Vasculitis-like herpes zoster in the course of treatment with tofacitinib in ulcerative colitis: An assessment of local viral distribution by RNA in situ hybridization.

A 67-year-old man had taken the janus kinase (JAK) inhibitor, tofacitinib, for ulcerative colitis. He was referred to our department for a refractory ulcer on his lower leg. We suspected vasculitis and performed skin biopsy. Histopathological examination showed multinucleated giant cells in the epidermis and fibrinoid degeneration of small vessels in the upper dermis. Varicella zoster virus (VZV) DNA was detected by polymerase chain reaction and we diagnosed the patient with atypical vasculitis-like herpes zoster. The patient was treated with oral valacyclovir, but the rash persisted and took 2 months to heal. Immunostaining using anti-VZV antibody was positive mainly in epidermal keratinocytes, but was also observed to be positive in cells in the dermis. We further performed RNA in situ hybridization using a VZV ORF9 mRNA probe and clearly showed that the distribution of VZV mRNA extended into the dermis, including the dermal vessel walls and the eccrine sweat glands as well as the epidermis. The internal administration of JAK inhibitors may induce regional widespread VZV infection including vessels and involved in the formation of prolonged vasculitis-like manifestation. RNA in situ hybridization can be a potent tool for detecting the spread of VZV infection in the skin.

Barrier function-related genes and proteins have an altered expression in acne-involved skin.

BACKGROUND: Acne vulgaris provides a unique disease setting in which a prominent skin inflammation is coupled with the overproduction of lipid-rich sebum. OBJECTIVES: Our goal was to evaluate the expression of barrier molecules in papular acne skin samples obtained from untreated patients and compare those to the results of healthy and of papulopustular rosacea-involved ones at the mRNA and protein levels. In addition, we aimed to assess the effects of various sebum composing lipids on the expression of proteins involved in barrier formation in keratinocytes. METHODS: Available microarray data sets of papular acne and papulopustular rosacea-affected skin samples were re-analysed with a focus on epidermal barrier-related pathways. Immunohistochemistry was performed to detect barrier molecules in the interfollicular regions of human acne and healthy skin samples. Protein levels of barrier-related genes were measured by western blot in samples of HaCaT keratinocytes treated with selected lipids. RESULTS: Meta-analysis of whole transcriptome data sets revealed that barrier-related pathways are significantly affected in acne vulgaris skin samples. While an altered expression of key molecules in maintaining barrier functions such as filaggrin, keratin 1, involucrin, desmoglein 1, kallikrein 5 and 7, was also observed at the protein levels, our data demonstrated that sebum composing lipids may selectively modify the levels of epidermal barrier-related molecules. CONCLUSIONS: Our results suggest that although not as prominently as in the dry papulopustular rosacea skin, the epidermal barrier in the interfollicular region may be damaged also in the lipid-rich skin samples of papular acne. Furthermore, our findings indicating diverse regulatory effects of various sebum lipids on the expression of barrier molecules in keratinocytes suggest, that they may influence the moisturization of the skin as well. Altogether, our findings could have implications in the development of sebum-modulating anti-acne therapies and even in the care of symptom-free skin.

Multivalent cation and polycation polymer preparations influence pharmacokinetics of dolutegravir via chelation-type drug interactions.

Dolutegravir (DTG) is an integrase inhibitor, whose gastrointestinal absorption is impaired by the formation of chelates with multivalent metal cation preparations. However, little is known regarding the interactions of DTG with preparations containing other multivalent metal cations or with polycation polymer preparations. This study examined how the pharmacokinetics of DTG are affected by co-administration with Al(OH)3, LaCO3, and the polycation polymers bixalomer (Bxl) and sevelamer (Svl). Prior to oral administration of DTG (5 mg/kg), rats were orally administered Al(OH)3 (150 or 300 mg/kg), LaCO3 (50 or 75 mg/kg), Bxl (250 or 500 mg/kg), or Svl (300 or 600 mg/kg). Serum concentrations of DTG were then measured over the next 24 h. Compared to the administration of DTG alone, its co-administration with Al(OH)3, LaCO3, Bxl, and Svl led to reduced serum concentration of DTG, and consequently, a significantly reduced area under the curve. These comparisons also revealed a considerable reduction in the maximum concentration, suggesting that the interactions of these agents with DTG in the intestinal tract inhibit absorption of DTG. The above results demonstrate that Al(OH)3, LaCO3, Bxl, and Svl affect the pharmacokinetics of DTG and indicate the need for caution when combining any of the above preparations with DTG.

Concurrent administration with multivalent metal cation preparations or polycationic polymer preparations inhibits the absorption of raltegravir via its chelation.

OBJECTIVES: Raltegravir (RAL) that can form chelates with multivalent metal cations shows lateral interactions with multivalent metal cation and polycationic polymer. We investigated the interactions of RAL with multivalent metal cation preparations, Al(OH)3 and LaCO3 , and polycationic polymer preparations, bixalomer (Bxl) and sevelamer (Svl). METHODS: Immediately before the oral administration of 40 mg/kg RAL, the rats were administered orally with the vehicle, Al(OH)3 , LaCO3 , Bxl, or Svl, and the time course of RAL serum concentration was followed. The in vitro binding affinity of RAL with multivalent metal cation and polycationic polymer was also evaluated using isothermal titration calorimetry (ITC). RESULTS: When Al(OH)3 , LaCO3 , Bxl, or Svl was concomitantly administered with RAL, the maximum concentration and area under the curve were significantly lower than those when RAL was administered alone. ITC showed the interaction of RAL with Al(OH)3 as an enthalpy-driven reaction and its interactions with LaCO3 and Bxl as entropy-enthalpy mixed reactions. CONCLUSIONS: The interaction of RAL with Al(OH)3 , LaCO3, Bxl, or Svl can inhibit RAL absorption into the gastrointestinal tract, and thus, the multivalent metal cation and polycationic polymer are the modifying factors that can affect RAL pharmacokinetics.