Prolactin: A Mammalian Stress Hormone and Its Role in Cutaneous Pathophysiology.

The hormone prolactin (PRL) is best recognised for its indispensable role in mammalian biology, specifically the regulation of lactation. Bearing in mind that the mammary gland is a modified sweat gland, it is perhaps unsurprising to discover that PRL also plays a significant role in cutaneous biology and is implicated in the pathogenesis of a range of skin diseases, often those reportedly triggered and/or exacerbated by psychological stress. Given that PRL has been implicated in over 300 biological processes, spanning reproduction and hair growth and thermo- to immunoregulation, a comprehensive understanding of the relationship between PRL and the skin remains frustratingly elusive. In an historical curiosity, the first hint that PRL could affect skin biology came from the observation of seborrhoea in patients with post-encephalitic Parkinsonism as a result of another global pandemic, encephalitis lethargica, at the beginning of the last century. As PRL is now being postulated as a potential immunomodulator for COVID-19 infection, it is perhaps timeous to re-examine this pluripotent hormone with cytokine-like properties in the cutaneous context, drawing together our understanding of the role of PRL in skin disease to illustrate how targeting PRL-mediated signalling may represent a novel strategy to treat a range of skin diseases and hair disorders.

Retroperitoneoscopic adrenalectomy may be superior to laparoscopic transperitoneal adrenalectomy in terms of costs and profit: a retrospective pair-matched cohort analysis.

BACKGROUND: A direct comparison of the cost-benefit analysis of retroperitoneoscopic adrenalectomy (RPA) versus the minimally invasive transperitoneal access (LTA) approach is currently lacking. We hypothesized that RPA is more cost effective than LTA; promising significant savings for the healthcare system in an era of ever more limited resources. METHODS: We performed a monocentric retrospective observational cohort study based on data from our Endocrine Surgery Registry. Patients who were operated upon between 2019 and 2022 were included. After pair-matching, both cohorts (RPA vs. LTA) were compared for perioperative variables and treatment costs (process cost calculation), revenue and profit. RESULTS: Two homogenous cohorts of 43 patients each (RPA vs. LTA) were identified following matching. Patient characteristics between the cohorts were comparable. In terms of both treatment-associated costs and profit, the RPA procedure was superior to LTA (costs: US$5789.99 for RPA vs. US$6617.75 for LTA, P = 0.043; profit: US$1235.59 for RPA vs. US$653.33 for LTA, P = 0.027). The duration of inpatient treatment and comorbidities significantly influenced the cost of treatment and the overall profit. CONCLUSIONS: RPA appears not only to offer benefits over LTA in terms of perioperative morbidity and length of hospital stay, but also has a superior financial cost/benefit profile.

Effect of obesity on venous blood flow in the lower limbs.

BACKGROUND AND OBJECTIVES: Although obesity is a recognized risk factor for the development of lower limb venous disease, less attention has been paid to objectively measuring the effect of centripetal obesity on blood flow in the lower limbs. PATIENTS AND METHODS: The diameter of lower limb veins and venous blood flow were measured in 44 patients (65.6 ± 12.5 years, 25 females, 19 males) with centripetal obesity and chronic venous disease. RESULTS: The mean diameter of both common femoral veins (CFV) increased significantly in the semi-supine position following elevation of the panniculus (right: ∆0.73 ± 1.21 mm; p ≤ 0.001, left: ∆1.16 ± 1.42 mm; p ≤ 0.001). Moreover, there was a significant increase in venous flow volume in the left CFV (∆62.96 ± 117.85 ml/min; p  =  0.001). Similarly, there was an increase in the diameter of left great saphenous vein (∆0.24 ± 0.41 mm; p  =  0.002), measured at the mid-thigh, when the patient lifted their abdominal panniculus. Finally, the grade of obesity correlated with the extent of the venous disease. CONCLUSIONS: These data provide preliminary evidence that centripetal obesity results in both structural and hemodynamic changes in the lower limb veins, even in the absence of classical reflux.

Disease Recurrence during Adjuvant Immune Checkpoint Inhibitor Treatment in Metastatic Melanoma: Clinical, Laboratory, and Radiological Characteristics in Patients from a Single Tertiary Referral Center.

Despite the dramatic improvements in recurrence-free survival in patients with metastatic melanoma treated with immune checkpoint inhibitors (ICI), a number of patients develop metastases during adjuvant therapy. It is not currently possible to predict which patients are most likely to develop disease recurrence due to a lack of reliable biomarkers. Thus, we retrospectively analyzed the case records of all patients who commenced adjuvant ICI therapy between January 2018 and December 2021 in a single university skin cancer center (n = 46) (i) to determine the rates of disease recurrence, (ii) to examine the utility of established markers, and (iii) to examine whether re-challenge with immunotherapy resulted in clinical response. Twelve out of forty-six (26%) patients developed a relapse on adjuvant immunotherapy in our cohort, and the median time to relapse was 139 days. Adjuvant immunotherapy was continued in three patients. Of the twelve patients who developed recurrence during adjuvant immunotherapy, seven had further disease recurrence within the observation period, with a median time of 112 days after the first progress. There was no significant difference comparing early recurrence (<180 days after initiation) on adjuvant immunotherapy to late recurrence (>180 days after initiation) on adjuvant immunotherapy. Classical tumor markers, including serum lactate dehydrogenase (LDH) and S-100, were unreliable for the detection of disease recurrence. Baseline lymphocyte and eosinophil counts and those during immunotherapy were not associated with disease recurrence. Interestingly, patients with NRAS mutations were disproportionately represented (60%) in the patients who developed disease recurrence, suggesting that these patients should be closely monitored during adjuvant therapy.

Telmisartan induces a specific gut microbiota signature which may mediate its antiobesity effect.

Telmisartan prevents diet-induced obesity (DIO) in rodents. Given that the precise underlying mechanism is not known, we examined whether a gut-related mechanism might be involved. Sprague-Dawley rats received cafeteria diet (CD) for 3 months to develop DIO and were administered either telmisartan (8 mg/kgbw) or vehicle. In addition, pair-fed (PF) rats received CD adjusted to TEL and control rats (CON) only received chow. Stool samples were analysed by 16 S rRNA gene amplicon sequencing. CD-fed rats became obese while TEL, PF and CON rats remained lean. Alpha diversity analyses indicated that bacterial diversity was similar before the study but changed over time. Beta diversity revealed a time-, CD- and telmisartan-dependent effect. The Firmicutes/Bacteroidetes ratio and the abundance of Blautia, Allobaculum and Parasutterella were higher in DIO and PF than in CON, but not in TEL. Enterotype (ET)-like clustering analyses, Kleinberg's hub network scoring and random forest analyses also indicated that telmisartan induced a specific signature of gut microbiota. In response to stool transfer from telmisartan-pre-treated donor to high-fat fed acceptor mice, body weight gain was slightly attenuated. We attribute the anti-obesity action of telmisartan treatment to diet-independent alterations in gut microbiota as the microbiota from telmisartan-treated, CD-fed rats clearly differed from those of DIO and PF rats. ET-like clustering network, random forest classification and the higher stability in bacterial co-occurrence network analyses indicate that there is more than one indicator species for telmisartan's specific signature, which is further strengthened by the fact that we cannot identify a single indicator species.

Immune checkpoint inhibitors and tuberculosis: an old disease in a new context.

Tuberculosis, the leading cause of infection-related death in developing regions, is a leading cause of morbidity and mortality worldwide. Screening for, and treatment of, latent Mycobacterium tuberculosis infection is routine before initiation of anti-tumour necrosis factor α (anti-TNFα) agents in the management of psoriasis, Crohn's disease, and rheumatoid arthritis. By contrast, screening for latent tuberculosis before immune checkpoint inhibitor treatment in cancer is not routine, despite the increasing number of reports of primary infection with M tuberculosis or reactivation of latent M tuberculosis infection during such treatment. We present our experience with M tuberculosis screening in 70 patients who underwent immune checkpoint inhibitor therapy for metastatic skin cancer. Based on our understanding of the interaction between M tuberculosis and the immune system, we present the argument for tuberculosis screening before immune checkpoint inhibitor therapy and its use when considering anti-TNFα treatment for severe immune-related adverse events. We call for increased vigilance during immune checkpoint inhibition until its effects on tuberculosis pathophysiology are fully ascertained.

The Role of the Cutaneous Microbiome in Hidradenitis Suppurativa-Light at the End of the Microbiological Tunnel.

The development of next generation sequencing, coupled with advances in bio-informatics, has provided new insights into the role of the cutaneous microbiome in the pathophysiology of a range of inflammatory skin diseases. In fact, it has even been suggested that the identification of specific skin microbial signatures may not only be useful in terms of diagnosis of skin diseases but they may also ultimately help inform personalised treatment strategies. To date, research investigating the role of microbiota in the development of inflammatory skin diseases has largely focused on atopic eczema and psoriasis vulgaris. The role of the microbiome in Hidradenits suppurativa (HS)-also known as acne inversa-a chronic auto-inflammatory skin disease associated with significant morbidity, has received comparatively little attention. This is despite the fact that antimicrobial therapy plays a central role in the treatment of HS. After briefly outlining the clinical features of HS and current treatment strategies, we move on to review the evidence of microbial dysbiosis in HS pathophysiology. We conclude by outlining the potential for metagenomic studies to deepen our understanding of HS biology but more importantly to identify novel and much needed treatment strategies.

Intralesional interleukin-2: A novel option to maximize response to systemic immune checkpoint therapy in loco-regional metastatic melanoma.

The management of metastatic melanoma has been transformed by the development of immune checkpoint inhibitors. However, disease control in patients with extensive locoregional metastases remains a significant challenge. In this context, intralesional interleukin 2 (IL-2) presents a useful therapeutic option to maximize intratumoural drug concentration and minimize systemic toxicity. The utility of combined intralesional IL-2 and systemic immune checkpoint therapy, particularly in loco-regional disease, is unknown. We report the clinical and cellular effects of combined anti-programmed death-1 blockade and intralesional IL-2 therapy in two patients with loco-regional metastatic melanoma. Combined intralesional and systemic therapy induced a lasting resolution of the injected skin tumors; maintained for up to 2 years. This impressive response was associated with increased PD-L1 expression and CD8 T cell infiltration. To our knowledge, this is the first report that raises the possibility of a synergistic effect between intralesional IL-2 and systemic checkpoint inhibition. The lasting remission of injected metastases may be in part due to an altered tumor microenvironment; characterized by increased PD-L1 expression and increased CD8 T cell infiltration. If this interesting and novel preliminary observation is confirmed in larger studies, combined local and systemic immunotherapy could highlight a novel treatment strategy for extensive loco-regional disease.

Mineralocorticoid Receptor Antagonists Stimulate Human Hair Growth ex vivo.

Whilst topical steroids represent one of the most frequently administered treatments for skin and hair diseases, predominantly based on their glucocorticoid receptor-mediated anti-inflammatory effects, the mineralocorticoid effects of topical steroids have received surprisingly little attention. However, the role of mineralocorticoid receptor (MR) signaling is now known to extend beyond the kidney, with human skin, including the hair follicle (HF), expressing the MR. Using microdissected female HFs treated ex vivo with MR agonists and antagonists, we sought to determine the effects of MR-mediated signaling in the cutaneous context. Indeed, not only did the skin and HF epithelium express the MR at both the gene and protein level, but its expression was hair cycle dependent. Moreover, the selective MR antagonist eplerenone promoted hair shaft elongation and hair matrix keratinocyte proliferation whilst delaying catagen (HF regression). These novel observations suggest that the female human HF is sensitive to the inhibition of MR signaling and provide the first evidence that sustained MR signaling may even be required to maintain the growth phase (anagen) of human scalp HFs. Indeed, these data encourage the systematic evaluation of MR agonists and antagonists in human hair growth control so as to identify much-needed, novel anti-hirsutism and/or hair growth-promoting agents, respectively.

Prolactin as a candidate sebotrop(h)ic hormone?

Recognised for its key role in lactation, it is less well appreciated that the neurohormone prolactin (PRL) is actually one of the most pleiotropic hormones known. Not only does PRL exert both tropic and trophic effects in a wide range of tissues, but it is also expressed in human skin and hair follicles and regulates multiple complex cutaneous functions, including keratin expression and hair growth. Despite several clinical indications that PRL may also play a role in sebaceous gland (SG) biology, the effects of PRL on SG function have received little attention. In this Viewpoint essay, we argue that PRL may be a sebotrop(h)ic hormone and could represent a novel therapeutic target in human dermatoses affecting the SG. We provide preliminary evidence in support of this hypothesis (based on findings in human skin organ culture) and chart the major open questions in SG biology and pathology from a PRL research perspective. We close by delineating how these questions can be experimentally addressed so as to identify new therapeutic strategies that are either sebogenic or sebostatic, for example in the management of acne and cutaneous ageing.

A distinct cutaneous microbiota profile in autoimmune bullous disease patients.

Bullous pemphigoid (BP) is the most common autoimmune blistering disease in Europe. As both the incidence of the disease and the relative proportion of the elderly population continue to rise, it represents a significant medical burden. Whereas some progress has been achieved in defining genetic risk factors for autoimmune blistering diseases, no environmental agent has been conclusively identified. Emerging evidence suggests that host immunity may influence the skin microbiota, while the latter modulates cutaneous immunity. Nevertheless, the relationship between skin microbial communities and autoimmune bullous disease has yet to be studied in humans. Here, we aim to characterise and compare the skin microbiome of patients with BP and healthy, age-matched controls at numerous body sites. Similar to what has been shown in healthy controls, the composition of skin microbiota in patients with BP appears to be very divergent and site specific. Microbial phylum abundances differ between perilesional sites of patients with BP and the same anatomic locations of control patients. A distinct cutaneous microbiota profile, which correlates with BP, further strengthens the significance of commensal-host interaction on our immune system. Moreover, these results raise the possibility that the cutaneous microbiome may contribute to the pathogenesis of BP, with important implications for the treatment of this disease.