Adenosine deaminase, purine nucleoside phosphorylase and 5'-nucleotidase activities in infectious mononucleosis

[Clinical features and pathogenesis of Glial fibrillary acidic protein (GFAP) antibody-associated disorders]

Glial fibrillary acidic protein (GFAP) antibody-associated disorders (AD) were recently proposed to be immune-mediated neurological disorders. The pathogenesis of GFAP antibody-AD is poorly understood. Pathologically, there is a marked infiltration of large numbers of lymphocytes, including CD8+ and CD4+ T cells, into the meningeal and brain parenchyma, especially around the perivascular areas. GFAP-specific cytotoxic T cells are considered to be the effector cells of GFAP antibody-AD. The common phenotype of GFAP antibody-AD includes meningoencephalitis with or without myelitis. During the clinical disease course, patients present with consciousness disturbances, urinary dysfunction, movement disorders, meningeal irritation, and cognitive dysfunction. The detection of GFAP antibodies in the cerebrospinal fluid (CSF) by cell-based assay is essential for a diagnosis of GFAP antibody-AD. The CSF can be examined for lymphocyte-predominant pleocytosis and elevated protein levels. Brain linear perivascular radial enhancement patterns are observed in about half of GFAP antibody-AD patients. Spinal cord magnetic resonance imaging is used to detect longitudinal extensive spinal cord lesions. Although corticosteroid therapy is generally effective, some patients have a poor prognosis and relapse.

Identification of ADA as a Biomarker for Atypical Epstein Barr Virus Infection in Children

OBJECTIVE

This study aims to explore the ability of adenosine deaminase (ADA) to discriminate atypical Epstein Barr virus (EBV) infection in children from acute febrile illness.

METHODS

All children admitted to the Children's Hospital of Soochow University between 2018 and 2019, who were acute febrile patients and subjected to the plasma EBV-DNA polymerase chain reaction (PCR) and indirect immunofluorescence (IIF) assay for EBV-specific antibodies assays. The diagnostic value of each detection index was compared by the area under the ROC curve.

RESULTS

In children with atypical Epstein Barr virus infection, the sensitivity, specificity, positive predictive value, negative predictive value and Youden index were 62.87%, 100.00%,100.00%, 61.73% and 0.63 for EBV-DNA PCR assay, 80.84%, 100.00%, 100.00%, 75.76% and 0.81 for VCA-IgG avidity and 89.22%, 87.00%, 91.98%, 82.86% and 0.76 for ADA. VCA-IgG avidity (AUC=0.904, P<0.01) and ADA (AUC=0.881, P<0.01) assays had the great diagnostic efficiency. In addition, the sensitivity, specificity and AUC were 92.75%,91.43% and 0.921(95%CI: 0.856-0.985) for ADA in the course≤3 days group, respectively.

CONCLUSIONS

ADA has a good diagnostic value in the early stage of atypical EBV infection, and is not affected by primary EBV infection and reactivation. SCHLüSSELWöRTER: Adenosine deaminase, Epstein -Barr virus, Biomarker, children.

Concordance of adenosine deaminase with immunoglobulins and lymphocyte subsets in EBV-related diseases

BACKGROUND

Clinical manifestations of Epstein-Barr virus (EBV) infection are diverse. This study aimed to explore the immune response in EBV-related diseases and the correlation between immune cells and adenosine deaminase (ADA) levels.

METHODS

This study was conducted at the Children's Hospital of Soochow University. In total, 104 patients with EBV-associated respiratory tract infection (EBV-RTI), 32 patients with atypical EBV infection, 54 patients with EBV-associated infectious mononucleosis (IM1, with normal alanine aminotransferase [ALT] levels), 50 patients with EBV-IM2 (with elevated ALT levels), 50 patients with acute respiratory infection (AURI, with other pathogens), and 30 healthy controls were enrolled in this study. Indicators of ADA, immunoglobulins (Igs), and lymphocyte subsets were analyzed for EBV-related diseases.

RESULTS

Differences in the white blood cell, lymphocyte counts, ADA levels, IgA, IgG and IgM titers, percentage of CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺, CD16⁺CD56⁺, CD3^-CD19⁺, and CD19⁺CD23⁺ lymphocytes, and CD4⁺/CD8⁺ ratio between EBV-related disease groups were all statistically significant (P < 0.01). ADA levels in the EBV-related disease groups were significantly higher than those in the control group (P < 0.01). The lymphocyte count, ADA levels, IgA and IgG titers, and percentage of CD3⁺ and CD3⁺CD8 + lymphocytes in the atypical EBV infection, EBV-IM1, and EBV-IM2 groups were significantly higher than those in the EBV-RTI, AUTI, and control groups (P < 0.01), whereas the percentage of CD3⁺CD4⁺, CD3^-CD19⁺, and CD19⁺CD23⁺ lymphocytes and CD4⁺/CD8⁺ ratio showed the opposite trend. ADA levels were consistent with and closely related to the viral load and cellular and humoral immunity in EBV-related diseases.

CONCLUSIONS

ADA levels, humoral immunity, and cellular immunity were diverse in EBV-related diseases, and ADA was closely related to Igs and lymphocyte subsets.

Diversity of adenosine deaminase in children with EBV-related diseases

Background

Adenosine deaminase (ADA) is an enzyme involved in purine metabolism with an important role in cellular immunity. Thus, this study investigated the association between ADA and Epstein–Barr virus (EBV)-related diseases.

Methods

We retrospectively collected data from all children admitted to the Children’s Hospital of Soochow University, Suzhou, China, between May 1, 2018, and March 31, 2019, who underwent plasma EBV-DNA polymerase chain reaction, alanine aminotransferase (ALT), and ADA testing.

Results

Of 6868 children, 1877 had an elevated level of ADA, and 4991 had a level within the normal range. Multivariate logistic regression analysis indicated that ALT (adjusted odds radio [aOR] = 1.001, 95% confidence interval [CI]: 1.001–1.002), EBV infection (aOR = 8.486, 95% CI: 6.753–10.663), inflammatory disease (aOR = 3.915, 95% CI: 3.198–4.794), autoimmune disease (aOR = 2.307, 95% CI: 1.823–2.920), and malignant disease (aOR = 1.381; 95% CI: 1.101–1.734) were risk factors for an elevated ADA level. Furthermore, the ADA levels among EBV-related diseases significantly differed, including infectious mononucleosis, atypical EBV infection, respiratory infection, malignant disease, and other diseases (P < 0.05). In addition, the ADA level positively correlated with the Epstein–Barr viral load (r = 0.501, P < 0.05).

Conclusions

This large, retrospective study identified a correlation between ADA and EBV-related diseases, which may help clinicians detect these diseases earlier based on the plasma ADA concentration.

Adenosine deaminase as a marker for the severity of infectious mononucleosis secondary to EBV in children

Background

Infectious mononucleosis, a common disease in children and young adults, is often accompanied by elevated transaminase levels and rarely, liver failure. This study aimed to determine whether adenosine deaminase is a marker of severity in children with infectious mononucleosis, especially those with elevated alanine transaminase levels.

Methods

This case-control study was conducted at the Children’s Hospital of Soochow University. A total of 104 children with infectious mononucleosis and 50 controls with other acute infections and fever, tonsillitis, or lymphadenitis, were enrolled in the study. Among the 104 children with infectious mononucleosis, 54 had normal alanine transaminase levels and 50 had elevated alanine transaminase levels. The children’s clinical and laboratory data were analyzed to assess the diagnostic value of adenosine deaminase in the three groups.

Results

The adenosine deaminase level in the infectious mononucleosis group was significantly higher than that in the control group (P < 0.001). The adenosine deaminase levels were highly correlated with lymphocyte count, CD3⁺CD8⁺ T cells (%), CD4⁺/CD8⁺ ratio, and CD3⁻CD19⁺ (%) (r > 0.7, P < 0.01). The sensitivity and specificity of adenosine deaminase in predicting children with infectious mononucleosis were 97.1% and 94.0%, respectively. Furthermore, multivariate regression analysis revealed that adenosine deaminase level was a risk factor for elevated alanine transaminase in children with infectious mononucleosis.

Conclusions

Adenosine deaminase may be a marker of the severity of infectious mononucleosis in children, and a predictor of elevated alanine transaminase in children with infectious mononucleosis.

Serum and synovial fluid adenosine deaminase activity in patients with rheumatoid arthritis, osteoarthritis, and reactive arthritis

Adenosine deaminase activity was determined in paired samples of serum and synovial fluid taken from patients with rheumatoid arthritis (n = 12), reactive arthritis (n = 13), and osteoarthritis (n = 7), and the value of this investigation in the diagnosis of synovial swellings was assessed. Increased activity was found in the synovial fluid taken from patients with rheumatoid disease and reactive arthritis, though values were less raised in the latter. Synovial fluid taken from patients with osteoarthritis did not show significantly raised adenosine deaminase activity as compared with that of normal controls (n = 3).