Abstract
While incresed levels of circulating antibody to various microorganisms have been reported in sarcoidosis patients, the pathogenesis of the disease is still unknown. In this report, the levels of antibody activities against Propionibacterium acnes (P. acnes) were measured in bronchoalveolar lavage fluid (BALF) in patients with sarcoidosis, using an enzyme-linked immunosorbent assay method.
Each immunoglobulin class of antibody activity to P. acnes was corrected by albumin concentrations in BALF. The levels of whole immunoglobulin antibody activities to P. acnes in BALF were as follows: 412.3±443.9 O. D./albumin 1mg (M±SD) in 31 untreated sarcoidosis patients, 556.6±341.8 in 10 sarcoidosis patients treated with prednisolone, and 231.5±156.8 in 16 control individuals. The levels of antibody activities were significantly elevated in untreated patients (p<0.05) and in treated patients (p<0.02) compared to those of controls. However, considering the treated vs. untreated patients, there was no significant difference in levels.
The serum levels of whole immunoglobulin antibody activities were 0.484±0.191 O. D. in 38 untreated patients, 0.410±0.166 in 13 treated patients and 0.571±0.254 in 52 controls. The levels of antibody activity were significantly lower in treated patients than in the controls (p<0.05). However, there was no significant difference between the untreated patients and controls.
To assess the site of antibody production, the secretion ratio was calculated by dividing the levels in BALF to those in serum. For this purpose, each serum level of antibody activity was also corrected by serum albumin concentration as with BALF. In 29 sarcoidosis patients, the BALF to serum levels of whole immunoglobulin antibody activities, IgG-, IgA-, IgM-class, were 431.9±295.7 to 97.8±42.5 O. D./albumin 1mg, 732.2±504.8 to 133.4±49.5, 486.2±409.5 to 62.7±10.1 and 202.9±140.2 to 72.3±14.0, respectively. As a result, the ratio of whole immunoglobulin activity, IgG-, IgA-, IgM-class, was 4.7±2.9, 5.7±3.7, 7.7±5.9, and 2.±2.0, respectively. The level of anti-P. acnes antibody activities in BALF was higher than that in serum of sarcoidosis patients.
Our data indicate that P. acnes could play a significant role in the pulmonary immunity of sarcoidosis patietns.
