Homocysteine plasmatic status in patients with psoriasis

ARTICLE

ejd.2011.1455

Auteur(s) : Antonio Giovanni Richetta¹ antoniorichetta@hotmail.com, Carlo Mattozzi¹, Laura Macaluso¹, Carmen Cantisani¹, Simona Giancristoforo¹, Sara D’epiro¹, Monica Salvi¹, Marco Scarnò², Stefano Calvieri¹

¹ Department of Dermatology, Policlinico “Umberto I” University of Rome “La Sapienza”, Viale del Policlinico, 155, 00133 Rome, Italy

² CASPUR Department of medical statistics, Italy

Hyperhomocysteinaemia represents an independent risk factor for atherosclerotic cardiovascular disease, stroke, peripheral arterial occlusive disease and venous thrombosis [1]. Psoriasis is a chronic inflammatory skin disease associated with several comorbidities, such as atherosclerosis, chronic ischemic heart disease, obesity and diabete mellitus [2].

Elevated homocysteine levels may cause irritation of the blood vessels; the endothelial injury of hyperhomocysteinaemia and the cardiovascular risks that derive from it are gradual and continuous. The authors investigated the relationship between plasma homocysteine levels and the severity of chronic psoriasis in a selected cohort of patients without known risk factors for acquired hyperhomocysteinaemia.

Plasma homocysteine levels were analyzed in 70 patients with psoriasis and in 30 controls, matched for sex, age and body mass index. The distribution of variables in the study groups was assessed by Kolmogorov-Simirnov test. Statistical differences between data from the patients and control groups were determined according to Student's t-test of Mann-Whitney U-test. P<0.05 was considered significant.

The inclusion criteria for the case were age >18 years, diagnosis of psoriasis made at least 1 year before enrolment and suspension of systemic and topical steroid treatment respectively from 4 and 2 weeks. Exclusion criteria were: intake of drugs known to cause hyperhomocysteinaemia; intake of antipsoriatic drugs including methotrexate with folic acid supplementation and acitretin; presence of chronic renal and hepatic diseases; systemic lupus erythematosus, hypothyroidism, stroke and peripheral vascular disease. Severity of psoriasis was assessed according to the Psoriasis Area Severity Index (PASI). Our patients were matched in three subgroups according to the PASI score: 9 patients were affected by mild psoriasis (PASI<10), 30 by moderate psoriasis (PASI 10-20), and 31 by severe psoriasis (PASI>20) with a PASI ranging from 4 to 60 (mean 18.9) (tables 1 and 2).

Table 1 Descriptive characteristics of cases and controls.

Table 2 Psoriatic patients with hyperhomocysteinaemia

The results showed that patients with moderate to severe psoriasis had plasma homocysteine levels higher than controls (52.86% of cases vs 20% of controls having hyperhomocysteinaemia (≥ 15 μmol/L)) (figure 1). In psoriasic patients, homocysteine levels correlated directly with psoriasis severity and consequently with the PASI score (p<0.05; Pearson Index 0.85) (figure 2). The control group showed normal ranges of homocysteine plasmatic levels, with the exception of 6/30 controls with minimal increases of plasmatic homocysteine (aminoacid concentration between 15 and 20 μmol/L).

All patients and controls underwent epiaortic ultrasound examination. 35 patients with hyperhomocysteinaemia presented signs of subclinical atherosclerosis; two of them developed severe cardiovascular events after twenty years of disease.

Data from the literature confirm our results; several studies have shown that the homocysteine plasmatic concentration in psoriatic patients is higher than in healthy controls [1, 3-5]; however, the correlation we found between homocysteine serum levels and psoriasis severity measured by PASI score has hardly ever been reported in the literature. Few studies show a relationship between homocysteine blood levels and disease activity [4, 6].

These studies also demonstrate that psoriatic patients often present low levels of folic acid as a result of an increasing vitamin utilization in the skin and/or reduced gut absorption [4, 5]. Physicians must find a pharmacological treatment that reduces the plasmatic homocysteine levels, even when these are only moderately high; we know that folic acid, vitamin B6 and vitamin B12 are all involved in breaking down homocysteine in the blood. Therefore dietary supplementation with folic acid and vitamins B6 and B12 is recommended. Treatment of hyperhomocysteinaemia may not only reduce atherosclerotic plaque areas, but also it may decrease the risk of ischaemic heart disease, deep vein thrombosis and stroke [4].

Based on their findings, the authors suggest that psoriatic patients should be treated by a global management taking into account cardiovascular risk factors.

Disclosure

Financial support: none. Conflict of interest: none.

References

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