Adenosine deaminase activity in the aetiological diagnosis of community-acquired pneumonia

Serum adenosine deaminase, catalase and carbonic anhydrase activities in patients with bladder cancer

OBJECTIVES

The relationship between adenosine deaminase and various cancers has been investigated in several studies. However, serum adenosine deaminase activity and carbonic anhydrase and catalase activities in patients with bladder cancer have not previously been reported. Therefore, the aim of this study was to measure serum adenosine deaminase, carbonic anhydrase and catalase activities in patients with bladder cancer.

MATERIALS AND METHODS

Forty patients with bladder cancer and 30 healthy controls were enrolled in the study. Serum adenosine deaminase, carbonic anhydrase and catalase activities were measured spectrophotometrically.

RESULTS

Serum adenosine deaminase, carbonic anhydrase and catalase activities were significantly higher in patients with bladder cancer than controls (all significant, p<0.001).

CONCLUSIONS

These markers might be a potentially important finding as an additional diagnostic biochemical tool for bladder cancer.

Malondialdehyde level and adenosine deaminase activity in adenoid tissue of patients with OME and obstructive adenoid hypertrophy

OBJECTIVE

The aim of our study was to determine and compare adenosine deaminase (ADA) activity and malondialdehyde (MDA) level in adenoid tissue of patients with or without otitis media with effusion (OME).

METHODS

The study included 30 patients undergoing adenoidectomy due to obstructive adenoid hypertrophy (OAH) or OME. Tissue MDA level was measured by the method of Okawa with modification and tissue ADA activity by the method of Giusti. We measured, superoxide dismutase (SOD) and catalase (CAT) activities as well.

RESULTS

In patients with OAH, mean tissue MDA level and ADA activity were 4.13 ± 0.90 nmol/mg Pr and 0.39 ± 0.04 U/mg Pr, respectively, which were significantly higher than those of OME group (1.43 ± 0.41 nmol/mg Protein and 0.22 ± 0.04 U/mg Pr, respectively) (P<0.05). SOD and CAT activities were found to be increased in patients with OAH when compared to the OME group but they did not reach statistically significant level (P=0.06 and 0.05 respectively).

CONCLUSIONS

The present study showed the presence of measurable ADA activity in adenoid tissue, and also significant increases in both tissue MDA level and ADA activity in OAH tissue when compared to adenoid tissue of the patient with OME. However, the significance of changes in MDA and ADA activation in the pathogenesis of OAH requires further study.

High adenosine deaminase activity in the pleural effusion of a patient with Legionnaires' disease

Although Legionnaires' disease (LD) is frequently accompanied by pleural effusion, the characteristics of pleural effusions in LD have not been well studied. Levels of adenosine deaminase (ADA) activity in pleural fluid >40 IU/L have a high sensitivity (81-100%) and specificity (83-100%) for tuberculosis. ADA activity in pleural effusions due to LD has not been previously reported. The case of a patient with LD complicated by a pleural effusion with high ADA activity is reported. In countries where the prevalence of tuberculosis is high and pleural fluid ADA activities are frequently measured, LD should be included in the differential diagnosis of an exudative pleural effusion with high ADA activity.

Malondialdehyde level and adenosine deaminase activity in nasal polyps

OBJECTIVE

Although there are many reports on adenosine deaminase (ADA) activities in different tissues, no information is available about the enzyme activity in nasal mucosa and polyp tissues. Whereas ADA is related to the production of free radicals by neutrophils, malondialdehyde (MDA) is an indicator of lipid peroxidation that is a general mechanism of tissue damage by free radicals. This study is aimed at determining and comparing the ADA activity and MDA level in nasal polyps and normal mucosa.

STUDY DESIGN AND SETTING

Twenty-three patients with nasal polyps and a control group consisting of 14 patients with septal deviation and lower turbinate hypertrophy were included in the study. Tissue MDA level was measured by the method of Okawa with modification and tissue ADA activity by the method of Giusti.

RESULTS

In patients with nasal polyp, mean tissue MDA level and ADA activity were 2.43 +/- 0.38 nmol/mg protein (Pr) and 0.235 +/- 0.055 U/mg Pr, respectively, which were significantly higher than those of control nasal mucosa (1.03 +/- 0.41 nmol/mg protein and 0.056 +/- 0.011 U/mg Pr, respectively) (P < 0.05). In addition, tissue MDA level was positively correlated to ADA activity in nasal polyps (r = 0.701, P < 0.001).

CONCLUSIONS

The present study showed the presence of detectable ADA activity in nasal mucosa, and also significant increases in both tissue MDA level and ADA activity in NP tissue when compared to normal turbinate tissue.

EBM RATING

B-2b.

The activities of serum adenosine deaminase and xanthine oxidase enzymes in Behcet's disease

BACKGROUND

Adenosine deaminase (AD) and xanthine oxidase (XO) are enzymes of purine catabolism that catalyze the conversion of adenosine to inosine, deoxyadenosine to deoxyinosine, hypoxanthine to xanthine and xanthine to uric acid, respectively. AD is known to be an important enzyme in the maturation and function of T lymphocytes. The aim of this prospective study was to evaluate whether there are changes in serum AD activity as an index of T lymphocyte function in Behcet's disease (BD) which is known as having T cell-mediated immune response.

METHODS

A total of 32 patients and 26 sex- and age-matched healthy control subjects were analysed for AD and XO activities. The patients with BD were divided into two subgroups: BD with and without eye lesions. Twelve patients with complete BD and four patients with incomplete BD had eye complications. AD and XO activities in serum were measured with spectrophotometric methods.

RESULTS

There was a remarkable increase in AD activity and moderate increase in XO in patients with BD compared to controls indicating T cell activation and increased maturation. Serum AD activity of complete BD was higher than that of incomplete BD. There was no difference in XO activity between the subgroups of BD. Significant positive correlation was found between AD and XO in BD, although there was no correlation in control group.

CONCLUSIONS

The results indicate that increased AD and XO activities may provide an additional benefit for the diagnosis of BD and subtyping of the disease as having eye complication or not and complete and incomplete BD. Further studies are needed to bring to light the exact mechanism of AD and XO activity elevation.

[Community-acquired pneumonia: serum adenosine-deaminase activity in the aetiological diagnosis]

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.

Adenosine deaminase: functional implications and different classes of inhibitors

Adenosine deaminase (ADA) is an enzyme of the purine metabolism which catalyzes the irreversible deamination of adenosine and deoxyadenosine to inosine and deoxyinosine, respectively. This ubiquitous enzyme has been found in a wide variety of microorganisms, plants, and invertebrates. In addition, it is present in all mammalian cells that play a central role in the differentiation and maturation of the lymphoid system. However, despite a number of studies performed to date, the physiological role played by ADA in the different tissues is not clear. Inherited ADA deficiency causes severe combined immunodeficiency disease (ADA-SCID), in which both B-cell and T-cell development is impaired. ADA-SCID has been the first disorder to be treated by gene therapy, using polyethylene glycol-modified bovine ADA (PEG-ADA). Conversely, there are several diseases in which the level of ADA is above normal. A number of ADA inhibitors have been designed and synthesized, classified as ground-state and transition-state inhibitors. They may be used to mimic the genetic deficiency of the enzyme, in lymphoproliferative disorders or immunosuppressive therapy (i.e., in graft rejection), to potentiate the effect of antileukemic or antiviral nucleosides, and, together with adenosine kinase, to reduce breakdown of adenosine in inflammation, hypertension, and ischemic injury.