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Only a small number of patients with IgG subclass deficiencies (IgGSD) have been observed to have bronchiectasis. Moreover, in the series of patients with bronchiectasis, IgGSD have not been found at any frequency, and the etiology of bronchiectasis remains unclear in 29 to 49% of cases. Serum concentrations of total IgG, IgA, and IgG subclasses as well as pulmonary function were measured in 65 patients (aged: 10 to 74 yr) with bronchiectasis of unknown etiology. An ELISA test was performed to quantify subclasses 1 through 4 using subclass-specific antihuman monoclonal antibodies. IgG subclass estimation in a healthy population with age-stratified normal ranges was derived from 100 adults, 37 children aged between 10 and 12 yr, and 27 adolescents aged between 13 and 16 yr. Serum concentrations of specific IgG antibodies to Haemophilus influenzae type b capsular polysaccharide (Hib-PRP) were also assayed by an ELISA test in 19 of the patients (10 with IgGSD and nine with non-IgGSD) and in 58 healthy individuals before and 3 wk after immunization with Hib-PRP conjugated to meningococcal outer membrane protein complex (OMPC). Thirty-one patients (48%) had low serum concentrations of one or more IgG subclasses (19 IgG2 deficiencies, 2 IgG3 deficiencies, 3 IgG4 deficiencies, and 7 combined subclass deficiencies). All patients showed increased levels of total IgG, IgG1, and IgA, but this rise was significantly higher in patients without IgGSD. Patients with IgGSD showed impaired antibody response to Hib-PRP compared with patients with non-IgGSD and the control group. IgGSD, particularly IgG2 deficiency, are not an unusual cause of bronchiectasis. Therefore, serum levels of IgG subclasses must be assayed whenever other causes of bronchiectasis have been ruled out.

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Our objective was to determine the prevalence of antinuclear antibodies (ANAs) in patients with malignancies and to investigate if their presence might be related with development of musculoskeletal symptoms or paraneoplastic rheumatic syndromes. Antinuclear antibodies were determined by indirect immunofluorescence on Hep-2 cells in 274 neoplastic patients and in a control group of 140 age-adjusted healthy subjects. Antinuclear antibody specificities (anti-DNA and anti-ENA) were investigated in patients with rheumatological symptoms and positive ANA. Antinuclear antibodies were detected in 76 of 274 (27.7%) patients with malignancies and in nine of 140 (6.4%) healthy subjects. Twenty patients reported paraneoplastic rheumatic symptoms or syndromes. Two of them developed clinical symptoms mimicking rheumatoid arthritis (rheumatoid-like arthropathy), one systemic lupus erythematosus (lupus-like syndrome), one dermatomyositis and four cutaneous vasculitides. Musculoskeletal symptoms and paraneoplastic rheumatic symptoms and syndromes were both more frequently observed in patients with positive ANA. Antinuclear antibody specificities were found in only two cases. We can conclude that there is an increased incidence of antinuclear antibodies in malignant conditions. Musculoskeletal symptoms and rheumatic paraneoplastic symptoms and syndromes seem to be more frequent in patients with cancer-related positive ANAs. The failure to find ANA specificities (anti-ENA, anti-DNA) in patients with malignancies and positive ANAs in our study may simply reflect molecular differences between the autoantigens involved in cancer and those characteristically involved in the systemic autoimmune diseases.

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Well-validated methods for measuring airborne occupational allergens are essential for effective control and reduction of allergen exposures. For wheat flour allergens, specific immunoassays are available, but there is a need for optimisation and standardization of sample processing procedures. Wheat flour allergen elution and storage were studied using airborne dust samples collected in bakeries with a new parallel sampler. Forty-eight series of 9 parallel filters were subjected to extraction procedures varying in elution medium, shaking method, extraction vial, and centrifugation speed. Wheat allergens were measured with enzyme immunoassays, and the effect of various procedures evaluated by mixed regression analyses. The stability of the eluted allergens was assessed after storage for 20 days and 4 months at -20 degrees C, in the presence or absence of casein in the medium. Only the type of elution medium had significant effects on allergen recovery: addition of Tween-20 resulted in 3- to 100-fold increased levels, an effect that was most pronounced at low concentrations. Allergen levels in extracts were stable for at least 4 months at -20 degrees C, irrespective of the presence of casein in the medium. Addition of Tween-20 to the elution medium is essential for optimal extraction of wheat allergen. The recommended procedure further includes the use of conventional polystyrene tubes, simple shaking methods, and centrifugation after extraction. Wheat dust extracts in PBS-Tween can be stored frozen for at least 4 months, and addition of a stabilising protein is not required.

The rabbit IgG EIAs are valid substitutes for the human IgG4 inhibition EIA, with important practical advantages. The inhibition EIA is recommended for routine wheat allergen measurements. The sandwich EIA may be used to measure low allergen levels, as in short task-related exposure measurements or in subfractions of airborne dust samples.