Serum and urinary prostate-specific antigen and urinary human glandular kallikrein concentrations are significantly increased after testosterone administration in female-to-male transsexuals

BACKGROUND

The genes that encode prostate-specific antigen (PSA) and human glandular kallikrein (hK2) are up-regulated by androgens and progestins in cultured cells, but no published studies have described the effect of androgen administration in women on serum and urinary PSA or hK2.

METHODS

We measured serum and urinary PSA and hK2 before, and 4 and 12 months post testosterone treatment by immunofluorometric methods in 32 female-to-male transsexuals.

RESULTS

Mean serum PSA increased from 1.1 ng/L to 11.1 ng/L and then to 22 ng/L by 4 and 12 months post treatment, respectively; the corresponding mean values in urine were 17, 1420, and 18 130 ng/L, respectively. Serum hK2, another kallikrein closely related to PSA, remained undetectable at the three time points. However, urinary hK2 concentration rose from below the detection limit (<6 ng/L) before treatment to 18 and 179 ng/L by the 4th and the 12th month of treatment, respectively. All changes were statistically significant (P <0.001) at 4 months.

CONCLUSIONS

Testosterone administration increases serum and urinary PSA and urinary hK2 in women. These measurements may be useful as indicators of androgenic stimulation in women.

A dual-monoclonal sandwich assay for prostate-specific membrane antigen: levels in tissues, seminal fluid and urine

BACKGROUND

Prostate-specific membrane antigen (PSMA) is a 750-residue integral membrane glycoprotein and the target of an in-vivo imaging agent for metastatic prostate carcinoma (PCa). PSMA expression in normal and diseased prostatic tissues has previously been demonstrated by immunohistochemical techniques. In order to quantify PSMA levels in tissue homogenates and physiological fluids, we have developed a dual monoclonal antibody (mAb) sandwich assay which detects the antigen at a sensitivity <1 ng/mL and which is linear across the working range 0-50 ng/mL.

METHODS

The assay involves capture of the PSMA by a biotinylated mAb (7E11) immobilized onto a streptavidin-coated microtiter plate; this mAb binds to the N-terminus of the antigen. The captured PSMA is detected by an Eu-labelled mAb (PEQ226) which binds in the region corresponding to Residues 134-437 of the antigen. PSMA was purified from LNCaP cells by immunoaffinity chromatography, and used as a calibrator, based on its concentration by the bicinchoninic acid (BCA) protein assay.

RESULTS

The assay was applied to a panel of normal and tumor tissues. Levels were highest in the prostate tissues (292-4254 ng/mg protein). Low levels (21-51 ng/mL) were observed in membranes from ovary and breast, and neglible levels (1-10 ng/mg) in membranes from skin, liver, intestine, and kidney. Levels in the corresponding cytosol fractions were 20-to 50-fold lower. The average PSMA level in seminal fluid from 21 donors was 9, 012 ng/mL. On average, levels in normal-male urine (3.47 ng/mL) were ten-fold higher than in normal-female urine (0.3 ng/mL).

CONCLUSIONS

This report is the first to describe absolute quantitation of PSMA in tissues and fluids. Congruent with earlier tissue studies based on immunohistochemical staining and Western-blot analysis, prostate tissue membranes expressed the highest levels of PSMA.

Dramatic suppression of plasma and urinary prostate specific antigen and human glandular kallikrein by antiandrogens in male-to-female transsexuals

PURPOSE

Prostate specific antigen (PSA) and human glandular kallikrein (hK2) are mainly produced by the prostate and their genes are regulated by androgens through the androgen receptor. We determine whether PSA and hK2 change significantly in plasma and urine after antiandrogen treatment in male-to-female transsexuals.

MATERIALS AND METHODS

Plasma and urine PSA and hK2 were measured with highly sensitive immunofluorometric procedures capable of detecting within 1 or 6 ng./l. PSA or hK2, respectively. Study groups consisted of 10 men treated with cyproterone acetate only (group 1), 15 transdermal estradiol plus cyproterone acetate (group 2) and 31 ethinyl estradiol plus cyproterone acetate (group 3). Plasma and urine samples were collected before initiation of treatment as well as after 4 months of hormonal therapy. For a subset of group 3 patients blood and urine samples were also obtained after 12 months of treatment.

RESULTS

Cyproterone acetate, a steroidal antiandrogen, alone or with estradiol was able to suppress greater than 90% of plasma and urinary PSA and hK2 concentration after 4 or 12 months of therapy.

CONCLUSIONS

Cyproterone acetate therapy causes dramatic suppression of plasma and urinary PSA and hK2 in men without prostate cancer. Since cyproterone acetate is used for prostate cancer treatment, suppression of PSA after hormonal therapy may not accurately reflect therapy success in reducing tumor burden.

The significance of recurrent PSA after radical prostatectomy: benign versus malignant sources

The purpose of this article is to review the available means to investigate whether an elevated serum prostate-specific antigen (PSA) after radical prostatectomy may be explained by the presence of residual benign tissue. To answer this question, one may consider the following features: the kinetics of recurrent/ persistent PSA, the incidence of rising PSA in the presence of capsular incisions exposing benign glands only, the level of urinary PSA and the ratio of free/total PSA in the urine, the results of anastomotic biopsy samples, and the detection of circulating prostate cells by PSA reverse transcriptase-polymerase chain reaction (RT-PCR) after surgery. Capsular incisions exposing benign tissue are not associated with a significant risk of biochemical failure. In case of an organ-confined cancer with negative surgical margins but a rising postoperative PSA, the systematic reevaluation of the initial pathological slides constantly shows capsular effraction or focal positive margins that have been overlooked at the first evaluation. Even when anastomotic biopsies document only benign tissue, the study of PSA doubling time is usually characteristic of the coexistence of residual tumoral cells. However, in a few cases, the persistent negative results of the detection of circulating prostate cells by PSA, RT-PCR in patients with organ-confined cancer and negative margins but elevated postoperative PSA might be explained by the presence of residual benign prostatic hyperplasia tissue. Most of the data in the literature are in favor of the responsibility of persistent/recurrent cancer in the recurring PSA rather than that of benign prostatic hyperplasia/normal residual tissue. Therefore, a persistent/recurrent detectable level of PSA is the serum after radical prostatectomy characterizes biochemical failure.

The cleavage site specificity of human prostate specific antigen for insulin-like growth factor binding protein-3

The cleavage site of human insulin-like growth factor binding protein-3 by urinary prostate specific antigen was examined. Human insulin-like growth factor binding protein-3 was incubated with urinary prostate specific antigen at 37 degrees C and its proteolyzed fragments were separated by a reversed phase HPLC followed by N-terminal amino acid sequence analysis, demonstrating that the cleavage mainly occurred at Tyr-159. The synthetic peptide including Tyr-159 was also cleaved at the same site, although its reaction rate was relatively low. These results indicate that human insulin-like growth factor binding protein-3 is specifically cleaved at Tyr-159 by prostate specific antigen. Human insulin-like growth factor binding protein-3 was previously reported to be cleaved at five sites including Arg-97, Arg-132, Tyr-159, Phe-173 and Arg-179 by another group, however, prostate specific antigen preparation is possibly contaminated by trypsin-like protease. In contrast, our purified urinary prostate specific antigen had only a chymotrypsin-like activity, demonstrating that prostate specific antigen has the high substrate specificity for human insulin-like growth factor binding protein-3.

[Malakoplakia of the prostate]

OBJECTIVE

To study the diagnosis and treatment of prostatic malakoplakia.

METHOD

Two cases of malakoplakia were reported, and the cases and articles were reviewed.

RESULT

The disease is an inflammation of the prostate, and lower immunocompetence is concomitance. The patients had symptoms of dysuria and urethralgia. The tubercle could be found. Pathological section revealed malakoplakia cells and Michaelis-Gutman inclusion bodies. Many patients were performed radical prostatectomy because of misdiagnosis.

CONCLUSION

Biopsy of the prostate and antibiotics should be used clinically.

Influence of digital rectal massage on urinary prostate-specific antigen: interest for the detection of local recurrence after radical prostatectomy

BACKGROUND

Following radical prostatectomy, urinary prostate-specific antigen (uPSA) may originate from periurethral glands or from recurrent carcinomatous prostatic cells. We evaluated massage of the urethro-vesical anastomosis as a uPSA-releasing method for the detection of local recurrence.

METHODS

PSA was assessed (PSA IMx, Abbott Diagnostic, Rungis, France) in serum and in the first voided urine before and after massage in 59 patients: 7 after cystoprostatectomy for bladder cancer, 22 with prostate in situ, and 30 after radical prostatectomy for prostate cancer.

RESULTS

No significant changes of uPSA were induced by the massage in cystoprostatectomy patients and in 4 radical prostatectomy patients with a negative biopsy of the anastomosis. In contrast, a significant increase of uPSA was observed after massage in the patients with prostate in situ and in 6 radical prostatectomy patients with biopsy-proven local relapse.

CONCLUSIONS

uPSA before and after massage of the prostatic fossa may constitute a new and efficient tool for the detection of local recurrence, if these preliminary results are confirmed on a larger scale.

Molecular forms of prostate-specific antigen and human kallikrein 2 (hK2) in urine are not clinically useful for early detection and staging of prostate cancer

OBJECTIVES

Prostate-specific antigen (PSA), a member of the human kallikrein (hK) family, is the most important tumor marker for early detection, staging, and monitoring of men with prostate cancer today. However, the sensitivity of serum PSA is not sufficient to be used alone for prostate cancer screening. Recently, it was reported that the serum-to-urinary total PSA ratio improves the detection of men with prostate cancer, especially in men with a serum total PSA level between 4.0 and 10.0 ng/mL. We tested this hypothesis by evaluating the clinical usefulness of this PSA ratio as well as the use of the different molecular forms of PSA and human kallikrein 2 (hK2) in urine for detection and staging of prostate cancer.

METHODS

One hundred ten fresh, midstream urine specimens (prostate cancer 62, benign prostatic hyperplasia [BPH] 38, healthy male control 5, women 5) were collected. Serum total PSA, urine total PSA, urinary free PSA, urinary alpha 1-antichymotrypsin-bound PSA, and urinary hK2 levels were determined by monoclonal antibody assays (Hybritech Inc.). The serum-to-urinary total PSA ratio was calculated.

RESULTS

The serum-to-urinary total PSA ratio did not accurately distinguish between men with BPH and men with prostate cancer. There was no significant difference between the urinary levels of any of the molecular forms of PSA or hK2 between men with prostate cancer and men with BPH. Among men with prostate cancer, neither urinary hK2 nor urinary levels of any of the molecular forms of PSA correlated with age, pathologic stage, or Gleason grade.

CONCLUSIONS

In our study, the serum-to-urinary total PSA ratio did not improve the detection of men with prostate cancer. Furthermore, measurement of the molecular forms of PSA and hK2 in urine did not improve the detection or staging of prostate cancer over serum PSA alone.

Purification and characterization of prostate specific antigen from human urine

Prostate specific antigen (uPSA) was purified to homogeneity from human urine using SuperQ-Toyopearl, Sulfate-Cellulofine, Phenyl-Toyopearl, CM-Sepharose, anti-urokinase IgG Sepharose and Sephadex G-100. The purified uPSA gave a major band at 32.9 kDa on SDS-PAGE under the reduced condition. However, it shows multiple bands on native PAGE. Substrate specificity of purified uPSA is identical with that of PSA from human seminal plasma and uPSA shows the kallikrein and chymotrypsin-like activities. On the analysis of N-terminal amino acid, two amino acid residues at N-terminal position of uPSA were detected and other amino acid sequence of uPSA was identical with that of sPSA. In addition, we isolated the multiple components of uPSA using anion-exchange chromatography. They were almost the same in amino acid composition and N-terminal amino acid sequences and showed differences in lectin-blotting pattern.

[Urinary PSA (uPSA) in the monitoring of local recurrence following radical prostatectomy]

The level of urinary PSA (PSAu) was measured for use as a marker in some clinical situations involving prostate cancer patients. Limits of physiological and pathological values, a quantity of which comes from the urethral glands and the umbilical median ligament (urachus), are still unknown. To establish the quantity of PSA secretion in the urethra, female PSAu was measured and found to be significantly low (< 0.1 ng/ml). The Authors report on 25 PR patients with negative margins and who had not received hormonal therapy for 30 months. The PSAu and the PSAs were measured on the 30th and the 60th day, and every 3 months thereafter in the first year and every 6 months in the second year. In 5 cases we observed an increase of PSAu between the 5th and 18th months. In 3 cases the PSAs increased 2 to 6 months later compared to the PSAu. In these 3 cases the biopsy indicated the presence of a localized relapse. Therefore the Authors recommend measuring the PSAu (cut-off 0.1 ng/ml) in the follow-up of the PR patients because the measurement may both identify a localized relapse earlier than the PSAs and indicate the localized response to hormonal or radiotherapy.

[Serum and urine prostate-specific antigen ratio: its value in the distinction between prostate cancer and adenoma when serum prostate-specific antigen level is between 4 and 10 ng/ml]

BACKGROUND

In an earlier study, we demonstrated that benign prostatic hyperplasia (BPH) was associated with significantly higher urine levels of prostate-specific antigen (PSA) than in prostate cancer (PC). These early results led to the present study: we assessed, in patients undergoing a prostate biopsy, the clinical value of the PSA serum/urine ratio (PSA S/U) in patients for the differential diagnosis of PC, particularly when the pre-biopsy serum level of PSA lies between 4.0 and 10.0 ng/ml.

METHODS

All patients without an indwelling drain who underwent transrectal echoguided biopsy were prospectively included in this study from November 1994 to December 1995. All serum and urine PSA measurements were done by the same laboratory using a Tandem R kit (Hybritech). Blood and urine samples were obtained during the 24 hour period prior to surgery during which all urethral or rectal manipulation was avoided.

RESULTS

We studied 130 patients with BPH (n = 73) or PC (n = 57). The PSA serum levels and the PSA S/U were significantly different between the BPH and the PC groups. In the subgroup of 50 patients with a serum PSA level in the 4-10 ng/ml range, the difference between the BPH and PC patients was not significantly different except for the PSA S/U ratio. Receiver operating characteristic (ROC) curves showed that the diagnostic power of PSA S/U was greater than serum PSA.

CONCLUSION

These results suggest that the PSA S/U ratio could be useful to distinguish between BPH and PC, particularly when diagnosis is uncertain in patients whose serum PSA is in the 4.0-10.0 ng/ml range.

[Post-treatment PSA, indicator of radical treatment effectiveness of localized cancer of the prostate]

Prostate specific antigen (PSA) has become essential to the follow-up of radical treatment for T1-T2 tumours. Various assays are available, but require a correlation coefficient to homogenize their results. PSA is probably the most reliable marker for the follow-up of radical prostatectomy (RP), as this operation should make PSA undetectable after 3 weeks. Highly sensitive tests, with a limit of detection of 0.1 ng/ml, allow the earlier laboratory detection of tumour escape (20 to 45%). Anastomotic biopsies are positive in 35 to 50% of cases. Seminal vesicle invasion and positive resection margins are more frequently associated with recurrence. The doubling time and rate of progression of PSA after RP can be used to distinguish local recurrence from metastasis. Urinary PSA is not useful in the follow-up of RP, as it is secreted by the periurethral glands. The use of the PSA after radical radiotherapy is less clearly established, as this treatment is not designed to eliminate all prostatic tissue or render PSA undetectable. Therapeutic efficacy is situated between 1 and 1.5 ng/ml according to the tests and is achieved in approximately 40% of cases after 4 years. A PSA level greater than 3 ng/ml at 3 months is indicative of a poor prognosis. Prospects for the future include the use of highly sensitive assays and reverse transcriptase polymerase chain reaction (RT-PCR) to detect circulating prostatic cells. The use of PSA has led to a re-evaluation of the efficacy of radical treatments and could influence the indications for adjuvant treatments.

Development of a highly sensitive immunochemiluminometric assay for prostate-specific antigen

OBJECTIVES

An assay is described for measuring very low concentrations of prostate-specific antigen (PSA) which could be used to reliably monitor patients with radical prostatectomies potentially to detect early recurrence of prostate cancer.

METHODS

A combination of immobilized and acridinium ester-labeled monoclonal antibodies was used to develop a two-step, 90-minute chemiluminometric assay. The reference standards for the serum assays were prepared by adding patient sera with a high concentration of PSA to base pools of female sera, which were selected because of low background counts and good recovery of added PSA. The assay was standardized to match the Abbott IMx PSA Assay.

RESULTS

The serum-based analytic detection limit (calculated as response 2.5 standard deviations [SD] above the zero standard) is 0.004 ng/mL, whereas the "biologic detection limit" (calculated as 2.0 SD above the analytic detection limit) is 0.008 ng/mL. The assay is highly reproducible with interassay coefficients of variation (CV) under 12% down to 0.02 ng/mL, qualifying this as a "second generation" assay (eg, CV < 20% at 0.05 ng/mL).

CONCLUSION

This assay can measure very low concentrations of PSA in plasma and a wide range of PSA concentrations in urine. This assay will provide a valuable analytic tool for the future evaluation of the clinical utility of "ultrasensitive" PSA measurements for the management of prostate cancer.

Prostate-specific antigen in urine

We investigated concentrations of prostate-specific antigen (PSA) in mid-stream urine of 213 patients. Among them were 34 females. Diagnoses of the male patients were 42 benign prostatic hypertrophy (BPH), 21 localized prostate cancer prior to radical prostatectomy (RP), 15 post-RP without distant or local recurrence, 5 post-RP with local recurrence and 82 with other urological diseases. PSA levels were determined by the Hybritech Tandem E method. Female urine samples were positive in 38% of the cases. This and the finding of PSA in urine of men after RP is most likely due to extraprostatic production by periurethral glands. Urinary PSA levels do not differ between patients with BPH, organ-confined prostate cancer and other diagnoses. In some cases, however, urine PSA levels can be elevated in men with local tumor recurrence after RP when serum levels are still undetectably low. This indicates that the determination of urinary PSA concentration might be useful in the follow-up of patients after RP.

Urinary prostate specific antigen levels after radical prostatectomy

It was recently demonstrated that urinary prostate specific antigen (PSA) is discordant with serum PSA in many patients after radical prostatectomy. This observation led to the speculation that elevated urinary PSA in the face of undetectable serum PSA may indicate early disease recurrence. We measured urinary PSA levels in 30 patients who had undergone radical prostatectomy for prostate carcinoma and 7 patients who had undergone cystoprostatectomy for bladder cancer. PSA levels of randomly collected urine samples ranged from 0.00 to 22.9 ng./ml. and 0.01 to 8.37 ng./ml., respectively. There was no correlation among urinary and serum PSA levels, pathological stage or type of operation. In 14 patients who had undergone radical prostatectomy and who had measurable levels of urinary PSA voided specimens were divided into initial stream and end stream voided samples. The PSA levels in the end stream voided samples were significantly less than the initial stream sample in 12 of the 14 patients. In men who had undergone radical prostatectomy urethral swab samples were analyzed for PSA. Of 26 patients 24 had detectable levels of urethral swab PSA (range 0.01 to 39.04 ng./ml., median 0.93 ng./ml.). Urethral swab PSA levels did not correlate with serum PSA values or pathological stage of disease. Of 7 patients who had defunctionalized urethras after radical cystoprostatectomy 5 had significantly elevated PSA in the urethral wash or swab samples (range 4.3 to 24.5 ng./ml.). Immunohistochemical analysis of urethrectomy specimens demonstrated positive staining for PSA in 3 of 4 specimens. We conclude that the major source of urinary PSA following total prostatectomy is the urethra itself rather than residual prostate tissue. Measuring serial urinary PSA appears to have limited value in monitoring patients after radical prostatectomy. Whether this urethral PSA can ever contaminate the serum levels of PSA after radical prostatectomy is currently under investigation.

Decreased expression of prostatic secretory protein PSP94 in prostate cancer

cDNA libraries were generated from the prostate gland tissue obtained from a normal donor and from a patient with prostate cancer. Subtractive cDNA cloning was used to identify phenotype-specific cDNA sequences from both normal and cancerous prostate tissue. One clone, pN44, isolated from normal prostate tissue, codes for the prostate protein PSP94, expression of which appeared to be down-regulated in the cancerous cells. Rabbit antisera against PSP94 were generated, and these antisera can be used to detect PSP94 in urine. Two other clones, pN23a and pN141f, were also found to be down-regulated.

An analysis of urinary prostate specific antigen before and after radical prostatectomy: evidence for secretion of prostate specific antigen by the periurethral glands

We investigated whether urinary prostate specific antigen (PSA) might be a useful marker to detect locally recurrent tumor after radical prostatectomy. We also investigated whether PSA in the first 1 to 5 cc of voided urine is a more useful indicator of urinary PSA levels than the midstream urine PSA, since the first portion of the voided urine contains the highest concentration of prostatic and urethral secretions. To determine the response of urinary PSA to radical prostatectomy, we obtained first voided and midstream urine PSA levels in 18 patients with adenocarcinoma of the prostate before and after surgery. Mean first voided urine PSA levels decreased from 915.1 ng./ml. (range 21 to 2,853) preoperatively to 21.4 ng./ml. (range 0.9 to 88) postoperatively, while mean midstream urine PSA levels decreased from 245.9 ng./ml. (range 5 to 1,312) preoperatively to 1.8 ng./ml. (range 0 to 20.4) postoperatively. We also obtained postoperative first voided and midstream urine PSA levels in 9 prostate cancer patients who had undergone radical prostatectomy, and were considered to be cured by rigid clinical and histological criteria. To distinguish bladder versus urethral sources of urinary PSA in patients without a prostate, we additionally studied 11 patients without prostate cancer who had undergone cystoprostatectomy with orthotopic bladder substitution and who had undetectable serum PSA levels by the ultrasensitive assay. In the cured prostatectomy patients the mean first voided urine PSA level was 40.2 ng./ml. (range 2.8 to 100) and the mean midstream urine PSA level was 3.4 ng./ml. (range 0.1 to 15.2), while in the cystoprostatectomy patients these levels were 15.5 ng./ml. (range 0.8 to 49.9) and 1.2 ng./ml. (range 0 to 6.4), respectively. We conclude that the first voided urine sample better reflects local PSA production by the prostate than the midstream sample, first voided urine PSA decreases significantly in response to radical prostatectomy but is still present in measurable amounts even in surgically cured prostate cancer patients and urethral secretion of low levels of PSA persists after radical prostatectomy. This finding diminishes the chance that the first voided urine PSA level will be a useful marker to detect locally recurrent tumor after radical prostatectomy. Further studies are needed to determine if there is a critical level of first voided urine PSA after radical prostatectomy above which there is an increased likelihood of locally recurrent tumor but overall urinary PSA is highly unlikely to be clinically useful.