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Impaired metabolic function of polymorphonuclear leukocytes in glycogen storage disease Ib
Abstract:
To elucidate the basis for the recurrent infections in patients with glycogen storage disease (GSD) Ib we tested polymorphonuclear leukocyte (PMN) function in one patient. Bactericidal capacity and phagocytosis-induced O2 consumption were reduced. Also, phorbol myristate acetate-stimulated superoxide production and glucose oxidation through the hexose monophosphate shunt were diminished compared to control subjects. Therefore it could be speculated that in PMN of patients with GSD Ib, glucose-6-phosphate has no access to the enzymes of the hexose monophosphate shunt due to a transport-related defect as shown for glucogenesis in hepatocytes.
Insights
Patients with Glycogen Storage Disease (GSD) Ib exhibit recurrent infections due to impaired polymorphonuclear leukocyte (PMN) function. A transport defect likely prevents glucose-6-phosphate access to the hexose monophosphate shunt in these cells.
Area of Science:
- Immunology
- Metabolic Disorders
- Cellular Biology
Background:
- Glycogen Storage Disease (GSD) Ib is a rare genetic disorder affecting glucose metabolism.
- Recurrent infections are a common clinical manifestation in GSD Ib patients, suggesting immune system dysfunction.
- Polymorphonuclear leukocytes (PMNs) are critical immune cells involved in fighting bacterial infections.
Observation:
- This study investigated the functional capacity of PMNs from a patient with GSD Ib.
- Key immune functions, including bactericidal capacity and phagocytosis-induced oxygen consumption, were assessed.
- Specific enzyme activities related to glucose metabolism within PMNs were also examined.
Findings:
- PMNs from the GSD Ib patient demonstrated reduced bactericidal capacity.
- Phagocytosis-induced oxygen consumption and superoxide production were significantly diminished.
- Glucose oxidation via the hexose monophosphate shunt was also impaired in the patient's PMNs.
Implications:
- The findings suggest a transport-related defect in GSD Ib PMNs, hindering glucose-6-phosphate utilization.
- This metabolic defect likely compromises the oxidative burst and overall immune function of PMNs.
- Understanding this mechanism could lead to improved management strategies for infections in GSD Ib patients.