Absence of erythrocyte adenosine deaminase associated with severe combined immunodeficiency

Adenosine-deaminase-associated immunodeficiency. I. Differential sensitivities of lymphocyte subpopulations exposed to 2-deoxycoformycin in vivo

In order to obtain a better understanding of the degree of immune dysfunctions caused by the absence of adenosine deaminase, we gave a single i.p. injection of 2'-deoxycoformycin (2-dcf), a potent inhibitor of the enzyme ADA at various doses into adult Syrian hamsters. These animals were examined for their ability to mount primary in vivo antibody responses to helper T cell dependent (Th-d) and helper T cell independent (Th-ind) antigens. Hamsters treated with 0.5 mg/kg of 2-dcf mounted enhanced splenic plaque-forming cell (PFC) responses to sheep erythrocytes, a Th-d antigen, and to pneumococcal polysaccharide type III (SIII), a Th-ind antigen. Treatment of animals with 1.0 mg/kg of 2-dcf resulted in a significantly depressed (P less than 0.001) PFC response to Th-d antigen, but a further enhanced response to Th-ind antigen. One mechanism which may be responsible for such a dichotomous response to these two types of antigens was selective dysfunction of T cell subpopulations. At higher doses (1.5-4.0 mg/kg), PFC responses to both types of antigens were significantly suppressed. Immunoenhancement at low doses of 2-def was attributed to an increased susceptibility of T suppressor cells to 2-dcf. This hypothesis was confirmed by priming the 2-dcf-treated animals with low-dose Th-ind antigens. These animals failed to induce low-dose tolerance by stimulation of antigen-specific suppressor T cell subsets. At low doses, B cells and T helper cell functions were found to be intact, as further confirmed by priming the animals with the carrier keyhole limpet haemocyanin (KLH) and challenging with trinitrophenyl-KLH. This dose-dependent selective susceptibility of various T cell subpopulations and B cells may explain the heterogeneity of clinical, biochemical and immunological parameters observed in children with ADA deficiency severe combined immunodeficiency.

Pegademase bovine: replacement therapy for severe combined immunodeficiency disease

Severe combined immunodeficiency (SCID) represents a syndrome characterized by abnormal function of cellular and humoral immunity. Of the various types of SCID, approximately one-fourth are associated with adenosine deaminase (ADA) deficiency. Treatment consists of bone marrow transplantation, red blood cell transfusions, enzyme replacement, and, more recently, gene therapy. Pegademase bovine is the sole agent available for enzyme replacement therapy of SCID associated with ADA deficiency. The drug is administered intramuscularly to infants from birth and to children of any age at time of diagnosis. At present, few adverse effects or drug interactions have been documented. Although it is expensive (approximately $60,000 annually), pegademase bovine offers an alternative to standard means of therapy.

Short stature/short limb skeletal dysplasia with severe combined immunodeficiency and bowing of the femora: report of two patients and review

We report two patients with severe combined immunodeficiency and short stature/short limb skeletal dysplasia. Case 1 presented at birth with rhizomelic shortening of the extremities and bowing of the femora. She developed clinical signs of severe combined immunodeficiency at 13 months and died at 21 months. Case 2 had severe prenatal shortening and bowing of the extremities and a small, malformed chest. Symptoms of severe combined immunodeficiency and severe failure to thrive developed soon after birth and she died at 5 months. The diagnosis of severe combined immunodeficiency in our patients was based on their clinical course and necropsy findings, supported in case 1 by the results of immune function tests. The results of investigation of immune function (immunoglobulins, lymphocyte subpopulations, lymphocyte function) are very variable in this syndrome as in other variants of severe combined immunodeficiency. Bone histopathology in both patients showed grossly irregular costochondral junctions, but normal transition of proliferating to hypertrophic chondrocytes. These cases belong to early lethal type 1 short limb skeletal dysplasia with severe combined immunodeficiency. Review of previously published cases with severe combined immunodeficiency and well documented skeletal findings show eight patients with prenatal onset of bowing and shortening of the extremities and metaphyseal abnormalities. These include two sib pairs concordant for the skeletal changes. In these cases, adenosine deaminase levels were not reported. An additional four published cases with associated adenosine deaminase deficiency had only mild metaphyseal abnormalities, but subsequently showed no linear growth.(ABSTRACT TRUNCATED AT 250 WORDS)

The associations of HLA and other genetic markers with glomerulonephritis

One hundred and seventy-nine patients with various forms of glomerulonephritis confirmed histologically were tested for HLA A and B antigens: Thirty-four with membranous glomerulonephritis were also typed for DR antigens. One hundred and forty-one of these patients were further tested for blood group, red cell enzyme, and plasma protein systems. The minimal-change and the mesangio-capillary glomerulonephritis showed a significant association with B8 and Bw44 antigens respectively, whereas the membranous nephritis in addition to B8 was also found to be associated with DR3 antigen. Previously described associations with Henoch-Schönlein and Berger's nephritis were not proved. A large group with nonspecific proliferative glomerulonephritis did not show any association with HLA. Among the other single-gene characters studied, a significant association was found with Bf (Factor B or C3 proactivator) and adenosine deaminase, both markers thought to be involved in the immune response. The close association of the markers located on chromosome 6 and glomerulonephritis indicates that there may be an immunological component in the aetiology of the disease. The significance of the various associations found is discussed.

Purine metabolism in relation to leukemia and lymphoid cell differentiation

A number of inborn errors of purine metabolism have been associated with immunodeficiency diseases. From studies to the possible mechanism(s) leading to the defects in the immune system, it appeared that the accumulation of deoxyATP and deoxyGTP and the subsequent inhibition of ribonucleotide reductase played an important role. The inhibition of methylation pathways through the accumulation of s-adenosylmethionine seems to be a second valid concept. The amount to which certain subtypes of lymphoid cells were affected by the enzyme deficiencies was strongly related to the enzymatic make-up of the cells. Lymphoid cells from different maturation stages could be affected in a specific way, depending on the different enzyme activities of these cells. Studies on human lymphoblastic leukemias showed that, related to the immunological subtype, the different leukemias could be characterized by a different enzymatic make-up. In this paper we discuss the possibilities for a specific enzyme directed chemotherapy, directed against specific subtypes of human lymphoblastic leukemias. Experimental evidence indicates that for example the adenosine deaminase inhibitor 2'deoxycoformycin can be used as a specific drug against acute lymphoblastic leukemia with the T cell phenotype.

Inhibition of purine nucleoside phosphorylase activity and of T-cell function with allopurinol-riboside

Allopurinol-riboside competitively inhibits the action of purine nucleoside phosphorylase on inosine in vitro with a Ki of 277 mumol. After simple incubation of allopurinol-riboside with PNP, allopurinol was not formed. Lymphocyte blastogensis induced by PHA and Con A was significantly suppressed by allopurinol-riboside in a concentration-dependent manner. When LPS was used as a mitogen, the inhibition of allopurinol-riboside on lymphocyte proliferation was less marked. Humoral immunity was not suppressed by allopurinol-riboside. In contrast, cellular immunity was significantly suppressed by allopurinol-riboside in vivo. These results suggested that allopurinol-riboside is a drug which produces a model of PNP deficiency, and that it may be a useful inhibitor of cellular immunity.

Urinary excretion of orotic acid, orotidine and other pyrimidines in a patient with purine nucleoside phosphorylase deficiency

Urinary orotidine and orotic acid have been determined in a patient with purine nucleoside phosphorylase (PNP) deficiency under various dietary therapeutic conditions. For this purpose a new procedure for the analysis of both compounds has been developed, consisting of prefractionation with Dowex 1X8, followed by two HPLC steps on a micro Bondapak NH2 and a micro Bondapak C18 column. With this method normal as well as slightly elevated excretions of orotic acid have been found in our patient. No evidence was obtained for inhibition of OPRT by purine (deoxy)nucleosides as a cause of pyrimidine starvation. A significant increase of urinary orotidine was found after loading with allopurinol. For comparison excretory values in a patient with ornithine transcarbamylase deficiency and also in a patient with orotic aciduria type I are shown. The possible cause of the slight increase in urinary orotic acid in our patient has been discussed.

Action of purine nucleosides on the release of intracellular enzymes from rat lymphocytes

Rat lymphocytes incubated under hypoxic conditions in vitro show a time-dependent release of intracellular enzymes. As reported previously, enzyme release (lactate dehydrogenase) is decreased by metabolite, notably ATP and glucose, that contribute towards lymphocyte energy metabolism. The action of purine nucleosides in relation to enzyme release was investigated. Inosine was shown to decrease significantly lactate dehydrogenase release, whereas adenosine exerted a supportive action only at concentrations less than 0.5 mmol/l. Inosine decreased enzyme efflux maximally at concentrations of at least 2--3 mmol/l. The mechanism of inosine action was deduced to be primarily ribose 5-phosphate formation and its subsequent metabolism by energy-yielding pathways. Inosine was presumed also to enter the purine 'salvage pathway' and thereby maintain intracellular adenine nucleotide pools.

Limited effect of erythrocyte and plasma infusions in adenosine deaminase deficiency

A 10-month-old child with a profound deficiency of adenosine deaminase and severe combined immunodeficiency was treated for a period of 17 months with red cell and plasma transfusions containing normal amounts of the deficient enzyme. Following each transfusion, the plasma adenosine, red cell and lymphocyte ATP, urinary adenine, and urinary deoxyadenosine decreased transiently. During this period, the absolute blood lymphocyte count rose and a limited increased in the response of the lymphocytes to PHA-P was observed. Delayed hypersensitivity skin tests remained negative during the transfusion periods. A quantitative elevation of serum immunoglobulins occurred, but specific antibody formation was not elicited. In contrast to a previous report of successful therapy of ADA deficiency with red cell and plasma infusions, this patient responded poorly to enzyme replacement therapy. The difference may be related to a more profound enzyme deficiency in our patient.

Increased purine nucleotides in adenosine deaminase-deficient lymphocytes

It was found that ATP and cyclic AMP were greatly increased in human blood lymphocytes which were deficient in ADA. Certain other purine and pyrimidine nucleotides were elevated but to a lesser degree. Energy production in these cells may be inhibited by the increase in nucleotides since the ATP:ADP ratio was significantly below normal. Thus it appears that the immunologic deficiency in human ADA deficiency is related to increased nucleotide concentrations in the lymphocytes.

[Adenosine deaminase deficiency in primary immunodeficiencies (author's transl)]

The occurrence of severe combined immunodeficiency (SCID) with adenosine deaminase (ADA) deficiency in erythrocytes has been reported in 14 patients. Enzyme deficiency may result in early depression of the lymphatic system. ADA is detectable in different tissues by photometric and electrophoretic methods. The gene locus for ADA has been localised on chromosome 20. Studies on the enzyme defect in different forms of primary immunodeficiencies led to the description of a well defined nosological entity. New aspects can be expected in the fields of pathogenesis, prenatal diagnosis, genetic councelling, and possibly therapeutic trials.

The chondro-osseous dysplasia of adenosine deaminase deficiency with severe combined immunodeficiency

Three children, two of them siblings, with severe combined immunodeficiency and adenosine deaminase deficiency died within the first six months of life from the complications of acute bacterial infections. Subtle radiographic abnormalities were seen at the costochondral junctions, at the apophysis of the iliac bones, and in the vertebral bodies. At autopsy, the thymus showed evidence of early differentiation and, in one instance, aborted Hassall's corpuscles. Histologic study of the bone disclosed lack of organized cartilage columnar formation, large lacuni containing hypertrophied cells, and lack of trabecular formation with uninterrupted areas of calcified cartilage. These changes are distinctly different from those observed in the metaphyseal chondrodysplasias or in other chondrodystrophies.

Adenosine metabolism in phytohemagglutinin-stimulated human lymphocytes

The association of a human genetic deficiency of adenosine deaminase activity with combined immunodeficiency prompted a study of the effects of adenosine and of inhibition of adenosine deaminase activity on human lymphocyte transformation and a detailed study of adenosine metabolism throughout phytohemagglutinin-induced blastogenesis. The adenosine deaminase inhibitor, coformycin, at a concentration that inhibited adenosine deaminase activity more than 95%, or 50 muM adenosine, did not prevent blastogenesis by criteria of morphology or thymidine incorporation into acid-precipitable material. The combination of coformycin and adenosine, however, substantially reduced both the viable cell count and the incorporation of thymidine into DNA in phytohemagglutinin-stimulated lymphocytes. Incubation of lymphocytes with phytohemagglutinin for 72 h produced a 12-fold increase in the rate of deamination and a 6-fold increase in phosphorylation of adenosine by intact lymphocytes. There was no change in the apparent affinity for adenosine with either deamination or phosphorylation. The increased rates of metabolism, apparent as early as 3 h after addition of mitogen, may be due to increased entry of the nucleoside into stimulated lymphocytes. Increased adenosine metabolism was not due to changes in total enzyme activity; after 72 h in culture, the ratios of specific activities in extracts of stimulated to unstimulated lymphocytes were essentially unchanged for adenosine kinase, 0.92, and decreased for adenosine deaminase, 0.44. As much as 38% of the initial lymphocyte adenosine deaminase activity accumulated extracellularly after a 72-h culture with phytohemagglutinin. In phytohemagglutinin-stimulated lymphocytes, the principal route of adenosine metabolism was phosphorylation at less than 5 muM adenosine, and deamination at concentrations greater than 5 muM. In unstimulated lymphocytes, deamination was the principal route of adenosine metabolism over the range of adenosine concentrations studied (0.5-250 muM). These studies demonstrate the dependence of both the unstimulated and stimulated lymphocyte on adenosine and may account for the observed sensitivity of mitogen-stimulated lymphocytes to the toxic effects of exogenously supplied adenosine in the presence of the adenosine deaminase inhibitor coformycin. A single case of immunodeficiency disease has been reported in association with purine nucleoside phosphorylase deficiency. The catabolism of guanosine was also found to be enhanced in stimulated normal lymphocytes; phosphorolysis of guanosine to guanine by intact lymphocytes increased six fold after 72-h culture with phytohemagglutinin. The specific activity of purine nucleoside phosphorylase in extracts, with guanosine as substrate, was essentially the same in stimulated and unstimulated lymphocytes after 72 h of culture.

Purine metabolism in adenosine deaminase deficiency

Purine and pyrimidine metabolites were measured in erythrocytes, plasma, and urine of a 5-month-old infant with adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) deficiency. Adenosine and adenine were measured using newly devised ion exchange separation techniques and a sensitive fluorescence assay. Plasma adenosine levels were increased, whereas adenosine was normal in erythrocytes and not detectable in urine. Increased amounts of adenine were found in erythrocytes and urine as well as in the plasma. Erythrocyte adenosine 5'-monophosphate and adenosine diphosphate concentrations were normal, but adenosine triphosphate content was greatly elevated. Because of the possibility of pyrimidine starvation, pyrimidine nucleotides (pyrimidine coenzymes) in erythrocytes and orotic acid in urine were measured. Pyrimidine nucleotide concentrations were normal, while orotic acid was not detected. These studies suggest that the immune deficiency associated with adenosine deaminase deficiency may be related to increased amounts of adenine, adenosine, or adenine nucleotides.

Adenosine-aminohydrolase activity in the erythrocytes, lymphocytes, and plasma of healthy subjects and kidney transplant recipients

Adenosine-aminohydrolase activity in the red blood cells and lymphocytes of transplant patients were assayed by continuous flow analysis. This enzyme, which has been implicated in the ability of lymphocytes to mount an immune response, was evaluated in renal allografted patients immunosuppressed by azothiprine and methylprednisone. Red cell adenosine-aminohydrolase activity was depressed in all patients when compared to nontreated health controls. Adenosine aminohydrolase activity was raised in the lymphocytes of the renal allografted patients. Renal transplant patients' in vitro lymphocyte reactivity to antigens, mitogens, or skin testing to specific antigens, confirmed the depressive effects of immunosuppression observed in vivo. We conclude from these studies that red cell adenosine-aminohydrolase activity may be a more sensitive index of the state of immunoresponsiveness than the corresponding enzyme activity in the lymphocyte.

Restoration of in-vitro lymphocyte responses with exogenous adenosine deaminase in a patient with severe combined immunodeficiency

Deficiency of adenosine deaminase (A.D.A.) occurs in an autosomal recessive form of severe combined immunodeficiency (S.C.I.D.). The role of this enzyme deficiency in the pathogenesis of the immune defects is not clear. A patient with A.D.A. S.C.I.D., studied during the first six weeks of life, was found to have B and T lymphocytes as well as 25% of normal lymphocyte responses to mitogens. This patient subsequently became severely lymphopenic with loss of mitogen responsiveness. Addition of calf-intestinal A.D.A. or human-erythrocyte A.D.A. to cultures of this patient's lymphocytes restored their ability to proliferate when stimulated with mitogens. These data indicate that A.D.A. deficiency is causally related to the cellular immune defects observed in A.D.A. S.C.I.D. and suggests a possible role for enzyme replacement in the therapy of this disorder.

Quantitative measurement of adenosine deaminase from human erythrocytes

Methods for measuring enzymatic activity of adenosine deaminase from human erythrocytes were examined and compared with each other. Determination of ADA by the method in which adenosine is converted into inosine with uric acid as the final product by the action of nucleoside phosphorylase and xanthine oxidase appears to yield the most reliable results. In the recommended assay saponin is used for lysis of erythrocytes when testing adenosine deaminase activity in red blood cells. Storage of erythrocyte samples is optimal at +4 degrees C; storage at room temperature or at -20 degrees C leads to loss of adenosine deaminase activity.

Adenosine deaminase activity in leukaemia

Adenosine deaminase (EC 3.5.4.4., ADA) has been measured in the blast cells of 36 patients with acute lymphoblastic, acute myeloid, chronic myeloid and chronic myeloid blast crisis leukaemia. Particularly high levels were found in acute lymphoblastic and chronic myeloid blast crisis patients. The measurement of ADA may be useful diagnostically in the undifferentiated acute leukaemias and in detecting the early onset of blast crisis in chronic myeloid leukaemia. Possible reasons for the elevation of ADA in malignant cells are discussed.

Adenosine inhibition of lymphocyte-mediated cytolysis: possible role of cyclic adenosine monophosphate

The in vitro destruction of tumor cells by specifically sensitized mouse lymphocytes was inhibited by adenosine; this inhibition was markedly potentiated by the presence of an inhibitor of adenosine deaminase. The inhibition of cytolysis by adenosine was accompanied by a rapid elevation in lymphocytic adenosine 3',5'-monophosphate (cyclic AMP) concentrations. Both the inhibition of cytolysis and the elevation of cyclic AMP were reversed by prolonged incubation of the lymphocytes in the presence of adenosine or, more rapidly, by removal of the adenosine. Low concentrations of adenosine also caused an elevation of cyclic AMP in human lymphocytes, and this effect of adenosine may contribute to the lack of immune response associated with adenosine deaminase deficiency.

Erythrocyte adenosine deaminase and purine nucleoside phosphorylase activity in gout

1. Erythrocyte adenosine deaminase (EC 3.5.4.4) and purine nucleoside (inosine) phosphorylase (EC 2.4.1.1) were measured in 33 healthy controls and 43 primary gouty subjects. Adenosine deaminase activity in controls and gouty subjects was 0.373 plus or minus 0.108 and 0.457 plus or minus 0.140 A unit per 5-10-3 ml packed red cells per h, respectively. The difference was statistically significant (P less than 0.01). Mean adenosine deaminase: inosine phosphorylase (X10) in primary gout was also significantly higher than in controls (P less than 0.05). Inosine phosphorylase activities in the two groups were not significantly different. 2. When gouty patients were divided into two groups according to weight, normal weight gouty subjects had a higher adenosine deaminase activity and an increased ration of adenosine deaminase to inosine phosphorylase when compared with overweight patients (P less than 0.10). In two control groups divided according to the percentage overweight, such differences were not found. In the case of two gouty groups divided according to the existence of gouty heredity, tophi or renal impairment, adenosine deaminase and inosine phosphorylase activity in the two groups were not significantly different. The possible biochemical role of adenosine deaminase activity in primary gout is discussed.

Combined immunodeficiency disease associated with adenosine deaminase deficiency. Report on a workshop held in Albany, New York, October 1, 1973

Fifty-five children with CID and known ADA status were studies at a workshop held in Albany, New York. Erythrocyte ADA determinations were performed in 22 of the 55 patients, 13 of whom were ADA negative. The ADA defect appears to be transmitted as an autosomal recessive trait. Some patients with CID and ADA deficiency have characteristic radiologic abnormalities of the skeleton, which are not found in other illnesses. The thymus glands of all patients with CID and ADA deficiency who could be examined have evidence of thymic involution manifested by presence of Hassall's corpuscles and differentiated germinal epithelium; this is in contrast to "classic" thymus findings in CID with normal ADA. Adenosine deaminase probably plays an important, although as yet undefined, role in lymphocyte development and/or function. The deficiency of ADA in CID is the first enzyme defect observed in a deficiency disease of specific immunity.

Inhibition of mitogen mediated lymphocyte blastogenesis by adenosine

The effect of adenosine on the proliferative response of human peripheral circulating lymphocytes to stimulation by concanavalin A, phytohemagglutinin and pokeweed mitogen was evaluated. Increasing concentrations of adenosine substantially inhibited mitogen mediated lymphocyte blastogenesis. Erythro-9(2-hydroxyl-3-nonyl) adenine. HCl enhanced the inhibitory effect of adenosine. Inosine, the deamination product of adenosine, had an inhibitory effect which was less than that of adenosine. Inhibition by adenosine may be relevant to the normal regulation of immune function and may account in part for the pathophysiological relationship between severe combined immunodeficiency disease and adenosine deaminase deficiency.