Serum adenosine deaminase and cytidine deaminase activities in patients with systemic lupus erythematosus

Diagnostic value of total testosterone and free androgen index measured by LC-MS/MS for PCOS and insulin resistance

BACKGROUND

The objective of the study was to explore the clinical significance of steroid hormones in the diagnosis of PCOS and PCOS-related insulin resistance through liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and chemiluminescent immunoassay (CLIA).

METHODS

The study included 114 patients with PCOS and 100 controls. Steroid hormone levels in serum were measured using LC-MS/MS and CLIA. The Bland-Altman method was used to check the consistency between the two methods. The diagnostic value of the LC-MS/MS method for female hyperandrogenemia and PCOS was evaluated.

RESULTS

Women with PCOS were younger than controls on average (p < 0.001). PCOS patients had higher luteal hormone (LH, p < 0.001), insulin (p = 0.002), estradiol (E2, p < 0.001), total testosterone (TT, p < 0.001), free androgen index (FAI, p = 0.021), dehydroepiandrosterone sulfate (DHEA, p = 0.021), insulin resistance index (HOMA-IR) (p = 0.034), and fasting glucose (p = 0.017) levels than controls as measured by CLIA. The diagnostic value of TT was the best, and the area under the AUC curve was 0.766. Women with PCOS had higher androstenedione (A2, p < 0.001), FAI (p < 0.001), TT (p < 0.001), and 17-hydroxyprogesterone (17-OHP, p < 0.001) levels than controls as measured by LC-MS/MS. The ROC curve showed that the diagnostic efficacy of A2, TT, and 17-OHP was 0.830, 0.851, and 0.714, respectively. The consistency of TT detected by LC-MS/MS and CLIA was poor according to the Bland-Altman method. Detected TT by LC-MS/MS had the highest diagnostic efficiency for PCOS. The diagnostic power of the LC-MS/MS results for PCOS-related insulin resistance was analyzed. The results showed that the FAI had the highest diagnostic power, with an ROC curve of 0.798.

CONCLUSION

LC-MS/MS is more sensitive and accurate than CLIA in the determination of serum TT and FAI. TT is more effective for the diagnosis of PCOS, whereas FAI is more valuable in the diagnosis of insulin resistance.

The roles of adenosine deaminase in autoimmune diseases

Autoimmune diseases patients are characterized by the autoimmune disorders, whose immune system can't distinguish between auto- and foreign- antigens. Thus, Immune homeostasis disorder is the key factor for autoimmune diseases development. Adenosine deaminase (ADA) is the degrading enzyme for an immunosuppressive signal - adenosine, and play an important role in immune homeostasis regulation. Increasing evidences have shown that ADA is involved in various autoimmune diseases. ADA activity were changed in multiple autoimmune diseases patients and could be served as a biomarker for clinical diagnosis. In this study, we analyze the change of ADA activity in patients with autoimmune diseases, and we underline its potential diagnostic value for autoimmune diseases patients.

Serum adenosine deaminase activity and coronary artery disease: a retrospective case-control study based on 9929 participants

Background:

Adenosine deaminase (ADA) regulates purine metabolism through the conversion of adenosine to uric acid (UA). Adenosine and UA are closely associated with cardiovascular events, but the correlation between serum ADA activity and coronary artery disease (CAD) has not been defined.

Methods:

We performed a hospital-based retrospective case-control study that included a total of 5212 patients with CAD and 4717 sex- and age-matched controls. The serum activity of ADA was determined by peroxidase assays in an automatic biochemistry analyzer.

Results:

Serum ADA activity in the CAD group (10.08 ± 3.57 U/l) was significantly lower than that of the control group (11.71 ± 4.20 U/l, p < 0.001). After adjusting for conventional factors, serum ADA activity negatively correlated with the presence of CAD (odds ratio = 0.852, 95% confidence interval: 0.839–0.865, p < 0.001). Among the patients with CAD, serum ADA activity was lowest in patients with myocardial infarction (MI; 9.77 ± 3.80 U/l). Diabetes mellitus and hypertension increased the serum ADA activity in CAD patients.

Conclusions:

Serum ADA activity is significantly attenuated in patients with CAD, particularly in MI. We propose a mechanism by which the body maintains adenosine levels to protect the cardiovascular system in the event of CAD.

The Emerging Role of Cytidine Deaminase in Human Diseases: A New Opportunity for Therapy?

The recycling activity of cytidine deaminase (CDA) within the pyrimidine salvage pathway is essential to DNA and RNA synthesis. As such, CDA deficiency can lead to replicative stress, notably in Bloom syndrome. Alternatively, CDA also can deaminate cytidine and deoxycytidine analog-based therapies, such as gemcitabine. Thus, CDA overexpression is often associated with lower systemic, chemotherapy-related, adverse effects but also with resistance to treatment. Considering the increasing interest of CDA in cancer chemoresistance, the aims of this review are to describe CDA structure, regulation of expression, and activity, and to report the therapeutic strategies based on CDA expression that recently emerged for tumor treatment.

Serum adenosine deaminase activity in patients with systemic lupus erythematosus: a study based on ADA1 and ADA2 isoenzymes pattern

Adenosine deaminase (ADA) plays a crucial role in the development and maintenance of normal immune system. So, any immunological imbalances could associate with its altered activity in serum. This study evaluated the activity of total ADA and its isoenzymes in serum of 45 patients with systemic lupus erythematosus (SLE). Included were 23 patients with active SLE, 22 during the inactive phase of the disease, and 45 healthy subjects. Our results provided evidence that the significantly elevated total ADA activity in serum of SLE patients is correlated mainly with the increased ADA2 level. The highest mean ADA2 activity during the relapse phase of the disease could be an indication to the macrophages, the main source of ADA2. It might be concluded that ADA and its isoenzymes analysis in serum of patients could be used as a useful and non-invasive diagnostic tool in evaluation of SLE active phase and the disease severity.

Adenosine deaminase in patients with primary immunodeficiency syndromes: the analysis of serum ADA1 and ADA2 activities

OBJECTIVES

We aimed to investigate the activity of ADA and its isoenzymes in serum of patients with various primary immunodeficiency (PID) syndromes.

DESIGN AND METHODS

Total ADA (tADA) and its isoenzymes were measured in 76 children with PID syndromes and 30 healthy controls using the Ellis method.

RESULTS

Our results indicated that tADA and ADA2 levels were higher in patients with Chronic Granulomatous Disease (CGD), Leukocyte Adhesion Deficiency (LAD), hyper IgM (HIM) and Wiskott-Aldrich Syndrome (WAS) than those of corresponding controls (P<0.01). There was a significant elevation of tADA and ADA1 activities in IgA deficiency patients as compared to healthy individuals (P<0.01).

CONCLUSIONS

Our results hypothesized that altered ADA activity may be associated with altered immunity. Therefore, serum ADA level could be used as an indicator along with other parameters in follow up of patients with CGD, LAD, IgA deficiency, HIM and WAS.

Adenosine deaminase activity in the serum and malignant tumors of breast cancer: the assessment of isoenzyme ADA1 and ADA2 activities

OBJECTIVE

The potential relationship between adenosine deaminase activity and cancer progression was examined by investigating the activity of total ADA and its isoenzymes in serum and simultaneously in the cancerous tissue of each patient with breast cancer.

METHODS

Total ADA and its isoenzymes were measured using the Giusti method. ADA2 activity was measured in the presence of a specific ADA1 inhibitor, EHNA.

RESULTS

Our results indicated that ADA2 and total ADA activities were higher in serum and malignant tissues than those of corresponding controls (P < 0.05). Tumor ADA2 and total ADA activities were significantly (P < 0.05) correlated with lymph node involvement, histological grade and tumor size, whereas their levels in serum were significantly (P < 0.05) correlated with menopausal status and patient age.

CONCLUSION

Although serum and tumor total ADA activity and its ADA2 isoenzyme were both found to be increased, distinct correlation patterns were observed with some of the prognostic factors. It can be speculated that increased ADA and isoenzyme activities in serum originated from sources other than the breast tumors.

Effect of melatonin on lipid peroxidation, glutathione and glutathione-dependent enzyme activities in experimental otitis media with effusion in guinea pigs

Melatonin plays a role in the prevention of oxidative damage. In the present study, we investigated whether the increased oxidative stress in experimental otitis media with effusion (OME) induced by histamine is reflected in erythrocytes and middle ear effusion fluid. Lipid peroxidation in effusion fluid was measured to determine the effects of melatonin on oxidative stress. Erythrocyte and middle ear effusion malondialdehyde (MDA) levels, erythrocyte glutathione (GSH) levels and glutathione peroxidase (GPx), glutathione reductase (GRd) and glutathione-S-transferase (GST) activities were measured in three groups of six guinea pigs each at 3 hr after the injection of 0.1 mL of histamine (or saline) into the middle ear. In erythrocyte and middle ear effusion samples, MDA levels showed a significant increase in guinea pigs with experimental OME group when compared with the control animals. Erythrocyte GPx, GST, GRd activities and GSH levels significantly reduced in experimental OME guinea pigs when compared with the control and melatonin-treated animals. Erythrocyte GPx activity also significantly increased after melatonin treatment when compared with the control group. These findings suggest that reactive oxygen species play a role in histamine-induced OME. Pretreatment with melatonin increases antioxidant enzyme activities and reduced formation of MDA, an indicator of lipid peroxidation, in histamine-induced OME.

Plasma purine nucleoside phosphorylase in cancer patients

BACKGROUND

Purine nucleoside phosphorylase (PNP) is the purine salvage enzyme that converts guanosine to guanine and inosine to hypoxanthine.

METHODS

279 samples from patients with differing cancers were collected during treatment at both pre- and post-dose stages for plasma PNP activity and compared with a normal population.

RESULTS

Normal plasma PNP activity was found to be 3.2+/-1.4 U/l (n=55) as compared with the cancer patients (pre-dose 12.3+/-7.4 U/l [n=215] and post-dose 11.2+/-5.9 U/l [n=64]). Levels of plasma PNP did not differ greatly between the different cancer types but were on average four times greater than that found in the reference population.