Serum homocysteine, folic acid and vitamin B12 levels in vitiligo

ARTICLE

Auteur(s) : Didem Didar Balci¹, Zafer Yonden², Julide Zehra Yenin¹, Nese Okumus²

¹Mustafa Kemal University, Faculty of Medicine, Department of Dermatology, Hatay, Turkey
²Mustafa Kemal University, Faculty of Medicine, Department of Biochemistry, Hatay, Turkey

The aetiopathogenesis and mechanisms of vitiligo are not fully understood. An association has been suggested between vitiligo and pernicious anaemia and/or folic acid deficiency [1]; however, this issue remains controversial [2, 3]. Levels of folic acid and vitamin B12 are major determinants of homocysteine (Hcy) levels [4]. Recently, Shaker and El-Tahlawi [5] reported that serum Hcy levels were increased in vitiligo patients, compared with healthy controls. A relationship between Hcy levels and the activities of vitiligo has also been suggested [5]. In the present case-control study, we evaluated the Hcy, folic acid, and vitamin B12 levels in vitiligo patients and healthy controls.

Forty-eight consecutive patients with vitiligo and thirty-one age- and sex-matched healthy controls were included in this study. Informed consent and ethics committee approval were obtained. Current smokers, subjects who were receiving drugs, and subjects with a disease known to affect the levels of folic acid, vitamin B12, or Hcy were excluded. Vitiligo involvement was measured according to the Vitiligo Area Scoring Index (VASI) [6]. Vitiligo was clinically defined as localised, generalised, or universal, whereas disease activity was identified as stable or progressive. Serum total Hcy levels were measured by micro ELISA system using an Axis Homocysteine Enzyme Immunoassay Kit (Axis-Shield Diagnostics Ltd., Dundee, UK). Serum levels of folic acid and vitamin B12 were assessed by immunoassay using an autoanalyser Unicel DxI 800, Access Immunoassay System, Beckman Coulter , Inc., Fullerton, CA, USA). Folic acid levels of < 2.5 ng/mL and vitamin B12 levels of < 126.5 pg/mL were considered to be below the normal range.

The major demographic, clinical, and laboratory features of the subjects are shown in table 1. The disease was progressive in 28 patients, and stable in 20. Twelve patients were localised, 34 were generalised, while the remaining two were universal-type. There were no significant differences in the Hcy, folic acid, and vitamin B12 levels between the vitiligo patients and controls (p > 0.05). Only one vitiligo patient (2.1%) demonstrated a decreased folic acid level, whereas no decreased folic acid levels were found in the healthy subjects (p = 0.608). A decreased level of vitamin B12 was found in eleven (22.9%) of 48 vitiligo patients and in eight (25.8%) of 32 healthy controls (p = 0.486). Regarding the type and activity of the vitiligo, no significant differences were found among the groups in terms of the levels of Hcy, folic acid, and vitamin B12. There was no significant correlation between the Hcy, folic acid, or vitamin B12 level and the age of the patients, VASI, or duration of disease in the vitiligo group (p > 0.05).

Our results are similar to those of Kim et al. [2], who reported no significant differences in folic acid or vitamin B12 levels in vitiligo patients, compared to healthy controls, and those of Song et al. [3], who reported no cases of pernicious anaemia in 1,088 vitiligo patients. In contrast to Shaker and El-Tahlawi’s results [5], we did not detect any differences in Hcy levels between the vitiligo patients and healthy controls. There are a number of possible explanations for this discrepancy. First, the fact that Shaker and El-Tahlawi selected vitiligo patients with a more severe disease classification may have affected the Hcy levels. Second, ethnic differences among the vitiligo patients between the two studies may have affected the Hcy levels. Methylenetetrahydrofolate reductase (MTHFR) plays a role in Hcy metabolism. It was previously shown that a polymorphism in MTHFR (677C>T) affected plasma Hcy levels [7]. Third, their patient group may have diminished levels of folic acid and vitamin B12, which are known to be causative factors in hyperhomocysteinaemia [4]. They did not evaluate the levels of folic acid or vitamin B12 in their study. As for folic acid and vitamin B12, previous studies have yielded conflicting results. This case-controlled study showed that Hcy, folic acid and vitamin B12 levels were not significantly different in vitiligo patients from healthy controls. Additional studies in larger series are needed to investigate the potential role of Hcy, folic acid, and vitamin B12 in vitiligo.

Acknowledgements

References

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