High pleural fluid hyaluronan concentrations in rheumatoid arthritis.

Previous studies have shown that high pleural fluid (Pf) hyaluronan (HYA) concentrations may be due not only to malignant mesothelioma but also to inflammatory diseases. The objective of this study was to evaluate Pf-HYA in various nonmalignant inflammatory pleural disorders. A radiometric assay was used to determine HYA in Pf and serum (S) of 126 patients, 12 of whom had rheumatoid arthritis (RA), 22 tuberculosis, 22 pneumonia, 41 lung cancer, 10 malignant mesothelioma and 19 congestive heart failure. Pf-HYA values were correlated with values for Pf-tumour necrosis factor (TNF)-alpha and Pf-interleukin (IL)-1beta, as determined by radioimmunoassay. The highest median Pf-HYA (125.6 mg x L(-1), range 0.04-386.5 mg x L(-1)) occurred in patients with malignant mesothelioma. Among patients with nonmalignant inflammatory diseases, significantly higher median Pf-HYA were observed in those with rheumatoid arthritis (64.2 mg x L(-1), range 25.8-106.9 mg x L(-1)) than in those with tuberculosis (25.5 mg x L(-1), range 14.9-57.1 mg x L(-1), p<0.0005) or pneumonia (20.9 mg x L(-1), range 9.5-129.4 mg x L(-1), p<0.005). There was no correlation between Pf-HYA and S-HYA. Pf-HYA correlated positively with Pf-TNF-alpha (r=0.62) and Pf-IL-1beta (r=0.52). High pleural fluid hyaluronan occurs not only in malignant mesothelioma, but also in certain nonmalignant inflammatory diseases, especially rheumatoid arthritis. One explanation for the increase in pleural fluid hyaluronan may be local production of proinflammatory cytokines, such as tumour necrosis factor-alpha and interleukin-1beta.

Neurone-specific enolase levels in pleural effusions in patients with rheumatoid arthritis.

BACKGROUND: High pleural fluid levels of neurone-specific enolase (NSE) have been reported, not only in patients with small cell lung cancer but also in those with chronic inflammatory diseases. METHODS: NSE concentrations were determined in pleural fluid and serum from 342 patients with pleural effusions including 17 with rheumatoid arthritis. RESULTS: The median NSE concentration in pleural fluid was higher in rheumatoid effusions than in any other condition studied. The median pleural fluid:serum NSE ratio was highest in patients with rheumatoid arthritis (11.6) and about unity in all other diseases including small cell lung cancer (0.9). In patients with rheumatoid arthritis pleural fluid concentrations of NSE correlated inversely with pleural fluid glucose concentrations and the pH of the pleural fluid. CONCLUSIONS: A high pleural fluid:serum NSE ratio was found consistently in pleural effusions from patients with rheumatoid disease.

Testing of methicillin resistance by in vitro susceptibility and the presence of the mecA gene in clinical Staphylococcus aureus isolates in Finland.

A total of 140 epidemiologically unrelated Staphylococcus aureus strains collected in Finland between 1983 and 1994 were sent to the reference laboratory with verified or suspected methicillin resistance. These strains and 37 S. aureus strains previously identified as methicillin-susceptible were retested using 5 different susceptibility test methods including agar screening, disc diffusion, growth around methicillin (25 micrograms) test strips and minimal inhibitory concentration (MIC) determinations by an agar dilution method and E-test. The isolates were also analyzed for the presence of the mecA gene by the polymerase chain reaction (PCR). Based on in vitro susceptibility, 69 strains were identified as methicillin-resistant and were positive for the mecA gene in PCR, while 84 strains were methicillin-susceptible and negative for this gene. Susceptibility testing gave conflicting results for 24 (14%) strains. When the tests were repeated in triplicate for each isolate, discrepant results were still achieved with 18 of the 24 strains in at least 2 different tests. Thus, based on in vitro susceptibility, these strains could not be definitely classified as resistant or susceptible to methicillin. Yet 7 of them were positive for the mecA gene as an indication of genetic resistance to methicillin. Corroborating earlier studies, these results illustrate the difficulty of detecting methicillin resistance/susceptibility based only on susceptibility testing and underscore the importance of confirming methicillin resistance in S. aureus in specialized laboratories.

Pleural fluid soluble interleukin 2 receptor in rheumatoid arthritis and systemic lupus erythematosus.

OBJECTIVE: To study local cellular immune reactions in the pleural fluid of patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). METHODS: Using an immunoenzymometric assay, the concentration of soluble interleukin 2 receptor (sIL-2R) was measured in the pleural fluid of 13 patients with RA, 6 patients with SLE and 72 patients with pleural effusions of other etiologies, including tuberculosis, cancer, pneumonia and congestive heart failure. RESULTS: The mean pleural fluid sIL-2R concentration was significantly higher in patients with RA (593 pM, range 252-1558) than in patients with SLE (145 pM, range 94-236; p < 0.005), cancer (224 pM, range 98-521, p < 0.01), pneumonia (177 pM, range 60-343, p < 0.005) and congestive heart failure (139 pM, range 56-228, p < 0.005), but as high in patients with tuberculous pleurisy (mean 390 pM, range 151-512). The highest mean pleural fluid to serum sIL-2R ratios were observed in patients with RA and with tuberculosis. CONCLUSION: Measurement of sIL-2R in pleural fluid is useful for the differentiation of pleural effusions in RA from those occurring in SLE. High levels of sIL-2R associated with a local T cell mediated immune reaction may serve an immunoregulatory purpose in rheumatoid pleurisy.

Increased PMA-induced chemiluminescence from whole blood of patients with bronchial hyperreactivity.

Blood phagocytes from patients with asthma have an increased capacity to produce reactive oxygen metabolites. We studied whether whole blood luminol-dependent chemiluminescence could detect this phenomenon in patients with a normal spirometry but bronchial hyperreactivity as determined with a methacholine bronchial challenge test. Whole blood chemiluminescence, serum eosinophilic cationic protein (ECP), and serum myeloperoxidase (MPO) were determined from 50 patients referred for a methacholine challenge due to prolonged cough and/or dyspnoea. The chemiluminescence results were compared to those from 15 healthy persons. The hyperreactive patients (n = 18) had significantly higher phorbol 12-myristate 13-acetate (PMA)-induced whole blood chemiluminescence values (mean 18.8 mV.min-1; 95% confidence limits (C.L.) 16.3-21.3 mV.min-1) than the normoreactive patients (mean 14.2 mV.min-1; 95% C.L. 13.0-15.5 mV.min-1;) and the healthy controls (mean 12.8 mV.min-1; 95% C.L. 11.7-13.9 mV.min-1). There was no significant difference in PMA-induced chemiluminescence between the normoreactive patients and the controls. The hyperreactive patients had higher serum ECP values than the normoreactive patients, but there was no correlation between whole blood chemiluminescence and serum ECP levels or total eosinophil count. There was no significant difference in monocyte reactive oxygen metabolite production or serum MPO values between the normoreactive and the hyperreactive patients. We suggest that the increased PMA-induced whole blood chemiluminescence in bronchial hyperreactivity is due mainly to an activation of neutrophils, and that the assay might be useful as a systemic inflammatory marker in patients with pulmonary inflammatory processes resulting in bronchial hyperreactivity.

Individualized dietary counselling of families: serum cholesterol concentration and growth of children aged 7-13 months.

We studied the effect of a change in dietary fat composition on serum total and high-density lipoprotein cholesterol and growth in healthy infants between 7 and 13 months of age. The intervention families (n = 22) received individualized dietary counselling when the infant was 7, 8 and 10 months of age. The intervention diet was designed to have a fat content of 35-45 E% of total energy intake in infants aged 7-12 months and 30-35 E% after 12 months of age. The ratio of saturated to monounsaturated to polyunsaturated fatty acids was designed to be 1:1:1. The children in the control group (n = 23) were given no specific advice on the fat composition of the diet. Intake of polyunsaturated fatty acids was significantly higher in the intervention group than in the controls (5.9 E% versus 3.6 E%, p < 0.05). Serum total cholesterol concentration decreased significantly in the intervention group during the study from 4.16 +/- 0.41 mmol/l to 3.86 +/- 0.48 mmol/l (p < 0.05). The infants of both groups grew like average Finnish children. Modification of dietary fat composition, as widely recommended for adults and older children to prevent coronary heart disease, decreases cholesterol values in infants without affecting their normal growth.

A synergistic interaction between Bacillus Calmette-Guérin (BCG) and NADPH oxidase stimulants on the production of reactive oxygen metabolites by human mononuclear phagocytes.

Bacillus Calmette-Guérin (BCG) was added simultaneously with known NADPH oxidase stimulants to suspensions of human mononuclear leukocytes, and the subsequent production of reactive oxygen metabolites (ROMs) was studied by luminol-dependent chemiluminescence. BCG significantly amplified the ROM responses induced by zymosan, phorbol myristate acetate (PMA), and quartz, but not by concanavalin A and asbestos fibers. The stimulatory effect occurred rapidly when BCG was added to cells already phagocytosing zymosan, and vanished rapidly when extracellular BCG was removed from adherent monocyte cultures by washing prior to the addition of zymosan. The stimulatory effect of BCG could not be reproduced with recombinant interferon-gamma, tuberculin PPD, muramyl dipeptide, nor with the apathogenic Mycobacterium tuberculosis strain RV37. BCG and zymosan or PMA that had been incubated together prior to addition to the mononuclear cell suspensions caused ROM production with faster kinetics than if the reagents were added separately without preincubation. In conclusion, the synergy between BCG and some of the NADPH oxidase stimulants seems to be due to an interaction between BCG and the NADPH oxidase stimulants rather than to an interaction between BCG and the ROM-producing cells. Such interactions between mycobacteria and NADPH oxidase stimulants may be of importance as a factor affecting the individual susceptibility to tissue damage in tuberculosis, for example in silicotuberculosis.

Two new two-step immunoassays for free thyroxin evaluated: solid-phase radioimmunoassay and time-resolved fluoroimmunoassay.

We measured concentrations of free thyroxin (FT4) in serum by using two new two-step FT4 assays--a solid-phase two-step radioimmunoassay. Spectria, and a time-resolved fluoroimmunoassay. Delfia--and compared the results with those by a two-step FT4 assay (RIA-gnost), a one-step FT4 analog assay (Amerlex-M), and FT4 measured after equilibrium dialysis. The new FT4 assays classified 30 hypothyroid and 43 hyperthyroid patients (untreated) well. In 138 patients with nonthyroidal illness (NTI) and in late pregnancy (n = 36), fewer subnormal FT4 values were reported by Spectria (P less than 0.001), Delfia (P less than 0.001), and RIA-gnost (P less than 0.01) than by Amerlex-M. The results of the Spectria and Delfia methods correlated with the results of the dialysis method (r = 0.76) in NTI patients and pregnancy, and were in better agreement with the clinical state than was FT4 by Amerlex-M. The FT4 values by Amerlex-M, but not by other methods, correlated with albumin concentration. We conclude that these new two-step methods present good alternatives for FT4 analysis.

Bacteroides fragilis lipopolysaccharide and group B streptococcus serotype II glycocalyx have a common major antigenic determinant.

A monoclonal antibody (MAB) to the beta-1-6-linked digalactose structure in the lipopolysaccharide (LPS) of Bacteroides fragilis reacted with 47 of 416 group B Streptococcus (GBS) strains tested by an immunofluorescence technique (IF). The reactivity of MAB was, with a few exceptions, limited to type II GBS. Gas chromatography-mass spectrometry analysis demonstrated that an antigen purified by immunoaffinity chromatography using MAB from type II GBS contained galactose, glucose and fatty acids. This confirmed that MAB is directed to the digalactose (which in earlier studies was found to occur) in the capsular lipocarbohydrate specific to type II GBS. The positive strains yielded a strong, apple-green surface stain by means of the IF using MAB. Various immuno-electron microscopic (IEM) methods showed that the determinant was located in the glycocalyx layer of GBS at a distance of about 15 nm from the streptococcal cell wall. The structure harbouring the determinant was found to be very loosely attached to the bacteria. However the cross-reactive determinant seemed to maintain its immunoreactivity whether it was extracted by gentle washing with saline or with harsher treatments usually reserved for preparing streptococcal polysaccharide antigens. In conclusion, the study shows that the determinant is an integral part of the type-specific antigen of type II GBS and that MAB has a potential use as a serotyping reagent.

Detection of Bacteroides fragilis, Bacteroides thetaiotaomicron, and Bacteroides ovatus in clinical specimens by immunofluorescence with a monoclonal antibody to B. fragilis lipopolysaccharide.

A total of 1,897 clinical specimens (1,019 aspirates and 876 swabs) were studied by indirect immunofluorescence (IF) with a mouse monoclonal antibody (MAb) against a D-galactose oligomer of Bacteroides fragilis lipopolysaccharide. The MAb has been shown to react with 96% of clinical B. fragilis isolates and with about 50% of Bacteroides ovatus and Bacteroides thetaiotaomicron isolates but not with other aerobic or anaerobic organisms tested. The sensitivity of IF in comparison with culturing was 78.9% for all three species. Of the 32 strains originating from culture-positive, IF-negative specimens, 13 lacked the target determinant for the MAb. Sensitivity was highest with specimens taken from the perineal area (87.1%) and lowest with those taken from undefined sites (56.6%). Sensitivity was better with aspirates (86.8%) than with swabs (72.6%). The specificity of IF was 95.6% for all of the material. Positive and negative predictive values were 51.1 and 98.0%, respectively. Neither long transportation times of specimens nor antimicrobial therapy seemed to correlate with the occurrence of IF-positive, culture-negative specimens. This study shows that a single MAb can be used to establish an IF assay that can complement isolation in the detection of these three members of the B. fragilis group.

Characterization of the common immunodominant antigenic determinant in the lipopolysaccharide of Bacteroides fragilis by a monoclonal antibody.

The target determinant of a monoclonal antibody (MoAb) to Bacteroides fragilis lipopolysaccharide (LPS) was characterized by inhibition enzyme immunoassay (EIA), immunoblotting (IB), immunofluorescence technique (IF) and electron immunocytochemical (EIC) technique. The MoAb has been shown to react positively with 96% of B. fragilis isolates. LPS preparations from 14 different B. fragilis strains were tested by EIA and IB. Two LPS preparations did not react in any of the tests. In both preparations the D-galactose was either lacking or present in low amount compared with the other LPSs. In addition, inhibition experiments with synthetic disaccharides confirmed that the target determinant is composed of beta-1,6-linked galactose disaccharide. EIC showed that the target of the LPS-MoAb is located on the surface of the outer membrane. These results show that the galactose chain present in LPS isolated from most B. fragilis strains contains the immunodominant antigenic determinant.