clinic using skin prick testing and a questionnaire regarding allergic diseases. Children were assigned to risk groups according to parental atopic status (high risk, both parents atopic; medium risk, one parent atopic; low risk, neither parent atopic). A subgroup of those at high risk (with no pets in the home) was randomized to stringent environmental control (allergen impermeable covers for the parental and infant bed, hot washing of bedding weekly, HEPA vacuum cleaner, hard floor for the nursery), and the remainder followed a normal regime. The children have been followed prospectively. The environmental influences are very clearly defined. Measurements of environmental exposures include levels of house dust mite; cat and dog allergens during pregnancy and early life; pet ownership and exposure; childcare arrangements; number of siblings; vaccination uptake; thorough dietary questionnaire; and endotoxin exposure. Further unique objective outcome in the cohort is the assessment of lung function in preschool children using specific airways resistance, which at age 3 years clearly reflects both genetic and environmental influences.

Idiopathic pulmonary fibrosis (IPF) is a clinical syndrome in which the precipitating factors are unclear. An association between Epstein-Barr Virus (EBV) and IPF had previously been suggested using serology and immunohistochemistry. This study sought confirmation of the presence of EBV DNA in the lung tissue of patients with IPF. Lung tissue obtained surgically from 27 patients with IPF and 28 control subjects was investigated for the presence of EBV by immunohistochemistry and polymerase chain reaction (PCR) analysis. Immunohistochemistry used antibodies specific for EBV lytic cycle antigens (gp340/220 and VCA). Nested PCR analysis used oligonucleotide primers specific for EBV and was sensitive to one copy of EBV DNA. Twelve of the 27 patients with IPF (44%) and three of the 28 control subjects (10%) were EBV positive by immunohistochemistry (p = 0.005). Thirteen of the patients with IPF (48%) and four of the control subjects (14%) were EBV positive by PCR (p = 0.007). Eleven of the patients with IPF (41%) and none of the control subjects were EBV positive by both immunohistochemistry and PCR (p = < 0.001). These data further suggest an association between EBV and IPF. In addition it defines a novel method for detecting EBV in lung tissue. EBV may be involved in the pathogenesis of the disease; however, further studies are required to establish a causal relationship.