Serum levels of homocystiene , vitamin B 12 and folic acid in Indian patients with psoriasis : results of a pilot study

276 How to cite this article: Khatri G, Mahajan VK, Mehta KS, Sharma KK, Bhushan S, Chauhan PS. Serum levels of homocystiene, vitamin B12 and folic acid in Indian patients with psoriasis: results of a pilot study. Our Dermatol Online. 2016;7(3):276-279. Submission: 15.11.2015; Acceptance: 29.02.2016 DOI: 10.7241/ourd.20163.74 Serum levels of homocystiene, vitamin B12 and folic acid in Indian patients with psoriasis: results of a pilot study


INTRODUCTION
Psoriasis is a common inflammatory dermatosis with epidermal hyperproliferation in the basal layer.Both genetic and environmental influences (trauma, infection, drugs, alcohol, smoking, metabolic factors, psychological stress) are considered important in its pathogenesis.The disease has a significant impact on health related quality of life because of lifelong chronicity, extent of severity, periodicity of flares, and more importantly, from associated comorbidities.Elevated plasma homocystiene has been widely studied as an independent risk factor for atherosclerotic disease involving the coronary, peripheral, and cerebral circulations that may result in early death from myocardial infarction, pulmonary embolism or stroke [1,2].Psoriasis patients reportedly have significantly higher plasma homocysteine levels corresponding with severity of disease than control subjects [3].They also demonstrate significantly lower levels of vitamin B 12 , folate, and tissue plasminogen activator than controls.Reduced plasma folate and vitamin B 12 levels in psoriasis patients have been attributed to their increased utilization in the skin, reduced absorption from the gut, or as an adverse effect of systemic medications like methotrexate (folate antagonist) [3,4].Deficiencies in vitamin B 12 and folate have been associated with increased levels of plasma homocystiene, and supplementation is shown to decrease plasma homocystiene levels [1,3].It is possible that higher levels of plasma homocysteine perhaps contribute to the increased risk for cardiovascular morbidity observed in patients with psoriasis [5].We studied serum levels of homocystiene, vitamin B 12 and folic acid in Indian patients with psoriasis and age matched controls.

MATERIAL AND METHODS
Serum levels of homocystiene, vitamin B 12 and folic acid were studied in 55 consecutive adult males having chronic plaque psoriasis for at least 6 months after written/informed consent during Jan-Dec 2012.The study was approved by the Institutional Protocol Review Board and Institutional Ethics Committee (Rgn no ECR/490/Inst/HP/2013).Patients were instructed to stop taking alcohol, coffee or any topical/systemic treatment for 1 week, 2 weeks and 4 weeks, respectively, and consumption of animal protein 24 h prior to blood sampling.Only topical emollients and oral antihistaminics were allowed.Patients having palmoplantar psoriasis, psoriatic arthritis, systemic diseases (thyroid, hepatic or renal disease, hematologic disorders diabetes mellitus, coronary heart disease, stroke, peripheral vascular disease, systemic lupus erythematosus), on antifolate medications (anticonvulsants, penicillin, levodopa, cyclosporine, isoniazide), or drugs that cause hyperhomocystienemia (phenytoin, carbamazapine, theophylline, oral contraceptives, azathioprine, thiazide diuretics, metformin), were excluded from the study.Patients with history of substance (opium) abuse and current smokers were also excluded.A detailed demographic profile, medical history and clinical details of psoriasis were recorded.Body Surface Area (BSA) involvement was calculated as per 'Rule of Nines' and the Psoriasis Area-and-Severity Index (PASI) score was determined as suggested originally by Fredriksson and Pettersson [6].Fifty-five age-matched males with minor dermatoses (scabies, dermatophytoses) were enrolled from the outpatient clinic after informed written consent as controls for serum sampling in a similar manner.
Venous blood (5ml) samples were collected after overnight fasting between 8.00 and 10.00 AM for complete blood count including platelets, fasting blood glucose, urea, creatinine, bilirubin, serum glutamic oxaloacetic transaminase and serum glutamic pyruvate transaminase, alkaline phosphatase and thyroid functions tests.Quantitative estimation for serum homocystiene vitamin B 12 and folic acid levels was performed in institutional biochemistry laboratory by standard chemiluminescence enzyme immunoassay (CLIA) method [7] and as per manufacturer protocol using Immulite® ready to use in-vitro kits purchased from Siemens Healthcare, Diagnostic Products Ltd, United Kingdom.Results were analyzed using unpaired student's t-test and standard deviation for mean.A 'p' value <0.05 calculated at 5% level (95% confidence limits) was considered statistically significant.

Ethics
This study was performed on human subjects; thus, all patients were aware of the presence of the study and they were fully informed about study parameters.

Biochemical Parameters
None of the patients or controls showed any alteration in routine hemogram, serum biochemistry or thyroid function tests.Other studied biochemical parameters of 55 patients and 55 controls are tabulated (Table 1).Elevated homocystiene levels (normal 5-12 µmol/L) in the range of 12.8 to >50 µmol/L (mean 31.49± 9.99 µmol/L) were seen in all patients while in controls the values ranged between 5.1 and 22.3 µmol/L (mean 9.99 ±3.71 µmol/L).The difference was statistically significant when compared with controls.However, the elevated serum homocystiene levels did not vary with BSA/PASI score (Figs.1a,b,c and 2a,b).The vitamin B 12 levels in patients ranged from <150 to 502 pg/ml (mean 230.74 ± 64.09 pg/ml) and were on the lower side of the normal range (174-878 pg/ml).Serum vitamin B 12 measuring between <150 and 156 pg/ml were lower than normal in 6 (10.9%) patients and controls each.Mean serum folic acid levels in all the patients were 14.42 ± 5.21 ng/ml and ranged from 5.65 to >24 ng/ml (normal 3-17 ng/ml).The mean value of serum folic acid levels of >17ng/ml (17.83 ->24ng/ml) in 17 (30.9%)patients was above the normal range.The mean value of serum folic acid levels of controls was 13.51±4.64ng/ml (range 5.9-25ng/ml).Overall, except for slightly elevated serum homocystiene levels (12.1-24 µmol/L) in 11 (22%) controls, all parameters were within normal range and the difference was not statistically significant (Table 2).

DISCUSSION
High plasma homocystiene is considered an independent risk factor for coronary artery disease, stroke, peripheral vascular disease and possibly Alzheimer's disease especially in patients with homocystienuria [8].A non-linear and inverse association between plasma homocystiene concentration, vitamin B 12 and plasma folate concentration has been well documented and attributable to either deficient absorption or excessive utilization of folic acid, vitamins B 6 and B 12 [3].All the 55 (100%) patients in our study had high serum homocystiene levels (mean 31.49±9.99 µmol/L, range 12.8 ->50 µmol/L) as compared to the controls (mean 9.99 ± 3.71 µmol/L, range 5.1-22.3µmol/L) and the difference was statistically significant (p <0.05).The levels of serum vitamin B 12 were at the lower levels (mean 217.7±46.22pg/ml, range 150-310 pg/ml) of the normal in 26 (86.6%) patients while in 6 (10.9%) patients the values were lower (<174 pg/ml) than the normal.Serum folic acid levels (ng/ml), normal 1.9-25 ng/ml The difference was not statistically significant when compared with controls.Serum folic acid levels varied between 5.65 and >24 ng/ml (mean 14.42±5.21ng/ml) and 5.9 and 25 (mean 13.51±4.64ng/ml) in all the patients and controls, respectively, and were within normal range.Brazzeli et al [9] also made similar observations in a cohort of 98 patients with chronic plaque psoriasis and 98 healthy controls.They observed significantly higher prevalence of hyperhomocystienemia and low serum vitamin B 12 levels in psoriasis patients as compared to healthy controls but not for serum folic acid.In a similar study, Malerba et al [3] noted higher plasma homocystiene levels and lower folic acid levels in 40 chronic plaque psoriasis patients without known risk factors for acquired homocystienemia than 30 agematched controls.Although the plasma homocystiene levels in patients with psoriasis also correlated directly with disease severity and inversely with folic acid levels, no abnormalities were detected in plasma vitamin B 6 and B 12 levels.In a similar study by Cakmak et al [10] serum homocystiene levels inversely correlated with serum folic acid levels but not with serum vitamin B 12 both in 70 patients with psoriasis and healthy controls.However, authors did not find any difference between their serum levels in patients and controls.Trends towards low serum folic acid and hyperhomocystienemia in patients with psoriasis were also observed by Tobin et al [11] but they did not study serum vitamin B 12 in their patients.Our observations of hyperhomocystienemia, serum vitamin B 12 at lower end of the normal and variable serum folic acid levels in all patients are suggestive of some significance of hyperhomocystienemia and low serum vitamin B 12 and folic acid levels.However, a possibility of avoiding non-vegetarian food altogether by these patients subsequent to development of their disease leading to serum vitamin B 12 at lower end of the normal range cannot be ruled out entirely.Hyperhomocystienemia in patients with psoriasis as in our 100% patients has been documented previously [3,[9][10][11].Contrarily, Uslu et al [12] in a recent study of 50 patients with psoriasis and 48 healthy controls found no statistically significant differences between the patients and the control group in terms of age, sex, body mass index (BMI), plasma homocystiene folic acid, and vitamin B 12 .They attributed this variation to the differences in the genetic pool of the studied Turkish population.

CONCLUSIONS
Hyperhomocystienemia, lower than normal levels of vitamin B 12 and variable serum folic acid levels in all our patients suggests their possible dysregulation in psoriasis patients.Implications of hyperhomocystienemia for cardiovascular comorbidities in psoriasis patients and whether supplementing vitamin B 12 and folic acid will prevent comorbidities by normalizing homocystiene metabolism needs further evaluation by large well designed studies in different ethnicities.

Statement of Human and Animal Rights
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008.

Statement of Informed Consent
Informed consent was obtained from all patients for being included in the study.

Table 2 :
Significance of the resultsSerum

Table 1 :
Biochemical parameters of patients and controls Serum