Raster-scanning optoacoustic mesoscopy biomarkers for atopic dermatitis skin lesions

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease worldwide. Its severity is assessed using scores that rely on visual observation of the affected body surface area, the morphology of the lesions and subjective symptoms, like pruritus or insomnia. Ideally, such scores should be complemented by objective and accurate measurements of disease severity to standardize disease scoring in routine care and clinical trials. Recently, it was shown that raster-scanning optoacoustic mesoscopy (RSOM) can provide detailed three-dimensional images of skin inflammation processes that capture the most relevant features of their pathology. Moreover, precise RSOM biomarkers of inflammation have been identified for psoriasis. However, the objectivity and validity of such biomarkers in repeated measurements have not yet been assessed for AD. Here, we report the results of a study on the repeatability of RSOM inflammation biomarkers in AD to estimate their precision. Optoacoustic imaging analysis revealed morphological inflammation biomarkers with precision well beyond standard clinical severity metrics. Our findings suggest that optoacoustic mesoscopy may be a good choice for quantitative evaluations of AD that are inaccessible by other methods. This could potentially enable the optimization of disease scoring and drug development.

Continued treatment with secukinumab is associated with high retention or regain of response

BACKGROUND

Conventional analyses present aggregate data, masking late responders and efficacy reductions. Secukinumab, a fully human monoclonal antibody that selectively neutralizes interleukin (IL)-17A, shows sustained efficacy in moderate-to-severe psoriasis.

OBJECTIVES

To determine stability of response to secukinumab, changes in efficacy were assessed in individual patients.

METHODS

This is a post hoc analysis of two phase III randomized controlled trials, FIXTURE (trial registration: NCT01358578) and CLEAR (trial registration: NCT02074982). Patients received secukinumab 300 mg (FIXTURE and CLEAR), etanercept 50 mg (FIXTURE) or ustekinumab 45 or 90 mg (CLEAR) over 52 weeks. Mutually exclusive response categories were defined: ≥ 90% improvement in the Psoriasis Area and Severity Index (PASI 90) ('excellent'), ≥ 75% improvement in PASI (PASI 75) and < PASI 90 ('good') and < PASI 75 ('insufficient'). Reductions in efficacy were defined as shifts from higher to lower response categories between two consecutive visits maintained for a third consecutive visit. Loss of efficacy was defined as a reduction of efficacy resulting in 'insufficient' response. All comparisons are descriptive.

RESULTS

At 52 weeks, in CLEAR, 90·2% (303/336) of patients on secukinumab achieved stable efficacy without loss and 77·7% (261/336) showed stable efficacy without any reduction of response [74·3% (252/339) and 59·9% (203/339) of patients for ustekinumab]. In FIXTURE, 83·5% (273/327) and 66·4% (217/327) of patients on secukinumab had stable efficacy without loss or reduction of response [58·3% (190/326) and 42·6% (139/326) for etanercept]. Response was regained by continuing secukinumab treatment in 50% (8/16) of patients in CLEAR and 26% (9/34) in FIXTURE. Similar patterns were observed for other response definitions.

CONCLUSIONS

Efficacy with secukinumab was stable over 52 weeks of treatment in most patients. Continued treatment with secukinumab resulted in regain of efficacy in some patients. Persistent loss of response was uncommon. What's already known about this topic? Secukinumab, a fully human monoclonal antibody that selectively neutralizes interleukin (IL)-17A, shows significant and sustained efficacy in the treatment of moderate-to-severe psoriasis. Secondary loss of response may be experienced by a minority of patients treated with secukinumab, as with other biologics, but the extent of this and the potential for regain of efficacy with continued treatment is not well understood. What does this study add? To determine stability of response to secukinumab and inform clinical practice, changes in efficacy were assessed at individual patient level using response categories. Efficacy with secukinumab was stable over 52 weeks of treatment in most patients, and continued treatment with secukinumab resulted in efficacy regain after loss in some patients. Persistent loss of response was uncommon. Patient factors such as body weight may affect the likelihood of loss of efficacy.

Is the humoral immunity dispensable for the pathogenesis of psoriasis?

BACKGROUND

Imbalances of T-cell subsets are hallmarks of disease-specific inflammation in psoriasis. However, the relevance of B cells for psoriasis remains poorly investigated.

OBJECTIVE

To analyse the role of B cells and immunoglobulins for the disease-specific immunology of psoriasis.

METHODS

We characterized B-cell subsets and immunoglobulin levels in untreated psoriasis patients (n = 37) and compared them to healthy controls (n = 20) as well as to psoriasis patients under disease-controlling systemic treatment (n = 28). B-cell subsets were analysed following the flow cytometric gating strategy based on the surface markers CD24, CD38 and CD138. Moreover, immunofluorescence stainings were used to detect IgA in psoriatic skin.

RESULTS

We found significantly increased levels of IgA in the serum of treatment-naïve psoriasis patients correlating with disease score. However, IgA was only observed in dermal vessels of skin sections. Concerning B-cell subsets, we only found a moderately positive correlation of CD138⁺ plasma cells with IgA levels and disease score in treatment-naïve psoriasis patients. Confirming our hypothesis that psoriasis can develop in the absence of functional humoral immunity, we investigated a patient who suffered concomitantly from both psoriasis and a hereditary common variable immune defect (CVID) characterized by a lack of B cells and immunoglobulins. We detected variants in three of the 13 described genes of CVID and a so far undescribed variant in the ligand of the TNFRSF13B receptor leading to disturbed B-cell maturation and antibody production. However, this patient showed typical psoriasis regarding clinical presentation, histology or T-cell infiltrate. Finally, in a group of psoriasis patients under systemic treatment, neither did IgA levels drop nor did plasma cells correlate with IgA levels and disease score.

CONCLUSION

B-cell alterations might rather be an epiphenomenal finding in psoriasis with a clear dominance of T cells over shifts in B-cell subsets.

Assessing nailfold microvascular structure with ultra-wideband raster-scan optoacoustic mesoscopy

Nailfold capillaroscopy, based on bright-field microscopy, is widely used to diagnose systemic sclerosis (SSc). However it cannot reveal information about venules and arterioles lying deep under the nailfold, nor can it provide detailed data about surface microvasculature when the skin around the nail is thick. These limitations reflect the fact that capillaroscopy is based on microscopy methods whose penetration depth is restricted to about 200 μm. We investigated whether ultra-wideband raster-scan optoacoustic mesoscopy (UWB-RSOM) can resolve small capillaries of the nailfold in healthy volunteers and compared the optoacoustic data to conventional capillaroscopy examinations. We quantified UWB-RSOM-resolved capillary density and capillary diameter as features that relate to SSc biomarkers, and we obtained the first three-dimensional, in vivo images of the deeper arterioles and venules. These results establish the potential of UWB-RSOM for analyzing SSc-relevant markers.

Addiction: an underestimated problem in psoriasis health care

BACKGROUND

Psoriasis is a disease of enormous socio-economic impact. Despite approval of numerous highly efficient and costly therapies, a minor proportion of severely affected patients actually receives sufficient treatment.

OBJECTIVE

To investigate whether addictions are associated with psoriasis and to develop evidence-based recommendations for dermatologists in their daily clinical practice in order to improve medical assessment of psoriasis and patients' quality of life.

PATIENTS AND METHODS

Psoriasis patients at the University Department of Dermatology were asked to fill out a paper-based self-reported anonymous questionnaire with 92 questions of validated screening tests for the six most common addictions in Germany (alcohol, nicotine, drugs and illegal drugs, gambling, food). Body weight and height as well as current Psoriasis Area and Severity Index (PASI) were documented as well.

RESULTS

Between October 2015 and February 2016, 102 patients (65 males, 37 females; mean age 49.7 years (SD 13.4), range 18-83 years) participated in the study. Fifty-seven of the 102 patients showed addictive behaviour. Of these, 23.8% were high-risk drinkers, 41% regular smokers, 11% at risk of drug abuse, 4.1% at risk of food dependency and 19% compulsive gamblers. Compared with the general population, these results are significantly higher for alcohol abuse (P < 0.005), nicotine (P < 0.001) and gambling (P < 0.001). Body mass index was significantly higher in the study population (P < 0.001).

CONCLUSION

Addictions and gambling are more prevalent in patients with psoriasis compared with the general population. Respective screening measures are recommended in daily practice for doctors treating psoriasis patients, and PeakPASI is suggested as a score to document patients' lifetime highest PASI. Parallel to new drug approvals and even more detailed insights into the pathomechanism of psoriasis, public health strategies and interdisciplinary approaches are essential for a general sustained psoriasis treatment.

Potential role of Th17 cells in the pathogenesis of type 2 autoimmune pancreatitis

Th17 cells have been shown to play an important role in the pathogenesis of a variety of autoimmune diseases. The aim of this study was to investigate the potential role of Th17 cells in autoimmune pancreatitis (AIP). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine gene expression of the signature cytokines of Th17 cells IL-17A and IL-21 and of the Th17 lineage-specific transcription factor retinoic acid receptor-related orphan receptor C (RORC) in human tissue specimens of AIP, classical chronic pancreatitis (CP), and normal pancreas (NP). Infiltrating immune cells were characterized by immunohistochemistry (IHC). Gene expression of IL-17A, IL-21, and RORC were found to be significantly increased in AIP. Accordingly, the number of Th17 cells was significantly increased in AIP compared to NP or CP. Both gene expression analysis and IHC revealed a clear difference between type 1 and 2 AIP. In the periductal compartment of type 2 AIP, which is characterized by granulocytic epithelial lesions (GELs), the number of infiltrating Th17 cells and neutrophilic granulocytes was significantly increased compared to type 1 AIP. Our data suggest that Th17 cells play a role in the pathogenesis of AIP, in particular of type 2 AIP. Cross-talk between Th17 cells and neutrophilic granulocytes mediated via IL-17A may be a potential mechanism by which neutrophils are recruited to the duct and acinar cells with subsequent destruction, a process that is pathognomonic for type 2 AIP.

Dissecting susceptibility from exogenous triggers: the model of alopecia areata and associated inflammatory skin diseases

BACKGROUND

Alopecia areata (AA) is a T-cell-driven autoimmune disease of the hair follicle and frequently reported to be associated with inflammatory skin diseases (ISD) such as atopic eczema (AE) or psoriasis. Interestingly, AA on the one hand and both AE and psoriasis on the other hand are believed to be driven by mutually antagonistic T-cell subsets.

OBJECTIVE

To characterize AA-specific T-cell profiles and inflammatory pattern by intra-individual comparison of AA and coexistent ISD.

METHODS

112 patients with AA were recruited and investigated for coexisting ISD. In-depth analyses were performed in patients with AA and AE (n = 2), AA and psoriasis (n = 1), AA and psoriasis and AE (n = 1) and AA and lichen planus (n = 1), using histology, immunohistochemistry and cytokine staining of T cells isolated from lesional skin.

RESULTS

Of 112 AA patients investigated, 23 suffered from an ISD. The prevalence of AE, vitiligo, psoriasis and lichen planus was higher in the investigated AA cohort than in the normal population. The clinical as well as histological phenotype of AA the coexistent ISD were unequivocal. In line with this, T-cell infiltrates were found to be disease-characteristics with AA and lichen planus dominated by CD8+ and IFN-γ+ TNF-α+ producing T cells while psoriasis lesions in the same patients were dominated by IL-17+ and AE by IL-4+ T cells.

CONCLUSION

AA patients have a higher incidence of various T-cell-driven inflammatory skin diseases than the normal population, a phenomenon which might relate to over-activation of skin-homing T cells and to specific immune triggers as the primary cause of inflammation. More importantly, we showed that by using AA as a model disease, our approach of intra-individual comparison of distinct inflammatory responses in the same patient is feasible and offers the unique possibility to gain insights into disease pathogenesis independent from genetic susceptibilities.