Plasma homocysteine and its relationships with atherothrombotic markers in psoriatic patients

Psoriasis and vascular disease-risk factors and outcomes: a systematic review of the literature

BACKGROUND

Psoriasis afflicts 2-3% of the world's population. Affected patients commonly have risk factors for cardiovascular disease (CVD). In addition, psoriasis is independently associated with CVD and mortality.

PURPOSE

To determine which CVD risk factors are associated with psoriasis independent of confounders, whether psoriasis is associated with CVD independent of CVD risk factors, and whether there is increased mortality among patients with psoriasis.

DATA SOURCES

MEDLINE, Embase, and Cochrane Collaborations from inception through October 2009. We reviewed bibliographies of retrieved articles for additional references.

STUDY SELECTION

Cross-sectional, cohort-based, case-control, and randomized controlled trials which involved patients with psoriasis.

DATA EXTRACTION

Two investigators independently reviewed studies and resolved any discrepancies by consensus.

DATA SYNTHESIS

Of the 2,303 articles identified by literature search, 90 studies met inclusion criteria for this review; 15 were cohort-based studies, 45 were case-control, and 30 were cross-sectional.

LIMITATIONS

The quality of evidence was limited by study heterogeneity and lack of large scale prospective studies with long-term follow-up.

CONCLUSIONS

Patients with psoriasis demonstrate a higher prevalence of cardiovascular risk factors and appear to be at increased risk for ischemic heart disease, cerebrovascular disease, and peripheral arterial disease. This increase in vascular disease may be independent of shared risk factors and may contribute to the increase in all-cause mortality. Future research should aim to more confidently distinguish between a true causal relationship or merely an association resulting from multiple shared risk factors. Physicians should screen for and aggressively treat modifiable risk factors for CVD in patients with psoriasis.

C-reactive protein and markers for thrombophilia in patients with chronic plaque psoriasis

Chronic plaque psoriasis is associated to an increased risk of cardiovascular events. The aim of our study is to test patients with psoriasis for common markers of acquired and inherited thrombophilia. A cross-sectional study on 172 patients with psoriasis and 198 controls was carried out. The plasma levels of coagulation protein C, coagulation protein S, homocysteine, folic acid, C-reactive protein (CRP) and fibrinogen as well as activated protein C resistance and antithrombin III activity, were measured. CRP and homocysteine levels were higher in patients with psoriasis than in controls (5.9 ± 7.1 vs 3.1 ± 2.4 mg/L, p=0.0003 and 16.3 ± 12.8 vs 10.4 ± 4.6 umol/L, p=0.0001; mean ± SD) whereas folic acid was lower in psoriatic patients compared to controls (4.3 ± 7.2 vs 12.6 ± 7.9 p=0.006). Levels of coagulation protein C, coagulation protein S, fibrinogen as well as activated protein C resistance, antithrombin III activity were within normal ranges both in cases and controls. In a multivariate regression analysis, psoriasis severity was an independent predictor of higher CRP. In conclusion, high levels of serum CRP and homocysteine were found in patients with psoriasis, related to the severity of the disease. These data suggest that the increased risk of thrombotic cardiovascular events observed in psoriasis patients should be ascribed to an acquired rather than inherited thrombophilic status.

Homocysteine, vitamin B12 and folic acid levels in psoriatic patients and correlation with disease severity

Hyperhomocysteinaemia represents an independent risk factor for atherosclerotic cardiovascular disease, stroke, peripheral arterial occlusive disease and venous thrombosis. Psoriasis is a chronic inflammatory skin disease associated with increased atherothrombosis and cardiovascular risk profile. The aim of this study is to investigate homocysteine, folic acid and vitamin B12 levels in a cohort of psoriatic patients and its relationship with the severity of the disease. A retrospective observational study in 98 patients with chronic plaque psoriasis and 98 healthy controls was performed. Total plasma homocysteine level, folic acid, vitamin B12 and PASI index were assessed in every patient. Patients with psoriasis had plasma homocysteine levels higher than controls (57% of cases and 25% of controls; p<0.0001). Folic acid and vitamin B12 plasma levels were lower in psoriatic patients than in controls (p = NS), lower levels of vitamin B12 were found in patients with hyperhomocysteinaemia compared to patients with a normal value of homocysteine (p = 0.0009). The severity of psoriasis assessed according to PASI (19.51+/-16.26) did not directly correlate either with higher levels of homocysteine or with vitamin B12 and folic acid plasma levels. In conclusion, a significantly higher prevalence of hyperhomocysteinaemia was found in psoriatic patients compared to healthy controls. A significant correlation between hyperhomocysteinaemia and lower vitamin B12 levels, but not folic acid, was evidenced. On the contrary, our data do not correlate the high level of homocysteine with higher PASI scores or psoriasis type, suggesting that homocysteine level can be considered an independent risk factor in psoriatic patients.

Psoriasis therapy and cardiovascular risk factors: a 12-week follow-up study

BACKGROUND

Psoriatic patients present with an increased frequency of cardiovascular events.

OBJECTIVE

To study the impact of psoriasis duration and therapy on traditional and new cardiovascular risk factors.

STUDY DESIGN

A longitudinal study performed between 2005 and the first trimester of 2008. Each patient was followed up for 12 weeks, and was observed before and 3, 6, and 12 weeks after starting therapy.

SETTING

Patients attending the Dermatology Service, University Hospital of Coimbra, Coimbra, Portugal were enrolled.

SUBJECTS

Thirty-four patients with psoriasis vulgaris and 37 healthy volunteers as controls.

MAIN OUTCOME MEASURES

Psoriasis Area and Severity Index (PASI); lipid profile, oxidized low-density lipoprotein (oxLDL), oxLDL/low-density lipoprotein (LDL), total antioxidant status, lipid peroxidation, C-reactive protein (CRP), and circulating levels of adiponectin.

INTERVENTION

Ten patients started therapy with topical treatment, 11 with narrow-band UVB radiation (NB-UVB), and 13 with psolaren plus UVA (PUVA).

RESULTS

Before starting therapy, psoriatic patients presented with several risk changes in their lipid profiles, and significantly higher CRP, oxLDL, and oxLDL/LDL, and lower adiponectin levels (vs control subjects), which may further contribute to inflammation and atherogenesis. After treatment of the patients, although no significant differences were observed in the lipid profile compared with baseline, some changes suggested that the treatment could somehow alter lipid metabolism, as the reduction in high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A and the increase in the atherogenic index cholesterol/HDL-C maintained an even higher significance (as shown by p-values) when compared with the control group. After topical therapy, there was a significant reduction in thiobarbituric acid reactivity only, suggesting that the reduction in the hyperproliferative process within the lesions is important for lipid peroxidation. After NB-UVB therapy, oxLDL/LDL, cholesterol/HDL-C, lipoprotein (a) [Lp(a)], and CRP remained higher than in the control subjects, reflecting persistent inflammation and atherogenic risk. After PUVA treatment, there was a significant reduction in Lp(a), associated with an almost significant increase in apolipoprotein-B (p = 0.054); these changes were not observed after NB-UVB treatment. However, after PUVA and NB-UVB treatment, CRP and, in the NB-UVB group, oxLDL/LDL were persistently higher than controls.

CONCLUSION

Our data show that psoriatic patients present with several lipid profile changes that seem to be related to the severity of the disease and/or the treatment used. Mild psoriasis patients receiving topical treatment presented before starting therapy with a lipid profile similar to controls, whereas those undergoing NB-UVB and PUVA, who had higher PASI scores, presented with several risk factors. Moreover, PUVA therapy seems to interact in a different way with lipids that might result from an interaction of psoralen with plasma lipids, namely Lp(a). Inflammation, a hallmark of psoriasis, also seems to be related to psoriasis severity. Both NB-UVB and PUVA were effective, as shown by the reduction in PASI score, as well as in the oxidative and inflammatory stress markers. However, after NB-UVB and PUVA, a low-grade inflammatory process still persisted, which might be related to the duration of remission of the disease.

Lipid disturbances in psoriasis: an update

Psoriasis is a common disease with the population prevalence ranging from 2% to 3%. Its prevalence in the population is affected by genetic, environmental, viral, infectious, immunological, biochemical, endocrinological, and psychological factors, as well as alcohol and drug abuse. In the recent years, psoriasis has been recognised as a systemic disease associated with numerous multiorgan abnormalities and complications. Dyslipidemia is one of comorbidities in psoriatic patients. Lipid metabolism studies in psoriasis have been started at the beginning of the 20th century and are concentrated on skin surface lipids, stratum corneum lipids and epidermal phospholipids, serum lipids, dermal low-density lipoproteins in the psoriatic skin, lipid metabolism, oxidative stress and correlations between inflammatory parameters, lipid parameters and clinical symptoms of the disease. On the basis of the literature data, psoriasis can be described as an immunometabolic disease.

Cardiovascular Disease and Risk Factors in Patients with Psoriasis and Psoriatic Arthritis

Objective.

Patients with psoriasis and psoriatic arthritis (PsA) have an increased incidence of cardiovascular disease (CVD) and cardiovascular risk factors such as smoking, hypertension, and metabolic syndrome compared to the normal population. Patients with psoriasis and PsA may also have increased risk from nonconventional risk factors such as raised levels of homocysteine and excessive alcohol consumption. We conducted a comprehensive review of the literature on CVD and all cardiovascular risk factors in patients with psoriasis and PsA.

Methods.

Data sources: All studies identified from a Medline (www.ncbi.nlm.nih.gov) search pertaining to CVD, individual risk factors in psoriasis, and PsA were included. Study selection: Studies included a healthy reference population, were published between 1975 and 2009, and were written in English.

Results.

Our search yielded 14 studies that documented rates of CVD in patients with psoriasis and PsA compared to controls. Substantial evidence points to elevated risk of CVD in patients with psoriasis and PsA.

Conclusion.

It remains difficult to conclude if risk factors are caused by psoriasis or share a common pathogenesis. Physicians treating patients with psoriasis and PsA must be aware of all potential cardiovascular risk factors in their patients.

Safety and Efficacy of Calcium Folinate in Psoriasis: An Observational Study

An association between psoriasis and cardiovascular diseases has been reported, and treatment of this condition is often considered difficult because the conventional systemic therapies often show several side effects. To assess the efficacy and tolerability of a new drug, folinate calcium, to treat psoriasis, a total of 58 patients affected by active psoriasis were enrolled in a variable period study. These patients had clinically stable, plaque psoriasis involving ≥ 6% body surface area. Thirty of these patients were treated with folinate calcium therapy, 15 mg orally once daily, for a variable period based on each patient's clinical response. The comparison was made with 28 psoriatic patients treated with conventional systemic therapies (cyclosporine, acitretin, etanercept, efalizumab, infliximab, adalimumab). A clinical improvement was observed in both group, but in the first one we did not observe any side effects, whereas some important side effects were observed in the second. These preliminary results support the effectiveness and tolerability of folinate calcium treatment in psoriasis.

Comorbidities in patients with psoriasis

Psoriasis is a common chronic inflammatory disease that is associated with serious comorbidities, including psoriatic arthritis, reduced quality of life, depression, malignancy, and cardiovascular comorbidities. Patients with psoriasis have been shown to have an increased incidence of metabolic syndrome and cardiovascular disease compared with the general population. The chronic inflammatory nature of psoriasis has been suggested to be a contributing and potentially independent risk factor for the development of cardiovascular comorbidities. Understanding the interrelationship between these conditions is important for the management of psoriasis and the associated comorbidities. This review will focus on the range of comorbidities associated with psoriasis, with emphasis on cardiometabolic conditions and the aim of encouraging primary care physicians to screen psoriatic patients for cardiometabolic disorders and risk factors.

Lipoprotein (a) in patients with psoriasis: associations with lipid profiles and disease severity

BACKGROUND

Lipoprotein (a) [Lp(a)] is a genetically determined molecule whose role has been implied in cardiovascular pathology, and whose levels have been reported to be elevated in patients with psoriasis. Aim To assess the serum levels of Lp(a) in patients with psoriasis, and to investigate the associations of Lp(a) with other lipids and with psoriasis severity.

METHODS

Thirty-four patients with psoriasis and 26 healthy control subjects took part in the study. Serum levels of Lp(a) and total, high density lipoprotein (HDL), low density lipoprotein (LDL), and very low density lipoprotein (VLDL) cholesterol fractions were measured in all participants. The levels of triglycerides and total cholesterol were measured using enzymatic colorimetric tests; HDL and LDL cholesterol concentrations were determined by precipitation methods; the VLDL concentration was calculated according to the formula: VLDL cholesterol = triglycerides/5.

RESULTS

Patients with psoriasis showed significantly higher serum levels of Lp(a) relative to controls. Even when controlling for normolipidemic vs. hyperlipidemic status, abnormal levels of Lp(a) (> 30 mg/dL) were observed significantly more often in patients than in controls. In both patients and controls, Lp(a) levels correlated positively with total and HDL cholesterol levels. In patients, Lp(a) levels correlated positively with psoriasis severity.

CONCLUSIONS

Lp(a) may be a factor contributing to an increased cardiovascular risk in patients with psoriasis. A pathogenetic link may exist between this lipoprotein and psoriatic pathophysiology.

Folic acid in general medicine and dermatology

Folic acid is a vitamin B essential for the integrity and function of DNA. Relative deficiency of folic acid may occur in conditions such as pregnancy and hyperproliferative or chronic inflammatory disorders. Folic acid supplementation has been proven to be beneficial in the prevention of neural tube defects and in limiting methotrexate side effects, and may reduce the risk of colorectal cancer. Folate is a critical vitamin in determining plasma homocysteine levels, which in turn is a major risk factor for cardiovascular diseases. The results of large clinical trials with dietary supplementation of folic acid, vitamin B12 and vitamin B6 have shown that this homocysteine-lowering therapy is effective in the secondary prevention of non-fatal strokes, but had no effect in the prevention of fatal cardiovascular diseases. Hyperhomocysteinemia has also been reported in age-related neurological conditions with cognitive impairment (e.g. dementia), and psychiatric disorders such as depression. Elevated homocysteine levels are frequent in patients with chronic immune-mediated disorders including rheumatoid arthritis, systemic lupus erythematosus, chronic plaque psoriasis and psoriatic arthritis, which have in common a tendency to an accelerated atherosclerosis leading to increased deaths from cardiovascular events. Folic acid supplementation appears as a reasonable therapeutic option in patients affected by chronic inflammatory skin diseases, such as moderate to severe psoriasis; in particular, those with concomitant hyperhomocysteinemia, low plasma folate and additional cardiovascular risk factors.

MTHFR (methylenetetrahydrofolate reductase) C677T polymorphism and psoriasis

The aim of the study was to evaluate possible association of MTHFR C677T gene polymorphism (NM_005957) with psoriasis. Genotypes of MTHFR C677T gene polymorphism were determined in a sample of 654 Caucasian (Czech) subjects. Case group (n = 410) included patients with psoriasis (plaque psoriasis diagnosed in 285 patients, other subtypes of psoriasis were observed in 125 patients). Control group (n = 244) consisted of healthy subjects without individual history of psoriasis, with similar age and gender characteristics. The MTHFR C677T polymorphism genotypes were determined by a polymerase chain reaction and a subsequent restriction analysis with HinfI. The genotypes of C(677)T methylenetetrahydrofolate reductase (MTHFR) gene polymorphism were determined in a sample of 654 Caucasian (Czech) subjects. We proved a significant difference in genotype distribution (P(g) = 0.03) and allelic frequency (P(a) = 0.02) between psoriatic and control subjects (Table 3). The CC (the thermostabile) genotype was significantly more frequent in psoriatic patients compared to controls [OR = 1.55, 95% confidential interval (CI) = 1.12-2.15, P = 0.004814, P(corr) = 0.01]. But, a significant increase of T allele in MTHFR gene was observed in patients with positive family history of diabetes (P(a) = 0.02) and in those with a frequent tonsillitis/tonsillectomy (P(a) = 0.04). No difference was observed between patients with and without positive family history of psoriasis (P(a) = 0.251). But, when psoriatic patients were described for FHDM, FH-Ps, and PH-T simultaneously, The highest incidence of CT + TT genotypes was calculated for psoriasis patients with positive history of psoriasis and diabetes mellitus together with personal history of repeated tonsillitis/tonsillectomy compared to patients without all these three phenotypes (odds ratio = 3.17, 95% CI 1.33-7.56, P(corr) = 0.04). In conclusion, MTHFR C677T polymorphism is marginally associated with psoriasis. The T allele (thermolabile) appears to be more frequent in psoriasis patients with positive history of psoriasis and diabetes mellitus together with personal history of repeated tonsillitis/tonsillectomy. This could reflect an inborn predisposition in complex regulation in one-carbon moieties transport in psoriatic patients and therefore, MTHFR genotype can be a part of genetic background of psoriasis.

Is there a relationship between homocysteine and vitiligo? A pilot study

BACKGROUND

Pigmentary dilution is observed in patients with homocystinuria. Therefore, it is possible that an increase of local homocysteine (Hcy) interferes with normal melanogenesis and plays a role in the pathogenesis of vitiligo. Vitamin B12 and folic acid, levels of which are decreased in vitiligo, are important cofactors in the metabolism of Hcy. Consequently, a nutritional deficiency in either of these two vitamins will result in an increase in homocysteine in the circulation, a finding that we expect to find in vitiligo.

OBJECTIVE

To determine the level of Hcy in the blood of patients with vitiligo as a first step in revealing if it has any relationship with the pathogenesis of vitiligo and consequently if this will have an impact on the treatment of vitiligo.

METHODS

Twenty-six patients of both sexes with vitiligo (age range 20-50 years, mean 31.4 +/- 8.09) and 26 age-matched healthy controls were included in the study. After excluding factors that may affect serum Hcy levels, blood samples from patients and controls were obtained for homocysteine determination by enzyme immunoassay.

RESULTS

The mean serum level of Hcy was significantly higher in patients with vitiligo than in controls (21.61 +/- 13.28 vs. 13.1 +/- 4.88 micromol L(-1); P < 0.001). The Hcy level was significantly higher in male patients than in female patients (28.67 +/- 15.95 vs. 15.56 +/- 6.2 micromol L(-1); P < 0.001) and in male controls compared with female controls (15.07 +/- 4.61 vs. 12.05 +/- 4.82 micromol L(-1); P < 0.001). The homocysteine level was related to the activity of vitiligo and was significantly higher in patients with progressive disease than in controls (25.4 +/- 14.99 vs. 13.1 +/- 4.88 micromol L(-1); P < 0.001). No significant difference in Hcy levels was found between either untreated vitiligo patients (22.77 +/- 13.36 micromol L(-1)) or patients receiving ultraviolet therapy (20.45 +/- 13.73 micromol L(-1)) and the total patient group (21.62 +/- 13.28 micromol L(-1)).

CONCLUSION

An elevated homocysteine level may be a precipitating factor for vitiligo in predisposed individuals. In view of the biological role of vitamin B(12) and folic acid in Hcy metabolism, we present our recommendations regarding the investigation and treatment of this common disease.

Plasma total homocysteine: instigator or indicator of cardiovascular disease?

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in developed countries. However, traditional risk factors cannot fully account for this. In the last 20 years, there has been an explosion of interest in plasma total homocysteine (tHcy) as a potential modifiable risk factor for CVD. Recent meta-analyses of epidemiological studies support the concept that increased tHcy concentrations are associated with CVD. This has led to the ‘homocysteine hypothesis’, which states that lowering plasma tHcy using folic acid and other B-vitamins will reduce the risk of CVD. In experimental studies, homocysteine has been shown to cause oxidative stress, endothelial cell dysfunction and promote thrombogenesis. However, data from recent large randomized controlled trials have shown that there is no clinical benefit to lowering plasma tHcy concentrations with folic acid and other B-vitamins. This lack of effect of tHcy lowering strongly suggests that homocysteine is not an instigator but merely an indicator of CVD.

Psoriasis comorbidities

Psoriasis is a chronic and debilitating inflammatory disease associated with serious comorbidities. Psoriasis can have a significant impact on a patient's quality of life and is associated with loss of productivity, depression, and an increased prevalence of malignancy. Emerging comorbidities of psoriasis include cardiovascular disease and metabolic syndrome. Psoriasis patients have an increased prevalence of the core components of metabolic syndrome, including obesity, dyslipidemia, and insulin resistance. The relationship between psoriasis and comorbidities such as metabolic syndrome and cardiovascular disease is likely linked to the underlying chronic inflammatory nature of psoriasis. The molecular mechanisms involved in psoriasis-associated dysregulation of metabolic function are believed to be due, in large part, to the action of increased levels of proinflammatory factors, such as tumor necrosis factor-alpha, that are central to the pathogenesis of psoriasis. Recent studies investigating the effects of tumor necrosis factor antagonists on the treatment of cardiovascular disease and metabolic syndrome support this concept.

Psoriasis and vascular disease: an unsolved mystery

Psoriasis is an immune disease most commonly recognized for its skin and joint manifestations. These produce significant physical, social, and psychological distress in affected patients and resultant reductions in their quality of life. As expected, these concerns are vital in providing symptomatic improvement and in selecting an individualized therapy. Yet, the approach in management of these patients is likely to change given the growing body of evidence linking psoriasis and vascular disease. Stemming from an anecdotally described relationship, the association between psoriasis and vascular disease has become a focus of current research to further elucidate the pathophysiology underlying and connecting these two diseases. This article includes a review of the classical cardiovascular risk factors, the atherothrombotic markers, and the environmental stressors associated with psoriasis, as well as a critical review of the observed vascular diseases, the proposed mechanism of atherosclerosis, and the benefits of treatment of psoriasis.

Psoriasis: a possible risk factor for development of coronary artery calcification

BACKGROUND

Psoriasis is a chronic inflammatory skin disorder affecting about 2% of white-skinned individuals. Epidemiological data on the prevalence and degree of coronary artery calcification (CAC) as an indicator for cardiovascular diseases in patients with psoriasis are contradictory.

OBJECTIVES

To study the prevalence and degree of CAC as an indicator for cardiovascular diseases in 32 patients with psoriasis matched for age, sex and risk factors to an equally sized control population.

METHODS

Noncontrast-enhanced 16-row spiral computed tomography was performed in patients and controls.

RESULTS

We found a significantly increased prevalence (59.4% vs. 28.1%, P = 0.015) and severity (CAC score according to Agatston 3.7 vs. 0.0, P = 0.019) of CAC in patients with psoriasis. Multiple linear regression calculations identified psoriasis as a likely independent risk factor for CAC.

CONCLUSIONS

Our results point towards the potentially systemic nature of the inflammatory processes underlying the pathogenesis of psoriasis, which may therefore be considered a potentially severe systemic disease.

Unfavorable cardiovascular risk profiles in untreated and treated psoriasis patients

Psoriasis is a chronic inflammatory skin disease that is associated with an increased cardiovascular risk profile. The systemic inflammation present in psoriasis, various systemic treatments for psoriasis and an increased prevalence of unhealthy life style factors may all contribute to this unfavorable risk profile. The purpose of this article is to provide an overview of what is known about these risk factors in psoriasis, the way they influence the cardiovascular risk of psoriasis patients, and what can be done to reduce this risk. Genetic studies demonstrate that psoriasis and cardiovascular disease share common pathogenic features in which, for example inflammatory cytokines like TNF-alpha and IL-1 play an important role. The chronic inflammation in psoriasis has an unfavorable effect on the cardiovascular risk profile. Multiple cardiovascular risk factors seem to be influenced; the blood pressure, oxidative stress, dyslipidemia, endothelial cell dysfunction, homocysteine levels and blood platelet adhesion. Moreover, classic cardiovascular risk factors like smoking and obesity that have an increased prevalence among patients with psoriasis, indirectly also worsen the cardiovascular risk profile by stimulating the psoriasis activity. Systemic treatments in psoriasis reduce the cardiovascular risk by diminishing the inflammation, but it should be taken into account that most therapies also have adverse cardiovascular effects like dyslipidemia, hyperhomocysteinemia and hypertension. As a consequence preventive measures may be indicated at least during long-term treatments. Prospective research is warranted to accurately estimate the increased cardiovascular risk in psoriasis, to determine the underlying processes and to consider preventive measures according to the absolute risk of cardiovascular disease. The present overview provides data to advice health care providers to pay more attention to the cardiovascular risk profile in psoriasis patients.

Accumulation of oxidized low-density lipoprotein in psoriatic skin and changes of plasma lipid levels in psoriatic patients

Background. Psoriasis is a chronic inflammatory skin disease characterized by an accelerated turnover of epidermal cells and an incomplete differentiation in epidermis with lesion. However, the exact etiology of psoriasis is unknown. Abnormalities in essential fatty acid metabolism, free radical generation, lipid peroxidation, and release of lymphokines have been proposed. Objective. Our purpose was to evaluate the plasma lipids and oxidized low-density lipoprotein accumulation in psoriatic skin lesion in order to ascertain the possible participation of oxidative stress and oxidative modification of lipids in pathogenesis of psoriasis. Methods. The study group included 84 patients with psoriasis, and 40 sex- and age-matched healthy volunteers. Blood lipid profile was determined. Psoriatic and nonlesional skin samples of psoriatic patients were evaluated for the presence of oxidized low-density lipoprotein by using an immune-fluorescent staining method. Results. The mean levels of lipids (total cholesterol, triglyceride, and LDL cholesterol) in patients with psoriasis were found to be significantly higher than those of healthy subjects. Psoriatic skins were shown positive oxidized low-density lipoprotein staining. There was no staining in nonlesional skin samples of the same individuals. Conclusion. Lipid peroxidation mediated by free radicals is believed to be one of the important causes of cell membrane destruction and cell damage. This study shows for the first time the accumulation of oxidized low-density lipoprotein in psoriatic skin lesion. We believe that accumulation of ox-LDL in psoriatic skin may have an important role in the immune-inflammatory events that result in progressive skin damage.

Plasma homocysteine and folate levels in patients with chronic plaque psoriasis

BACKGROUND

Hyperhomocysteinaemia is a well-known risk factor for cardiovascular diseases. Patients with severe chronic plaque psoriasis have a higher risk of death due to arterial and/or venous thrombosis.

OBJECTIVES

To investigate the relationship among plasma homocysteine and folate levels and severity of chronic plaque psoriasis in a selected cohort of patients with psoriasis without known risk factors for acquired hyperhomocysteinaemia.

METHODS

We performed a case-control study in 40 patients with chronic plaque psoriasis and 30 age- and sex-matched healthy controls. Cases and controls were selected excluding individuals with conditions or diseases associated with acquired hyperhomocysteinaemia, and were also asked to stop alcohol and coffee consumption for 1 week before blood sampling. The plasma levels of homocysteine and folic acid were measured and were correlated with the severity of psoriasis (Psoriasis Area and Severity Index, PASI).

RESULTS

Patients with psoriasis had plasma homocysteine levels higher than controls (mean +/- SD 16.0 +/- 5.6 vs. 10.4 +/- 4.7 micro mol L(-1); P < 0.001). Conversely, folic acid levels were lower in patients with psoriasis compared with controls (mean +/- SD 3.6 +/- 1.7 vs. 6.5 +/- 1.7 nmol L(-1); P < 0.001). Plasma homocysteine levels in patients with psoriasis correlated directly with disease severity (PASI) and inversely with folic acid levels. Plasma folic acid levels were inversely correlated with the PASI. No abnormalities of plasma vitamin B(6) and B(12) were found.

CONCLUSIONS

Patients with psoriasis may have a tendency to hyperhomocysteinaemia, which may predispose to higher cardiovascular risk. Dietary modification of this risk factor appears relevant to the global management of patients with moderate to severe psoriasis.

Plasma homocysteine levels in multiple sclerosis

BACKGROUND

There is evidence that homocysteine contributes to various neurodegenerative disorders, and elevated plasma homocysteine levels have been observed in patients with multiple sclerosis (MS).

OBJECTIVE

To investigate if and why plasma homocysteine levels are increased in MS, and whether they play a role in the disease course.

METHODS

We compared plasma levels of homocysteine in 88 patients with MS and 57 healthy controls. In the MS group, 28 had a benign course, 37 were secondary progressive, and 23 primary progressive. To explore the underlying mechanisms, we measured serum levels of vitamins B6 and B12, folate, interleukin (IL)-12, tumour necrosis factor (TNF)-alpha, leukocyte nitric oxide production, and plasma diene conjugate levels (measure of oxidative stress).

RESULTS

Mean (SD) plasma homocysteine concentration was higher in patients (13.8 (4.9) micromol/l) than in controls (10.1 (2.5) micromol/l; p<0.0001). However, there were no significant differences in homocysteine levels between the three clinical subgroups of MS. Serum concentrations of vitamin B6, vitamin B12, and folate were not different between patients with MS and controls. In the MS group, there were no correlations between plasma homocysteine levels and the serum concentrations of IL-12 or TNF-alpha, leukocyte nitric oxide production, or plasma diene conjugate levels.

CONCLUSIONS

Elevated plasma homocysteine occurs in both benign and progressive disease courses of MS, and seems unrelated to immune activation, oxidative stress, or a deficiency in vitamin B6, vitamin B12, or folate.

Studies on the Formation of Glutathionylcobalamin: Any Free Intracellular Aquacobalamin Is Likely to Be Rapidly and Irreversibly Converted to Glutathionylcobalamin

A decade ago Jacobsen and co-workers reported the first evidence for the presence of glutathionylcobalamin (GSCbl) in mammalian cells and suggested that it could in fact be a precursor to the formation of the two coenzyme forms of vitamin B(12), adenosylcobalamin and methylcobalamin (Pezacka et al. Biochem. Biophys. Res. Commun. 1990, 169, 443). It has also recently been proposed by McCaddon and co-workers that GSCbl may be useful for the treatment of Alzheimer's disease (McCaddon et al. Neurology 2002, 58, 1395). Aquacobalamin is one of the major forms of vitamin B(12) isolated from mammalian cells, and high concentrations of glutathione (1-10 mM) are also found in cells. We have now determined observed equilibrium constants, K(obs)(GSCbl), for the formation of GSCbl from aquacobalamin and glutathione in the pH range 4.50-6.00. K(obs)(GSCbl) increases with increasing pH, and this increase is attributed to increasing amounts of the thiolate forms (RS(-)) of glutathione. An estimate for the equilibrium constant for the formation of GSCbl from aquacobalamin and the thiolate forms of glutathione of approximately 5 x 10(9) M(-1) is obtained from the data. Hence, under biological conditions the formation of GSCbl from aquacobalamin and glutathione is essentially irreversible. The rate of the reaction between aquacobalamin/hydroxycobalamin and glutathione for 4.50 < pH < 11.0 has also been studied and the observed rate constant for the reaction was found to decrease with increasing pH. The data were fitted to a mechanism in which each of the 3 macroscopic forms of glutathione present in this pH region react with aquacobalamin, giving k(1) = 18.5 M(-1) s(-1), k(2) = 28 +/- 10 M(-1) s(-1), and k(3) = 163 +/- 8 M(-1) s(-1). The temperature dependence of the observed rate constant at pH 7.40 ( approximately k(1)) was also studied, and activation parameters were obtained typical of a dissociative process (DeltaH++ = 81.0 +/- 0.5 kJ mol(-1) and DeltaS++ = 48 +/- 2 J K(-1) mol(-1)). Formation of GSCbl from aquacobalamin is rapid; for example, at approximately 5 mM concentrations of glutathione and at 37 degrees C, the half-life for formation of GSCbl from aquacobalamin and glutathione is 2.8 s. On the basis of our equilibrium and rate-constant data we conclude that, upon entering cells, any free (protein-unbound) aquacobalamin could be rapidly and irreversibly converted to GSCbl. GSCbl may indeed play an important role in vitamin B(12)-dependent processes.

Improving homocysteine levels through balneotherapy: effects of sulphur baths

BACKGROUND

Plasma homocysteine (tHcy) is a risk factor for cardio-vascular diseases. Furthermore it has been associated with antioxidative status. Additionally balneotherapeutic sulphur baths have been shown to influence antioxidative status.

METHODS

40 patients with degenerative osteoarthrosis were randomised into two equal groups, a treatment group, receiving stationary spa therapy plus daily sulphur baths (sulphur group) and a control group receiving spa therapy alone (control group). Blood tHcy levels and urinary 8-OHdG (an indicator for oxidative stress) were measured at the beginning and the end of spa therapy.

RESULTS

tHcy (micromol/l) was significantly reduced from 11.41 (+/-2.91) to 10.55 (+/-2.28) in the sulphur group (p=0.016) and rose insignificantly from 12.93 (+/-2.28) to 13.80 (+/-3.87) in the control group. 8-OHdG (ng 8-OHdG/mg creatinine) declined from 18.00 (+/-18.28) to 11.16 (+/-5.33) in the sulphur group (n.s.) and from 17.91 (+/-5.87) to 18.17 (+/-5.70) in the control group (n.s.). Differences between the two groups showed significant effects of sulphur baths for tHcy (p=0.006) but not for 8-OHdG (p=0.106).

CONCLUSIONS

Sulphur baths exert beneficial effects on plasma tHcyt whereas effects on 8-OHdG seem to be unlikely.