Assessment of serum level of prolactin, sex hormone and systemic manifestations in patients with scleroderma

Document Type: Original Article

Authors

1 Shiraz Geriatric Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

2 Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran

3 Endocrine and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

4 Autoimmune Disease Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

Abstract

This study aimed to determine the serum levels of prolactin and dehydroepiandrosterone (DHEA) in systemic sclerosis (SSc) and their correlation with disease duration and clinical manifestations. This case control study investigated 26 scleroderma patients and 26 healthy individuals adjusted for age and sex with the case group as controls. Serum levels of DHEA using radioimmunoassay (RIA) and prolactin using immune radiometric assay (IRMA) were measured in both groups. Clinical manifestations of the disease, disease duration, and fertility status at the time of the study were also determined for each scleroderma patient. The findings on 26 scleroderma patients (20 females and 6 males with mean age of 44 years and mean disease duration of 5±3 years) demonstrated that serum levels of DHEA were significantly lower in scleroderma patients than controls based on gender (males, p= 0.02) and fertility (fertile women, p= 0.01; menopausal women, p= 0.008). However, no significant difference was found in prolactin serum levels between the case and control groups. Moreover, only serum PRL levels correlated significantly with disease duration in fertile women.  Contrary to previous studies, this study manifested that serum PRL did not differ between scleroderma patients and normal individuals. Yet, serum DHEA was shown to be significantly lower in scleroderma patients. Only PRL levels correlated significantly with disease duration.

Keywords

Main Subjects


Introduction_____________________________

Systemic sclerosis (SSc) is an autoimmune disease with unknown etiology. It is characterized by excessive fibrosis of the skin and other internal organs following immune system dysfunction [1-3].

To maintain hemostasis in the body, a balance must be established between the neuroendocrine and immune systems [2,4]. Some previous studies have indicated the possible role of hypothalamic-pituitary-adrenal axis (HPA) disorders and alteration of androgen metabolism in the pathophysiology of scleroderma [5,6].

DHEA, produced abundantly by human adrenal glands, was found to be a regulatory factor for releasing pro-inflammatory cytokines such as interleukin 1 (IL-1), IL-2, and IL-6 and tumor necrosis factor α (TNFα) [8,10, 12]. 

Moreover, prolactin, a major hormone produced by hypothalamic-pituitary-adrenal axis (HPA), is known to be a lactogenic hormone secreted by the anterior pituitary gland; however, it can also be synthesized in various extra-pituitary sites such as the decidua, prostate, neurons, skin, immune cells, and mammary epithelium [4,9]. According to previous studies, in addition to its major role in reproduction, it is also capable of participating in the immune system [4,7,13]. This hormone can affect immune cells by stimulating the activation and proliferation of T cells and the production of TNF α, interferon γ (IFN γ), IL-1β, and IL-12 [4,7,11]. It has further been suggested that Prl can negatively affect the immune tolerance through regulatory T-cell suppression [14].

Previous studies have revealed high serum prolactin levels as well as low serum DHEA levels in both women and men with autoimmune diseases [7,8,15]; however, there can be found no study which compares the serum levels of these hormones in scleroderma patients with healthy individuals. Thus, the current study purposed to assess the serum levels of PRL and DHEA in scleroderma patients and compare them with healthy individuals in a control group. Furthermore, the correlation of these hormones with disease duration and clinical manifestations was also investigated in this study.

Materials and Methods____________________

Study design

This case control study was performed on scleroderma patients referring to the Tertiary Center of Rheumatology in Hafez Hospital, Shiraz University of Medical Sciences, Shiraz, Iran. Twenty-six scleroderma patients whose diagnosis was based on American College of Rheumatology (ACR) criteria were recruited in this study. Moreover, 21 healthy individuals adjusted for gender and age with the case group were also entered into the study as the control group.

Ethical approval for this study was obtained from the Ethics Committee of Shiraz University of Medical Sciences as per the Helsinki guidelines [16].

Female patients with a history of pregnancy and breast-feeding and ones with prolactinemia, hypothyroidism, or renal failure were excluded from this study. Moreover, individuals who took hormone-altering medications, such as corticosteroids and oral contraceptive pills, were also excluded [2,8,17].

Measurements

Data on the patients' clinical manifestations was gathered by reviewing documents in the scleroderma clinic and entering it into prepared data-gathering sheets.

The serum levels of DHEAS and prolactin were measured in both case and control groups. Blood samples were taken at 8-10 a.m. from participants in the fasted state. The serum was separated and incubated in -80°C. DHEAS was measured by radioimmunoassay (RIA) (Aria Pharmed Trade Co., Iran) and prolactin levels by immunoradiometric assay (IRMA) (Padyab Teb Co., Iran).

The results were compared between the case and control groups. All hormonal tests were performed in the endocrine and metabolism research center with a Gamma counter instrument (Kontron, made by Austria) which was calibrated regularly by the local representative company in Iran.

Statistical methods

All statistical analyses were performed using Statistical Analysis Package for Social Sciences, version 18 (SPSS, Inc., Chicago, IL, USA) [18]. The Mann-Whitney U test was used to compare the differences in serum levels of hormones between case and control groups. In addition, linear regression was applied to detect the relationship between hormones (DHEAS and Prl) as the dependent variable and disease duration as the independent variable. The component of β (coefficient beta) in the standardized linear regression was utilized to discern the strength of interrelation. Data was reported as means±SD for 95% CI with 5% degree of freedom. A p<0.05 was considered statistically significant.

Results__________________________________

The mean age of the scleroderma patients was 36.6±1.47 years in fertile females and 53.2±2.46 in post-menopausal females.

Statistical analysis revealed that DHEAS in childbearing females (p=0.01), postmenopausal females (p=0.008), and males (p=0.026) were significantly lower compared with healthy individuals. However, the level of Prl was not significantly different in either SSc patients or controls.

The results revealed that there was no significant association between hormone levels and disease manifestations based on gender. The linear regression results showed that the serum level of Prl had a significant relationship with disease duration in fertile females (p=0.023). The interpretation of β predicted the amount of change in the dependent variable, showing that individuals who had a beta coefficient of 0.548, for every unit change in disease duration there was a 0.548-unit increase in the serum level of Prl (Fig. 2). As for the remaining individuals (males and postmenopausal females), further linear regression analyses were not able to predict any connection between disease duration and hormone activities (Figs. 3 & 4).

Discussion_______________________________

Despite many studies on the pathophysiology of scleroderma, its etiology is still obscure. Some studies have suggested the possible role of a hormonal imbalance in the pathogenesis of this disease. However, there are many controversies regarding the role of hormones in SSc. Among the investigated hormones, DHEA and PRL were the most common ones revealed to play a role in scleroderma. Nevertheless, no definite result can be obtained through a literature review.

The current results demonstrated that serum levels of DHEAS were significantly lower in scleroderma patients compared with the controls; this confirmed the results reported by Luisa Mirone et al., Richard Imrich et al., and Straub et al.

Previous studies have proposed that age and depression are major factors contributing to low serum DHEA levels. However, the current results on the relationship between serum hormonal levels and SSc clinical manifestations did not show any significant correlation between these two variables. Furthermore, DHEA was shown to have anti-inflammatory functions. This finding reinforces the role of low serum DHEA levels in the pathogenesis of scleroderma.

Previous investigations have dealt with acute stressful conditions (i.e. hypoglycemia) to examine the hypothalamus-pituitary-adrenal (HPA) axis function in SSc patients [2], but the implementation of such approach revealed no significant changes in DHEAS levels regarding acute stress [25]. According to the statements above, the type and degree of stress can simply influence the regulation of body systems in a different way. Thus, the mechanism which led to a reduction of DHEAS in subjects of the current investigation may be attributed to the type (continuous) of stress that is a chronic disease. This can also be explained when inflammatory cytokines and/or any other trigger factor which play a role in this disease generates a continuous stimulus on the HPA axis and promotes further reduction in DHEAS [26].

Such contrast may be due to therapeutic effects which were able to control the inflammatory reaction.

The current data indicated that there was a direct interrelation between the serum level of Prl and disease duration in fertile females. Prl was shown to be essential for normal reproduction. Moreover, it was also found that the fertility of SSc patients does not differ with that of the normal population [27,28]. It seems that an adaptive response occurred in female scleroderma patients, which preserves fertility in these patients. According to the data, females with a prolonged disease duration were able to sustain higher Prl levels in their blood, but the Prl was not high enough to cause amenorrhea. These findings also suggested a difference in the endocrine behavior of male and female patients regarding Prl levels. No studies were found which reported higher levels of PRL in scleroderma patients.

The review of previous studies drew the authors to conclude that there can be a positive correlation between serum levels of Prl and DHEAS and age and gender [8, 29-32]. Nonetheless, the current results revealed that there is no relationship between the clinical manifestations of SSc and serum levels of hormones.

Fig. 1. The number of participants, excluded and included participants

Fig. 2. Comparing levels of dehydroepiandrostrone (DHEA) between groups based on sex and fertility

Fig. 3. Comparing levels of prolactin (PRL) between groups based on sex and fertility

Fig. 4. Correlation of serum prolactin levels of fertile women and disease duration

 

 

In conclusion, it was detected that DHEAS hormone levels were considerably lower in patients with SSc. In contrast, levels of the Prl hormone remained unchanged as compared with the controls. The results also indicated that there is no association between the basal plasma level of such hormones and systemic manifestations of SSc in the subjects.

Limitations of the study

Although this research was carefully prepared, it does have some limitations. The population of the study is small due to financial limitations. Also, a lack of time was a big constraint on this study.

Conflicts of interest

The authors declare no conflict of interest.

Acknowledgments

This manuscript was extracted from a thesis written by Farzane Yavari with the code number 3909 which was approved by the School of Medicine at Shiraz University of Medical Sciences.The authors would like to thank Shiraz University of Medical Sciences, Shiraz, Iran, the Center for Development of Clinical Research of Nemazee Hospital, and Dr. Nasrin Shokrpour for her editorial assistance.

  1. Ligon C, Hummers LK. Biomarkers in Scleroderma: Progressing from Association to Clinical Utility. Current Rheumatology Reports2016; 18(3): 1-14. doi: 10.1007/ s11926-016-0565-0.
  2. Imrich R, Lukac J, Rovensky J, Radikova Z, Penesova A, Kvetnansky R. et al. Lower adrenocortical and adrenomedullary responses to hypoglycemia in premenopausal women with systemic sclerosis. The Journal of rheumatology2006; 33(11): 2235-41.
  3. Zhang YJ, Zhang L, Huang XL, Duan Y, Yang LJ, Wang J. Association between cigarette smoking and impaired clinical symptoms in systemic sclerosis: A review. Cellular Immunology2017; 318: 1-7, doi: 10.1016/j.cellimm. 2017.04.002.
  4. De Bellis A, Bizzarro A, Pivonello R, Lombardi G, Bellastella A. Prolactin and autoimmunity. Pituitary2005; 8(1): 25-30. doi: 10. 1007/s11102-005-5082-5.
  5. Straub RH, Lehle K, Herfarth H, Weber M, Falk W, Preuner J. et al. Dehydroepiandrosterone in relation to other adrenal hormones during an acute inflammatory stressful disease state compared with chronic inflammatory disease: role of interleukin-6 and tumour necrosis factor. European Journal of Endocrinology2002; 146(3): 365-74, doi: 10.1530/eje.0.1460365.
  6. Jara LJ, Medina G, Saavedra MA, Vera-Lastra O, Torres-Aguilar H, Navarro C. et al. Prolactin has a pathogenic role in systemic lupus erythematosus. Immunologic Research2017; 65(2): 512-23, doi: 10.1007/s12026-016-8891-x.
  7. Shelly S, Boaz M, Orbach H. Prolactin and autoimmunity. Autoimmunity Reviews2012; 11(6-7): A465-A70. doi: 10.1016/j.autrev. 2011.11.009.
  8. Straub R, Zeuner M, Lock G, Schölmerich J, Lang B. High prolactin and low dehydroepiandrosterone sulphate serum levels in patients with severe systemic sclerosis. British Journal of Rheumatology1997; 36(4): 426-32, doi: 10.1093/rheumatology/36.4. 426.
  9. Trombetta AC, Meroni M, Cutolo M. Steroids and Autoimmunity. In: Endocrine Immunology. vol. 48. Karger Publishers; 2017: 121-32, doi: 10.1159/000452911.
  10. Sawalha AH, Kovats S. Dehydroepiandrosterone in systemic lupus erythematosus. Current Rheumatology Reports2008; 10(4): 286-91. doi: 10.1007/s11926-008-0046-1.
  11. Traish AM, Kang HP, Saad F, Guay AT. Dehydroepiandrosterone (DHEA)-A precursor steroid or an active hormone in human physiology (CME). Journal of Sexual Medicine2011; 8(11): 2960-82. doi: 10.1111/j.1743-6109.2011. 02523.x.
  12. Coronel-Restrepo N, Posso-Osorio I, Naranjo-Escobar J, Tobón GJ. Autoimmune diseases and their relation with immunological, neurological and endocrinological axes. Autoimmunity Reviews2017; 16(7): 684-92, doi: 10.1016/j.autrev. 2017.05.002.
  13. Fojtíková M, Cerna M, Pavelka K. A review of the effects of prolactin hormone and cytokine on the development and pathogenesis of autoimmune diseases. Vnitrni Lekarstvi2010; 56(5): 402-13.
  14. Legorreta-Haquet MV, Chávez-Rueda K, Montoya-Díaz E, Arriaga-Pizano L, Silva-García R, Chávez-Sánchez L. et al. Prolactin down-regulates CD4 +CD25 hiCD127 low/- regulatory T cell function in humans. Journal of Molecular Endocrinology2012; 48(1): 77-85. doi: 10.1530/JME-11-0040.
  15. Larouche V, Correa J, Cassidy P, Beauregard C, Garfield N, Rivera J. Prevalence of autoimmune disease in patients with prolactinomas and non-functioning pituitary adenomas. Pituitary2016; 19(2): 202-09, doi: 10.1007/s11102-015-0699-5.
  16. World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. Jama2013; 310(20): 2191-4. doi: 10.1001/jama.2013.281053.
  17. Mirone L, Barini A, Barini A: Androgen and prolactin (Prl) levels in systemic sclerosis (SSc): Relationship to disease severity. In: Annals of the New York Academy of Sciences. vol. 1069; 2006: 257-62.
  18. Carver R, Nash J. Doing data analysis with SPSS: version 18.0. 2011.
  19. Lally EV, Shah AA, Wigley FM. Overlooked Manifestations. In: Scleroderma. Springer; 2017: 533-50.
  20. Lawson E. Scleroderma. 2017.
  21. Rutkowski K, Sowa P, Rutkowska-Talipska J, Kuryliszyn-Moskal A, Rutkowski R. Dehydroepiandrosterone (DHEA): hypes and hopes. Drugs2014; 74(11): 1195-207, doi: 10.1007/ s40265-014-0259-8.
  22. Pluchino N, Drakopoulos P, Bianchi-Demicheli F, Wenger J, Petignat P, Genazzani A. Neurobiology of DHEA and effects on sexuality, mood and cognition. The Journal of steroid biochemistry and molecular biology2015; 145: 273-80, doi: 10.1016/j.jsbmb.2014. 04.012.
  23. Maggio M, De Vita F, Fisichella A, Colizzi E, Provenzano S, Lauretani F. et al. DHEA and cognitive function in the elderly. The Journal of Steroid Biochemistry and Molecular Biology2015; 145: 281-92, doi: 10.1016/j.jsbmb.2014.03. 014.
  24. Meijerink J, Poland M, Balvers MG, Plastina P, Lute C, Dwarkasing J. et al. Inhibition of COX‐2‐mediated eicosanoid production plays a major role in the anti‐inflammatory effects of the endocannabinoid N‐docosahexaenoylethanolamine (DHEA) in macrophages. British Journal of Pharmacology2015; 172(1): 24-37, doi: 10.1111/bph. 12747.
  25. Maninger N, Capitanio JP, Mason WA, Ruys JD, Mendoza SP. Acute and chronic stress increase DHEAS concentrations in rhesus monkeys. Psychoneuroendocrinology2010; 35(7): 1055-62. doi: 10.1016/j. psyneuen.2010.01.006.
  26. Oken BS, Chamine I, Wakeland W. A systems approach to stress, stressors and resilience in humans. Behavioural Brain Research2015; 282: 144-54, doi: 10.1016/j.bbr. 2014.12.047.
  27. Lidar M, Langevitz P. Pregnancy issues in scleroderma. Autoimmunity Reviews2012; 11(6-7): A515-A19. doi: 10.1016/j.autrev. 2011.11.021.
  28. Miniati I, Guiducci S, Mecacci F, Mello G, Matucci-Cerinic M. Pregnancy in systemic sclerosis. Rheumatology2008; 47(suppl_3): iii16-iii18, doi: 10.1093/ rheumatology/ken174.
  29. Maccario M, Ramunni J, Oleandri S, Procopio M, Grottoli S, Rossetto R. et al. Relationships between IGF-I and age, gender, body mass, fat distribution, metabolic and hormonal variables in obese patients. International Journal of Obesity & Related Metabolic Disorders1999; 23(6): 612-18, doi: 10.1038/sj.ijo.0800889.
  30. Quintero OL, Amador-Patarroyo MJ, Montoya-Ortiz G, Rojas-Villarraga A, Anaya J-M. Autoimmune disease and gender: plausible mechanisms for the female predominance of autoimmunity. Journal of Autoimmunity2012; 38(2): J109-J19, doi: 10.1016/j.jaut. 2011.10.003.
  31. Shelly S, Boaz M, Orbach H. Prolactin and autoimmunity. Autoimmunity Reviews2012; 11(6): A465-A70, doi: 10.1016/j.autrev. 2011.11.009.
32. Ferrari E, Cravello L, Muzzoni B, Casarotti D, Paltro M, Solerte S. et al. Age-related changes of the hypothalamic-pituitary-adrenal axis: pathophysiological correlates. European Journal of Endocrinology2001; 144(4): 319-29, doi: 10.1530/eje.0.1440319