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Urinary excretion of modified purines and nucleosides in immunodeficient children
Insights
Urinary purine and nucleoside levels were analyzed in children with severe combined immunodeficiency (SCID). Elevated levels of 1-methyladenosine and 1-methylinosine were observed in SCID patients, indicating potential biomarkers.
Area of Science:
- Biochemistry
- Immunology
- Pediatrics
Background:
- Severe combined immunodeficiency (SCID) is a group of rare genetic disorders characterized by profound defects in both the cellular and humoral immune systems.
- Purines and nucleosides are fundamental components of nucleic acids and play crucial roles in various metabolic pathways.
- Alterations in purine and nucleoside metabolism have been implicated in various diseases, including immune deficiencies.
Purpose of the Study:
- To quantitatively determine urinary purines and nucleosides in children with SCID.
- To identify potential biomarkers for SCID based on purine and nucleoside excretion patterns.
- To compare these levels with those in healthy children.
Main Methods:
- Utilized XAD-4 resin and ion-exchange chromatography for the analysis of urinary compounds.
- Quantitatively determined specific methylated purines and nucleosides, including 1-methyladenosine, 1-methylinosine, and methylthioadenosine sulfoxide.
- Included analyses of adenosine, cytidine, and deoxycytidine.
Main Results:
- 1-Methyladenosine and 1-methylinosine were consistently elevated in the urine of children with SCID compared to normal controls.
- Methylthioadenosine sulfoxide showed a marked increase in two SCID patients.
- A germ-free child with SCID exhibited lower overall excretion levels of these compounds than normal children.
Conclusions:
- Specific methylated purines and nucleosides, particularly 1-methyladenosine and 1-methylinosine, may serve as indicators for severe combined immunodeficiency.
- Urinary purine and nucleoside profiles can provide insights into the metabolic disturbances associated with SCID.
- Further research is warranted to explore the diagnostic and prognostic value of these biomarkers in SCID.
Abstract:
Studies have been carried out using an XAD-4 resin and ion-exchange chromatography for determination of urinary purines and nucleosides in seven children with severe combined immunodeficiency and in six normal children. These studies have included analyses for five methylated purines or nucleosides produced by catabolism of nucleic acids. The following compounds have been quantitatively determined: 1-methyladenosine, 1-methylinosine, 1-methylguanosine, 1-methylguanine, 3-methylcytidine, adenosine, methylthioadenosine sulfoxide, cytidine, and deoxycytidine. 1-Methyladenosine and 1-methylinosine were most consistently elevated in the urine of immunodeficient children. Methylthioadenosine sulfoxide was very markedly increased in urine of two of the immunodeficient children while more moderate increases were noted with a number of other nucleosides. The germ-free child with severe combined immunodeficiency showed consistently lower excretion levels of these compounds when compared to normal children.