ABSTRACT
An ELISA test has been employed for the detection of pneumolysin (PLY) in urine from 14 pneumococcal pneumonia patients and from 11 healthy adult volunteers. The urines of all the 11 healthy adult volunteers developed signals around the mean of the blanks, whereas all the pneumococcal pneumonia patient urines rendered signals at least five times this mean. Chemiluminescent Western blot analyses of these urines, carried out with the PLY-specific rabbit polyclonal IgG preparation used in ELISA, were negative. The 30-kDa filtrates of three high-signal urines were ELISA negative, suggesting that this ELISA test mainly detected high molecular weight forms in urine rather than free PLY-derived antigenic fragments. The urine sample, which rendered the highest ELISA signal, was then concentrated by filtration through a 10-kDa filter. When this concentrate was subjected to Western blot with the ELISA-capture monoclonal antibody, a major band was developed. Its relative molecular mass was similar to that of recombinant PLY and its peptide mass fingerprinting showed peptides corresponding to amino acid stretches from the four domains of the PLY molecule. When the pool of PLY-negative urines was sham-contaminated with purified recombinant pneumolysin, a conspicuous matrix effect was observed; nevertheless, this ELISA test was still reproducible and highly sensitive, detecting pneumolysin in the order of picograms per milliliter. A comparison was also made between this PLY-ELISA and the Binax NOW Streptococcus pneumoniae Urinary Antigen Test in analysing bacterial isolates. On the basis of the minimum number of pneumococci examined, both tests were shown to have similar potency, but strain-dependent discrepancies were observed. This ELISA could provide an alternative to the Binax NOW Streptococcus pneumoniae Urinary Antigen Test in the diagnosis of pneumococcal pneumonia.
Subject(s)
Antibodies, Bacterial/immunology , Pneumonia, Pneumococcal/urine , Streptococcus pneumoniae/immunology , Streptolysins/urine , Adult , Amino Acid Sequence , Bacterial Proteins , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Humans , Luminescent Measurements , Molecular Sequence Data , Pneumonia, Pneumococcal/microbiology , Recombinant Proteins , Sensitivity and Specificity , Streptolysins/chemistry , Streptolysins/genetics , Streptolysins/immunologyABSTRACT
BACKGROUND: Adenosine deaminase (ADA) is a cytoplasmic enzyme which activity is increased in disorders that stimulate cells involved in the immune system. In community-acquired pneumonia (CAP), increased levels of serum ADA have been associated with the presence of atypical microorganisms as the source of the former. Previous studies have shown ADA increases in non-infectious diseases. We evaluated the factors that may influence plasmatic ADA (ADAp) levels in CAP patients. PATIENTS AND METHODS: A study with cases (245 episodes of CAP) and controls (49) was designed, and the differences in ADAp activity with regard to organisms, comorbidity factors and complications were analyzed. A logistic regression analysis was performed. RESULTS: CAP caused by atypical microorganisms were found to have increased ADAp values. Variables that independently increased ADAp levels were: atypical etiology (OR = 5.9), liver disease (OR = 5.8), diabetes mellitus (OR = 1.9), and prior antibiotic consumption (OR = 1.7). CONCLUSIONS: ADAp is an etiologic marker that could be useful in the empiric approach of the treatment of CAP.
Subject(s)
Adenosine Deaminase/blood , Pneumonia/blood , Pneumonia/microbiology , Aged , Biomarkers/blood , Case-Control Studies , Community-Acquired Infections/blood , Community-Acquired Infections/enzymology , Community-Acquired Infections/microbiology , Female , Humans , Male , Middle Aged , Pneumonia/enzymologyABSTRACT
FUNDAMENTO: La adenosindesaminasa (ADA) es una enzima intracitoplasmática cuya elevación ha sido demostrada tanto en procesos infecciosos que estimulan la inmunidad celular como en otro tipo de enfermedades (diabetes y hepatopatías, entre otras). El objetivo de este estudio es determinar la capacidad del ADA plasmático (ADAp) para predecir el tipo de germen causante en la neumonía adquirida en la comunidad (NAC) y poder guiar el tratamiento antibiótico empírico. PACIENTES Y MÉTODO: Estudio de cohortes (245 casos y 49 controles) para contrastar las diferencias en el valor de ADAp estudiando tanto variables microbiológicas (tipo de germen) como factores de comorbilidad y complicaciones. Se practicó una regresión logística. RESULTADOS: Las NAC causadas por gérmenes atípicos elevan significativamente el valor del ADAp, que se normaliza en la convalecencia. Las variables con capacidad independiente para elevar dicho valor fueron la presencia de germen 'atípico' (odds ratio [OR] = 5,9), hepatopatía (OR = 5,8), diabetes (OR = 1,9) y toma previa de antibióticos (OR = 1,7).CONCLUSIONES: La ADAp puede ser utilizada como marcador etiológico para guiar el tratamiento antibiótico empírico en la NAC, en ausencia de diabetes, hepatopatía y toma de antibióticos previa a la determinación (AU)
Subject(s)
Middle Aged , Aged , Male , Female , Humans , Duodenoscopy , Gastroscopy , Case-Control Studies , Biomarkers , Community-Acquired Infections , Pneumonia , Retrospective Studies , Prognosis , Adenosine Deaminase , Gastrointestinal HemorrhageABSTRACT
FUNDAMENTO: La adenosindesaminasa (ADA) es una enzima intracitoplasmática cuya elevación ha sido demostrada tanto en procesos infecciosos que estimulan la inmunidad celular como en otro tipo de enfermedades (diabetes y hepatopatías, entre otras). El objetivo de este estudio es determinar la capacidad del ADA plasmático (ADAp) para predecir el tipo de germen causante en la neumonía adquirida en la comunidad (NAC) y poder guiar el tratamiento antibiótico empírico. PACIENTES Y MÉTODO: Estudio de cohortes (245 casos y 49 controles) para contrastar las diferencias en el valor de ADAp estudiando tanto variables microbiológicas (tipo de germen) como factores de comorbilidad y complicaciones. Se practicó una regresión logística. RESULTADOS: Las NAC causadas por gérmenes atípicos elevan significativamente el valor del ADAp, que se normaliza en la convalecencia. Las variables con capacidad independiente para elevar dicho valor fueron la presencia de germen 'atípico' (odds ratio [OR] = 5,9), hepatopatía (OR = 5,8), diabetes (OR = 1,9) y toma previa de antibióticos (OR = 1,7). CONCLUSIONES: La ADAp puede ser utilizada como marcador etiológico para guiar el tratamiento antibiótico empírico en la NAC, en ausencia de diabetes, hepatopatía y toma de antibióticos previa a la determinación (AU)
