In order to
evaluate the results of the immunological tests against the clinical diagnosis, two steps are needed in each case: a comprehensive diagnostic approach and validated serological test. Our 12 patients underwent specific inhalation challenges with MDI MM-102 nmr (none of the control subjects did approve for either SIC or MDI-prick tests). Their atopy status, skin-prick test results, serial lung function testing, demographic data and clinical diagnosis are given in Tables 3, 4. Four subjects showed positive specific IgE reaction (3.3–50.4 kU/L of sMDI-IgE) and 10 had specific IgG antibodies: (3.5–74 mg/L sMDI-IgG); 4 MDI-asthma patients showed low values of sIgG (3.3–9.6 mg/L sIgG; 0.3–6.6 mg/L higher than the unspecific settled value of 3 mg/L), whereas the 4 hypersensitivity pneumonitis patients had mostly higher sIgG values (up to 74 mg/L). Figure 4a shows serum samples for individual patients with presumed isocyanate asthma (for patient data see Tables 3, 4). We have observed here that improved IgE assay (in-vapor vs. in-solution) may enhance the diagnostic sensitivity for individual patients. Additionally, one patient (pat#1, Tables 3, 4) was followed over a period of 9.5 years (after first MDI-asthma diagnosis in our outpatient
clinic). The patient, man, 27 year old, smoker, with obstructive ventilation disorder, recurrent wheeze and difficulty in breathing was working on a machine bending wood bands (spruce) with heated Adavosertib datasheet MDI containing glue for braces, post and bridges (the later were hand-notched, glued and doweled into ribs). He developed isocyanate asthma and suffered dermatitis, showed NSBHR and positive SIC reactions, was positive to common ALOX15 allergens in SPT and also showed an immediate-type MDI-SPT reaction, and his total IgE values was 261 kU/L. Asthma improved and dermatitis symptoms were not observed after he changed his job and had no further contact to isocyanates in the following check-up periods. The specific IgE data cover
4 years of MDI exposure and 5.5 years free from exposure (Fig. 4b). Interestingly, significant IWR-1 datasheet levels of sIgE antibodies persisted in this patient throughout the 4 years subsequent to the MDI exposure. This was a surprising result and contradicts the widely held belief that sIgE levels decay quickly upon the removal from exposure to isocyanate. Given the assumed short half-life of IgE (his specific IgG values were lower than 3 mg/L estimated non-specific reference values), this might be important for the diagnosis of patients currently no more exposed to isocyanates. Fig. 4 Specific IgE antibody level may persist for several exposure-free years. a Serum IgE antibody levels for all patients with presumed MDI-asthma (see Tables 3, 4 for patient details) measured with fluorescence enzyme immune assay using MDI-HSA conjugates prepared either, in-solution (i.s., hatched columns), in-vapor (i.v.