Deficiency of adenosine deaminase 2 (DADA2) with bilateral renal subcapsular hematoma: a case report and literature review.

Introduction and importance: Deficiency of adenosine deaminase 2 (DADA2) is a rare autosomal recessive genetic disorder caused by loss-of-function mutations in the adenosine deaminase 2 (ADA2) gene. This condition primarily manifests in pediatric cases before the age of 10 years, with sporadic cases reported in adults. ADA2 is a critical enzyme involved in macrophage differentiation and immune homeostasis. The clinical manifestations of DADA2 vary widely and can affect multiple organ systems. Our case uniquely highlights an infrequent DADA2 manifestation. Case presentation: An 18-year-old female presented with right flank pain, fever, and a history of joint pain, Raynaud's phenomenon, livedo-like rash, and chronic abdominal pain. Physical examination revealed subcapsular hematoma in the right kidney. Further evaluation showed positive serologic tests for rheumatoid factor and antinuclear antibody (ANA). Genetic testing confirmed DADA2 homozygosity. The patient was discharged on the appropriate medications. Clinical discussion: DADA2 is associated with vascular dysfunction and systemic vasculopathy. The clinical manifestations of DADA2 encompass a spectrum of organ involvement, including the skin, nervous system, gastrointestinal system, renal system, and the cardiovascular system. Early recognition and diagnosis are crucial for appropriate management. Conclusion: This case report highlights the diverse clinical presentations of ADA2 deficiency, specifically focusing on bilateral renal subcapsular hematoma. This finding emphasizes the importance of considering DADA2 as a differential diagnosis in patients presenting with unexplained renal manifestations. Increased awareness of the varied clinical presentations of DADA2 will contribute to earlier diagnosis, appropriate management, and improved outcomes in patients affected by this rare genetic disorder.

To correlate clinical and biochemical profile of pleural effusion: a retrospective study in tertiary care centre of central India.

BACKGROUND: Pleural effusion indicates an imbalance between pleural fluid formation and removal. Classified into exudative and transudative, with common symptoms of dry cough, dyspnea and pleuritic chest pain. Confirmed etiology has to be established for effective treatment. OBJECTIVE: Correlate clinical and biochemical profile of various etiologies of pleural effusion. MATERIALS & METHODS: Retrospective observational study of 2 years in the department of respiratory medicine, GMC Bhopal on 280 cases of pleural effusion. RESULTS: Most common etiology was tubercular 202 (72.4%) followed by malignant in 36 (12.8%). With respect to tubercular, malignant pleural effusion has relative risk (RR) of 0.138 (p value < 0.05) in the age group of 51-60 years, which is statistically significant. Patients of tuberculosis complained of fever 158 (78.2%) whereas with malignancy complained of chest pain 16 (44.4%) followed by hemoptysis 12 (33.3%). For hemoptysis, with respect to tubercular, malignant effusion has RR of 5.68 (p value < 0.05) which is significant. History of smoking was significant in malignant effusion with RR of 2.57 (p value < 0.05) as compared to tubercular. Pleural fluid ADA was >70 in 83.7% in tubercular effusion, glucose was <60 mg/dl in 79% tubercular, malignant and bacteriological cause, LDH was >1000 in 88.4% in bacteriological and 72.3% in malignant effusion. CONCLUSION: Lack of tools for confirming diagnosis leads to diagnostic dilemma and delay in treatment initiation, leading to deterioration and untoward fatality in some cases. Our goal is early diagnosis by correlating clinical symptoms with biochemical profile and help initiate rapid treatment.

Early bone marrow alterations in patients with adenosine deaminase 2 deficiency across disease phenotypes and severities.

BACKGROUND: Deficiency of adenosine deaminase 2 (DADA2) is a complex monogenic disease caused by recessive mutations in the ADA2 gene. DADA2 exhibits a broad clinical spectrum encompassing vasculitis, immunodeficiency, and hematological abnormalities. Yet, the impact of DADA2 on the bone marrow (BM) microenvironment is largely unexplored. OBJECTIVE: This study comprehensively examined the BM and peripheral blood of pediatric and adult patients with DADA2 presenting rheumatologic/immunologic symptoms or severe hematological manifestations. METHODS: Immunophenotyping of hematopoietic stem cells (HSCs), progenitor cells, and mature cell populations was performed for 18 patients with DADA2. We also conducted a characterization of the mesenchymal stromal cells (MSCs). RESULTS: Our study revealed a significant decrease in primitive HSCs and progenitor cells, alongside their reduced clonogenic capacity and multilineage differentiation potential. These BM defects were evident in patients with both severe and non-severe hematological manifestations, including pediatric patients, demonstrating that BM disruption can emerge silently and early on, even in patients who do not show obvious hematological symptoms. Beyond stem cells, there was a reduction in mature cell populations in the BM and peripheral blood, affecting myeloid, erythroid, and lymphoid populations. Furthermore, BM MSCs in DADA2 patients exhibited reduced clonogenic and proliferation capabilities and were more prone to undergo cellular senescence marked by elevated DNA damage. CONCLUSION: Our exploration into the BM landscape of DADA2 patients sheds light on the critical hematological dimension of the disease and emphasizes the importance of vigilant monitoring, even in the case of subclinical presentation.

Inside the Brain: Cerebrospinal Fluid Insights in Meningitis.

Background Our study focused on meningitis, an infection that can spread through the bloodstream as a primary or secondary infection from other body parts, such as sinuses, ears, and lungs. It can affect patients who have experienced trauma or surgery, as well as those with congenital defects like spina bifida. Specifically, we examined bacterial, viral, and tuberculous meningitis (TBM) cases. The primary method for confirming the diagnosis of these types of meningitis is to analyze the cerebrospinal fluid (CSF). Early diagnosis can utilize cytological and biochemical parameters. Our objective is to determine CSF's cytological and biochemical profile in patients with these specific types of meningitis. Methods A study was carried out at the central pathology lab from October 24, 2017, to April 24, 2018. CSF samples from suspected meningitis patients were examined for various parameters, including hematological, biochemical, microbiological, and cytomorphological aspects and specific tests for bacterial, fungal, and TBM. The study focused on patients aged 16 and above, excluding those under 16, non-compliant patients, and individuals with specific health conditions. Data were analyzed using IBM SPSS Statistics for Windows, Version 20 (Released 2011; IBM Corp., Armonk, New York, United States), and the results were presented through the use of mean, standard deviation, and percentages. Statistical tests were utilized to compare categorical variables and mean, with a significance level of p<0.05. Results We included a total of 156 cases, with the mean age of presentation being 56.628 years. The male-to-female ratio was 1.0526:1. Of the patients, 81 (52.1%) had been diagnosed with TBM, had elevated adenosine deaminase (ADA) levels of 48.8733±37.43740 IU/L, and CSF lymphocytosis (99%). Additionally, cases of bacterial meningitis showed markedly raised mean total leukocyte count (TLC) of 2085.50±445.47727 cells/mm3 and mean CSF protein levels of 349.45±113.73105 mg/dL. The study found a significant increase in protein levels and a decrease in glucose levels in the CSF of TBM and bacterial meningitis patients compared to those with other causes of meningitis (p<0.001). Guillain-Barre syndrome (GBS) and multiple sclerosis (MS) patients had TLC and ADA within normal limits. CSF ADA level greater than 6 IU/L showed a sensitivity of 97.53% and a specificity of 96.0%, making it the most specific test. A protein level in the CSF greater than 45 mg/dL demonstrated a sensitivity of 98.78% and a specificity of 24.32%, indicating it is sensitive but less specific in diagnosing TBM. Lymphocytic predominance, defined as TLC of more than 5 cells/mm3 with at least 50% of the cells being lymphocytes in the CSF of TBM patients, showed a sensitivity of 97.53% and a specificity of 6.67%. CSF glucose had a sensitivity of 38.27%, making it the least reliable indicator for diagnosing meningitis. Conclusion The CSF analysis is the primary diagnostic method for detecting meningitis. Its cost-effectiveness is a key factor, especially for patients from lower socioeconomic backgrounds in government medical colleges in India, where access to expensive diagnostic tests is limited. The efficiency of CSF analysis for early diagnosing different types of meningitis aids in management, helping to prevent complications and fatal outcomes.

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Inborn errors of immunity (IEI) are a diverse group of disorders caused by defects in immune system structure or function, involving both innate and adaptive immunity. The 2022 update of the IEI classification includes 485 distinct disorders, categorized into ten major disease groups. With the rapid development of molecular biology, the specific pathogenesis of many IEI has been revealed, making gene therapy possible in preclinical and clinical research of this type of disease. This article reviews the advancements in gene therapy for IEI, aiming to increase awareness and understanding of these disorders.

Diagnosis and Management of Tuberculous Pleural Effusion in a Patient With Chronic Obstructive Pulmonary Disease: A Case Report.

A 63-year-old man had been smoking bidis for 25 years and developed tubercular empyema, further complicated by pneumothorax and other pulmonary issues. Over a period of three weeks, the individual experienced a gradual onset of symptoms, including progressive shortness of breath, cough, fever, and chest pain. Radiographic examinations revealed significant left-sided pleural effusion with consolidation and evidence of pneumothorax. Other findings included anemia, hyponatremia, substantially increased lactate dehydrogenase, and adenosine deaminase (ADA), consistent with tubercular or chronic infection. The comprehensive treatment plan involved the administration of antibiotics, antitubercular drugs, draining of the pleural fluid, nebulized bronchodilators, corticosteroids, and broad-spectrum antibiotics. The patient exhibited a positive response, showing notable clinical improvement, which was closely monitored through sequential chest X-rays and ECGs. This would continue to highlight the vital need for early tuberculosis detection in patients with chronic obstructive pulmonary disease due to clinical overlap with other diseases. To diagnose and follow up on tuberculous pleural effusion cases, it was critical to integrate both clinical and radiographic findings with laboratory data. It emphasizes the necessity for a multidisciplinary approach to improve overall treatment outcomes.

Deficiency of Adenosine Deaminase 2

Adenosine deaminase 2 (ADA2) deficiency is an autosomal recessively inherited autoinflammatory disorder caused by loss-of-function mutations in the ADA2 gene. Although the pathogenesis involves the triggering of a proinflammatory cascade due to increased production of inflammatory cytokines such as tumor necrosis factor (TNF)-α and dysregulation of neutrophil extracellular trap formation resulting from an excess accumulation of extracellular adenosine, the pathogenetic mechanism still needs further clarification due to the broad clinical spectrum. In addition to the initially described vasculitis-related symptoms, hematological, immunological, and autoinflammatory symptoms are now well recognized. The diagnosis is made by demonstration of pathogenic variants of ADA2 with biallelic loss of function and identification of low plasma ADA2 catalytic activity. Currently, TNF-α inhibitors are the treatment of choice for controlling vasculitis manifestations and preventing strokes. However, in patients presenting with severe hematologic findings, TNF-α inhibitors are not the treatment of choice and hematopoietic stem cell transplantation has been shown to be successful in selected cases. Recombinant ADA2 protein and gene therapy are promising treatment modalities for the future. In conclusion, ADA2 deficiency has a broad phenotype and should be considered in the differential diagnosis of different clinical situations. In this review, we summarize the disease manifestations of ADA2 deficiency and available treatment options.

Evolving spectrum of adenosine deaminase (ADA) deficiency: Assessing genotype pathogenicity according to expressed ADA activity of 46 variants.

BACKGROUND: Deficiency of adenosine deaminase (ADA or ADA1) has broad clinical and genetic heterogeneity. Screening techniques can identify asymptomatic infants whose phenotype and prognosis are indeterminate, and who may carry ADA variants of unknown significance. OBJECTIVE: We systematically assessed the pathogenic potential of rare ADA missense variants to better define the relationship of genotype to red blood cell (RBC) total deoxyadenosine nucleotide (dAXP) content and to phenotype. METHODS: We expressed 46 ADA missense variants in the ADA-deficient SØ3834 strain of Escherichia coli and defined genotype categories (GCs) ranked I to IV by increasing expressed ADA activity. We assessed relationships among GC rank, RBC dAXP, and phenotype in 58 reference patients with 50 different genotypes. We used our GC ranking system to benchmark AlphaMissense for predicting variant pathogenicity, and we used a minigene assay to identify exonic splicing variants in ADA exon 9. RESULTS: The 46 missense variants expressed ∼0.001% to ∼70% of wild-type ADA activity (40% had <0.05% of wild-type ADA activity and 50% expressed >1%). RBC dAXP ranged from undetectable to >75% of total adenine nucleotides and correlated well with phenotype. Both RBC dAXP and clinical severity were inversely related to total ADA activity expressed by both inherited variants. Our GC scoring system performed better than AlphaMissense in assessing variant pathogenicity, particularly for less deleterious variants. CONCLUSION: For ADA deficiency, pathogenicity is a continuum and conditional, depending on the total ADA activity contributed by both inherited variants as indicated by GC rank. However, in patients with indeterminate phenotype identified by screening, RBC dAXP measured at diagnosis may have greater prognostic value than GC rank.

Validation of a diagnostic flowchart for tuberculous pleurisy in pleural fluid with high levels of adenosine deaminase.

INTRODUCTION: Adenosine deaminase (ADA) in pleural fluid is a useful marker for diagnosing tuberculous pleurisy. However, recent studies have reported a lower specificity of pleural fluid ADA levels. We previously developed a diagnostic flowchart for patients with pleural fluid ADA ≥40 U/L, incorporating variables such as pleural fluid lactate dehydrogenase <825 U/L, predominant pleural fluid neutrophils or cell degeneration, and a pleural fluid ADA/total protein ratio <14. This flowchart was effective in distinguishing between tuberculous pleurisy and other diseases. Here, we conducted a validation analysis of this flowchart. MATERIALS AND METHODS: We retrospectively collected data from 458 patients with pleural fluid ADA concentrations ≥40 U/L across eight institutions from January 2019 to December 2023. The diagnostic accuracy rate, sensitivity, and specificity of the diagnostic flowchart were analysed and compared to those in the original study. RESULTS: Eighty-seven patients were diagnosed with tuberculous pleurisy, and 371 patients were diagnosed with other diseases. The diagnostic accuracy, sensitivity, and specificity for diagnosing tuberculous pleurisy were 77.7%, 86.2%, and 75.7%, respectively. Compared with that in the original study, the rate of tuberculous pleurisy was lower (19.0% vs. 44.5%, p < 0.001), but the diagnostic accuracy rates were not significantly different (p = 0.253). On the basis of the findings from this validation study, we have revised the flowchart to enhance its utility. CONCLUSION: The diagnostic flowchart exhibited high diagnostic accuracy in this validation study, comparable to that in the original study. This validation confirms the effectiveness of the flowchart, even in settings with a low incidence of tuberculosis.

Structural perspectives on adenosine to inosine RNA editing by ADARs.

Adenosine deaminases acting on RNA (ADARs) are enzymes that catalyze the hydrolytic deamination of adenosine to inosine. The editing feature of ADARs has garnered much attention as a therapeutic tool to repurpose ADARs to correct disease-causing mutations at the mRNA level in a technique called site-directed RNA editing (SDRE). Administering a short guide RNA oligonucleotide that hybridizes to a mutant sequence forms the requisite dsRNA substrate, directing ADARs to edit the desired adenosine. However, much is still unknown about ADARs' selectivity and sequence-specific effects on editing. Atomic-resolution structures can help provide additional insight to ADARs' selectivity and lead to novel guide RNA designs. Indeed, recent structures of ADAR domains have expanded our understanding on RNA binding and the base-flipping catalytic mechanism. These efforts have enabled the rational design of improved ADAR guide strands and advanced the therapeutic potential of the SDRE approach. While no full-length structure of any ADAR is known, this review presents an exposition of the structural basis for function of the different ADAR domains, focusing on human ADAR2. Key insights are extrapolated to human ADAR1, which is of substantial interest because of its widespread expression in most human tissues.

Utility of the Ratio of Adenosine Deaminase and Serum C-reactive Protein in Differentiating Parapneumonic, Tuberculous, and Malignant Pleural Effusions.

Introduction Pleural effusion is a challenging diagnosis at times, especially due to the overlap of symptoms in effusions of various etiologies. In this study, we aimed to identify if pleural fluid adenosine deaminase (ADA) or serum C-reactive protein (CRP) can be used as an additional novel biomarker for ADA in diagnosing tubercular, parapneumonic, and malignant pleural effusions. Materials and methods A prospective, observational, cross-sectional study was conducted on 79 patients diagnosed with tubercular, parapneumonic, or malignant pleural effusion from August 2022 to April 2024 at the Department of Respiratory Medicine at Dr. D. Y. Patil Medical College, Hospital & Research Centre, Pimpri, Pune. The pleural fluid ADA/serum CRP ratio was identified in each group, and analysis was done to compare the ratio in each group. The correlation with pleural fluid ADA was also identified. Results A total of 79 patients were enrolled in this study. Out of these patients, 53 (67.1%) were identified as having tubercular pleural effusion, 10 (12.7%) patients had parapneumonic effusion, and 16 (20.3%) had malignant pleural effusion. For malignant effusions, the area under the curve (AUC) using the receiver operating characteristic (ROC) for the ADA/CRP ratio was observed to be 0.862. Sensitivity was 87.50% and specificity was 82.54% at a cut-off value of ≤0.5. The positive predictive value was found to be 56%, and the negative predictive value was found to be 96.3%. For parapneumonic effusions, the AUC using the ROC for the ADA/CRP ratio was observed to be 0.880. Sensitivity was 100% and specificity was 69.57% at a cut-off value of ≤0.67. The positive predictive value was found to be 32.3%, and the negative predictive value was found to be 100%. For tubercular effusions, the AUC using the ROC for the ADA/CRP ratio was observed to be 0.955. Sensitivity was 92.45% and specificity was 88.46% at a cut-off value of >0.54. The positive predictive value was found to be 94.2%, and the negative predictive value was found to be 85.2%. The Pearson correlation coefficient (r) of 0.633 indicates a moderately strong positive linear relationship between ADA and ADA/CRP levels. Conclusion The pleural fluid ADA-to-serum CRP ratio can be used as a useful diagnostic tool for differentiating between tubercular, parapneumonic, and malignant pleural effusions. ADA/CRP ratio has added diagnostic value over ADA. In clinically puzzling scenarios, the ADA/CRP ratio can be a cost-effective tool before opting for a more expensive and invasive procedure, which is also often difficult to obtain in resource-limited healthcare settings. More research with a larger sample size is indicated to incorporate the ADA/CRP ratio as an added diagnostic tool along with ADA.

A Clinical Neurological Approach to the Child With Adenosine Deaminase Deficiency.

BACKGROUND: Severe combined immunodeficiency secondary to adenosine deaminase deficiency is rare. The deficiency of this enzyme results in the accumulation of substrates in the tissues, including the brain. Clinical signs of neurological involvement may include seizures, neurodevelopmental disorders, hypotonia, and sensorineural hearing loss. Hematopoietic stem cell transplantation corrects the failure of the immune system but not the neurological involvement. OBJECTIVES: To describe the spectrum of neurological complications identified in a series of children with severe combined immunodeficiency due to adenosine deaminase deficiency. Additionally, we propose a neurological approach including electrophysiological, radiological, and neurocognitive studies to address this group of children in an efficient and timely manner. METHODS: A descriptive, observational, retro-, and prospective analysis of patients with a confirmed immunological diagnosis seen between 1996 and 2021 and referred to the Department of Neurology for neurological evaluation was conducted. RESULTS: Ten patients met the inclusion criteria. The median age at diagnosis was 4 months (range, 1-36 months). All patients had neurodevelopmental delay with hypotonia in six, language delay in three, sensorineural hearing loss in four, and spastic paraparesis in one patient. Two children developed an epileptic syndrome, consisting of generalized epilepsy in one and focal epilepsy in the other. Neuroimaging showed brain calcifications in the basal ganglia and/or centrum semiovale in four patients and enlarged subarachnoid spaces in two other patients. CONCLUSION: In this pediatric series, the rate of neurological involvement associated with abnormalities on neuroimaging was high. Although this involvement could be related to accumulation of adenosine metabolites in the central nervous system, the possibility of associated chronic infections should be ruled out. Given the neurological manifestations, it is important to involve the pediatric neurologist in the multidisciplinary follow-up team.

Adenosine Deaminase-Like Gene-Carried Lentivirus Toolkit for Identification of DNA N6-Methyladenine Origins.

Post-replicative DNA N6-methyladenine (pr6mdA) can form via bona fide methylase-catalyzed adenine methylation, playing a pivotal role in embryonic development and other biological processes. Surprisingly, pre-methylated adenine can be erroneously incorporated into DNA as misincorporated N6-methyladenine (i6mdA) via DNA polymerase-mediated replication. Despite pr6mdA and i6mdA sharing identical chemical structures, their biological functions diverge significantly, presenting a substantial challenge in distinguishing between the two. Here, for the first-time, it is exploited that the adenosine deaminase-like (Adal) protein and a corresponding activity-null mutant to construct an Adal lentivirus toolkit. With this newly designed toolkit, both pr6mdA and i6mdA can be identified and quantified simultaneously. The presence of 6mdA in the bone marrow cells of mice is shown, with its levels serving as indicators for growth with age, probably reflecting the cellular stress-caused changes in RNA decay, nucleotide pool sanitation, and transcription. Collectively, a powerful toolkit to advance understanding of both pr6mdA and i6mdA is demonstrated.

Soluble CD26: From Suggested Biomarker for Cancer Diagnosis to Plausible Marker for Dynamic Monitoring of Immunotherapy.

Soluble CD26 (sCD26), a glycoprotein with dipeptidyl peptidase (DPP4) enzymatic activity, can contribute to early diagnosis of colorectal cancer and advanced adenomas and has been studied, including for prognostic purposes, across various other types of cancer and disease. The latest research in this field has confirmed that most, though not all, serum/plasma sCD26 is related to inflammation. The shedding and/or secretion of sCD26 from different immune cells are being investigated, and blood DPP4 activity levels do not correlate very strongly with protein titers. Some of the main substrates of this enzyme are key chemokines involved in immune cell migration, and both soluble and cell-surface CD26 can bind adenosine deaminase (ADA), an enzyme involved in the metabolism of immunosuppressor extracellular adenosine. Of note, there are T cells enriched in CD26 expression and, in mice tumor models, tumor infiltrating lymphocytes exhibited heightened percentages of CD26+ correlating with tumor regression. We employed sCD26 as a biomarker in the follow-up after curative resection of colorectal cancer for the early detection of tumor recurrence. Changes after treatment with different biological disease-modifying antirheumatic drugs, including Ig-CTLA4, were also observed in rheumatoid arthritis. Serum soluble CD26/DPP4 titer variation has recently been proposed as a potential prognostic biomarker after a phase I trial in cancer immunotherapy with a humanized anti-CD26 antibody. We propose that dynamic monitoring of sCD26/DPP4 changes, in addition to well-known inflammatory biomarkers such as CRP already in use as informative for immune checkpoint immunotherapy, may indicate resistance or response during the successive steps of the treatment. As tumor cells expressing CD26 can also produce sCD26, the possibility of sorting immune- from non-immune-system-originated sCD26 is discussed.

Correlation of serum Adenosine Deaminase levels with microbiological parameters in Pulmonary Tuberculosis.

Accurate diagnosis of pulmonary tuberculosis is largely based on sputum smear microscopy, culture, and GeneXpert MTB/RIF tests; culture being the gold standard. All these diagnostic tests require sputum sample to be positive for Mycobacterium tuberculosis, while many active TB patients often do not present with M. tuberculosis positive sputum. Biochemical markers play an important role in early diagnosis, disease prevention, and drug response in tuberculosis. This study aims to find the association of serum adenosine deaminase (a biomarker) with the various microbiological parameters like sputum smear microscopy, culture and CBNAAT in pulmonary tuberculosis patients. A total of 40 cases were collected from November 2019 to October 2021, and the presumptive cases of pulmonary tuberculosis diagnosed by Ziehl-Neelsen staining for acid fast bacilli and/or CBNAAT were recruited. Serum adenosine deaminase levels were estimated.The following variables were significantly associated (p < 0.05) with serum adenosine deaminase levels: age, sputum smear microscopy findings, time to culture positivity, CBNAAT category and Ct value (Mean).This study does witness few significant correlations between serum adenosine deaminase levels and various microbiological parameters used in diagnosis of TB, which can be further explored and utilised in diagnosis and treatment of pulmonary tuberculosis.

Adenosine deaminase 2 regulates the activation of the toll-like receptor 9 in response to nucleic acids.

Human cells contain two types of adenosine deaminases (ADA) each with unique properties: ADA1, which is present in all cells where it modulates intracellular functions and extracellular signaling, and ADA2, which is secreted by immune cells. The exact intracellular functions of ADA2 remain undetermined and less defined than those of ADA1. ADA2 has distinct characteristics, such as low adenosine affinity, heparin-binding ability, and putative lysosomal entry. Here, we confirm that ADA2 is a lysosomal protein that binds toll-like receptor 9 (TLR9) agonists, specifically CpG oligodeoxynucleotides (CpG ODNs). We show that interferon-alpha (IFN-α) is secreted in response to TLR9 activation by CpG ODNs and natural DNA and markedly increases when ADA2 expression is downregulated in plasmacytoid dendritic cells (pDCs). Additionally, the pretreatment of pDCs with RNA further stimulates IFN-α secretion by pDCs after activation with CpG ODNs. Our findings indicate that ADA2 regulates TLR9 responses to DNA in activated pDCs. In conclusion, decreasing ADA2 expression or blocking it with specific oligonucleotides can enhance IFN-α secretion from pDCs, improving immune responses against intracellular infections and cancer.

Detection of drug-resistant Mycobacterium tuberculosis in pericardial fluid culture and its correlation with cartridge based nucleic acid amplification test and adenosine deaminase activity.

BACKGROUND: Pericardial effusion is the accumulation of fluid in the pericardial cavity. In nations with high tuberculosis (TB) load, TB is the most common cause of pericardial effusion. 1-2% of patients with pulmonary TB develop Pericardial TB worldwide. Multi-drug-resistant (MDR) TB, including extrapulmonary TB (EPTB) cases, are rising in number. Adenosine Deaminase (ADA) is an enzyme in lymphocytes and myeloid cells, which has certain immune functions in the body. ADA levels are increased in inflammatory conditions, like pleural, pericardial, or joint effusions, of bacterial etiology, granulomatous conditions, neoplasms, and autoimmune pathologies. TB is the only lymphocytosis involving disease with increased ADA levels. MDR EPTB is rare, but cases are on the rise, and tuberculous pericardial effusion is one such example. Hence, it is important to know the percentage of cases detected by a culture that can be identified by cartridge-based nucleic acid amplification test (CBNAAT), their resistance patterns, and to identify potential markers like ADA, which can help in early identification of cases. The objectives of this study were to identify the Mycobacterium tuberculosis (MTB) bacilli in culture, and correlate them with cartridge-based nucleic acid amplification test (CBNAAT) results and their drug-resistance, in the Pericardial tubercular effusion, and to find if Adenosine Deaminase (ADA) levels can be used as a predictor of the presence of MTB in pericardial fluid. METHODOLOGY: We enrolled 52 patients with moderate to large tuberculous pericardial effusion, based on pericardial fluid analysis, CBNAAT, and culture methods, between January 2021 and December 2021. RESULTS: The mean age of the patients was 41.85 + 17.88 years, with a median of 38 years. Males made up 57.7% of the total patients. MTB was detected in 16 (30.8%) patients in the CBNAAT evaluations. 14 (87.5%) of the CBNAAT-positive TB patients were sensitive to Rifampicin, whereas the remaining 2 (12.5%) were resistant to Rifampicin on CBNAAT. MTB was found to be growing in 8 (15.38%) drug sensitivity test cultures. Out of these 8, 6 were sensitive to first-line drugs, whereas 2 were resistant to both Isoniazid and Rifampicin. The presence of cough was found to have a significant difference between CBNAAT-detected MTB positive and negative patients (p = 0.020), whereas an insignificant difference was found for the presence of hypertension, diabetes mellitus, obesity, dyspnea, or fever. There was also an insignificant difference between the number of patients positive for the Tuberculin skin test, between the two groups. ADA was significantly higher in the MTB-detected CBNAAT group (85.91 + 37.60U/L vs 39.78 + 24.31U/L, p = 0.005), whereas the total leukocyte count, lymphocytes, neutrophils, random blood sugar levels, and serum protein levels had no significant difference. The area under the Receiver Operator Curve (CBNAAT positive: dependent variable; ADA: test result variable) was 0.854 (null hypothesis rejected), with a standard error of 0.078. CONCLUSIONS: Culture is the gold standard method to diagnose tuberculosis. Detection of MTB on pericardial fluid culture is very uncommon, though in our study, culture came out positive in 16% of patients, and 4% were resistant to rifampicin and isoniazid. Higher ADA levels in pericardial fluid are an indicator of tuberculous pericardial effusion.

Opening SCID newborn screening for novel exon genetic variants through whole-exome sequencing in China.

BACKGROUND: Severe combined immunodeficiency (SCID) is the most fatal form of inherited primary immunodeficiency disease. Known molecular defect mutations occur in most children with SCID. METHODS: Herein, we report Adenosine Deaminase-SCID (ADA-SCID) using whole-exome sequencing (WES), explore exome mutational landscape and significance for 17 SCID samples, and verify the mutated exon genes using the Gene Expression Omnibus (GEO) datasets. A total of 250 patients, who were hospitalized at the Neonatal Intensive Care Unit (NICU) of The Seventh Medical Center of the PLA General Hospital for 3 years (from 2017 to 2020), were screened for SCID. We collected mutated genes from the WES data of 17 SCID children. GSE609 and GSE99176 cohorts were used to identify the expressions of mutated exon genes and molecular features in SCID. Gene set variation analyses (GSVA) and correlation analyses were performed. RESULTS: The detection rate with approximately 6.8 % (17/250) of SCID is high in the NICU. A total of 16 genes were identified among 17 SCID samples, of which the Top 2 genes (MUC6 and RP11-683L23.1) might be crucial in the progression of SCID with 94 % mutation frequency. Furthermore, CNN2 and SCGB1C1 had significant co-mutations and may cooperate to affect SCID development. Importantly, the phylogenetic tree classification results of 17 SCID samples are more correlated to MUC6 with the most significant mutations. Expression profiles of seven mutated genes and five mutated genes were documented in GSE609 and GSE99176 cohorts based on microarray, respectively. Several immune-related pathways were significantly enriched, and Foxd4, differing from the other four mutated genes, was inversely correlated with the GSVA-enriched pathway. CONCLUSION: Due to its high detection rate (6.8%) and fatality rate (100%), the inclusion of SCID in newborn screening (NBS) is urgent for children in China. The WES successfully identified several common exonic variants (e.g., MUC6) and depicted the feature of mutations and evolution, which will help develop new diagnostic methods for SCID.

[Clinical Significance of Serum ADA Combined with GLB, CREA, ß2-MG and HGB in Newly Diagnosed Multiple Myeloma].

OBJECTIVE: To investigate the role of serum adenosine deaminase (ADA) combined with globulin (GLB), creatinine (CREA), ß2-microglobulin (ß2-MG) and hemoglobin (HGB) in the initial screening of multiple myeloma (MM), in order to reduce missed diagnosis and misdiagnosis of MM. METHODS: A retrospective analysis was performed on 62 newly diagnosed multiple myeloma (NDMM) patients who were admitted to the Department of Hematology of the First Affiliated Hospital of Chengdu Medical College from April 2018 to December 2021, and 33 patients with benign hematologic diseases and 30 healthy subjects were selected as the control group. The expression of ADA in pan-cancer was analyzed using TCGA and GTEx databases. The general data and laboratory indicators of the subjects were collected, and the differences of ADA activity and other laboratory indicators in each group were compared. The relationship between serum ADA activity and clinical data of NDMM patients was analyzed. The changes of ADA activity before and after chemotherapy in NDMM patients and the differences of ADA activity in NDMM patients with different DS and ISS stages were compared. Multivariate logistic regression was used to analyze the risk factors of NDMM. The receiver operating characteristic(ROC) curve was used to evaluate the diagnostic efficacy of ADA and other laboratory indicators in MM. Bioinformatics method was used to analyze the co-expression networks and enrichment pathways of ADA. RESULTS: ADA level was significantly upregulated in tissues of 14 types of cancer in TCGA database, and ADA was highly expressed in 11 types of cancer in TCGA combined with GTEx databases. The serum levels of ADA, GLB, uric acid (UA), cystatin C (CysC) and ß2-MG in the NDMM group were significantly higher than those in benign hematologic disease group and healthy control group ( P < 0.05), while the levels of ALB and the value of albumin to globulin ratio (A∶G) in the NDMM group were significantly lower than those in the other two groups ( P < 0.001). There were significant differences in DS stage (P =0.036), ISS stage (P =0.019) and the levels of CREA (P =0.036), UA (P =0.034), ß2-MG (P =0.019) in NDMM patients with different ADA activity levels. After primary chemotherapy, ADA activity and ß2-MG concentration were decreased in NDMM patients ( P < 0.01). The comparison results of patients in different stages showed that ADA activity of patients in DS stage I+II was significantly lower than that of patients in DS stage III (P <0.05), and ADA activity of patiens in ISS stage I+II was significantly lower than that of patients in ISS stage III ( P < 0.01). Multivariate logistic regression analysis showed that increased GLB, increased ADA activity, increased CREA, increased ß2-MG and decreased HGB were independent risk factors for NDMM. The area under the curve (AUC) of ADA in the diagnosis of MM was 0.847, and the AUC of ADA combined with GLB, CREA, ß2-MG and HGB in the diagnosis of MM was 0.940. The results of co-expression network and enrichment pathway analysis showed that ADA bounded to 20 proteins and it was significantly associated with the metabolic pathways of purine, pyrimidine, nicotinate and nicotinamide. CONCLUSION: The detection of ADA activity in serum is of positive significance for the auxiliary diagnosis, therapeutic evaluation and monitoring the progress of NDMM patients. ADA combined with GLB, CREA, ß2-MG and HGB can improve the detection rate of MM, and reduce missed diagnosis and misdiagnosis to a certain extent.

A crucial role of adenosine deaminase in regulating gluconeogenesis in mice.

Adenosine deaminase (ADA) catalyzes the irreversible deamination of adenosine (ADO) to inosine and regulates ADO concentration. ADA ubiquitously expresses in various tissues to mediate ADO-receptor signaling. A significant increase in plasma ADA activity has been shown to be associated with the pathogenesis of type 2 diabetes mellitus. Here, we show that elevated plasma ADA activity is a compensated response to high level of ADO in type 2 diabetes mellitus and plays an essential role in the regulation of glucose homeostasis. Supplementing with more ADA, instead of inhibiting ADA, can reduce ADO levels and decrease hepatic gluconeogenesis. ADA restores a euglycemic state and recovers functional islets in db/db and high-fat streptozotocin diabetic mice. Mechanistically, ADA catabolizes ADO and increases Akt and FoxO1 phosphorylation independent of insulin action. ADA lowers blood glucose at a slower rate and longer duration compared to insulin, delaying or blocking the incidence of insulinogenic hypoglycemia shock. Finally, ADA suppresses gluconeogenesis in fasted mice and insulin-deficient diabetic mice, indicating the ADA regulating gluconeogenesis is a universal biological mechanism. Overall, these results suggest that ADA is expected to be a new therapeutic target for diabetes.