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From the * Longitudinal Studies Section, Clinical
Research Branch and the Laboratory of Immunology, National Institutes of
Health, National Institute on Aging, Baltimore, Maryland;
the Department of Oncology, Division of
Biostatistics; Johns Hopkins University School of Medicine, Baltimore,
Maryland; the Department of Oncology, Prostate
Cancer Research Program, Kimmel Cancer Center at Johns Hopkins, Baltimore,
Maryland; and the Department of Medicine,
Division of Endocrinology, Johns Hopkins University School of Medicine,
Baltimore, Maryland.
| Correspondence to: Dr Shehzad Basaria, Department of Medicine, Division of Endocrinology and Metabolism, Johns Hopkins University School of Medicine, Bayview Medical Center, 4940 Eastern Avenue, Suite B-114, Baltimore, MD 21224 (e-mail: sbasari1{at}jhmi.edu). |
| Received for publication March 21, 2006; accepted for publication June 8, 2006. |
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Abstract |
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Key words: Hypogonadism, inflammation
Recently, there has been a growing interest in understanding the interaction between testosterone levels and inflammatory markers. Animal studies have shown that castration results in an inflammatory state (Spinedi et al, 1992). Observational studies have shown that women are more prone to develop autoimmune diseases than men; however, men with hypogonadism have a higher incidence and prevalence of autoimmune diseases compared to eugonadal men (Bizzarro et al, 1987). These data support the notion that testosterone may influence immune cell activation and prevent autoimmune disease development.
Few interventional studies have evaluated the relationship between male
hypogonadism and serum levels of pro- and/or anti-inflammatory cytokines. In
one study, acute induction of hypogonadism with GnRH agonists in healthy
elderly men was followed by elevated serum levels of inflammatory cytokines
TNF-alpha and IL-1 beta, suggesting an anti-inflammatory role for testosterone
(Khosla et al, 2002). Indeed,
testosterone replacement in hypogonadal men results in a significant decrease
in pro-inflammatory cytokines TNF-
and IL-1 ß and a significant
increase in the anti-inflammatory cytokine IL-10
(Malkin et al, 2004). Recent
population studies have further confirmed the inverse relationship between
testosterone and inflammatory cytokines
(Maggio et al, 2006).
Given that men undergoing ADT have profound hypogonadism and that the cytokine profile in patients on long-term ADT is not known, we hypothesized that men undergoing long-term ADT may demonstrate increased serum levels of pro-inflammatory and decreased levels of anti-inflammatory cytokines compared to age- and disease-matched controls. Since osteoporosis, sarcopenia, and metabolic derangements have been associated with an inflammatory state, the findings of this study may have important implications.
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Materials and Methods |
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The men undergoing ADT provided an excellent clinical model (since they have profound hypogonadism) to examine the association between hypogonadism and inflammatory cytokines. The evaluation of the non-ADT group permits us to account for any influence of the disease (PCa) itself on cytokine expression, while the control group allows us to account for any influence that aging may have on these inflammatory markers. Men in the ADT and non-ADT groups were recruited from the Kimmel Cancer Center at Johns Hopkins. The age-matched control group was recruited from a database of eugonadal men at the Johns Hopkins Hospital Clinical Trials Unit. None of these subjects were suffering from any acute or chronic inflammatory conditions. The cytokine levels were measured in those subjects in the 3 groups for whom sufficient serum samples were available (Table). All subjects signed informed consent that was approved by the Institutional Review Board of the Johns Hopkins Medical Institutions (Basaria et al, 2002).
Exclusion Criteria
Men were excluded from the study if they had any of the following: liver
function tests or serum creatinine >2 times the upper limit of normal,
glucocorticoid use in the previous 3 months, history of thyroid disease,
history of any form of hypogonadism prior to the diagnosis of PCa (both ADT
and non-ADT groups), and past or present cytotoxic chemotherapy.
Hormonal Methods
Total and free testosterone, PSA, lipid profile, and glucose levels were
measured commercially (Quest Diagnostics). The normal range for total
testosterone was 241–827 ng/dL and for free testosterone 8–24
ng/dL. Serum concentrations of inflammatory [MIP-1b, TNF-, IL-7, IL-8, IL-12
(p70), IL-13] and anti-inflammatory (IL-10) cytokines were assessed using a
Luminex soluble human multiplex cytokine assay according to the manufacturer's
instructions (LINCO Research Inc, St Charles, Mo). Briefly, thawed sera were
assayed for soluble cytokines using the Luminex fluorescent microsphere
technology and compared to the fluorescence intensity values derived from
standard curves for each cytokine. Samples were incubated with fluorescent
microspheres coupled to antibodies to MIP-1b, TNF-, IL-7, IL-8, IL-10, IL-12
(p70), and IL-13 and were analyzed using a Luminex100 cytometer fitted with an
XY Platform and Luminex Data Collector software (Luminex Corporation, Austin,
Tex). Fluorescent beads (300 beads per analyte) that were bound by cytokine
were differentiated from free beads through the use of a phycoerythrin-bound
reporter antibody to the cytokine analyte. Based on the standard curves
generated for each cytokine, concentrations were determined for each serum
sample and are expressed as pg/mL. The intra-assay precision of these assays
range from 4.4%–7.6% CV (average 5.6% CV). The sensitivity of this assay
system for these various cytokines using patient sera ranged from 0.5–16
pg/mL.
Statistical Analysis
T tests were used to test for differences in mean age and BMI between the 3
two-sample combinations of the groups (ADT vs non-ADT, ADT vs controls, and
non-ADT vs controls). The distributions of age and BMI were separately
examined across the 3 groups using ANOVA. Nonparametric Mann-Whitney tests
were used to test for differences in the medians of the cytokines,
testosterone, and estradiol between the 3 two-sample combinations of the
groups. The distributions of these variables across the 3 groups were examined
separately using nonparametric Kruskal-Wallis tests. The distribution of race
(white vs nonwhite) between the 3 two-sample combinations of groups and all 3
groups simultaneously was examined using Fisher's exact
test.
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Results |
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Discussion |
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Review of the literature suggests that testosterone does indeed exert immunosuppressive properties. This is supported by the observation that men with Klinefelter syndrome have a higher incidence of autoimmune diseases than their age-matched counterparts (Bizzarro et al, 1987). We recently showed in a cross-sectional study of elderly men that serum testosterone levels were inversely related to soluble IL-6 receptor (sIL-6r) (Maggio et al, 2006). Importantly, interventional studies with testosterone replacement have revealed similar information. A recent study of testosterone replacement in hypogonadal men showed a significant decrease in pro-inflammatory and a significant increase in anti-inflammatory cytokines (Malkin et al, 2004).
Based on this paradigm, we hypothesized that ADT in men with PCa (which results in profound hypogonadism) would be associated with elevated serum levels of pro-inflammatory cytokines. However, our results did not support this hypothesis. Our current findings are in contrast to those of Khosla et al (2002). In this study, Khosla and coworkers induced hypogonadism in healthy elderly men and found that short-term suppression of gonadal axis resulted in an increase in circulating pro-inflammatory cytokine (TNF-alpha, IL-6, and sIL-6r) expression. The discrepancy between our results and the Khosla study may be explained by the duration of hypogonadism. In the Khosla study, the duration of hypogonadism was only 4 weeks, while the minimal duration of ADT in our study was 12 months. Hence, it is conceivable that during the acute phase of hypogonadism there is an increase in inflammatory cytokines, but that over time there may be an adaptation of the immune system, resulting in normalization in circulating cytokines.
Few prior studies have measured inflammatory cytokines in men with PCa and attempted to correlate cytokine levels with the extent of their disease. One study reported elevated levels of inflammatory cytokines in cachectic men with advanced PCa (Pfitzenmaier et al, 2003). In our study, although some men on ADT had demonstrated metastatic disease before the initiation of ADT, their disease was in remission and their metastases had resolved prior to the initiation of the study. Similarly, men in the non-ADT group were also healthy and only showed evidence of biochemical recurrence (elevated PSA) at the time of recruitment (Basaria et al, 2002). Hence, absence of cancer cachexia in our study population may account for the difference in our results from the subjects studied by Pfitzenmaier et al. In another study, Wise and colleagues measured inflammatory cytokines in 3 groups of men, namely those with hormone sensitive PCa, hormone refractory PCa, and untreated benign prostatic hyperplasia (BPH) (Wise et al, 2000). The authors found increased levels of IL-6, IL-4, and IL-10 only in the hormone refractory group. In contrast, in our study all men in the ADT group had responded successfully to ADT and were in remission. Hence, the patient populations in these 2 studies are quite distinct.
Our current study possesses several strengths. Firstly, we examined men who had been on ADT for a long period of time (range 1–9 years). To the best of our knowledge, this is the first study that has examined the levels of inflammatory cytokines in patients on long-term androgen deprivation. Secondly, we included 2 different groups of men to compare to the ADT group. The evaluation of a non-ADT group permitted us to account for any influence of PCa itself on cytokine expression, and the control group provided us the opportunity to account for the influence of age on cytokine levels. Lastly, we evaluated a wide array of cytokines in this study. Despite these strengths, our study also has several limitations. First, this study was cross-sectional. Hence, prospective studies would be necessary to determine if changes in cytokine levels occur immediately after the initiation of ADT. Second, the majority of men in the 3 groups examined were Caucasians. Future studies should include subjects from diverse ethnic backgrounds. Finally, we did not measure IL-6, sIL-6r, C reactive protein, or TNF-alpha receptor levels in this study. Measurement of these markers could have strengthened our data.
In conclusion, our data suggest that long-term ADT in men with prostate cancer is not associated with a significant increase in pro-inflammatory or decrease in anti-inflammatory cytokines. These data should be confirmed in prospective studies.
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Footnotes |
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References |
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TopAbstractMaterials and MethodsResultsDiscussionReferences |
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Bizzarro A, Valentini G, DiMartino G, DaPonte A, De Bellis A, Iacono G. Influence of testosterone therapy on clinical and immunological features of autoimmune diseases associated with Klinefelter's syndrome. J Clin Endocrinol Metab. 1987 Jan; 64: 32–36.
Khosla S, Atkinson EJ, Dunstan CR, O'Fallon WM. Effect of estrogen
versus testosterone on circulating osteoprotegerin and other cytokine levels
in normal elderly men. J Clin Endocrinol Metab. 2002; 87: 1550
–1554.
Landis SH, Murray T, Bolden S, Wingo PA. Cancer statistics, 1999.
CA Cancer J Clin. 1999; 49: 8
–31.
Maggio M, Basaria S, Ble A, Lauretani F, Bandinelli S, Ceda GP,
Valenti G, Ling SM, Ferrucci L. Correlation between testosterone and the
inflammatory marker soluble interleukin-6 receptor in older men. J
Clin Endocrinol Metab. 2006; 91: 345
–347.
Malkin CJ, Pugh PJ, Jones RD, Kapoor D, Channer KS, Jones TH. The
effect of testosterone replacement on endogenous inflammatory cytokines and
lipid profiles in hypogonadal men. J Clin Endocrinol
Metab. 2004;89: 3313
–3318.
Messing EM, Manola J, Sarosdy M, Wilding G, Crawford ED, Trump D.
Immediate hormonal therapy compared with observation after radical
prostatectomy and pelvic lymphadenectomy in men with node-positive prostate
cancer. N Engl J Med. 1999; 341: 1781
–1788.
Pfitzenmaier J, Vessella R, Higano CS, Noteboom JL, Wallace D Jr, Corey E. Elevation of cytokine levels in cachectic patients with prostate carcinoma. Cancer. 2003; 97: 1211 –1216.[CrossRef][Medline]
Smith MR, Finkelstein JS, McGovern FJ, Zietman AL, Fallon MA,
Schoenfeld DA, Kantoff PW. Changes in body composition during androgen
deprivation therapy for prostate cancer. J Clin Endocrinol
Metab. 2002;87: 599
–603.
Spinedi E, Suescun MO, Hadid R, Daneva T, Gaillard RC. Effects of gonadectomy and sex hormone therapy on the endotoxin-stimulated hypothalamo-pituitary-adrenal axis: evidence for a neuroendocrine-immunological sexual dimorphism. Endocrinology. 1992; 131: 2430 –2436.[Abstract]
Wise GJ, Marella VK, Talluri G, Shirazian D. Cytokine variations in patients with hormone treated prostate cancer. J Urol. 2000; 164: 722 –725.[CrossRef][Medline]
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