The extra-enzymic function of cell-surface adenosine deaminase (ADA), an enzyme mainly localized in the cytosol but also found on the cell surface of monocytes, B cells and T cells, has lately been the subject of numerous studies. Cell-surface ADA is able to transduce co-stimulatory signals in T cells via its interaction with CD26, an integral membrane protein that acts as ADA-binding protein. ...

Genetic polymorphism of erythrocyte adenosine deaminase (ADA) was first described by Spencer et al. in 1968 [1]. Its three phenotypes, ADA 1, ADA 2, and ADA 2-1, were found to represent the homozygous or heterozygous expression of two allelic genes at the ADA autosomal locus. Subsequent studies revealed several rare phenotypes representing heterozygosity for either the ADA1 or ADA2 allele and a...

Adenosine deaminase (ADA)-deficient Severe Combined Immunodeficiency (ADA-deficient SCID) is characterized by impaired lymphocyte development and function resulting from the adenosine metabolism defect. Enzyme replacement therapy with polyethylene glycol-conjugated adenosine deaminase (PEG-ADA) minimizes infectious complications of ADA-deficient patients who have not received bone marrow transp...

We read with interest the recent paper by QUEROL JM, BARBE F, MANRESA F, EsTEBAN L and CANETE [1]. The authors presented some patients with tuberculous pleural effusion and adenosine deaminase activity (ADA) values less than 43 U·I-• We reported previously that ADA values (Guisti method) were statistically significantly higher in tuberculous pleural effusions than in most other diseases [2]. Hi...

OBJECTIVES Adenosine deaminase (ADA) can aid in the diagnosis of tuberculous pleural effusions, but false-positive findings from lymphocytic effusions have been reported. We studied the ADA levels in a variety of nontuberculous lymphocytic effusions and analyzed the relationships between ADA and conventional hematologic and biochemical parameters. METHODS One hundred six lymphocytic pleural f...

Genetic variation of the enzyme, adenosine deaminase (ADA), can be detected by starch gel electrophoresis of human red cell lysates and an appropriate staining procedure (Spencer, Hopkinson, and Harris, 1968). Three phenotypes (ADA 1, ADA 2-1, and ADA 2) appear to be determined by two structural alleles, ADA' and ADA2. The frequency of the less common allele, ADA2, was reported to be 0 03 and 0...

CD26 is a lymphocyte marker that can anchor adenosine deaminase (ADA) on the T cell surface. We found that ADA is regulated by cytokines on the cell surface during T cell activation. By means of flow cytometry, immunofluorescence, and immunoblotting techniques, we found that interleukin (IL)-2 and IL-12 up-regulate ecto-ADA and CD26 expression. In clear contrast, IL-4 led to down-regulation of ...

Deficiency of erythrocytic and lymphocytic adenosine deaminase (ADA) occurs in some patients with severe combined immunodeficiency disease (SCID). SCID with ADA deficiency is inherited as an autosomal recessive trait. ADA is markedly reduced or undetectable in affected patients (homozygotes), and approximately one-half normal levels are found in individuals heterozygous for ADA deficiency. The ...

Neurons immunoreactive for the enzyme adenosine deaminase (ADA) in the posterior basal hypothalamus of the rat have a distribution pattern similar to those immunoreactive for histidine decarboxylase (HDC) and are particularly numerous in the tuberal (TM), caudal (CM) and postmammillary caudal (PCM) hypothalamic magnocellular nuclei which harbor neurons containing glutamic acid decarboxylase (GA...

Genetic variation of the enzyme, adenosine deaminase (ADA), can be detected by starch gel electrophoresis of human red cell lysates and an appropriate staining procedure (Spencer, Hopkinson, and Harris, 1968). Three phenotypes (ADA 1, ADA 2-1, and ADA 2) appear to be determined by two structural alleles, ADA' and ADA2. The frequency of the less common allele, ADA2, was reported to be 0 03 and 0...