Plasma somatomedin-C levels in systemic sclerosis

We have measured the plasma levels of somatomedin-C (SM-C) or insulin-like growth factor I (IGF-I) in 13 patients with progressive systemic sclerosis (PSS) and age and sex matched healthy controls. We found the plasma SM-C levels to be within normal limits in all the patients. Thus, if somatomedin-C plays a role in the pathogenesis of PSS, it is more likely to be at the fibroblast receptor level or in the synthetic response of fibroblasts to SM-C.     

Plasma melatonin levels in psoriasis

Melatonin is synthesized and secreted by the pineal gland. A daily rhythm of melatonin secretion, with high plasma values during the dark period, has been found in all vertebrates studied so far. In psoriatics, several hormones, including GH and prolactin, have altered chronobiology, and some studies in humans suggest that melatonin affects the levels of GH and prolactin. We investigated circadian melatonin rhythm in 13 male psoriatics and 13 healthy males with an RIA specific for measuring the hormone in plasma. Samples were taken at 6 a.m., 8 a.m., 12.00, 4 p.m., 8 p.m. and 2 a.m. Differences in (mean +/- SD) plasma melatonin levels were analysed by Student's t-test. Our results show that psoriatic patients had lost the nocturnal peak and usual circadian rhythm of melatonin secretion. Levels of melatonin were significantly lower than in controls at 2 a.m., and higher at 6 and 8 a.m. and at 12 noon. Further investigations of this disorder of melatonin secretion in psoriasis are needed to understand its significance.     

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 μmol 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 B₆ and B₁₂ 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 exchanges in psoriasis

Five patients with resistant psoriasis were treated with plasma exchanges performed ten times over a 4-week period. Improvement was noted after three exchanges in all five. One patient with erythrodermic psoriasis became paler but relapsed 2 days after treatment. Improvement in four patients was of short duration with relapses occurring in 2 to 4 weeks. Circulating immune complexes were elevated before treatment and fell after each exchange by 20 to 70% of the former values.     

Selenium plasma levels in psoriasis

Little is known about factors that may have modulating effects on inflammatory diseases such as psoriasis. Recently it has been proposed that trace elements like selenium may play an active role. Selenium concentrations were determined in plasma and in whole blood from 64 patients with psoriasis. Values were compared with those of matched controls: no significant reduction was observed in contrast with previous reports of reduced selenium levels in psoriasis.     

Growth hormone levels in psoriasis

Summary Plasma growth-hormone levels in 12 fasting psoriatics were 4.4±1.4 mU/l (mean±SEM), compared to 2.7±1.7 in 5 patients with eczema and 1.2±0.3 in 6 normal subjects. The differences in mean values were not statistically significant and were due to exceptionally high levels of growth hormone in five patients with psoriasis and one patient with eczema. In the psoriatic group the exceptional patients were not distinguished by age or the area of involved skin but they tended to be leaner than those with low plasma-growth hormone levels. We conclude that raised plasma growth hormone cannot be the cause of psoriasis but might be a secondary effect of the skin disease in some patients.     

Plasma levels of 8-methoxypsoralen after bath-PUVA for psoriasis: relationship to disease severity

Plasma levels of 8-methoxypsoralen (8-MOP) were determined by high-pressure liquid chromato-graphy in 19 patients with psoriasis who were receiving bath-PUVA treatment, at different time points after the psoralen bath. The levels of 8-MOP varied between < 5 ng/ml (lower limit of detection) and 34 ng/ml, and we found a relationship between the plasma psoralen levels and the severity of the disease.     

Plasma lactoferrin reflects neutrophil activation in psoriasis

We used a biotinylated antibody ELISA technique to measure plasma levels of lactoferrin (LF) and the LF content of peripheral blood PMN in 20 patients with psoriasis, 21 with eczema or other inflammatory skin conditions, 19 patients with malignant skin tumours and 20 healthy control individuals. In psoriasis, plasma LF levels were significantly increased compared with levels in the other skin conditions and in the healthy controls (P less than 0.01). Furthermore, in psoriasis the LF content of circulating PMN was decreased. These findings provide further evidence that in psoriasis systemic activation ('priming') of circulating PMN may take place.     

Increased urine neopterin levels in psoriasis

The production of neopterin closely reflects activation of T-lymphocyte-mediated immunity. Oxidized and reduced forms of urine neopterin were measured by reversed-phase ion-pair high-performance liquid chromatography in patients with moderate to severe chronic plaque psoriasis (n = 40), and in a heterogeneous group of patients (n = 14) with cutaneous T-cell malignancies (CTCM). Results were compared with healthy non-psoriatic control subjects (n = 30). Neopterin levels were repeated after a course of ultraviolet B therapy (UVB) plus topical tar or dithranol, or photochemotherapy (PUVA), in 12 psoriatic patients. Fully oxidized urine neopterin levels and neopterin/creatinine ratios were significantly elevated in the psoriatic group compared with controls (P < 0.002, P < 0.05) but not in the CTCM group. Both neopterin and its creatinine ratio were significantly reduced by treatment (P < 0.05, P < 0.01). Psoriasis area and severity index scores (PASI) correlated strongly with urine neopterin levels (P < 0.001). These findings indicate that urine neopterin concentrations may be a marker of psoriatic disease activity, and further support the importance of activated T lymphocytes in the pathogenesis of psoriasis.     

Plasma trough levels of adalimumab and infliximab in terms of clinical efficacy during the treatment of psoriasis

We examined the relation between adalimumab and infliximab plasma trough levels, anti‐adalimumab and anti‐infliximab antibody formation. We analyzed plasma from 32 adalimumab‐treated and 20 infliximab‐treated psoriasis patients for evaluating trough levels of each drug. The presence of anti‐adalimumab and anti‐infliximab antibodies was analyzed and the severity of psoriasis was evaluated. At week 28, 25 out of 32 and at week 48, 21 out of 30 adalimumab‐treated patients maintained as more than PASI 75. At week 28, 12 out of 20 and at week 48, nine out of 18 infliximab‐treated patients were evaluated as more than PASI 75. In patients treated with 40 mg adalimumab every other week, the mean trough level was 7.62 μg/mL (range, 0.05–10.6) at week 48. In patients treated with 80 mg adalimumab every other week, the mean trough level was 8.61 μg/mL (range, 0.08–13.5) at week 48. Mean trough level of infliximab‐treated cases (4.1–5.2 mg/kg; mean, 4.6) was 4.64 μg/mL (range, 0.03–16.9) at week 48. Anti‐adalimumab antibody was detected in five out of 32 cases and anti‐infliximab antibody was detected in six out of 20 cases, respectively, at weeks 24 and 48. The optimal cut‐off values of adalimumab and infliximab concentration for more than PASI 75 were more than 7.84 μg/mL and more than 0.92 μg/mL, respectively. The trough levels of adalimumab and infliximab in psoriasis patients were positively associated with clinical response and were significantly lower in cases having anti‐adalimumab or anti‐infliximab antibodies.     

Plasma 8-methoxypsoralen concentrations in photochemotherapy of psoriasis

A quantitative study of 8-methoxypsoralen plasma profiles in patients with psoriasis undergoing photochemotherapy shows that a poor response to the treatment may be explained in terms of abnormal pharmacokinetic behaviour. However, not all ‘poor responders’ exhibit an abnormal pattern and for these an alternative explanation is required.