The imidazole derivative liarozole is a potent inhibitor of cytochrome P450-dependent 4-hydroxylation of endogenous all-trans retinoic acid, thereby increasing the levels of all-trans retinoic acid in both plasma and skin. As part of a large, double-blind, randomized clinical study, we investigated the cell biological alterations in uninvolved and lesional skin of 20 patients with severe plaque psoriasis, who were treated with either liarozole or acitretin. The extent and severity of the skin lesions, as recorded by the Psoriasis Area and Severity Index score, was significantly reduced (P

Objective To evaluate the CSF levels of chitinase proteins during the presymptomatic and early symptomatic phases of amyotrophic lateral sclerosis (ALS). Methods CSF samples were obtained from 16 controls, 55 individuals at‐risk for ALS (including 18 carrying a mutation in C9ORF72, 33 in SOD1), 12 ALS patients, and 7 phenoconverters (individuals diagnosed with ALS during follow‐up). At‐risk individuals and phenoconverters were enrolled through the Pre‐fALS study, which includes individuals carrying an ALS‐associated gene mutation without disease manifestations at initial assessment. Longitudinal CSF collections, where possible, took place every 3‐12 months for ALS patients and every 1‐2 years for others. CSF levels of chitotriosidase 1 (CHIT1), chitinase‐3‐like protein 1 (CHI3L1, YKL‐40) and chitinase‐3‐like protein 2 (CHI3L2, YKL‐39) were measured by ELISA, along with CHIT1 activity. Longitudinal changes in at‐risk individuals and phenoconverters were fitted to linear mixed effects models. Results Slowly rising levels of CHIT1 were observed over time in the at‐risk individuals (slope 0.059 log10[CHIT1] per year, P < 0.001). Among phenoconverters, CHIT1 levels and activity rose more sharply (0.403 log10[CHIT1] per year, P = 0.005; 0.260 log10[CHIT1 activity] per year, P = 0.007). Individual levels of both CHI3L1 and CHI3L2 remained relatively stable over time in all participant groups. Interpretation The CHIT1 neuroinflammatory response is a feature of the late presymptomatic to early symptomatic phases of ALS. This study does not suggest a long prodrome of upregulated glial activity in ALS pathogenesis, but strengthens the place of CHIT1 as part of a panel of biomarkers to objectively assess the impact of immune‐modulatory therapeutic interventions in ALS.

No abstract

Liarozole is a novel inhibitor of the enzyme cytochrome P₄₅₀ which has inhibitory effects on the 4-hydroxylation of retinoic acid. Previous studies have shown that liarozole is effective in the treatment of psoriasis. We performed an immunohistochemical study on the lesional skin from 7 patients with extensive plaque psoriasis, who were treated with systemic liarozole 75 mg BID for a period of at least 2 months. The effects of liarozole treatment on clinical and histological parameters were investigated. In particular, the effect of liarozole on the integrin markers CD11b and CD18 was studied.For immunohistochemistry, three consecutive biopsies were taken: before treatment, after 4, and after 8 weeks of treatment. Clinical scores and side effects were recorded before and during treatment.The medication was well tolerated and only mild side effects were reported, which were comparable with hypervitaminosis A. After 2 months of treatment a statistically significant decrease of the extent of body involvement was observed. In the psoriatic plaque, markers for epidermal proliferation and cutaneous inflammation decreased, and markers for epidermal differentiation increased to values comparable to normal skin. The first therapeutic effects in the psoriatic plaque occurred after 4 weeks of treatment, and consisted of a decreased induration, accompanied by a decrease of the total number of inflammatory infiltrate cells and a decreased epidermal ICAM-1 expression. Already after 4 weeks of treatment, a decrease of CD11b-positive cells was observed. Subsequently, after 8 weeks of treatment the recruitment of cycling epidermal cells and the number of involucrin-positive cell layers decreased.The present study demonstrates that liarozole treatment of psoriasis results in a reduction of aspects of cutaneous inflammation and subsequently a reduction of epidermal proliferation and promotion of differentiation. After 4 weeks of treatment, effects are observed on the epidermal ICAM-1 expression and on the CD11b-positive cell population.