Serum ADA Levels Research Articles

Evaluation of Efficacy of Serum Adenosine Deaminase Values for Detection of Pulmonary and Extra Pulmonary Tuberculosis

Background Tuberculosis is one of the leading cause of morbidity and mortality worldwide and in Nepal. Despite advances in its diagnosis, majority of the cases still go undetected. These account for sputum smear negative and extra pulmonary cases where demonstration of the microorganism is challenging. ADA an enzyme found in all mammalian species is found raised in various effusion body fluids of organs affected by the disease. Time tested studies have also shown that serum values of ADA are elevated in patients affected with the disease thus can aid as supportive evidence in doubtful cases.MethodsAn Analytical cross sectional Hospital Based study involving 110 with 75 cases and 35 healthy participants was conducted in College of Medical Sciences for 5 months from January to June 2024. Serum ADA levels were measured in all participants, diseased and healthy and collected data was analyzed for significance.ResultsThe mean Serum ADA level in TB patients was found to be 47.01 and that of healthy participants was 14.68. Significant difference in the mean serum ADA level between TB and non TB patients (p-value < 0.001) was found concluding that TB patients have high serum ADA level. Comparisons between mean serum ADA levels in Different types of TB found no significant difference among them with all p- values in each pair being more than 0.5 suggesting that serum ADA levels rise in all forms of TB.Conclusions Serum ADA values are raised in all forms of tuberculosis and can serve as a supportive evidence in patients with Smear negative and Extrpulonary TB where microorganisms is difficult to demonstrate. However further validation need to be done by more studies in the future.

Clinical significance of pleural fluid lactate dehydrogenase/adenosine deaminase ratio in the diagnosis of tuberculous pleural effusion

BackgroundPleural fluid is one of the common complications of thoracic diseases, and tuberculous pleural effusion (TPE) is the most common cause of pleural effusion in TB-endemic areas and the most common type of exudative pleural effusion in China. In clinical practice, distinguishing TPE from pleural effusion caused by other reasons remains a relatively challenging issue. The objective of present study was to explore the clinical significance of the pleural fluid lactate dehydrogenase/adenosine deaminase ratio (pfLDH/pfADA) in the diagnosis of TPE.MethodsThe clinical data of 618 patients with pleural effusion were retrospectively collected, and the patients were divided into 3 groups: the TPE group (412 patients), the parapneumonic pleural effusion (PPE) group (106 patients), and the malignant pleural effusion (MPE) group (100 patients). The differences in the ratios of pleural effusion-related and serology-related indicators were compared among the three groups, and receiver operating characteristic curves were drawn to analyze the sensitivity and specificity of the parameter ratios of different indicators for the diagnosis of TPE.ResultsThe median serum ADA level was higher in the TPE group (13 U/L) than in the PPE group (10 U/L, P < 0.01) and MPE group (10 U/L, P < 0.001). The median pfADA level in the TPE group was 41 (32, 52) U/L; it was lowest in the MPE group at 9 (7, 12) U/L and highest in the PPE group at 43 (23, 145) U/L. The pfLDH level in the PPE group was 2542 (1109, 6219) U/L, which was significantly higher than that in the TPE group 449 (293, 664) U/L. In the differential diagnosis between TPE and non-TPE, the AUC of pfLDH/pfADA for diagnosing TPE was the highest at 0.946 (0.925, 0.966), with an optimal cutoff value of 23.20, sensitivity of 93.9%, specificity of 87.0%, and Youden index of 0.809. In the differential diagnosis of TPE and PPE, the AUC of pfLDH/pfADA was the highest at 0.964 (0.939, 0.989), with an optimal cutoff value of 24.32, sensitivity of 94.6%, and specificity of 94.4%; this indicated significantly better diagnostic efficacy than that of the single index of pfLDH. In the differential diagnosis between TPE and MPE, the AUC of pfLDH/pfADA was 0.926 (0.896, 0.956), with a sensitivity of 93.4% and specificity of 80.0%; this was not significantly different from the diagnostic efficacy of pfADA.ConclusionsCompared with single biomarkers, pfLDH/pfADA has higher diagnostic value for TPE and can identify patients with TPE early, easily, and economically.

Abstract 736: ACTM-838 safely and comprehensively re-activates the immunosuppressive TME by exploiting myeloid biology intrinsic in many cancers

Abstract ACTM-838 is a genetically modified bacterial vehicle encoding a DNA plasmid with two engineered payloads, IL-15plex and constitutively active eSTING. The bacterial vehicle is a highly attenuated S. typhimurium, engineered to facilitate safe IV administration. ACTM-838 is designed to specifically enrich in the TME via auxotrophic dependency on extracellular adenosine and purine metabolites. ACTM-838 is then selectively internalized by tumor-resident myeloid cells achieving tumor-specific payload delivery. Previously, we showed ACTM-838 exhibited significant and durable anti-tumor efficacy across syngeneic tumor mouse models (EMT6 breast, MC38 colon) and MMTV-PyMT GEMM. To elucidate TME changes induced by ACTM-838, EMT6 tumors were analyzed post-treatment by scRNA-seq, which demonstrated that ACTM-838 induced significant transcriptional changes in several cell populations in the TME. Cytolytic pathways were upregulated in T and NK cells, while type I IFN and PDL1 were upregulated in myeloid populations consistent with previous bulk RNAseq analyses. To understand the tolerability and safety of ACTM-838, a GLP toxicology study was performed on naïve cynomolgus monkeys (NHP). No ACTM-838-related clinical or veterinary observations were reported at any dose level. Acute dose-dependent increases in serum cytokines were observed at 4 hours which reverted to baseline by 24 hours. ACTM-838 was cleared from blood by 24 hours post-dose with no significant shedding in urine or feces. ACTM-838 was only detected in the spleen in 2 and 1 animals at 22- and 49-days post treatment, respectively. Pre-existing ADA was observed in some animals with subsequent increases in ADA upon dosing in most animals. However, no correlation of serum ADA and blood PK levels suggested that the presence of ADA does not impact drug stability. The ACTM-838 mechanism of action requires high levels of adenosine or purine metabolites to enrich and colonize the TME as well as phagocytic internalization by tumor-intrinsic myeloid cells to achieve tumor-specific payload delivery. Myeloid cells comprise roughly half of all cells in the TME in human tumors. Bioinformatics analyses of the public patient datasets identified key tumor indications enriched in both adenosine and myeloid pathways. To further understand the spatial heterogeneity in the TME across tumors, we performed multiplex immunofluorescence on patient tumor microarrays to validate tumor types with a high prevalence of myeloid populations coupled with an active adenosine pathway, which will help guide future clinical study design. In summary, we demonstrate that ACTM-838 modulates the TME and is stable and safe in animal models. Additionally, our studies recommend the prioritization of certain tumor indications for treatment with ACTM-838 in the clinic. Citation Format: William Lu, Kyle Cron, Julie Janes, Leigh Berryman, Gurvinder Singh, Christopher Thanos, Akshata Udyavar. ACTM-838 safely and comprehensively re-activates the immunosuppressive TME by exploiting myeloid biology intrinsic in many cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 736.

Diagnostic value of serum ADA level in extra pulmonary tuberculosis cases in a tertiary care hospital, Bihar

Travelling through time, space and history if there is one disease which always comes to our mind is tuberculosis (TB). Still on many occasions it remains undiagnosed and hence not treated appropriately. In many instances patient is not able to give proper sputum sample or in a way it should be. On the top of it in resource poor countries availability of health care professionals is an issue to examine the sputum. Furthermore, when extra pulmonary TB is the case invasive diagnostic procedures such as biopsy becomes important which is a challenging thing to perform in many of our setups in our state. So, the aim of this study was to investigate the diagnostic value of ADA in extra pulmonary TB. Methods: It is an analytical study in which serum ADA values in EPTB cases were compared with controls.100 patients matched for age and sex were included. Data analysis was done using SPSS version 27. Results: Our data analysis showed mean ADA levels in EPTB patients was 43.6 which was significantly higher than control group(p value &lt;0.001).

Serum adenosine deaminase activity: A novel test for early diagnosis of pulmonary tuberculosis - What about efficacy?

Background: Pulmonary tuberculosis is a tremendous public health problem, increasing significantly, especially in developing countries. Getting a TB-free globe appears to be not more than a dream. Mycobacterial culturing is the gold standard for precise diagnosis but requires six-week time, in the meantime, patients remain a source of inadvertent disease dissemination in the community. The unavailability of sputum also poses a challenge several times. As adenosine deaminase level measurement is easy, rapid and independent of a sputum sample, this study was conducted to determine the diagnostic efficacy of adenosine deaminase activity for pulmonary tuberculosis.Patients and methods: This prospective study was conducted at Pulmonology-OPD, Gulab Devi Chest Hospital, Lahore, from 01-01-2019 to 30-06-2019. A total of 300 sputum smear-positive patients with clinical and radiological evidence consistent with diagnosis of pulmonary tuberculosis and 30 normal participants without any clinical, radiological or haematological evidence of tuberculosis were included. While, smear-negative patients and those having any evidence of hepatic disease, hematopoietic malignancy, infectious mononucleosis, typhoid or pregnancy were excluded. The serum ADA level of each participant was determined. All patients were subjected to AFB culture. Diagnostic accuracy was determined by considering sputum culture as a gold standard.Results: At cut-off value of &gt;15 IU/L, a sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of 98.30%, 100.00%, 100.00%, 85.71%, 98.46% respectively were defined. Conclusion: Serum ADA level, having excellent sensitivity and specificity, can diagnose pulmonary tuberculosis even if sputum sample is not available.

The association between serum adenosine deaminase levels and Graves’ disease

BackgroundAdenosine deaminase (ADA) is essential for the differentiation and maturation of lymphocytes, while lymphocytes infiltration in thyroid tissue is a vital pathological feature of Graves’ disease (GD). The aim of the present study was to compare the concentration of ADA between healthy controls (HC) and patients with GD, and evaluate the association between ADA and GD.MethodsA total of 112 GD patients and 77 matched HC were enrolled in this study. Each participant was examined for thyroid hormones and autoantibodies, ADA concentration, and thyroid ultrasonography.ResultsSerum ADA levels in GD patients were significantly higher than that in HC subgroup (P < 0.001). In GD patients, serum ADA levels were positively associated with serum-free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAb), thyroid-stimulating hormone receptor antibody (TRAb) levels, and total thyroid gland volume (thyroid VolT) and negatively associated with serum thyroid-stimulating hormone receptor (TSH) levels (all P < 0.05). There were no similar correlations in the HC subgroup. Multiple linear regression analysis suggested that serum TSH, FT3, and ADA levels played an important role in serum TRAb levels.ConclusionsOur results demonstrated that serum ADA levels were closely associated with GD.

Study of serum adenosine deaminase levels in head and neck malignancies

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; Head and neck malignancies are the malignancies occurring at various sites like scalp, ear, nose and paranasal sinuses, nasopharynx, oral cavity, oropharynx, hypopharynx, larynx, and salivary glands. There are various biomarkers which aid in early diagnosis and management of head and neck malignancies. In order to study various parameters aiding in early diagnosis, this study has been taken up to estimate serum adenosine deaminase levels among these patients.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Eighty-eight clinically diagnosed head and neck malignancy patients of both genders were included in this study on simple random basis. After obtaining the written informed consent from the patient, a peripheral venous sample of blood was taken and serum ADA levels were estimated. Data was analyzed using IBM SPSS Version 22.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Serum ADA levels are found to be statistically significant with respect to various stages of head and neck malignancies including malignancy of unknown origin. Mean ADA level in this study was 30.33 IU/l. Mean ADA levels in MUO, primary tumor with neck secondaries were 37 IU/l, 38.7 IU/l respectively. Mean ADA levels in patients with primary tumor without neck secondaries was 27.9 IU/l.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;The Serum ADA levels among head and neck malignancy patients including MUO is a simple, inexpensive diagnostic biomarker enzyme which is easy and rapid to estimate. This study emphasizes on using Serum ADA levels as a prognostic indicator among head and neck malignancies who are on various modalities of treatment.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;

Adenosine deaminase activity in type 2 diabetes mellitus: does it have any role?

BackgroundDiabetes mellitus is a group of metabolic disorders of carbohydrate metabolism in which glucose is underused, producing hyperglycemia. Diabetic patients are prone to opportunistic infection, thus serum ADA levels in these patients is very important as a screening test for Tuberculosis and autoimmune diseases. Thus, the present study was conducted to estimate the Serum ADA activity, glycated Haemoglobin (HbA1c), fasting and postprandial glucose level in patients with T2DM and to correlate the serum level of ADA with glycated Hemoglobin (HbA1c), fasting and postprandial glucose level in T2DM.MethodsThis is a Hospital based cross-sectional study done in BPKIHs, Dharan, Nepal. 204 diagnosed patients (102 males and 102 females) with T2DM and 102 healthy controls were enrolled in the study. Diabetic patients were categorized into Uncontrolled and Controlled Diabetes on the basis of HbA1C; HbA1c > 7% = Uncontrolled Diabetes, HbA1c < 7% = Controlled Diabetes.ResultsSerum ADA levels (U/L) was significantly raised in Uncontrolled Diabetic patients (49.24 ± 16.89) compared to controlled population (35.74 ± 16.78) and healthy controls (10.55 ± 2.20),p value < 0.001. A significant positive correlation was obtained between Serum ADA and HbA1c, Fasting Plasma Glucose and Post-prandial Glucose respectively.ConclusionThere is a significant increase in Serum ADA activity in DM with increase in HbA1c levels which may play an important role in predicting the glycemic and immunological status in these patients.

Serum Adenosine Deaminase Levels and Human Papillomavirus as Prognostic and Predictive Factors for Laryngeal and Pharyngeal Carcinomas.

Head and neck cancer is one of the most common cancers in the world, accounting for up to 30-40% malignancies in India. Research is always on the lookout for parameters that help in early diagnosis of such disease and to explore the possibility of discovering such parameters that would assist in management of the disease by its potential to predict and prognosticate the disease. To estimate serum ADA levels and to correlate with response to therapy and also to correlate between different clinical stages and serum ADA levels and to correlate HPV status to response to therapy. A prospective cohort study. 30 patients who were diagnosed with squamous cell carcinoma of the oropharynx, hypopharynx and larynx were considered in this study. The pre and post treatment values of serum ADA was estimated in these patients and the tumour was assessed for HPV status. The difference in the in the serum ADA levels before and after treatment was 9.982 which was statistically significant with a p value of < 0.001. HPV positive status and response to therapy in the form of recurrence shows a p value of 0.485 which is not statistically significant. Serum ADA level can be used as a parameter to assess the severity of the disease and the response to treatment in cases of carcinoma of the oropharynx, hypopharynx and larynx. HPV status of the disease has its limitation in prediction and prognosis of the disease.

Role of serum adenosine deaminase in pulmonary tuberculosis

BackgroundDefinitive laboratory diagnosis and confirmation of tuberculosis remains a major challenge because of lack of specificity and sensitivity of diagnostic methods especially in sputum smear negative tuberculosis. Many studies have proved the role of ADA in diagnosis of tuberculosis in effusion fluids and a decrease in ADA activity after treatment. This study was aimed to investigate the role of serum ADA level as an early diagnostic and prognostic marker for pulmonary tuberculosis (PTB). Material and methodsThis was a cohort study done on patients visiting the OPD Clinics of the department of Pulmonary Medicine at GMCH, Chandigarh. 50 sputum positive and 50 sputum negative tuberculosis patients and 100 controls were recruited. Serum ADA levels were measured at the start of treatment and again after two months of treatment. Its correlation with severity of disease was seen. ResultsMean serum ADA (IU/L) was found to be 35.293±30.941 in PTB patients and 11.819±8.023 in control groups and the difference was found to be highly significant (P<0.00). Mean ADA was 31.107±29.32 in sputum positive patients, 39.478±32.22 in sputum negative and 11.819±8.0235 in control groups. No statistically significant difference was observed amongst sputum positive and sputum negative patients. The levels decreased significantly after intensive phase of treatment. At the cut off values of 14.6IU/L, serum ADA had 78% sensitivity and 76% specificity (AUC=0.801, P value<0.00) to differentiate between PTB from healthy controls. ConclusionSerum ADA levels may be used as a biomarker for diagnosis of PTB and to evaluate the response to treatment at follow up.

Diagnostic Potential of Circulating Biomarkers in Adenosine Deaminase Diagnosed Pleural Tuberculosis Cases.

Pleural tuberculosis accounts for nearly 20% of Extra pulmonary tuberculosis. Adenosine deaminase, commonly used biomarker for the diagnosis, is non specific and there is paucity of literature on its correlation with conventional or newer methods for the diagnosis of extra pulmonary forms of TB. The aim of the study was to assess diagnostic potential of T cell function markers [interferon (IFN-γ), interleukin (IL-2) and IFN-γ/IL-2 ratio]; macrophage activation marker [neopterin]; and oxidative stress markers [protein carbonyl and malondialdehyde (MDA)] in pleural tuberculosis. 26 pleural TB cases diagnosed on the basis of suggestive chest X-ray and raised serum ADA levels and healthy controls were included in the study. Pleural fluid specimens were subjected to Zeihl Neelsen staining and culture on Lowenstein Jensen medium. Serum IFN-γ, IL-2, neopterin and protein carbonyl levels detection were done by ELISA and MDA levels were determined by measuring the thiobarbituric acid reactive substances. Median serum levels of IFN-γ, IL-2, IFN-γ/IL-2 ratio, neopterin, protein carbonyl and MDA were significantly different between cases and controls. Levels of all biomarkers except IL-2 were significantly higher in cases with contact history. Mean levels of ADA and ESR were 46.27U/L and 46.62mm/hr in PTB cases. AUC for IFN-γ, IL-2, IFN-γ/IL-2 ratio, neopterin, protein carbonyl and MDA were significantly discriminative for cases and controls. IFN-γ/IL-2 ratio was best discriminatory biomarker with highest area under ROC curve. Though no correlation was seen between ADA and any of the six biomarkers, ESR levels correlated significantly with all biomarkers except IL-2 by spearman's correlation coefficient. Though all the circulating biomarkers under study provide useful supportive evidence for the diagnosis of PTB, further studies involving diverse control groups particularly non-PTB effusion are needed to validate these results.

Estimation of Adenosine deaminase and proteinase inhibitory activity and their correlation with tuberculous effusion and other pleural effusion cases

Introduction: Diagnosis of tuberculous effusion is difficult with the conventional, bacteriological, cytological and histopathological methods in our country. Adenosine deaminase, serum proteins, phospholipids show marked variation in tuberculous exudates. Material and Methods: Twenty cases of pulmonary tuberculosis, 10 cases of malignant effusions and 8 cases of other para-pneumonic effusions visiting a tertiary care hospital were included in this study. After collecting blood and pleural fluid samples, Adenosine deaminase, Alpha-1 antitrypsin l, proteinase inhibitor activity, total lipid levels, phospholipid and Lipase activity were estimated. Observation and results: Serum ADA levels in tuberculous effusion was 21.8+ 9.8 U/L(10-45.08) P

English

BACKGROUND: Tuberculosis is one of the most widely prevalent infectious disease causing high morbidity and mortality in humans. Serum ADA is a low cost test with proven diagnostic significance. AIMS AND OBJECTIVES: To assess change of Serum ADA levels as an indicator of response to the treatment, the prognostic value of ADA levels in childhood tuberculosis and its role in early detection of drug resistance or treatment failure if any. MATERIALS AND METHODS: A prospective analytical study (n=59) was conducted in Niloufer hospital from July 2012 to September 2013. A total of 32 patients were enrolled in tuberculous meningitis group and 27 in pulmonary tuberculosis group. Blood samples were drawn at the time of diagnosis, 1 month and 2 months after starting treatment. ADA levels were measured using Guisti’s method. Data collected was analyzed using SPSS 16 software. RESULTS: Mean Serum ADA levels on Day 1, 1 month, 2nd month samples were [46.97±11.00], [31.51± 6.27], [21.67± 4.00] and [32.31± 5.90], [24.03± 4.38], [18.43± 2.76] in Pulmonary Koch’s and TBM group respectively. Serum ADA levels showed a significant decrease (p < 0.000) after the initiation of treatment. Sex, age and nutritional status as measured by weight for age did not have a significant effect on Serum ADA value. There was a significant difference between mean ADA levels in the pulmonary tuberculosis group and TBM group but age was confounding factor. In the TBM group, 5 children who succumbed to the disease had a significantly (p = 0.016) lower Serum ADA levels (mean = 22.08) when compared to other children who have not succumbed to the disease. The relative risk of a TBM child dying with the disease was calculated to be 8.9 if the Serum ADA levels were less than 22IU/dl. CONCLUSIONS: There was a significant sequential decrease in Serum ADA levels in tuberculosis patients with treatment and these were not influenced by age, sex and nutritional status. A low level of Serum ADA in TBM is a significant negative prognostic indicator.

Tu1148 Mechanisms of Loss of Response to Adalimumab in Crohn's Disease

of this study was to assess the degree of correlation of serum ADA and ATA levels with indices of serologic and endoscopic mucosal inflammation in patients with inflammatory bowel disease (IBD). Methods: We designed a cross-sectional study including patients 18 years or older with CD or UC on treatment with ADA. Predictive variables included were demographics, disease phenotype, concurrent use of immunosuppressive drugs (mercaptopurine, azathioprine or methotrexate) and/or steroids, and random ATA/ADA levels (measured using a validated non-radiolabeled homogeneous mobility shift assay by Prometheus Laboratories [San Diego, CA]). The primary outcomes were the presence of macroscopic mucosal inflammation (MMI) during endoscopic exam and C-reactive protein (CRP) level. Results: 66 patients were included; 59 had CD. 62 (94%) and 18 (27%) of IBD patients had detectable ADA and ATA, respectively. A minimum ADA cutpoint of 5 μg/mL best predicted elevation of CRP levels (ROC: 0.71). The mean ADA level was significantly higher in patients with undetectable ATA that in those with ATA (12.5 vs 5.7 μg/mL respectively, p=0.001). Mean ADA levels were higher in patients with mucosal healing than in those patients with MMI (13.3 vs 8.5 μg/mL, respectively, p=0.02). The mean serum CRP level was significantly higher in those patients with detectable ATA than those lacking ATA (12 vs 2.1 mg/dL respectively, p=0.002). Detectable ATA was associated with ADA ,5 μg/ mL (OR 8.6 [95%CI:2.3-31.8;p,0.001], MMI (OR 3.8 [95%CI:1.1-13.2;p=0.03], need for steroids (OR 3.7 [95%CI:1.1-12.9;p=0.03], and previous infliximab use (OR 3.9 [95%CI:1.015.2;p=0.04]. When compared to those patients prescribed ADA monotherapy, patients combining ADA therapy with an immunomodulator had a higher mean level of ADA (9 vs 14 ug/mL, respectively, p=0.026). Conclusions: Among patients with IBD, serum ADA and ATA levels correlate well with both serologic and endoscopic inflammatory activity. An ADA level ≥5 μg/mL correlates well with lower CRP, and combination therapy with immunosuppressive drugs improves serologic levels of ADA. Further work establishing the role of measuring ADA and ATA levels in clinical care are warranted.

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 isoenzymes and neopterin in liver cirrhosis.

The aim of this study was to define the pattern of neopterin and ADA isoenzymes in liver cirrhosis. A total of 117 patients with liver cirrhosis were included. Serum levels of ADA were assayed in the presence and absence of a specific inhibitor for ADA1. Serum neopterin was measured using a competitive enzyme-linked immunosorbent assay. The grade of liver insufficiency was assessed according to the Child-Pugh classification and the monoethylglycinexylidide test. Serum ADA, ADA1, ADA2 and neopterin were higher in cirrhotic patients than in control subjects. A stepwise increase in serum ADA level was observed with increasing severity of liver cirrhosis. The probability of ADA2 being greater than the mean was approximately 2.5 times higher (2.48, CI 95%: 1.36-4.52) in patients with liver cirrhosis due to hepatitis C virus (HCV) infection than in those patients with cirrhosis of a different etiology. No correlation was found between ADA2 and neopterin. Our data show that liver insufficiency and HCV infection increase the serum levels of ADA and its major isoenzyme ADA2. Furthermore, ADA isoenzyme determination adds no value to total ADA value. The absence of a correlation between ADA2 and neopterin suggests that different physiologic processes are involved in their increase.

Measurement of serum and peritoneal ADA and lysozyme levels for the diagnosis of peritoneal tuberculosis

Measurement of serum and peritoneal ADA and lysozyme levels for the diagnosis of peritoneal tuberculosis