Leukocytes and mediators in bronchoalveolar lavage during allergen-induced late-phase asthmatic reactions

We have measured the total and differential cell counts, histamine, leukotriene (LT) B4 and LTC4, immunoglobulins, complement (C3), eosinophil-derived basic proteins, and monocyte complement rosettes in bronchoalveolar lavage (BAL) 6 h after challenge with either antigen or diluent control in seven patients with antigen-induced single early reactions, and seven with dual (early and late phase) reactions. In both groups, the total cell counts in BAL were similar, irrespective of whether they were challenged with antigen or diluent. However, in the late-phase responders (LPR), there were significant increases in lymphocytes, neutrophils, and eosinophils (p less than 0.05), and significant decreases in the percentage of lung mast cells (p less than 0.05). The eosinophil major basic protein and eosinophil-derived neurotoxin increased in four of five subjects with dual responses and in the majority of single early responders (SER). BAL histamine concentrations increased in five of seven patients with dual responses. There were no consistent changes in LTB4 concentrations in either the LPR or the SER between diluent and antigen days, but a small but significant increase in LTC4 was observed in the LPR. Concentrations of IgG, IgA, IgM, IgE, C3, and albumin did not differ significantly. The percentage of monocyte complement rosettes also increased significantly (p less than 0.05) in LPR, but not in SER. These findings support the hypothesis that eosinophils and their products play a role in tissue injury in LPR and that eosinophil infiltration may be associated with macrophage activation.

Allergen-induced recruitment of bronchoalveolar helper (OKT4) and suppressor (OKT8) T-cells in asthma. Relative increases in OKT8 cells in single early responders compared with those in late-phase responders

We measured the numbers of helper (OKT4) and suppressor (OKT8) T-cells in blood and bronchoalveolar lavage (BAL) in 6 patients who developed single early reactions after allergen inhalational challenge and in 6 subjects who developed dual (early- and late-phase) responses. The asthmatics were lavaged twice. On the first occasion, they inhaled the diluent control (Dil) solution, and after an interval of at least 7 days, allergen (Ag) inhalational challenge was undertaken. Significant differences were observed in the single early responders (SER) only. For instance, when the results obtained on the Dil day were compared with those obtained on the Ag day, there was a significant (p less than 0.05) increase in the percentage of OKT4 cells in the blood of SER. Also in the BAL of SER there was a significant (p less than 0.05) decrease in the percentage of OKT4 and an increase (p less than 0.05) in the percentage and absolute numbers of OKT8 cells. Furthermore, the percentage of OKT4 was highly significantly (p less than 0.005) lower on the Ag day in the SER than on the Ag day in the late-phase responders (LPR). The OKT4/OKT8 ratio was significantly (p less than 0.05) lower on the Ag day than on the Dil day in BAL from SER and highly significantly decreased (p less than 0.001) when results on the Ag day in the SER were compared with those on the Ag day in the LPR. These findings raise the possibility that mobilization of suppressor T-cells into the lung after allergen-induced single early reactions in asthma might be associated with the prevention of a subsequent late-phase response.

Bronchoalveolar lavage in asthma: the effect of disodium cromoglycate (cromolyn) on leukocyte counts, immunoglobulins, and complement

In a double-blind, placebo-controlled study, we measured the effect of disodium cromoglycate (DSCG) on leukocyte counts, total IgE, IgG, IgA, IgM, house dust mite-specific IgE, C3, and C4 in bronchoalveolar lavage (BAL) fluid and peripheral blood in 36 atopic, perennial asthmatic subjects (DSCG 19; placebo 17). Differential cell counts on bronchial mucus were also performed. The percentage of eosinophils in bronchial mucus and BAL fluid was significantly less after DSCG. There was also a significant decrease in the concentration of total IgA (expressed as an IgA/albumin ratio) in BAL fluid after a 28-day treatment with DSCG. When the DSCG-treated patients were divided into responders and nonresponders on the basis of average daily symptom scores, the responders had significantly less bronchial mucus eosinophils, BAL eosinophils, and house dust mite-specific IgE (but not IgA) after DSCG. No significant differences in any of the measurements were observed in the nonresponders or the placebo group similarly subdivided on the basis of symptom scores. These results suggest that the efficacy of DSCG in bronchial asthma might be related to its ability to suppress the local accumulation of eosinophils and specific-IgE antibodies.