Serum interleukin-22 and vascular endothelial growth factor serve as sensitive biomarkers but not as predictors of therapeutic response to biologics in patients with psoriasis.

The T-helper (Th)17 cell plays a crucial role in the pathogenesis of psoriasis, and several biological therapies have shown to be highly efficient in the treatment. However, some patients respond poorly to these therapies and may even develop paradoxical adverse effects. To evaluate the significance of serum immunological factors or circulating competent cells for biomarkers or predictors to biological therapies, we retrospectively analyzed 28 patients with psoriasis (19 psoriasis vulgaris, three pustular psoriasis and six psoriasis arthropathica). The numbers of patients treated with each agents were 16 for ustekinumab, six for adalimumab and six for infliximab. Patients were classified into three types according to the responsiveness: 13 patients were high-responders showing a 75% or more reduction of Psoriasis Area and Severity Index (PASI); 10 patients were moderate-responders showing PASI reduction of less than 75%; and five patients were non-responders showing PASI elevation. During the treatments, serum levels of interleukin (IL)-22 and vascular endothelial growth factor (VEGH) [corrected] were monitored. At baseline, serum IL-22 levels were significantly higher in the psoriatic patients than the normal controls. Both serum IL-22 and VEGF levels significantly correlated with PASI. After the treatment, the high-responders showed significant decreases in serum IL-22 and VEGF. On the other hand, serum IL-22 levels in the non-responders were elevated. However, the baseline levels of serum IL-22 and VEGF were not significantly different between the three groups. These results suggest that serum IL-22 and VEGF levels serve as sensitive biomarkers but not as predictors of therapeutic response to biologics in patients with psoriasis.

Exogenous coproporphyrin III production by Corynebacterium aurimucosum and Microbacterium oxydans in erythrasma lesions.

Erythrasma is a superficial skin disease caused by Gram-positive Corynebacterium species. Coral-red fluorescence under Wood's light, strongly suggestive of erythrasma, can be attributed to the presence of porphyrins. Fractionated porphyrin analysis in erythrasma lesions is yet to be reported. We attempted to investigate erythrasma lesions by isolating the responsible bacteria and determining their exogenous porphyrin production by HPLC analysis. We observed a 78-year-old woman with erythrasma who had a well-demarcated slightly scaling patch on her left foot, between the fourth and fifth toes. Two kinds of colonies on 5 % sheep blood agar were obtained from this lesion. Analysis of the 16S rRNA sequence revealed the colonies to be Corynebacterium aurimucosum and Microbacterium oxydans. HPLC analysis demonstrated that coproporphyrin III (Copro III) levels were clearly elevated, although the amounts of protoporphyrin were diminished. These results indicate that the fluorescent substance was Copro III. This study supports the view that excess Copro III synthesis by C. aurimucosum and M. oxydans leads to accumulation of porphyrin in cutaneous tissue, which emits a coral-red fluorescence when exposed to Wood's light.