Prospective study on the effect of smoking and nicotine substitution on leucocyte blood counts and relation between blood leucocytes and lung function

BACKGROUND

The influence of smoking and of nicotine substitution on the counts of total blood leucocytes and leucocyte subsets and the relations between the counts and lung function was investigated.

METHODS

The study was a combined cross sectional and prospective study of 298 smokers and 136 non-smokers. Forced expiratory volume in one second (FEV1) was measured in all participants at baseline and six months after quitting smoking in 160 ex-smokers (quitters) and 138 persons with smoking relapse. Blood samples were obtained from all participants at baseline and from 160 quitters and 30 continuing smokers two, six, 12, and 26 weeks after smoking cessation and from 92 quitters one year after the cessation of smoking.

RESULTS

Blood leucocyte counts and leucocyte subsets were all higher in smokers than in non-smokers. In cigarette smokers total leucocyte, neutrophil, and lymphocyte blood counts showed a dose dependent relationship with the daily cigarette consumption and pack years consumption. In smokers the neutrophil blood count was independently associated negatively with FEV1 residuals. After quitting smoking total leucocyte, neutrophil, and lymphocyte blood counts decreased during the first 26 weeks and after one year lymphocyte blood counts were higher than in non-smokers. In quitters substituted with nicotine chewing gum (2 mg) the accumulated number of pieces of chewing gum used in the 12 weeks had an inverse relationship with the decrease in the total lymphocyte blood count at 12 weeks after smoking cessation.

CONCLUSIONS

Leucocyte blood counts are raised in smokers and decrease after smoking cessation. Neutrophil blood counts had an inverse relationship with lung function and nicotine may increase lymphocyte blood counts in smokers.

Is the expression of classical HLA class I antigens on trophoblast of importance for human pregnancy?

PROBLEM

Human leukocyte antigen (HLA)-C and possibly also HLA-B seem to be expressed on the extravillous trophoblast. These antigens carry epitopes that function as ligands for natural killer (NK)-cell-inhibitory receptors. Antitrophoblast cytotoxicity mediated by decidual NK cells might be involved in miscarriage. We thus found it relevant to elucidate whether parental HLA-C and -Bw polymorphism play a role in recurrent miscarriage (RM).

METHOD OF STUDY

HLA-C and -Bw investigations by DNA-based techniques were undertaken in 35 couples with unexplained RM and in 30 couples with normal fecundity. The number of HLA-C- and -Bw-related supertypic specificities that can bind NK-cell-inhibitory receptors was evaluated in selected couples.

RESULTS

The proportions of couples with RM and control couples carrying four HLA-C alleles with the same NK-cell-inhibitory supertypic specificities were equal. In 46% of studied couples with RM, all four HLA-B alleles carried the HLA-Bw6 supertypic specificity, which was significantly higher than the corresponding frequency (17%) in the control couples (P < 0.02).

CONCLUSIONS

The expression of polymorphic HLA-C on trophoblasts does not seem to play a role in RM. Assuming that HLA-B is expressed on trophoblasts, we may suggest that the revealed predominance of HLA-Bw6 expression (which excludes the presence of HLA-Bw4-protective antigens) may predispose a particular couple to the RM phenomenon.

Multiplex reverse transcription-polymerase chain reaction for simultaneous screening of 29 translocations and chromosomal aberrations in acute leukemia

We have developed a multiplex reverse transcription-polymerase chain reaction (RT-PCR) reaction, which enables us to detect 29 translocations/chromosomal aberrations in patients with acute lymphoid leukemia (ALL) and acute myeloid leukemia (AML). Through the construction and optimization of specific primers for each translocation, we have been able to reduce the set-up to 8 parallel multiplex PCR reactions, thus greatly decreasing the amount of work and reagents. We show the value of our set-up in a retrospective analysis on cryopreserved material from 102 AML and 62 ALL patients. The multiplex RT-PCR detected a hybrid mRNA resulting from a structural chromosomal aberration in 45 of 102 (44%) of the AML and in 28 of 62 (45%) of the pediatric ALL cases. Importantly, in 33% of AML and in 47% of the ALL cases with cytogenetic data, submicroscopic chromosomal aberrations or masked translocations were shown that were not detected in the cytogenetic analysis either for structural reasons or because of an insufficient number of metaphases obtained. This multiplex RT-PCR system, which can handle up to 10 patients with a response time of 2 working days, is thus an important tool that complements cytogenetic analysis in the up-front screening of acute leukemia patients and should provide a rapid and efficient characterization of leukemia cells, even in situations with sparse patient material.

Trisomy 10 survival: a literature review and presentation of seven new cases

Trisomy 10 as the only chromosome aberration is a rare phenomenon in malignant and premalignant hemopoietic disorders. We describe 7 new cases and have found another 12 in the literature. It appears that, whereas adult patients have myeloid disorders (acute myeloid leukemia, myeloproliferative, or myelodysplastic syndromes), in children the diagnosis is lymphocytic leukemia or lymphoma. The median survival was 122 months in the total material. Age above 60 years proved to be a significant adverse factor (median survival only 5 months; p = 0.003). None of the other clinical, cytogenetic, or hematological variables were of demonstrable prognostic importance. In contrast with the larger trisomy 10 clones, those of limited size were associated with nonleukemic diagnoses, normal or slightly elevated leukocyte counts, and few or no circulating blasts. This may suggest that expansion of the trisomy 10 clone is associated with clinical and hematological progression.

Blood eosinophil and monocyte counts are related to smoking and lung function

The aim of this study was to investigate the predictive value of peripheral eosinophil and monocyte blood counts regarding lung function in smokers and non-smokers, and to investigate the influence of smoking on these cell counts. Forced expiratory volume in 1 s (FEV1) measurements and blood samples were collected from 298 non-atopic smokers and 136 never-smokers. Blood samples were repeated in 160 smokers after cessation of smoking (quitters) and 30 continuing smokers, 2, 6, 12 and 26 weeks after smoking cessation. Monocyte (P < 0.05) but not eosinophil blood counts were higher in never-smokers compared to smokers. In never-smokers, blood eosinophil counts and monocyte counts correlated inversely (P < 0.05) and directly (P < 0.01), respectively, with standardized FEV1 residuals (FEVR). In smokers, blood eosinophil (P < 0.05) and monocyte (P < 0.05) counts correlated directly with FEVR independent of smoking history. After smoking cessation, monocyte blood counts (P < 0.05) increased. Both eosinophil and monocyte blood counts showed a greater increase in quitters with decreased lung function (P < 0.05). Former heavy smokers had higher blood eosinophil (P < 0.05) but lower monocyte (P < 0.05) count increase than had former light smokers. These data suggest that smoking influences eosinophil and monocyte blood counts and that this is associated with a small negative effect on lung function. Eosinophil blood counts had an opposite relation to lung function in smokers and non-smokers. Further research should include investigations of relations between smoking and stimulatory factors for recruitment and activity of eosinophils and monocytes.

MDS and AML with trisomy 8 as the sole chromosome aberration show different sex ratios and prognostic profiles: a study of 115 published cases

A number of chromosome aberrations occur nonrandomly as the sole aberration in malignant and premalignant hematological disorders. They imply very different prognoses. For most of them the survival consequences have been established. For trisomy 8, which is the most frequent numerical aberration in myeloid disorders, the prognostic implications have not been investigated. In order to clarify survival in patients with trisomy 8 as the sole aberration, the literature was searched for such cases. In 115 patients survival data were available. In 103 (89.6%), a myeloid disorder had been diagnosed. Acute myeloid leukemia (AML) or a myelodysplastic syndrome (MDS) occurred in 100 cases (87.0%). The median survival was found to be 17.1 months. On multivariate survival analysis (Cox), age above 60 and a leukemic diagnosis were found to be independent adverse prognostic indicators. MDS patients survived significantly longer (median 21 months) than AML patients (median 15 months). In MDS age and in AML the trisomy 8 clonal size was an independent prognostic factor. An unexpected observation was a clear male preponderance in trisomy 8 MDS (about two-thirds of cases). In trisomy 8 AML an approximate 1:1 ratio was found. Browsing of Mitelman's catalog confirmed these ratios.

Graphical interpretation of analytical data from comparison of a field method with reference method by use of difference plots

Various viewpoints have been offered regarding the appropriate use of scatter plots or difference plots (bias plots or residual plots) in comparing analytical methods. In many of these discussions it seems the basic concepts of identity (within inherent imprecision) and acceptability based on analytical goals (analytical quality specifications) have been forgotten. With the increasing number of Reference Methods in laboratory medicine, these basic concepts are becoming more important in validation of field methods. Here we describe a simple and effective graphical test of these hypotheses (identity and acceptability) by use of difference plots. These plots display the underlying hypothesis before the measured differences are plotted and allow interpretation of the results according to specific criteria. We further describe simple but effective interpretations of the data, when the hypothesis is not fulfilled, by using two data sets drawn from comparisons of field methods for S-creatinine with a Reference Method for this analyte. The difference plot is a graphical tool with related simple statistics for comparison of a field method with a Reference Method, focusing on (a) identity within the inherent analytical imprecision or (b) acceptability within analytical quality specifications. Calculation of the standard deviation of the differences is an indispensable tool for evaluation of aberrant-sample bias (matrix effects).

5q-: does longer survival of female patients explain the preponderance

Cases with deletion of part of the long arm of chromosome 5 (5q-) and a myeloid hemopoietic disorder show a marked female preponderance. We analysed the female preponderance of 328 published cases of myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML). MDS without clinical or cytogenetic progression shows by far the highest frequency in female patients. Cases with advanced MDS and/or chromosome aberrations in addition to 5q- show low to moderate preponderance. Female preponderance was found to correlate positively with relative survival: in the group with the highest frequency women survived significantly longer than men. In groups with lower preponderances the survival of the two sexes gradually converged. These data suggest that in 5q- related disorders the female preponderance is a consequence of increased female survival.

A comparison of aqueous suspensions of budesonide nasal spray (128 micrograms and 256 micrograms once daily) and fluticasone propionate nasal spray (200 micrograms once daily) in the treatment of adult patients with seasonal allergic rhinitis

The efficacy of aqueous suspensions of budesonide nasal spray and fluticasone propionate nasal spray, in the treatment of seasonal allergic rhinitis, was compared in a large, placebo-controlled, two-center study. A 1-week baseline period was followed by a 4- to 6-week treatment period during which 635 adult patients, aged 18-72 years, were randomized to receive either placebo, budesonide 128 micrograms, or 256 micrograms once daily, or fluticasone propionate, 200 micrograms once daily. Nasal and eye symptoms, overall treatment efficacy and safety assessments were made during the study period. Combined, as well as individual, nasal symptoms were significantly improved in all three active treatment groups compared with placebo therapy. Treatment with 256 micrograms/day of budesonide was found to be significantly more effective in reducing the sneezing score compared with 200 micrograms/day of fluticasone propionate. Analysis of symptom scores on days when the pollen count was greater than 10 grains/m3 revealed 256 micrograms/day of budesonide therapy to be significantly more effective in reducing combined symptom scores as well as the individual scores for sneezing and runny nose, compared with 200 micrograms/day fluticasone propionate. The higher dose of budesonide (256 micrograms/day) was also more effective than the lower dose (128 micrograms/day) in reducing sneezing scores and statistical significance was almost reached for the reduction in combined symptom and runny nose scores. Substantial or total control of symptoms was achieved by 31.4%, 85.3%, 88.4%, and 81.9% of patients receiving placebo, 128 micrograms/day of budesonide, 256 micrograms/day of budesonide, and 200 micrograms/day of fluticasone propionate, respectively. The incidence of adverse events was low in all treatment groups. In conclusion, both budesonide and fluticasone propionate treatments were effective and well-tolerated in the treatment of seasonal allergic rhinitis. However, 256 micrograms/day of budesonide tended to be more effective than 200 micrograms/day of fluticasone propionate and 128 micrograms/day of budesonide, especially when patients were exposed to a higher pollen load.

The monosomy 7 clone in interphase and metaphase cell population: a combined chromosome and primed in situ labeling study

Loss of a chromosome 7 is associated with a poor prognosis in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Some studies have shown higher frequencies of monosomy 7 (-7) in dividing than nondividing myeloid cells, which might indicate that -7 confers a proliferative advantage on the host cell. As other groups have not been able to confirm this, we compared the -7 frequencies in bone marrow metaphases as studied with conventional cytogenetics and in interphase cells using primed in situ (PRINS) labeling. We found significantly higher -7 frequencies in metaphase than in interphase cells irrespective of diagnosis and presence or absence of additional chromosome aberrations. Further, we found a significant correlation between the -7 percentages in resting and dividing cells. Finally, as our material showed a clear male preponderance, Mitelman's Catalog of Chromosome Aberrations in Cancer was searched for -7. Of 815 cases with AML or MDS, 491 (60.3%) were found to be men. To our knowledge, this is the first observation of a clear deviation from the 1:1 sex ratio in -7 patients.

Anatomy of the 5q- deletion: different sex ratios and deleted 5q bands in MDS and AML

Deletion of part of the long arm of chromosome 5 (5q-) is the most common structural chromosome aberration in patients with myeloid disorders. Most patients are women. Although widely varying 5q segments are deleted, the vast majority of cases share a common deleted region (5q31). Whether or not other deleted 5q regions are of clinical importance is unknown. In an attempt to throw light on this question, 439 published 5q- cases were analyzed. The female preponderance was found to be limited to refractory anemia (RA), RA with excess of blasts (RAEB) and myeloproliferative disease, all with 5q- as the only chromosome aberration. When other chromosome aberrations had developed or the diagnosis was AML, only marginal female preponderance was observed. The 5q31 was deleted in all patients with MDS and 5q- as the only aberration. In contrast, in AML and following cytogenetic progression other bands were deleted more often than 5q31. This difference, together with a different female preponderance suggests diverse pathogenetic mechanisms in MDS and AML. Furthermore, the bands 5q13-5q21 were found to be of importance for clinical progression from RA to RAEB, and 5q22-5q33 of importance for development of AML and cytogenetic progression. In conclusion, the 5q bands deleted affect both clinical and cytogenetic progression.

Assessment of the allergic reaction in seasonal rhinitis: acoustic rhinometry is a sensitive and objective method

BACKGROUND

Seasonal allergic rhinitis constitutes an excellent in vivo model of an allergic mucosal inflammatory reaction. This offers the opportunity of studying the fundamentals of allergic inflammation in addition to improvement of knowledge on the basal pathophysiological mechanisms of the disease. So far, monitoring methods of disease activity and treatment efficacy have mainly been based upon subjective assessments, illustrating the impact of introducing reliable objective methods.

OBJECTIVE

To investigate the allergic inflammatory reaction of seasonal rhinitis through different objective methods and evaluate these as indicators of disease activity and treatment efficacy.

METHODS

Functional parameters, i.e. acoustic rhinometry and nasal metacholine challenge, and biological markers, i.e. blood eosinophil count, eosinophil cationic protein in serum (s-ECP) and nasal lavage fluid (n-ECP), were assessed before and at peak pollen season in 27 patients with grass pollen induced rhinitis. Patients were randomized to either nasal corticosteroid or placebo treatment and recorded nasal symptom scores.

RESULTS

Acoustic rhinometry revealed a significant difference in favour of steroid treatment (P < 0.05) comparing nasal volumes before and during season. This difference primarily relied upon a decrease in the placebo group (P = 0.05). A reduction from baseline of s-ECP in the steroid group (P < 0.01) was obtained. N-ECP demonstrated a difference between treatment groups, although not significant. Symptom scores increased in all patients during the pollen season, although this was only significant in the placebo treated patients (P < 0.01). The remaining methods applied did not demonstrate further differences, either within or between treatment groups.

CONCLUSION

Our results demonstrate acoustic rhinometry to be a sensitive and objective method of assessment of nasal obstruction. Furthermore, acoustic rhinometry and s-ECP reflect the impact of nasal steroid therapy on seasonal allergic rhinitis.

WHO-sponsored international collaborative study to evaluate methods for subtyping Listeria monocytogenes: restriction fragment length polymorphism (RFLP) analysis using ribotyping and Southern hybridization with two probes derived from L. monocytogenes chromosome

Seven laboratories participated in a WHO-sponsored international collaborative study, to evaluate methods for subtyping Listeria monocytogenes, by performing restriction fragment length polymorph sm (RFLP) analysis-based subtyping of an international study set of 80 strains of L. monocytogenes that included 22 epidemiologically related groups. The RFLP analysis was done by Southern hybridization with one of two types of probes found in multiple copies on the chromosome of L. monocytogenes. Six laboratories performed ribotyping. These laboratories used EcoRI enzyme to restrict the L. monocytogenes DNA and ribosomal RNA or DNA as the probe for Southern hybridizations. The seventh laboratory used Ncil to restrict the DNA, and two probes, one randomly cloned and the other containing repeat sequences cloned from L. monocytogenes DNA. The overall discriminating power of ribotyping, as estimated by calculation of Simpson's index of diversity, ranged from 0.83 to 0.88 for the six laboratories. The discriminating power of the combination of two probes used by Laboratory 7 was 0.91. Ribotyping and the cloned probes used by Laboratory 7 discriminated poorly between serotype 4b strains. Neither method identified three atypical strains (identified by other subtyping methods) included in three apparently epidemiologically related groups. Ribotyping did not discriminate between strains of serotypes 4b and 4b(X) in one epidemiologically related group of strains; one cloned probe used by Laboratory 7 discriminated between these strains. Intra-laboratory reproducibilities for the seven laboratories ranged from 80.0 to 100%. as determined by their abilities to correctly identify 11 pairs of duplicate strains included in the study set. Inter-laboratory reproducibilities were generally very good considering that no attempt was made to standardize protocols used by the participants.

Controlled trial of lamotrigine (Lamictal) for treatment-resistant partial seizures

The antiepileptic effect of lamotrigine (Lamictal) was assessed in a double-blind, placebo-controlled, crossover trial in 56 adult patients with refractory partial seizures. Lamotrigine or placebo was added to the patients' existing antiepileptic drugs (AEDs). The dose of lamotrigine varied from 75 to 400 mg daily. Thirty-eight patients completed the trial and 7 withdrew because of adverse experiences. There was a statistically significant reduction in seizure counts on lamotrigine compared with placebo for total seizures (30.3% reduction, 95% CI 8.4%, 47.0%), complex partial seizures (29.2% reduction, 95% CI 3.8%, 47.9%) and secondary generalised seizures (37.9%, CI 18.9%, 52.4%). The analysis of total seizure days showed a similar significant reduction during lamotrigine treatment for the same seizure categories. There was no statistically significant difference in reporting of adverse events between lamotrigine and placebo except for dizziness which was reported more frequently on lamotrigine than on placebo. There were no differences in abnormal haematological or biochemical findings between lamotrigine and placebo, and lamotrigine had no effect on plasma concentrations of concomitant AEDs.

[MR-scanning in complex partial epilepsy]

In a prospective investigation concerning 50 consecutive patients suffering from complex partial epilepsy who all had a normal CT investigation pathological findings were recognized in 80% using MRI. The MRI examination included volume estimation of the hippocampus. The volume estimations were compared to a reference material. In 24% a focal pathology was recognized, that was suspected of being responsible for the epileptic condition. Only 20% of the examinations were evaluated as normal. Hippocampal atrophy was recognized in 50%. In the latter group a diagnosis of hippocampal sclerosis was established in 16%. It is concluded that MRI is the investigation of choice in complex partial epilepsy and that volume estimation of the hippocampus is important.

The effect of iron chelation on haemopoiesis in MDS patients with transfusional iron overload

Long-term follow-up data are presented on changes in peripheral blood counts and Hb requirements of 11 patients with myelodysplastic syndromes (MDS) during iron chelation treatment with desferrioxamine for up to 60 months. The erythroid marrow activity was indirectly evaluated by repeated determinations of the serum transferrin receptor concentration. The efficacy of iron chelation was evaluated by repeated quantitative determination of the liver iron concentration by magnetic resonance imaging. Reduction in the Hb requirement ( > or = 50%) was seen in 7/11 (64%) patients. Five patients (46%) became blood transfusion independent. Platelet counts increased in 7/11 (64%) patients and the neutrophil counts in 7/9 (78%) evaluable patients. All patients in whom iron chelation was highly effective showed improvement of erythropoietic output accompanied by an increase in the serum transferrin receptor concentration. It is concluded that reduction in cytopenia in MDS patients may be accomplished by treatment with desferrioxamine, if the iron chelation is efficient and the patients are treated for a sufficiently long period of time. Exactly how treatment with desferrioxamine works remains a challenge for further investigation.

Relation of blast cell survival and proliferation to chemotherapy resistance in AML

We have investigated the in vitro blast cell survival (viability) and drug resistance to cytosine arabinoside (Ara-C), daunorubicin (Dau), mitoxantrone (Mitox) and aclarubicin (Acla) of fresh leukaemic blast cells from 80 patients with newly diagnosed acute myeloid leukaemia (AML) employing the semiautomated colourimetric MTT(3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide)-assay. In 15 cases we concurrently investigated the relation between in vitro blast cell survival (MTT assay) and blast cell proliferation (3H-thymidine incorporation) in the presence and absence of myeloid growth factors (GFs) G-CSF, GM-CSF and IL-3 (individually and in combination). A highly significant correlation was found between blast cell survival and blast cell proliferation (r = 0.87, P < 1 x 10(-4). Furthermore, in 40 evaluable adult patients who completed intravenous induction chemotherapy and were evaluable for response to chemotherapy we found a positive correlation between in vitro blast survival (MTT assay) and response to chemotherapy with high blast survival being associated with poor response to chemotherapy (P = 0.05). Moreover, in a multivariate analysis, high blast cell survival was significantly associated with high CD13 expression and monocytic phenotype (P = 0.0003 and P = 0.02, respectively). Furthermore, we found an inverse relationship between the baseline proliferation of the blasts and the magnitude of response to the GFs (P < 0.02), indicating that cells with low baseline proliferation were more readily stimulated by growth factors. Finally, we found a significant correlation between leukaemic cell survival and cellular drug resistance towards Dau (P = 0.001) and Mitox (P = 0.03), but not towards Ara-C (P = 0.68) and Acla (P = 0.13). We conclude that high in vitro leukaemic cell survival is associated with drug resistance in vivo and in vitro, and furthermore is correlated with high blast cell proliferation and some adverse prognostic factors previously identified in AML.

Eosinophil and neutrophil activity in asthma in a one-year trial with inhaled budesonide. The impact of smoking

The object of this investigation was to study the long-term effects of antiasthma treatment on blood markers of inflammation and lung function in adult asthmatic subjects. For this purpose 85 allergic and nonallergic asthmatic subjects were randomized into three groups, which were given high-dose (1,600 micrograms/d) inhaled budesonide, low-dose (400 micrograms/d) inhaled budesonide, and oral theophylline (600 mg/d), respectively, and were followed for 11 mo with testing of lung function and blood sampling for the assay in serum of eosinophil cationic protein (ECP), eosinophil protein x/eosinophil derived neurotoxin (EPX/EDN) as eosinophil markers, and myeloperoxidase (MPO) and lactoferrin (LF) as neutrophil markers. Lung functions (FEV1% predicted, and histamine PC20) and the eosinophil markers ECP and EPX/EDN were improved and reduced, respectively, by budesonide in a dose-dependent and temporally parallel fashion. Theophylline did not alter lung functions but reduced ECP and EPX/EDN after prolonged treatment. The treatment efficacy of budesonide was attributed solely to an effect on nonsmoking asthmatic subjects, since neither lung functions nor eosinophil markers changed in smokers even with high-dose budesonide. MPO but not LF was reduced after several months of treatment in all three groups, but only in nonsmokers. We conclude that ECP and EPX/EDN may be used to monitor antiinflammatory treatment in asthmatic patients, and that smoking asthmatic subjects are resistant to inhaled corticosteroids.

Pig farmers have signs of bronchial inflammation and increased numbers of lymphocytes and neutrophils in BAL fluid

The purpose of this study was to investigate whether pig farmers had inflammation of the bronchial mucosa and activation of bronchoalveolar lavage (BAL) cells. Pig farmers are exposed to high dust levels and have a prevalence of work-related respiratory symptoms. Bronchoscopy and BAL were performed in 27 young large-scale pig farmers, who had never smoked. Fifty three lifetime nonsmoking healthy students participated as controls. All farmers and controls had normal lung function (forced expiratory volume in one second (FEV1) 109 and 105% predicted respectively. Estimation of macroscopic signs of inflammation in the bronchi (erythema, oedema, secretion and friability) showed that pig farmers had significantly increased signs of inflammation. The median score was 3 (range 0-6) compared to a median score of 0 (range 0-3) in controls. More pig farmers than controls (41 versus 25%) had a positive histamine challenge (provocative dose producing a 20% fall in FEV1 (PC20) < or = 32 mg.mL-1) but the difference was not significant. The cell concentration in BAL fluid was identical in the two groups. Pig farmers had a significantly increased percentage of lymphocytes (median 7, range 1-27 versus median 2, range 0-7) and neutrophils (median 2, range 0-30 versus median 1, range 0-4) compared to controls. Spontaneous migration (19.8 versus 5.5 microns) and chemotaxis (62.6 versus 11.2 microns) was significantly increased in pig farmers compared to controls. After stimulation with zymosan and phorbol myristrate acetate (PMA), the reactive oxygen radical generation of purified alveolar macrophages was also significantly increased in pig farmers. Lifetime nonsmoking pig farmers with normal lung function have macroscopic signs of bronchial inflammation and an increased number of neutrophils in bronchoalveolar lavage. Their alveolar macrophages showed biological signs of activation. The inflammation of pig farmers bronchi may be early signs of bronchitis.