Lung tissue from 20 patients undergoing resection for a peripheral carcinoma was studied using monoclonal antibodies to identify inflammatory cell types in the peripheral airways and to determine the location of the bronchial-associated lymphoid tissue (BALT). The patients were grouped according to their percent predicted FEV1 (%FEV1) into obstructed (%FEV1 less than 80%) and control (%FEV1 greater than 80%). The resected lungs were filled with dilute cryoembedding media (Tissue-Tek R), frozen over liquid nitrogen, sliced into 2-cm sagittal slices using a band saw, and sampled using a cork bore. Ten serial histologic sections cut from these samples were stained with monoclonal antibodies for specific inflammatory cell types, which were counted and expressed per square millimeter of airway wall area. The results showed that the patients with airway obstruction had more B-lymphocytes in the airway adventitia than did the control subjects (p less than 0.001) and that the number of submucosal polymorphonuclear leukocytes is related to the amount smoked (p less than 0.02). They also show the BALT has a different distribution in human than in rodent lungs in that the lymphoid collections are found in the outer walls of the airway rather than in the submucosa.

Studies have shown that exposure to ambient particulate matter is related to an increased cardiopulmonary morbidity and mortality. The present study was designed to measure the effect of repeated exposure to urban air particles (PM10) on the rate of production and release of polymorphonuclear leukocytes (PMN) from the bone marrow into the peripheral blood. Rabbits exposed to PM10 (5 mg) twice a week for 3 wk, were given a bolus of 5'-bromo-2'-deoxyuridine (BrdU) to label dividing cells in the marrow that allows us to calculate the transit time of PMN in the bone marrow mitotic and postmitotic pools. The PM10 exposure (n = 8) causes a persistent increase in circulating band cells (p < 0.05) and a shortening of the transit time of PMN through the postmitotic pool in the marrow (64.4 +/- 2.2 h to 56.3 +/- 2.2 h, p < 0.05) if compared with vehicle-exposed control subjects (n = 6). PM10 exposure increases the bone marrow pool of PMN particularly the mitotic pool of PMN (p < 0.05). The PM10 were distributed diffusely in the lung and caused a mild mononuclear inflammation. The percentage of alveolar macrophages containing PM10 correlated significantly with the bone marrow PMN pool size (total pool r2 = 0.56, p < 0.012, mitotic pool r2 = 0.61, p < 0.007) and the transit time of PMN through the postmitotic pool (r2 = -0.42, p < 0.043). We conclude that repeated exposure to PM10 stimulates the bone marrow to increase the production of PMN in the marrow and accelerate the release of more immature PMN into the circulation. The magnitude of these changes was related to the amount of particles phagocytosed by alveolar macrophages.

Polymorphonuclear leukocytes (PMN) labeled in vivo with 5'-bromo-2'-deoxyuridine (BrdU) in donor animals were transferred to recipients to determine the rate of clearance of labeled PMN from the circulation, their margination within the vascular space, and migration into Streptococcus pneumoniae-induced inflammatory sites. The donor animals received intravenous infusions at 25 mg/kg/day of BrdU for 7 days when cytospins of leukocyte-rich plasma (LRP) showed that 80 +/- 2.3% PMN were labeled. The BrdU labeled cells were then transfused to serum-compatible recipients as either whole blood, leukocyte-rich plasma, or PMN purified from an equal volume of whole blood. Twenty-four hours after transfer, the distribution of BrdU-labeled PMN in the lung, liver, spleen, bone marrow, and gut was determined morphometrically and by Southern blot analysis of DNA extracted from these organs. BrdU-labeled PMN transfused as either LRP or purified PMN provided no advantage over transfusing whole blood. The half-life of BrdU-labeled PMN in the recipient circulation after transfusing whole blood was 270.4 min (95% confidence intervals, 248.5 to 296.4 min). The majority of the BrdU-labeled DNA was found in the spleen, where DNA analysis showed that the white blood cells underwent programmed cell death by apoptosis. Four hours after infection with S. pneumoniae and 1 h after transfusion of labeled whole blood, BrdU-labeled PMN had migrated into the infected sites. We conclude that transfer of BrdU PMN in whole blood provides a simple, effective method of tracing labeled PMN in vivo.