Serum prolactin levels in psoriasis and correlation with cutaneous disease activity

A quantitative systems pharmacology model for certolizumab pegol treatment in moderate-to-severe psoriasis

Background

Psoriasis is a chronic immune-mediated inflammatory systemic disease with skin manifestations characterized by erythematous, scaly, itchy and/or painful plaques resulting from hyperproliferation of keratinocytes. Certolizumab pegol [CZP], a PEGylated antigen binding fragment of a humanized monoclonal antibody against TNF-alpha, is approved for the treatment of moderate-to-severe plaque psoriasis. Patients with psoriasis present clinical and molecular variability, affecting response to treatment. Herein, we utilized an in silico approach to model the effects of CZP in a virtual population (vPop) with moderate-to-severe psoriasis. Our proof-of-concept study aims to assess the performance of our model in generating a vPop and defining CZP response variability based on patient profiles.

Methods

We built a quantitative systems pharmacology (QSP) model of a clinical trial-like vPop with moderate-to-severe psoriasis treated with two dosing schemes of CZP (200 mg and 400 mg, both every two weeks for 16 weeks, starting with a loading dose of CZP 400 mg at weeks 0, 2, and 4). We applied different modelling approaches: (i) an algorithm to generate vPop according to reference population values and comorbidity frequencies in real-world populations; (ii) physiologically based pharmacokinetic (PBPK) models of CZP dosing schemes in each virtual patient; and (iii) systems biology-based models of the mechanism of action (MoA) of the drug.

Results

The combination of our different modelling approaches yielded a vPop distribution and a PBPK model that aligned with existing literature. Our systems biology and QSP models reproduced known biological and clinical activity, presenting outcomes correlating with clinical efficacy measures. We identified distinct clusters of virtual patients based on their psoriasis-related protein predicted activity when treated with CZP, which could help unravel differences in drug efficacy in diverse subpopulations. Moreover, our models revealed clusters of MoA solutions irrespective of the dosing regimen employed.

Conclusion

Our study provided patient specific QSP models that reproduced clinical and molecular efficacy features, supporting the use of computational methods as modelling strategy to explore drug response variability. This might shed light on the differences in drug efficacy in diverse subpopulations, especially useful in complex diseases such as psoriasis, through the generation of mechanistically based hypotheses.

Follicular-Stimulating Hormone, Luteinizing Hormone, and Prolactin Serum Level in Patients with Oral Lichen Planus in Comparison to Healthy Population

Materials and Methods

In this cross-sectional case control study, the serum level of LH, FSH, and prolactin of 40 women with lichen planus who have been referred to Shiraz Dental Faculty, Oral and Maxillofacial Disease Department during 2018-2019 has been evaluated in comparison to 40 healthy controls. Data were analyzed by SPSS version 18. Two-way ANOVA and Mann–Whitney test were used for data analysis.

Results

The mean serum level of FSH and LH was significantly higher in OLP patients while this difference was not reported for prolactin. Only FSH mean serum level was significantly higher in nonmenopausal OLP patients. The distribution of prolactin and FSH hormones' serum level was in normal range.

Conclusions

The high serum level of FSH and LH can affect OLP pathogenesis by estrogen and progesterone modulation.

Immunohistochemical study of psoriatic plaques and perilesional skin in psoriasis vulgaris patients: A pilot study

Psoriasis vulgaris, a chronic inflammatory skin disorder, is the result of immune mediated processes, genetic background and environmental factors. Prolactin and the vascular endothelial growth factor seem to play a key role in psoriasis pathogenesis regarding hyperproliferation of epidermal keratinocytes and dermal vascular ectasia. The aim of the study was to investigate the expression of tumor necrosis factor-α (TNF-α), vascular endothelial growth factor receptor 2 (VEGFR2) and prolactin receptor (PRLR) in psoriatic skin by immunohistochemical analysis and to evaluate the correlation with disease severity. Two skin biopsies, psoriatic lesion and perilesional skin, obtained by punch biopsy from 19 nontreated psoriasis patients were examined in hematoxylin and eosin staining and immunohistochemistry (IHC) for TNF-α, VEGFR2 and PRLR. The indirect IHC reaction was carried out automatically and visualized by 3,3-diaminobenzidine (DAB) technique. The average number of DAB-positive cells and the intensity of cell staining were quantified on a predefined scale. The results show a significant difference in the quantity and distribution of TNF-α positive cells in the two sample groups. In psoriatic plaque skin, an increased expression of TNF-α was found in the perivascular dermis and epidermic keratinocytes. In perilesional skin the immunostaining was predominant in the basal layer keratinocytes, while in psoriatic plaque, all the layers were positively marked, with stronger expression at the base. A statistically significant difference was found between the intensity of the immunostaining in the two types of tissue. Positive cells for VEGFR2 and PRL were identified in the basal layer keratinocyte cells (VEGFR2), sweat glands and hair outer shaft sheath (PRLR), without significant differences between the two types of samples. Our findings confirm the importance of TNF-α in psoriasis pathogenesis and a positive correlation with lesions severity. No significant differences were found for VEGFR2 and PRLR, but additional studies are necessary to establish their role.

Hyperprolactinemia: pathophysiology and therapeutic approach

Prolactin (PRL) is a hormone, mainly secreted by lactotroph cells of the anterior pituitary gland. Recent studies have shown it may also be produced by many extrapituitary cells. Its well-recognized PRL plays an important role in lactation during pregnancy, but it is involved in other biological functions such as angiogenesis, immunoregulation and osmoregulation. Hyperprolactinemia is a typical condition producing reproductive dysfunction in both sexes, resulting in hypogonadism, infertility and galactorrhea. It may be also asymptomatic. Lactotroph adenomas (prolactinoma) is one of the most common cause of PRL excess, representing approximately 40% of all pituitary tumors. Several other conditions should be excluded before a clear diagnosis of hyperprolactinemia is made. Hyperprolactinemia may be secondary to pharmacological or pathological interruption of hypothalamic-pituitary dopaminergic pathways or idiopathic. Stress, renal failure or hypothyroidism are other frequent conditions to exclude in patients with hyperprolactinemia. We will review biochemical characteristics and physiological functions of that hormone. Clinical and pharmacological approach to hyperprolactinemia will also be discussed.

Assessment of serum levels of osteopontin, selenium and prolactin in patients with psoriasis compared with healthy controls, and their association with psoriasis severity

BACKGROUND

The association between psoriasis and cardiovascular diseases is well documented, but the underlying mechanisms remain unknown. Overexpression of osteopontin (OPN) has been reported in the plasma of patients with psoriasis, with increased cardiovascular risk factors in these patients. Selenium compounds are effective in downregulating OPN expression.

OBJECTIVE

We investigated the levels of OPN, selenium and prolactin (PRL) in psoriasis, and their association with metabolic status in patients to identify a possible link between these markers and observed comorbidities.

METHODS

Plasma samples from 40 patients with psoriasis and 40 age- and sex-matched healthy controls (HCs) were collected for ELISA. The clinical significance of plasma OPN, selenium and PRL levels in patients compared with controls was analysed in relation to metabolic disorders.

RESULTS

There was no significant difference in median serum selenium levels between the two groups. Serum levels of PRL were not significantly different from those of HCs, but levels of OPN were significantly higher in patients with psoriasis than in HCs.

CONCLUSIONS

High plasma OPN is a predictor for occurrence of psoriasis. Our study showed that serum selenium and PRL were not decreased in patients with psoriasis, but there was a negative statistically significant correlation between OPN and selenium in all participants.

Biomarkers of psoriasis severity and therapy monitoring

Psoriasis is a chronic, recurrent inflammatory cutaneous disease. Psoriasis patients alternate between periods of remission and periods of exacerbation of the disease. Usually, psoriasis severity is clinically evaluated using tools like Psoriasis Area and Severity Index that present some limitations and subjectivity. Clinicians select the therapy according to psoriasis severity, aiming that patients achieve longer remission periods and improve their quality of life. Biological markers for diagnosis and prognosis of psoriasis help to establish its severity and to monitor the therapeutic response; moreover, biomarkers of psoriasis assist clinicians in their therapeutic decision to treat psoriasis and to choose earlier and more adequate therapeutic strategies, avoiding or minimising worsening of psoriasis. With these markers, they would be able to monitor therapeutics, avoiding unnecessary therapeutic surcharge or changes to a more aggressive therapy. As any attempt to identify these biomarkers should be encouraged, in this review, we will debate published data concerning the proposal of biomarkers to evaluate severity and response to treatment of psoriasis vulgaris.

Prolactin induces the production of Th17 and Th1 cytokines/chemokines in murine Imiquimod-induced psoriasiform skin

BACKGROUND

Prolactin (PRL) is a pituitary-derived neuropeptide hormone that has been suggested to promote the development of psoriasis, a Th17/Th1-mediated inflammatory dermatosis. PRL increases the expression of Th1 cytokines; however, its effects on Th17 responses are unknown.

OBJECTIVE

This study aims to determine the in vivo effects of PRL on the expression of Th17 cytokines/chemokines in imiquimod-induced psoriasiform skin inflammation in mice.

METHODS

BALB/c mice were intraperitoneally injected with PRL or phosphate-buffered saline, and imiquimod cream or Vaseline was applied to the shaved back skin for six consecutive days.

RESULTS

Intraperitoneal PRL increased the mRNA levels of IL-17A, IL-17F, IL-22, IL-23p19, IL-12p40, CCL20 and STAT3 in imiquimod-treated skin. Mice treated with imiquimod plus PRL, but not those treated with imiquimod plus phosphate-buffered saline, showed significantly increased mRNA levels of TNF-α, IFN-γ, IL-12p35 and CXCL2 compared with controls. Intraperitoneal PRL increased the numbers of CD3(+) and GR-1(+) cells in the dermis of imiquimod-treated skin.

CONCLUSIONS

These results suggest that intraperitoneal PRL enhances the expression of Th17 and Th1 cytokines/chemokines, and augments inflammation in imiquimod-induced psoriasiform skin. Prolactin may thus exacerbate psoriasis through the enhancement of Th17/Th1 responses.

Association of psoriasis severity with serum prolactin, thyroid hormones, and cortisol before and after treatment

Background. Prolactin (PRL) level is proposed to be associated with the severity of psoriasis although the previous studies reported different results. Objective. To find the association between PRL levels and severity of psoriasis before and after treatment. In addition, we aimed to find a difference in prolactin, thyroid stimulating hormone (TSH), thyroid hormones (T₃ and T₄), and cortisol levels between patients with psoriasis and normal controls. Methods. First, the levels of hormones were measured in 30 patients with psoriasis and 30 matched controls. The severity was assessed by psoriasis area and severity index (PASI). Then, patients were treated, and PASI was assessed every week until achieving PASI-75 response. At this time, the hormones were measured again and compared to the baseline. Results. No statistical significant difference was observed in the mean PRL, T₃, T₄, TSH, and cortisol levels between cases and controls. Comparing to the baseline, a significant decrease in PRL levels and a significant increase in T₃ and serum cortisol levels were observed after treatment (P < 0.05), while the changes in other hormones were not significant. Conclusion. After treatment, PRL significantly decreased, and T₃ and cortisol levels significantly increased. No correlation between hormone levels and improvement of PASI score existed.

Tumour necrosis factor alpha, interferon gamma and substance P are novel modulators of extrapituitary prolactin expression in human skin

Human scalp skin and hair follicles (HFs) are extra-pituitary sources of prolactin (PRL). However, the intracutaneous regulation of PRL remains poorly understood. Therefore we investigated whether well-recognized regulators of pituitary PRL expression, which also impact on human skin physiology and pathology, regulate expression of PRL and its receptor (PRLR) in situ. This was studied in serum-free organ cultures of microdissected human scalp HFs and skin, i.e. excluding pituitary, neural and vascular inputs. Prolactin expression was confirmed at the gene and protein level in human truncal skin, where its expression significantly increased (p = 0.049) during organ culture. There was, however, no evidence of PRL secretion into the culture medium as measured by ELISA. PRL immunoreactivity (IR) in female human epidermis was decreased by substance P (p = 0.009), while neither the classical pituitary PRL inhibitor, dopamine, nor corticotropin-releasing hormone significantly modulated PRL IR in HFs or skin respectively. Interferon (IFN) γ increased PRL IR in the epithelium of human HFs (p = 0.044) while tumour necrosis factor (TNF) α decreased both PRL and PRLR IR. This study identifies substance P, TNFα and IFNγ as novel modulators of PRL and PRLR expression in human skin, and suggests that intracutaneous PRL expression is not under dopaminergic control. Given the importance of PRL in human hair growth regulation and its possible role in the pathogenesis of several common skin diseases, targeting intracutaneous PRL production via these newly identified regulatory pathways may point towards novel therapeutic options for inflammatory dermatoses.

The HLA-Cw*06 allele and -1149 G/T polymorphism of extrapituitary promoter of PRL gene as a possible common genetic predisposing factors to psoriasis vulgaris and psoriatic arthritis in Czech population

Psoriatic arthritis (PsA) affects approximately 30 % of patients suffering from psoriasis vulgaris (PsV), but the risk factors for its development have not been well elucidated yet. The HLA-Cw*06 allele was described as a predisposing factor to PsV. Prolactin is known as an immune response modulator, and its elevated levels present risk for PsV development. It is possible that these factors interact and together emphasize the predisposition to both diseases. We tested on an association of HLA-Cw alleles and functional polymorphism -1149 G/T in PRL gene extrapituitary promoter with PsV and PsA in Czech population. We found a statistically significant association between HLA-Cw*06 allele and PsV (P corrected = 0.0013) that was most prominent in early onset disease subtype (P corrected = 0.0013). The association between HLA-Cw*06 and PsA was low (P corrected = 0.0585) and restricted to PsA patients with early PsV onset (P corrected = 0.0195). We found no association of -1149 G/T PRL gene polymorphism with either PsV or PsA.

Clinical efficacy of propylthiouracil and its influence on prolactin in psoriatic patients

OBJECTIVE

Propylthiouracil (PTU) is an effective drug for psoriasis treatment. Prolactin (PRL) is increased during psoriasis which has hyperproliferative effect on keratinocytes. Hence, the objective is to find the effect of PTU on PRL level in psoriatic patients.

DESIGN AND METHODS

25 psoriatic patients and 10 control subjects were involved in the study. Serum PRL, hematological and biochemical parameters, thyroid profile and histopathological examination were performed.

RESULTS

PTU treatment for 6 weeks and 12 weeks cleared psoriatic lesions indicated by decreased PASI score (p<0.001). Patients before treatment showed significantly increased PRL levels (male p<0.01, female p<0.001) when compared to controls, which was found to decrease significantly (male p<0.01, female p<0.001) after 12 weeks. Hematological and biochemical parameters showed no significant change. Histopathology showed reduced thickening of the epidermis and acanthosis after PTU treatment.

CONCLUSION

Since PRL is a growth hormone involved in hyperproliferation of keratinocytes, this study reveals the antiproliferative effect of PTU. Furthermore, no major side effects were observed following PTU treatment.