Lymphocyte enzyme activities in East African blacks: decrease in 5'nucleotidase and possible relation to...

Area of Science:

• Biochemistry
• Immunology
• Human Genetics

Background:

• Subcellular organelle marker enzyme analysis was performed on cryopreserved lymphocytes from East African individuals experiencing malnutrition and endemic diseases.
• Previous studies indicated enzyme stability post-cryopreservation, with catalase being a partial exception.

Purpose of the Study:

• To investigate alterations in lymphocyte enzyme activity in East African subjects with malnutrition and endemic diseases compared to Caucasian controls.
• To determine the specificity of any observed enzyme changes, particularly focusing on 5'nucleotidase.

Main Methods:

• Cryopreservation and microanalysis of subcellular organelle marker enzymes in lymphocytes.
• Comparison of enzyme activities between 26 African subjects, 20 Caucasian controls, and 17 socio-economically distinct East African individuals.
• Functional studies of 5'nucleotidase to assess potential differences in enzyme characteristics.

Main Results:

• A highly significant decrease in 5'nucleotidase activity was observed in African subjects compared to controls.
• Activities of gamma-glutamyl transferase and other intracellular organelle enzymes did not differ significantly between groups, indicating specificity of the 5'nucleotidase alteration.
• 5'Nucleotidase activity in high socio-economic status East Africans fell between the other two groups, not significantly different from either.

Conclusions:

• The specific decrease in 5'nucleotidase activity in African subjects warrants further investigation.
• Observed differences may be linked to the immunosuppressive effects of infectious diseases and malnutrition, or potentially have a genetic basis.
• These alterations could contribute to the pathogenesis of secondary immunodeficiency in the studied populations.