Large-scale serum analysis identifies unique systemic biomarkers in psoriasis and hidradenitis suppurativa

BACKGROUND

Hidradenitis Suppurativa (HS) is now recognized as a systemic inflammatory disease, sharing molecular similarities with psoriasis. Direct comparison of the systemic inflammation in HS with psoriasis is lacking.

OBJECTIVES

To evaluate the serum proteome of HS and psoriasis, and to identify biomarkers associated with disease severity.

METHODS

In this cross-sectional study, 1,536 serum proteins were assessed using the Olink Explore (Proximity Extension Assay/PEA) high-throughput panel in moderate-to-severe HS (n=11), psoriasis (n=10) and age- and BMI-matched healthy controls (n=10).

RESULTS

HS displayed an overall greater dysregulation of circulating proteins, with 434 differentially expressed proteins (|FCH|≥1.2, p-value≤0.05) in HS versus controls, 138 in psoriasis versus controls, and 503 between HS and psoriasis. IL-17A levels and Th1/Th17 pathway enrichment were comparable between diseases, while HS presented greater TNF and IL-1β-related signaling. Th17-associated markers, PI3 and LCN2, were able to accurately differentiate psoriasis from HS. Both diseases presented increases of atherosclerosis-related proteins. Robust correlations between clinical severity scores and immune and atherosclerosis-related proteins were observed across both diseases.

CONCLUSIONS

HS and psoriasis share significant Th1/Th17 enrichment and upregulation of atherosclerosis-related proteins. Nevertheless, despite the greater body surface area involved in psoriasis, HS presents a greater serum inflammatory burden.

Dermal tunnels influence time to clinical response and family history influences time to loss of clinical response in patients with hidradenitis suppurativa treated with adalimumab

BACKGROUND

Clinical response in hidradenitis suppurativa (HS) is most commonly assessed using the Hidradenitis Suppurativa Clinical Response (HiSCR) measure. Dermal tunnels, increased body mass index, smoking and antibiotic use significantly decrease the odds of achieving HiSCR. However, there are few data exploring if clinical features are also associated with length of time to achieve clinical response and/or time to lose clinical response.

AIM

To explore whether variables associated with achievement of HiSCR are associated with time to achieve HiSCR and time to loss of HiSCR in patients with HS treated with adalimumab 40 mg weekly in the PIONEER open-label extension study.

METHODS

Time-to-event analyses were performed to estimate time to achieve HiSCR and time to loss of HiSCR. The log rank test was used to compare cumulative incidence curves for a priori patient- and disease-associated factors. Cox regression analysis was performed to compare time-to-event outcomes in the presence of a priori variables. All statistical analyses were completed with R software (V3.5.3).

RESULTS

Presence of dermal tunnels significantly increased the time to achieve HiSCR (median 32.6 vs. 14.3 weeks, P = 0.02) and the hazard ratio (HR) was significant after controlling for patient and disease factors (HR = 0.70, 95% CI 0.51-0.96, P = 0.03). A positive family history of HS significantly decreased the time to loss of HiSCR (median 11.4 vs. 18 weeks, P < 0.001) and remained significant in Cox regression analysis (HR = 2.01, 95% CI 1.40-2.88, P < 0.001).

CONCLUSION

The presence of dermal tunnels significantly influences the odds of achieving HiSCR and the time to achieve HiSCR, while family history influences time to loss of HiSCR.

Doppler ultrasound-based noninvasive biomarkers in hidradenitis suppurativa: evaluation of analytical and clinical validity

BACKGROUND

There is a need for valid and reliable biomarkers in hidradenitis suppurativa (HS) for diagnosis and disease activity monitoring. Imaging-based biomarkers have the potential to fulfil this unmet need but no evaluation of analytical or clinical validity has yet been undertaken.

OBJECTIVES

To evaluate the analytical and clinical validity of sonographic epidermal thickness, Doppler ultrasound and dermal tunnel diameter in patients with HS.

METHODS

Twenty-two participants with HS were recruited and underwent a total of 65 matched ultrasound and skin biopsies of lesional, perilesional and unaffected tissue. Ultrasound measurements were performed in triplicate with mean values used. Skin biopsies underwent immunohistochemistry as per previously published methods. Analytical validity was assessed in individual ultrasound-biopsy pairs (n = 65) by comparisons of sonographic variables with histological correlates. Clinical validity was assessed in individual patients (n = 22) by comparing measures of overall disease activity with sonographic outcomes.

RESULTS

Epidermal thickness, dermal tunnel diameter and power Doppler intensity were assessed. Sonographic epidermal thickness and dermal tunnel diameter have high analytical validity with corresponding histological measurements. Power Doppler intensity demonstrated high correlation with dermal CD3⁺ and CD11c⁺ cell counts but not neutrophil elastase-positive cells. Power Doppler ultrasound has significant correlation with pain scores, abscess and nodule count, International HS Severity Scoring System score and number of draining tunnels.

CONCLUSIONS

Sonographic epidermal thickness and dermal tunnel diameter have acceptable levels of analytical validity in the assessment of HS lesions. Power Doppler intensity demonstrates acceptable clinical and analytical validity, suggesting it is a valid imaging-based biomarker in HS.

Spectral properties of topical retinoids prevent DNA damage and apoptosis after acute UV-B exposure in hairless mice

We showed in a recent study that topical retinyl palmitate prevented UV-B-induced DNA damage and erythema in humans. Given that retinyl palmitate is a precursor of retinoic acid, the biological form of vitamin A that acts through nuclear receptors, we wondered whether these protective effects toward UV-B exposure were either receptor dependent or linked to other properties of the retinoid molecule such as its spectral properties. We determined the epidermal retinoid profile induced by topical retinoic acid in hairless mice and analyzed its effect on markers of DNA photodamage (thymine dimers) and apoptosis following acute UV-B exposure; we compared these effects to those induced by other natural topical retinoids (retinaldehyde, retinol and retinyl palmitate) which do not directly activate the retinoid receptors. We then analyzed the direct action of these retinoids on UV-B-induced DNA damage and apoptosis in cultured A431 keratinocytes. Topical retinoic acid significantly decreased (approximately 50%) the number of apoptotic cells, as well as the formation of thymine dimers in the epidermis of mice exposed to acute UV-B. Interestingly, the other topical retinoids decreased apoptosis and DNA damage in a similar way. On the other hand, neither retinoic acid nor the other retinoids interfered with the apoptotic process in A431 keratinocytes exposed to UV-B, whereas DNA photodamage was slightly decreased. We conclude that the decrease of apoptotic cells in hairless mouse epidermis following topical retinoids and UV-B irradiation reflects a protection of the primary targets of UV-B (DNA) by a mechanism independent of the activation of retinoid nuclear receptors, rather than a direct inhibition of apoptosis.

Dermatofibrosarcoma protuberans in two patients with acquired immunodeficiency syndrome

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive cutaneous tumor of intermediate malignancy. Most commonly, it arises as an asymptomatic, indurated plaque on the trunk within which protuberant nodules develop over time. We describe its occurrence in two patients with human immunodeficiency virus, a previously unreported association. The first patient, a 41-year-old woman, complained of painful lesions around the left shoulder that developed within a scar from previous trauma to the area. The second patient, a 50-year-old man, developed a recurrent DFSP within the scar from a previous surgical procedure. Dermatofibrosarcoma protuberans was confirmed in both cases by the histopathologic and immunohistochemical findings.

Topical 9-cis-retinaldehyde for delivery of 9-cis-retinoic acid in mouse skin

The 9-cis-retinoic acid (9cRA) is an endogenous ligand of retinoid X nuclear receptors (RXRs). Although the epidermis contains five times more RXRs than RARs, little is known on the activity of topical 9cRA. In order to circumvent surface isomerization of topically applied 9cRA into all-trans-retinoic acid (atRA), we used topical 9-cis-retinaldehyde (9cRAL) as a precursor of 9cRA, hypothesizing that keratinocytes would metabolize 9cRAL into 9-cis-retinoic acid (9cRA). Retinoid content was determined by HPLC analysis of mouse tail skin that had been washed after the application of 9cRAL (0.05% for 14 days) to evaluate the metabolites produced within the epidermis. Biologic activities of 9cRAL and atRAL were analysed by assessing hyperplastic and metaplastic responses, by determining epidermal thickness and the levels of mRNAs encoding for specific keratins. atRAL and derived retinoids were found in skin treated with either atRAL or 9cRAL. The metabolite pattern obtained with 9cRAL was similar to that obtained with atRAL except the presence in 9cRAL samples of an unidentified nonpolar metabolite. However, treatment with 9cRAL yielded higher atRAL and lower retinyl ester concentrations. The biologic activities (hyperplastic and metaplastic responses) resulting from topical application of 9cRAL were lower than those induced by atRAL or atRA at similar concentrations. Taken together, these data show that topical 9cRAL does not deliver significant amounts of 9cRA and exerts less biologic activity than atRAL. Contrary to atRAL, 9cRAL does not appear therefore as a pertinent candidate for topical use in humans.

Topical retinaldehyde increases skin content of retinoic acid and exerts biologic activity in mouse skin

Retinaldehyde, a natural metabolite of beta-carotene and retinol, has been proposed recently for topical use in humans. Because retinaldehyde does not bind to retinoid nuclear receptors, its biologic activity should result from enzymatic transformation by epidermal keratinocytes into ligands for these receptors, such as all-trans retinoic acid and 9-cis-retinoic acid. In this study, we analyzed by high performance liquid chromatography the type and amounts of tissue retinoids as well as several biologic activities resulting from topical application of either retinaldehyde or all-trans retinoic acid on mouse tail skin. Biologic activities of all-trans retinoic acid and retinaldehyde were qualitatively identical in metaplastic parameters (induction of orthokeratosis, reduction of keratin 65-kDa mRNA, increase in filaggrin and loricrin mRNAs) and hyperplastic parameters (increase in epidermal thickness, increase in bromodeoxyuridine (BrdU)-positive cells, increase in keratin 50-kDa mRNA, and reduction in keratin 70-kDa mRNA). Some quantitative differences, not all in favor of all-trans retinoic acid, were found in several indices. Cellular retinoic acid-binding protein II and cellular retinol-binding protein I mRNAs were increased by both topical retinaldehyde and all-trans retinoic acid. Whereas all-trans retinoic acid, 9-cis-retinoic acid, and 13-cis-retinoic acid were not detectable (limit 5 ng/g) in vehicle-treated skin, 0.05% retinaldehyde-treated skin contained 13 +/- 6.9 ng/g wet tissue of all-trans retinoic acid (mean +/- SD), 12.6 +/- 5.9 ng/g 13-cis-retinoic acid, and no 9-cis-retinoic acid. In contrast, 9-cis-retinoic acid was detectable in 0.05% of all-trans retinoic acid-treated skin, which also contained 25-fold more all-trans retinoic acid and 5-fold more 13-cis-retinoic acid than retinaldehyde-treated skin. Our results show that topical retinaldehyde is transformed in vivo into all-trans retinoic acid by mouse epidermis. The small amounts of ligand for retinoic acid nuclear receptors thus produced are sufficient to induce biologic effects similar to those resulting from the topical application of the ligand itself in much higher concentration.

Midcarpal instability: is capitolunate instability pattern a clinical condition?

Five cases are presented with clinical findings of capito-lunate instability pattern of the wrist. All painful areas and tender points were dorsal, but variable in location and intensity. All plain radiographs and fluoroscopic instability series were normal. None of the cases had an explanation for the dorsal wrist pain other than a positive dorsal capitate-displacement test. Four out of five cases were treated in a cast for 4 weeks and two had subsequent splint immobilization. Although at short-term follow-up two of these five patients became pain-free, none was completely pain-free at long-term follow-up. Three patients treated with a cast had long-term follow-up. Only one could perform his original work. These findings support a clinical condition of midcarpal instability producing dorsal wrist pain reproduced with a simple stress test. Conservative, non-operative treatment will not usually produce long-term pain relief.

Photoionization used as a tool for the study of biomembranes: fate of tetramethylbenzidine photocation in purple membrane

Photoionization of hydrophobic probes has been developed in micelles or synthetic vesicles. Studies of the yields, compartmentation, and lifetimes of the photo-produced charged species have gathered reliable information on the interfacial and structural properties of these assemblies. Such an approach has never been applied to biological membranes. The present system is tetramethylbenzidine as the probe in native or modified (deionized and/or bleached) purple membrane from halobacteria. The data on photocation formation yields (phi ion) and lifetimes (tau 1/2) allow two main conclusions to be made: (1) tetramethylbenzidine, as the cation, is buried in the membrane core, and (2) its incorporation does not alter the biological activity of the protein. In this biological membrane the photocation lifetime and yield present the same trend of variation with the surface potential but to less of an extent than in model membranes. Bleaching of purple membrane completely modifies the photoionization process and the photocation decay. In addition, these experiments reveal a tight correlation between membrane structure and probe photoionization. Further evidence for structural modification of purple membrane, either by deionization or by bleaching is pointed out.