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Published on: March 20, 2021
Apoptotic cells in peripheral blood from patients with low serum cobalamin
R W Bunting1, M K Selig, G R Dickersin
1Department of Hematology, Spaulding Rehabilitation Hospital, Boston, MA 02114, USA.
Abstract:
Apoptotic leukocytes were found by using ultrastructural and light microscopic techniques to examine peripheral blood in ten of twelve patients with low serum cobalamin (vitamin B12) and rarely in normal controls. A total of 88 apoptotic cells (.14% of total leukocytes) were identified in all the patients. One patient also had apoptotic cells found on a routine blood smear. There was no correlation between the finding of these cells and nuclear hypersegmentation, serum cobalamin levels, serum intrinsic factor antibody, serum methylmalonic acid and homocysteine or the Schilling test. Two patients, however, with the most severe vitamin deficiency did not have increased numbers of apoptotic cells suggesting that these patients had lost the ability to initiate the cell death program.
Insights
Apoptotic leukocytes were observed in most patients with low vitamin B12. Severe deficiency may impair the cell death program, indicating a complex relationship between vitamin B12 and leukocyte apoptosis.
Area of Science:
- Hematology
- Cell Biology
- Nutritional Science
Background:
- Low serum cobalamin (vitamin B12) is a common deficiency with various clinical manifestations.
- Leukocyte apoptosis, or programmed cell death, is a critical process in maintaining immune homeostasis.
- The precise role of vitamin B12 in regulating leukocyte apoptosis remains incompletely understood.
Purpose of the Study:
- To investigate the presence and characteristics of apoptotic leukocytes in patients with low serum cobalamin.
- To explore potential correlations between apoptotic cell findings and established markers of vitamin B12 deficiency.
- To assess if severe vitamin B12 deficiency impacts the capacity for leukocyte apoptosis.
Main Methods:
- Peripheral blood samples from patients with low serum cobalamin and normal controls were examined.
- Ultrastructural and light microscopy techniques were employed to identify and quantify apoptotic leukocytes.
- Correlations were assessed between apoptotic cell counts and clinical/biochemical parameters including nuclear hypersegmentation, serum cobalamin, intrinsic factor antibody, methylmalonic acid, homocysteine, and Schilling test results.
Main Results:
- Apoptotic leukocytes were identified in ten of twelve patients with low serum cobalamin, and rarely in controls.
- A total of 88 apoptotic cells were found, representing 0.14% of total leukocytes across all patients.
- No significant correlation was observed between apoptotic cells and nuclear hypersegmentation, specific vitamin B12 deficiency markers, or Schilling test results.
- Two patients with the most severe deficiency showed no increase in apoptotic cells, suggesting a potential loss of the cell death program initiation.
Conclusions:
- Apoptotic leukocytes are frequently observed in peripheral blood of individuals with low serum cobalamin.
- The presence of apoptotic leukocytes does not correlate with standard clinical or biochemical markers of vitamin B12 deficiency severity.
- Severe vitamin B12 deficiency might be associated with an impaired ability of leukocytes to undergo apoptosis, highlighting a potential novel mechanism in severe deficiency states.
