Application of serum PSA to identify acute bacterial prostatitis in patients with fever of unknown origin or symptoms of acute pyelonephritis

Markers of Toxicity and Response to Radiation Therapy in Patients With Prostate Cancer

The main treatment modalities for localized prostate cancer are surgery and radiation. Surgery removes the whole prostate gland, whereas with radiation therapy the irradiated prostate remains within the patient's body. Biomarkers specific to the prostate gland should become undetectable after surgery, but this is not the case when radiation therapy is used, as residual prostate cells may still be metabolically active. Here, we review the role of tumor markers of toxicity and response to radiation therapy in patients with prostate cancer, including prostate specific antigen, human kallikrein 2, osteopontin, prostate cancer associated 3, citrulline, and others.

Focusing aptamer selection on the glycan structure of prostate-specific antigen: Toward more specific detection of prostate cancer

The development of chemical sensors capable of detecting the specific glycosylation patterns of proteins offers a powerful mean for the early detection of cancer. Unfortunately, this strategy is scarcely explored because receptors recognizing the glycans linked to proteins are challenging to discover. In this work, we describe a simple method for directing the selection of aptamers toward the glycan structure of the glycoproteins, with prostate-specific antigen (PSA) as a model target. Using this strategy, we identified one aptamer (PSA-1) that binds the glycan moiety of PSA with reasonable affinity (a dissociation constant of 177 ± 65 nM). Interestingly, an electrochemical sensor with a sandwich format employing the identified aptamer as a signaling receptor, provides a tool of discriminating human PSA from the unglycosylated protein, with a limit of detection of 0.66 ng/mL. The sensor responds to different levels of PSA in serum, correlating well with chemiluminescence ELISA used in hospitals even with higher potential to discriminate clinically meaningful prostate cancer. Although validation on a larger cohort is needed, this is the first demonstration of an aptamer-based sensor to detect PSA by focusing in its glycan moiety.

Validity of Prostate Health Index and Percentage of [-2] Pro-Prostate-Specific Antigen as Novel Biomarkers in the Diagnosis of Prostate Cancer: Omani Tertiary Hospitals Experience

OBJECTIVES

Prostate cancer is the leading cancer in older men. The Ministry of Health Oman Cancer Incidence Registry 2013 lists cancer of the prostate as the first most common cancer in males. Therefore, early detection is important and prostate-specific antigen (PSA) is widely used as an established laboratory test. However, despite its wide use, its value in screening, particularly in asymptomatic males, is controversial when considering the risks and benefits of early detection.

METHODS

This prospective, observational study included 136 males (67.0±8.9 years; range 45-90) who were scheduled for a prostate biopsy in two different tertiary care teaching hospitals in Oman: the Royal Hospital and Sultan Qaboos University Hospital. Blood specimens from these patients were collected at the same setting before obtaining a prostatic biopsy. Three PSA markers (total PSA (tPSA), free PSA (fPSA), and [-2]proPSA (p2PSA)) were measured and the Prostate Health Index (phi) calculated. The histopathological report of the prostatic biopsy for each patient was obtained from the histopathology laboratory of the concerned hospital along with clinical and laboratory data through the hospital information system.

RESULTS

Phi has the highest validity markers compared with other prostate markers, with a sensitivity of 82.1%, specificity of 80.6%, and area under the curve (AUC) value of 0.81 at a cutoff of 41.9. The other prostatic markers showed sensitivities and specificities of 78.6% and 25.9% for tPSA; 35.7% and 92.6% for %fPSA; and 64.3% and 82.4% for %p2PSA, respectively. The AUCs at the best cutoff values were 0.67 at 10.1 µg/L for tPSA; 0.70 at 11.6% for %fPSA; and 0.55 at 1.4% for %p2PSA. An association between phi values and aggressiveness of prostate malignancy was noted. Of the 28 patients with prostate cancer, 22 patients had tPSA > 4 µg/L. However, no patient had phi in the low-risk category, and five, six, and 17 patients had phi in the moderate-, high-, and very high-risk categories, respectively.

CONCLUSIONS

Phi outperforms tPSA and fPSA when used alone or in combination, and appears to be more accurate than both markers in excluding prostate cancer before biopsy. Use of this biomarker helps clinicians to avoid unnecessary biopsies, particularly in patients with gray-zone tPSA level. Phi is the strongest marker that correlates proportionally with Gleason Score; therefore, it is also useful in predicting the aggressiveness of the disease. This is the first reported experience for the use of p2PSA and phi in Oman, the Middle East, and North Africa.

Serum quantitative proteomic analysis reveals potential zinc-associated biomarkers for nonbacterial prostatitis

BACKGROUND

Prostatitis is one of the most common urological problems afflicting adult men. The etiology and pathogenesis of nonbacterial prostatitis, which accounts for 90-95% of cases, is largely unknown. As serum proteins often indicate the overall pathologic status of patients, we hypothesized that protein biomarkers of prostatitis might be identified by comparing the serum proteomes of patients with and without nonbacterial prostatitis.

METHODS

All untreated samples were collected from subjects attending the Fangchenggang Area Male Health and Examination Survey (FAMHES). We profiled pooled serum samples from four carefully selected groups of patients (n = 10/group) representing the various categories of nonbacterial prostatitis (IIIa, IIIb, and IV) and matched healthy controls using a mass spectrometry-based 4-plex iTRAQ proteomic approach. More than 160 samples were validated by ELISA.

RESULTS

Overall, 69 proteins were identified. Among them, 42, 52, and 37 proteins were identified with differential expression in Category IIIa, IIIb, and IV prostatitis, respectively. The 19 common proteins were related to immunity and defense, ion binding, transport, and proteolysis. Two zinc-binding proteins, superoxide dismutase 3 (SOD3), and carbonic anhydrase I (CA1), were significantly higher in all types of prostatitis than in the control. A receiver operating characteristic curve estimated sensitivities of 50.4 and 68.1% and specificities of 92.1 and 83.8% for CA1 and SOD3, respectively, in detecting nonbacterial prostatitis. The serum CA1 concentration was inversely correlated to the zinc concentration in expressed-prostatic secretions.

CONCLUSIONS

Our findings suggest that SOD3 and CA1 are potential diagnostic markers of nonbacterial prostatitis, although further large-scale studies are required. The molecular profiles of nonbacterial prostatitis pathogenesis may lay a foundation for discovery of new therapies.

Retroperitoneal disorders associated with IgG4-related autoimmune pancreatitis

IgG4-related autoimmune pancreatitis is frequently accompanied by relevant lesions in the genitourinary tract and retroperitoneal organs, which cause various clinical problems, ranging from non-specific back pain or bladder outlet obstruction to renal failure. The diagnosis of IgG4-related retroperitoneal fibrosis requires a multidisciplinary approach, including serological tests, histological examination, imaging analysis, and susceptibility to steroid therapy. Radiological examinations are helpful to diagnose this condition, but surgical resection is occasionally unavoidable to exclude malignancy, particularly for patients with isolated retroperitoneal involvement. Steroid therapy is the treatment of choice for this condition, the same as for other manifestations of IgG4-related disease. For patients with severe ureteral obstruction, additional ureteral stenting needs to be considered prior to steroid therapy to preserve the renal function. Some papers have suggested that IgG4-related disease can affect male reproductive organs including the prostate and testis. IgG4-related prostatitis usually causes lower urinary tract symptoms, such as dysuria and pollakisuria. Patients sometimes state that corticosteroids given for IgG4-related disease at other sites relieve their lower urinary tract symptoms, which leads us to suspect prostatic involvement in this condition. Because of the limited number of publications available, further studies are warranted to better characterize IgG4-related disease in male reproductive organs.

Paucisymptomatic infectious prostatitis as a cause of fever without an apparent origin. A series of 19 patients

According to the literature, prostatitis is a rare cause of prolonged fever without an apparent origin. However, this syndrome can be easily diagnosed using specific tests, either two-glass pre- and post-prostatic massage or the Meares-Stamey four-glass test. A retrospective study over a 5-year period (between August 1st 2006 and July 31st 2011) was performed. All patients who met the criteria for microbiological prostatitis were included and assigned to one of two groups, either a study group [paucisymptomatic infectious prostatitis (PIP)] or a control group [classic infectious prostatitis (CIP)]. Epidemiological, clinical, microbiological, and treatment-related variables were collected. A comparative study between both groups was performed. Thirty-nine patients were diagnosed with prostatitis. The main risk factors were unprotected anal intercourse, human immunodeficiency virus (HIV) infection, recent travel, and recurrent urinary tract infections. The most significant differences between the PIP (19 patients) and CIP (20 patients) groups were higher frequency of elevated inflammatory markers, higher frequency of monomicrobial etiology, and longer treatment. In monomicrobial prostatitis, the most common causative agents were coagulase-negative Staphylococcus spp., Escherichia coli, and Corynebacterium glucuronolyticum. According to the findings of this study, we believe that prostatitis should be included as a possible diagnosis in a man who complains of prolonged fever without an apparent origin and having at least one of the following risk factors: unprotected anal intercourse, HIV infection, recent travel, and recurrent urinary tract infections.

Kinetics of serum total and free prostate-specific antigen (PSA) after extended multisite prostate biopsy: Comparison among biopsy, transurethral resection of the prostate (TURP), and biopsy plus TURP

BACKGROUND

The kinetics and reproducibility of serum prostate-specific antigen (PSA) following extended multisite biopsies are unknown. The aim of this study was to examine the kinetics of hematogenous leakage of PSA molecules by comparing the postintervention PSA manner among extended biopsies, transurethral resection of the prostate (TURP) and biopsy plus TURP.

METHODS

Total and free PSA values were examined before and sequentially after intervention (at 1 hour, 24 hours, 2 days, 14 days, and 28 days), in patients who underwent 14-core prostate biopsy (Biopsy, n = 53), TURP (TURP, n = 21), or prostate biopsy plus TURP (Biopsy+TURP, n = 18).

RESULTS

Ten patients in the Biopsy group were histologically diagnosed as having prostate cancer, and all other patients were diagnosed with non-malignant disorders. One hour after intervention, the increase in total PSA in the Biopsy group (mean 19.58 +/- 24.78-fold) and Biopsy+TURP group (mean 14.00 +/- 10.52-fold) was higher than that of the TURP group (mean 6.189 +/- 7.567-fold) (P = 0.0207 and 0.0119, respectively). The increase in total PSA in the Biopsy+TURP group was not different from that of the Biopsy group. The increase in free PSA in the Biopsy group (mean 36.52 +/- 21.18-fold or more) was greater than that of the TURP group (mean 15.57 +/- 18.17-fold) (P = 0.0002 or less). Both total and free PSA values in the Biopsy group recovered to the initial levels 28 days after intervention (P = 0.380 and P = 0.0873, respectively). The course of both total and free PSA values in the Biopsy group was not different between prostate cancer and non-malignant disorders.

CONCLUSIONS

Extended multisite biopsies caused marked elevation of both total and free PSA compared with ordinary sextant protocol or TURP, and they reduced to the preoperative levels in about 4 weeks. The postintervention increase of PSA and its manner of recovery were comparable between the Biopsy and Biopsy+TURP groups, suggesting that the hematogenous leakage of PSA by biopsies occurs in an early phase just after biopsy and rapidly reduces also in the early phase.

Total and free prostate-specific antigen indexes in prostate cancer screening: value and limitation for Japanese populations

AIM

To assess the efficacy and limitation of free/total prostate-specific antigen ratio (f/tPSA) at a single institution in Japan, focusing on the avoidance of pointless prostate biopsies.

METHODS

In total, 631 men between 44 and 93 years old (mean 69.8 years) with elevated PSA underwent power-Doppler ultrasoundgraphy-guided transrectal 10-core prostate biopsies at Niigata Cancer Center Hospital, and their histological features were investigated with total PSA (tPSA) and f/tPSA.

RESULTS

PCa was detected in 126 of 134 patients (94.3%) with tPSA of 26 ng/mL or higher. The detection rate was 59.4% for tPSA of 21-25 ng/mL, followed by 39.2% for 16-20 ng/mL, 30.0% for 11-15 ng/mL, 20.0% for 4.1-10 ng/mL and 7.6% for = or <4.0 ng/mL. f/tPSA of the PCa group was significantly lower than that of non-malignamt disorders in any tPSA ranges (mean 0.122 vs. 0.160, P<0.001). Receiver-operating characteristics analyses showed that f/tPSA (AUC:0.664) performed more valuably than tPSA (AUC:0.559) in patients with tPSA between 3.0-10 ng/mL (P<0.01). Although f/tPSA of 0.250 for the cut-off value might miss 1.8% PCa patients, it potentially spares 9.2% of unnecessary biopsies.

CONCLUSION

f/tPSA is more valuable compared with tPSA alone for the prediction of the occurrence of PCa. We recommend 0.250 as the cut-off value for f/tPSA in PCa screening for Asian men having so-called grey-zone tPSA.

Sexually transmitted infections and prostatic inflammation/cell damage as measured by serum prostate specific antigen concentration

PURPOSE

Although inflammation and cell damage due to STIs are hypothesized to contribute to the later development of prostate disease, few clinical studies have been done to investigate the extent to which sexually transmitted agents infect and induce an inflammatory immune response in the prostate. We indirectly investigated this question by measuring serum PSA, a possible marker of prostatic inflammation and cell damage, in men with documented STIs.

MATERIALS AND METHODS

Archived serum specimens from young men with laboratory confirmed exudative STIs, including gonorrhea, chlamydia and trichomonosis, and young men with no STI diagnoses were identified in 2 prospective studies of patients at Baltimore City STI clinics, that is 84 in the STI Transmission and Acquisition Study, and 61 in the Mucosal Immunity Study. Serum specimens from visits before, during and after STI diagnoses in men with at least 1 exudative STI diagnosis and from all visits in men with no STI diagnoses were tested for total PSA concentration.

RESULTS

After combining the studies patients with STIs were more likely to have a 40% or greater increase in PSA than patients with no STI diagnoses (32% vs 2%, p <0.01).

CONCLUSIONS

These findings suggest that STIs may contribute to prostatic inflammation and cell damage in a subset of infected men. Further studies are warranted to replicate study findings and determine host and infection characteristics associated with large PSA increases.