Immune function in children with classical phenylketonuria and tetrahydrobiopterin deficiencies

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Tevfik Karagoz1, Turgay Coskun, Imran Ozalp

  • 1Nutrition and Metabolism Unit, Department of Pediatrics, Hacettepe University Faculty of Medicine, Sihhiye, Ankara 06100, Turkey. ktevfik@ hotmail.com

Indian Pediatrics
|October 8, 2003
PubMed

Insights

Phenylketonuria (PKU) patients with high phenylalanine (PA) levels show impaired immune responses, potentially linked to zinc deficiency. Tetrahydrobiopterin (BH4) deficiencies do not appear to affect these immune parameters.

Area of Science:

  • Immunology
  • Metabolic Disorders
  • Nutritional Science

Background:

  • Increased infection susceptibility is noted in phenylketonuria (PKU) patients.
  • The exact causes, whether amino acid alterations or other factors, remain unclear.

Purpose of the Study:

  • To assess B cell and T cell functions in children with PKU and BH4 deficiencies.
  • To investigate the impact of high plasma phenylalanine (PA) concentrations on immune parameters.

Main Methods:

  • Studied B and T cell functions in 33 children with PKU (two groups based on PA levels) and 11 with BH4 deficiencies.
  • Compared results with healthy controls and analyzed plasma PA, IgG, IgM, serum zinc, and iron levels.

Main Results:

  • Impaired delayed type skin hypersensitivity responses were observed in PKU patients with high PA (Group I) and BH4 deficiency (Group III).
  • Lower plasma IgG and IgM concentrations were found in Group I. Zinc and iron deficiencies were more pronounced in Groups I and III.
  • BH4 deficiency did not appear to significantly impact the studied immune parameters.

Conclusions:

  • High PA levels in PKU may contribute to low IgG, with zinc deficiency also playing a potential role.
  • Impaired skin hypersensitivity responses are likely linked to severe zinc deficiency in PKU and BH4 deficiency.
  • Further research is needed to clarify the PKU-immune function relationship after correcting micronutrient status.
Abstract

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