Capillary Electrophoresis in Diagnosis and Monitoring of Adenosine Deaminase Deficiency (original) (raw)
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The American Journal of Human Genetics, 1998
Adenosine deaminase (ADA) deficiency causes lymphopenia and immunodeficiency due to toxic effects of its substrates. Most patients are infants with severe combined immunodeficiency disease (SCID), but others are diagnosed later in childhood (delayed onset) or as adults (late onset); healthy individuals with "partial" ADA deficiency have been identified. More than 50 ADA mutations are known; most patients are heteroallelic, and most alleles are rare. To analyze the relationship of genotype to phenotype, we quantitated the expression of 29 amino acid sequence-altering alleles in the ADA-deleted Escherichia coli strain SØ3834. Expressed ADA activity of wild-type and mutant alleles ranged over five orders of magnitude. The 26 disease-associated alleles expressed 0.001%-0.6% of wild-type activity, versus 5%-28% for 3 alleles from "partials." We related these data to the clinical phenotypes and erythrocyte deoxyadenosine nucleotide (dAXP) levels of 52 patients (49 immunodeficient and 3 with partial deficiency) who had 43 genotypes derived from 42 different mutations, including 28 of the expressed alleles. We reduced this complexity to 13 "genotype categories," ranked according to the potential of their constituent alleles to provide ADA activity. Of 31 SCID patients, 28 fell into 3 genotype categories that could express X0.05% of wildtype ADA activity. Only 2 of 21 patients with delayed, late-onset, or partial phenotypes had one of these "severe" genotypes. Among 37 patients for whom pretreatment metabolic data were available, we found a strong inverse correlation between red-cell dAXP level and total ADA activity expressed by each patient's alleles in SØ3834. Our system provides a quantitative framework and ranking system for relating genotype to phenotype.
Journal of Clinical Immunology, 2023
Purpose Metabolic detoxification with enzyme replacement therapy (ERT) promotes immune recovery in patients with adenosine deaminase (ADA)-deficient severe combined immunodeficiency (ADA-SCID). Elapegademase is a PEGylated recombinant bovine ADA ERT developed to replace the now-discontinued bovine-derived pegademase. This study was a 1-way crossover from pegademase to elapegademase in 7 patients with ADA-SCID to assess efficacy and safety outcomes for elapegademase. Methods After once-weekly pegademase dosage was adjusted to achieve therapeutic metabolic detoxification and trough ADA activity, patients transitioned to a bioequivalent dose of elapegademase. Maintenance of metabolic detoxification and adequate ADA activity were evaluated periodically. Results One patient withdrew after 2 doses of an early elapegademase formulation due to injection-site pain caused by EDTA. The 6 remaining patients completed 71−216 weeks of elapegademase therapy with a formulation that did not contain EDTA. In these patients, elapegademase improved ADA activity compared with pegademase and maintained metabolic detoxification. Total lymphocyte counts increased for all completer patients from between 1.2-and 2.1-fold at the end of study compared with baseline. Elapegademase had a comparable safety profile to pegademase; no patient developed a severe infectious complication. Three patients had transient, non-neutralizing antibodies to pegademase, elapegademase, and/or polyethylene glycol ≤ 47 weeks of treatment without effect on trough plasma ADA activity or trough erythrocyte deoxyadenosine nucleotide levels. Conclusion Elapegademase was safe, well tolerated, achieved stable trough plasma ADA activity with weekly dosing, was effective in maintaining metabolic detoxification, and was associated with maintenance or improvements in lymphocyte counts compared with pegademase therapy in patients with ADA-SCID.
Adenosine deaminase deficiency in adults
1997
Adenosine deaminase (ADA) deficiency typically causes se-vated deoxyadenosine nucleotides. Both were heteroallelic for missense mutations: patient no. 1, G216R and P126Q vere combined immunodeficiency (SCID) in infants. We report metabolic, immunologic, and genetic findings in two (novel); patient no. 2, R101Q and A215T. Three of these mutations eliminated ADA activity, but A215T reduced activity ADA-deficient adults with distinct phenotypes. Patient no. 1 (39 years of age) had combined immunodeficiency. She by only 85%. Owing to a single nucleotide change in the middle of exon 7, A215T also appeared to induce exon 7 had frequent infections, lymphopenia, and recurrent hepatitis as a child but did relatively well in her second and third skipping. ADA deficiency is treatable and should be considered in older patients with unexplained lymphopenia and decades. Then she developed chronic sinopulmonary infections, including tuberculosis, and hepatobiliary disease; she immune deficiency, who may also manifest autoimmunity or unexplained hepatobiliary disease. Metabolic status and died of viral leukoencephalopathy at 40 years of age. Patient no. 2, a healthy 28-year-old man with normal immune func-genotype may help in assessing prognosis of more mildly affected patients. tion, was identified after his niece died of SCID. Both patients lacked erythrocyte ADA activity but had only modestly ele-᭧ 1997 by The American Society of Hematology. tion. She had been hospitalized eight times for pneumonitis in the
Nucleic Acids Research, 1984
In order to determine the molecular basis of adenosine deaminase (ADA) deficiency in cells derived from patients with severe combined immunodeficiency (SCID) disease, we used a human ADA cDNA clone (1) to analyse the organization and transcription of the ADA gene in both normal and ADA SCID cells. In five lymphoblastoid ADA SCID cell lines we could detect no deletions or rearrangements in the ADA gene and its flanking sequences. Furthermore, synthesis and processing of ADA mRNA appeared to be normal in the ADA-SCID cells, and ADA-specific mRNA from two ADA SCID cells could be translated in vitro into a protein with the molecular weight of normal ADA; this protein, however, could hardly be precipitated with an ADA antiserum. The results indicate that in these two ADA SCID cell lines, the lack of ADA activity is not due to transcriptional or translational defects, but to subtle changes in the configuration of the protein affecting both its enzymatic and immunological characteristics.
Blood, 2012
Adenosine acts as anti-inflammatory mediator on the immune system and has been described in regulatory T cell (Treg)mediated suppression. In the absence of adenosine deaminase (ADA), adenosine and other purine metabolites accumulate, leading to severe immunodeficiency with recurrent infections (ADA-SCID). Particularly ADA-deficient patients with lateonset forms and after enzyme replacement therapy (PEG-ADA) are known to manifest immune dysregulation. Herein we provide evidence that alterations in the purine metabolism interfere with Treg function, thereby contributing to autoimmune manifestations in ADA deficiency. Tregs isolated from PEG-ADA-treated patients are reduced in number and show decreased suppressive activity, whereas they are corrected after gene therapy. Untreated murine ADA ؊/؊ Tregs show alterations in the plasma membrane CD39/ CD73 ectonucleotidase machinery and limited suppressive activity via extracellular adenosine. PEG-ADA-treated mice developed multiple autoantibodies and hypothyroidism in contrast to mice treated with bone marrow transplantation or gene therapy. Tregs isolated from PEG-ADAtreated mice lacked suppressive activity, suggesting that this treatment interferes with Treg functionality. The alterations in the CD39/CD73 adenosinergic machinery and loss of function in ADA-deficient Tregs provide new insights into a predisposition to autoimmunity and the underlying mechanisms causing defective peripheral tolerance in ADA-SCID. Trials were registered at www.clinicaltrials.gov as NCT00598481/NCT00599781.
Blood, 1985
The purine metabolic enzymes adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) are important in lymphocyte differentiation, and genetic deficiencies of either enzyme have been associated with hereditary immunodeficiency states. Both ADA and PNP activity were measured in null cell-enriched and T cell-enriched peripheral blood lymphocytes from 16 patients with the acquired immune deficiency syndrome (AIDS), seven patients with the AIDS-related symptom complex (ARC), and seven asymptomatic homosexuals. ADA activity in nmol/10(6) lymphocytes/h was significantly elevated in null lymphocytes from AIDS (161 +/- 12) as compared with 23 healthy heterosexual controls (127 +/- 8;P less than .025). PNP activity was also significantly increased in null lymphocytes from AIDS patients (96 +/- 10;P less than .005) as well as those from ARC patients (84 +/- 11:P less than .025) relative to controls (61 +/- 5). No significant differences in enzyme activity were noted in T cell-enric...
Atypical hemolytic-uremic syndrome in a patient with adenosine deaminase deficiency
LymphoSign Journal, 2015
Inherited defects in the ubiquitous adenosine deaminase (ADA) enzyme disrupt the function of the immune system as well as many other organs and tissues. Some patients may also suffer from kidney damage. Here we report on an ADA-deficient patient who was treated with ADA replacement therapy from infancy and at 6 years of age developed acute kidney failure, thrombocytopenia, and severe anemia. A kidney biopsy demonstrated mesangiolysis and occlusion of kidney loops by erythrocytes and platelet aggregates, which is consistent with hemolytic-uremic syndrome (HUS). There was no evidence of exposure to Shiga toxins, nor were any complement abnormalities detected. The kidney function improved following hemodialysis. Our report demonstrates the increased susceptibility of ADA-deficient patients to develop HUS and expands the nonimmune abnormalities associated with ADA deficiency. This further emphasizes the vigilance required when caring for such patients. Statement of novelty: Here we prov...