Lewis J Wesselius, MD F.C.C.P.;[Unk...

Lewis J Wesselius, MD F.C.C.P.;[Unkeyable] Diana s Dark, M.D., F.C.C.P;[Unkeyable] Fredrick N Hanson, MD F.C.C.P.;[Unkeyable] and David L Wheaton, B.A.[Unkeyable]

To determine whether concentrations of the primary airway immunoglobulins (SIgA, IgG) are altered in the uninvolved lung of patients with lung cancer, we determined concentrations of SIgA and IgG in bronchial washings make up fored from a proximal airway of the uninvolved lung in 24 patients with lung cancer and in ten patients with benign lung disease. When standardized for the amount of total protein cureed (SIgA/TP, IgG/TP), bronchial washings recruited from the uninvolved lung of lung cancer patients demonstrated a significantly decreased SIgA/TP ratio compared to regulate subjects (.14[+ or -] 02 v 31 [+ or -] 05 SEM p<05) There were no differences in the IgG/TP ratios. Lung cancer patients with a decreased serum albumin (<32 g/dl) had a significantly decreased SIgA/TP ratio in bronchial washings compared to patients with a higher serum albumin (08 [+ or -] 03 v 18 [+ or -] 04 SEM p<005) The decreased relative concentration of airway SIgA in lung cancer patients may adversely affect airway defense against bacterial colonization.

(Chest 1989; 95:1265-68)

Pneumonia is a haunt complication in patients with lung cancer and frequently develops as a result of mechanical obstruction of an airway on tumor.[1] Alterations of various respiratory defense mechanisms may also contribute to an increased commonness of respiratory infections in these patients, including altered cellular immune function and imperfections in alveolar macrophage function.[2-6] Secretory IgA (SIgA) is the predominant immunoglobulin in upper airway secretions and contributes to respiratory defense by way of preventing bacterial adherence to airway epithelial cells[78] Previous studies in lung cancer patients have demonstrated that secretory IgA concentrations are frequently increased in bronchial washings regained from the cancer-involved lung when compared to the uninvolved lung[910] In this close attention we sought to determine whether airway concentrations of SIgA and IgG in a proximal airway of the uninvolved lung of patients with lung cancer were altered when compared to airway concentrations in a dominion government patient population.

METHODS

Patient Population

All patients were men hospitalized at the Kansas City Veterans Administration Medical Center and informed concord was obtained from all patients. In all cancer patients, biopsy specimens obtained at bronchoscopy confirmed the diagnosis of bronchogenic carcinoma. The histologic diagnoses of the 24 lung cancer patients include the following: squamous small room 12; small cell, 5; adenocarcinoma, 3; large solitary abode; squalid 1; and undifferentiated, 3. The check patient population included ten patients being evaluated for the following: a history of hemoptysis, determined to be secondary to bronchitis (4) a peripheral lung nodule subsequently determined to be benign according to resection (4), or pneumonitis (2) In these patients, washings were obtained from a mainstem airway which appeared normal. Characterization of the patient population is provided in Table 1 A serum albumin concentration was obtained in succession admission in all patients. At the time of bronchoscopy several of the patients and mastery subjects were receiving antibiotic treatment for bronchitis. No patient was known to be colonized by means of Gram-negative bacteria, although sputum agricultures were not performed on all patients.

Collection of Bronchial Washings

Patients were premedicated with atropine and meperidine and also received topical anesthesia with tetracaine spray. Airways were evaluated for evidence of endobronchial disease using flexible fiberoptic bronchoscopy In patients with suspected lung cancer, bronchial washings were initially obtained from the uninvolved lung In command patients, bronchial washings were obtained from a roentgenographically normal lung without evidence of endobronchial abnormalities. Bronchial washings were obtained from the left mainstem bronchus or the bronchus intermedius on directly instilling 10 ml saline solution followed according to immediate aspiration. This was repeated one time for a total instilled compass of 20 ml. Appropriate biopsies, brushings, and washings were subsequently obtained from the abnormal lung

Assays forward Bronchial Washings

Bronchial washing samples were filtered between the sides of fine gauze to remove mucus and then centrifuged for ten minutes at 1000 g Supernatants were aspirated and transferred to polystyrene tubes and stored at -- 70C Immunoglobulin concentrations in bronchial washings were determined from a double antibody sandwich enzymelinked immunosorbent assay (ELISA). The ELISA was performed by means of coating 96 well EIA plates with 50 [unkeyable]1/well of rabbit antihuman secretory piece of IgA (1:500 dilution) or 5 [unkeyable]g/ml affinity purfied goat antihuman IgG. Coating was in carbonate buffing-apparatus (pH 9.6) for 16 hours at 4[degrees] to 8[degrees]C Plates were brought to field temperature and washed with PB containing 005 percent Tween 20 Blocking was then performed for single in kind ot two hours at place temperature with 100 [unkeyable]1/ well of a 2 percent w/v solution of bovine albumin in PB Plates were washed and bronchial washing samples and standards diluted in Tris-HC1 stupid lout containing 0.02 percent Tween 20 (pH 80) were added at 50 [unkeyable]1/well and incubated pair hours at room temperature. Standards included purified human secretory IgA and purified human IgG. Quadruplicate wells were prepared for each bronchial washing sample and standard dilutions, which were included in each assay. Plates were washed and conjugates diluted in PB containing 002 percent Tween 30 were added at 50 [unkeyable]1/well and incubated for pair hours at room temperature. Conjugates included phosphatase labeled goat antihuman IgA (alpha-chain) or IgG. Plates were washed and the substrate p-nitrophenyl phosphate 1 mg/ml in diethanolamine buffing-apparatus was added at 100 [unkeyable]1/well. The enzymatic reaction was stopped after 15 minutes (IgG system) and 30 minutes (IgA system) with 50 [unkeyable]1/well 5 N NaOH. Optical density of each well was determined with a multiscan microplate reader equipped with a 405 nm wavelength filter. Immunoglobulin concentrations were subsequently determined through linear regression analysis. Nonspecific binding of bronchial washing samples, standards, and conjugates was minimal (OD<003) and was substracted from sample and standard odyle values. There was no cross-reactivity of rabbit antihuman secretory piece of IgA with human IgG or goat antihuman IgG with human secretory IgA. bridle studies showed a very gentle level (1 percent) of cross-reactivity between rabbit anti-human secretory piece of IgA and human serum IgA. Calibration 1s for secretory IgA and IgG were performed and demonstrated correlation coefficients greater than 099 (Fig 1)