Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activity of the lymphocyte ectoenzyme 5'-nucleotidase is very low in the majority of patients with primary 'common variable' hypogammaglobulinaemia. In order to test whether this can be explained by lymphocyte subpopulation deficiencies we measured 5'-nucleotidase activity, using both biochemical and histochemical techniques, in purified T and B cells from patients and healthy subjects. Purified B cells from normal subjects have about four times the activity of T cells. This explains why the levels of lymphocyte 5'-nucleotidase activity are at the lower limit of the normal range in patients with X-linked hypogammaglobulinaemia who lack B cells. The low levels in the 'common variable' group can be explained by low activity in their T lymphocytes associated with either low activity in their B cells or depletion of B cells. The finding that inhibition of the enzyme does not interfere with in vitro lymphocyte transformation or immunoglobulin production in normal subjects indicates that the enzyme deficiency is not directly responsible for the hypogammaglobulinaemia. These and other studies suggest that this enzyme appears on lymphocytes at a certain stage of development and that both T and B lymphocytes in some patients with 'common variable' hypogammaglobulinaemia are developmentally immature.
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PMID:Ecto 5'-nucleotidase deficiency in primary hypogammaglobulinaemia. 38 54

Lymphocytes from patients with primary immunodeficiency were tested histochemically for ecto 5'-nucleotidase (5'N) and alpha-naphthyl (non-specific) esterase. More than half the patients with 'common variable' hypogammaglobulinaemia, all those with X-linked hypogammaglobulinaemia and some of those with selective IgA deficiency had a very low percentage of lymphocytes staining for 5'N as compared to controls. A lack of B cells probably explains the finding in X-linked hypogammaglobulinaemia, but does not fully explain the results in the other groups. Most patients with 'common variable' hypogammaglobulinaemia had a very low percentage of lymphocytes with granular staining for alpha-naphthyl (non-specific) esterase in contrast to normal numbers in those with X-linked hypogammaglobulinaemia and most of those with selective IgA deficiency. Granules containing non-specific esterase are characteristically found in 'mature' T lymphocytes. The enzyme abnormalities in the T and B cells of 'common variable' hypogammaglobulinaemic patients could be explained by 'immature' cell types.
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PMID:Histochemical studies for 5'-nucleotidase and alpha-naphthyl (non-specific) esterase in lymphocytes from patients with primary immunoglobulin deficiencies. 46 56

The 5'-nucleotidase (5'-N) deficiency on circulating mononuclear cells of patients with 'common variable' hypogammaglobulinaemia (CV-H) was shown to be the result of one or more of three factors: reduced T cell 5'-N activity, a reduced percentage of circulating B cells, and a low B cell 5'-N activity. A lack of circulating B lymphocytes, together with a low T cell 5'-N activity in some cases, was found to be responsible for the deficiency of lymphocyte 5'-N in patients with X-linked hypogammaglobulinaemia (X-H). The low levels of 5'-N activity in CV-H and X-H patients were not due to abnormal compartmentalization of the enzyme, altered enzyme kinetics, or the presence of a regulatory factor. Cord Blood B and T cells have a lower 5'-N activity than adult lymphocytes. The patient and cord blood data are discussed in relation to the stage of cellular maturity.
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PMID:Lymphocyte 5'-nucleotidase in primary hypogammaglobulinaemia and cord blood. 624 81