An immunohistological study of granulomatous prostatitis

Assessing the causal relationship between immune cells and prostatitis: evidence from bidirectional mendelian randomization analysis

Prostatitis represents a common disease of the male genitourinary system, significantly impacting the physical and mental health of male patients. While numerous studies have suggested a potential link between immune cell activity and prostatitis, the exact causal role of immune cells in prostatitis remains uncertain. This study aims to explore the causal relationship between immune cell characteristics and prostatitis using a bidirectional Mendelian randomization approach. This study utilizes data from the public GWAS database and employs bidirectional Mendelian randomization analysis to investigate the causal relationship between immune cells and prostatitis. The causal relationship between 731 immune cell features and prostatitis was primarily investigated through inverse variance weighting (IVW), complemented by MR-Egger regression, a simple model, the weighted median method, and a weighted model. Ultimately, the results underwent sensitivity analysis to assess the heterogeneity, horizontal pleiotropy, and stability of Single Nucleotide Polymorphisms (SNPs) in immune cells and prostatitis. MR analysis revealed 17 immune cells exhibiting significant causal effects on prostatitis. In contrast, findings from reverse MR indicated a significant causal relationship between prostatitis and 13 immune cells. Our study utilizes bidirectional Mendelian Randomization to establish causal relationships between specific immune cell phenotypes and prostatitis, highlighting the reciprocal influence between immune system behavior and the disease. Our findings suggest targeted therapeutic approaches and the importance of including diverse populations for broader validation and personalized treatment strategies.

Histopathology of nonspecific granulomatous prostatitis with special reference to eosinophilic epithelial metaplasia: Pathophysiologic, diagnostic and differential diagnostic correlations

Background

Recently, we publish two case reports about association of nonspecific granulomatous prostatitis (NSGP) and eosinophilic metaplasia (EM) in benign prostatic epithelium. There is no investigation of large series of this association in medical literature. Aim of the current study is to investigate the frequency of association of NSGP and prostatic EM in a large series of cases and their relationship with the basic prostate pathology: benign prostatic hyperplasia (BPH), National Institutes of Health-category IV prostatitis (so-called histologic prostatitis (HP)), and prostatic adenocarcinoma (PCa).

Materials and Methods

A retrospective record review for NSGP was performed on a total of 2366 prostatic specimens of all types of material. All cases of NSGP were reviewed for the presence of EM, BPH, and HP. NSGP with EM-cases and control cases with high grade PCa with endocrine differentiation (so-called Paneth cell-like changes) were evaluated immunohistochemically.

Results

NSGP was found in nine cases (0.38%). EM was detected in benign perigranulomatous secretory epithelial cells in 100% of cases with NSGP and were closely associated with BPH and HP. Immunohistochemically, in 55.5% of cases with EM, there was weak focal apical false-positive staining for p504s.

Conclusion

EM is a very common lesion in NSGP and reflects histologically a nonspecific cellular response, connected with repeated inflammation, in close relation with BPH and HP. We speculate that EM might serve as a morphological precursor of the immunologic phase of NSGP. This constant morphological finding could facilitate the histopathological differential diagnosis of NSGP with other types of granulomatous prostatitis and high grade PCa with or without endocrine differentiation.

Characterization of the seminal plasma proteome in men with prostatitis by mass spectrometry

Background

Prostatitis is an inflammation of the prostate gland which affects approximately 10% of men. Despite its frequency, diagnosing prostatitis and monitoring patient response to treatment remains frustrating. As the prostate contributes a substantial percentage of proteins to seminal plasma, we hypothesized that a protein biomarker of prostatitis might be found by comparing the seminal plasma proteome of patients with and without prostatitis.

Results

Using mass spectrometry, we identified 1708 proteins in the pooled seminal plasma of 5 prostatitis patients. Comparing this list to a previously published list of seminal plasma proteins in the pooled seminal plasma of 5 healthy, fertile controls yielded 1464 proteins in common, 413 found only in the control group, and 254 found only in the prostatitis group. Applying a set of criteria to this dataset, we generated a high-confidence list of 59 candidate prostatitis biomarkers, 33 of which were significantly increased in prostatitis as compared to control, and 26 of which were decreased. The candidates were analyzed using Gene Ontology and Ingenuity Pathway analysis to delineate their subcellular localizations and functions.

Conclusions

Thus, in this study, we identified 59 putative biomarkers in seminal plasma that need further validation for diagnosis and monitoring of prostatitis.

Granulomatous prostatitis - an infrequent diagnosis

BACKGROUND

Granulomatous prostatitis is an unusual benign inflammatory process of the prostate. Clinically, it mimics prostatic carcinoma, thus requiring pathological examination for diagnosis.

MATERIALS AND METHODS

Histopathological records of 1353 prostate specimens received in the Department of Pathology, Government Medical College, Chandigarh, India, over a period of 8 years (1995-2002) were reviewed and 20 cases of granulomatous prostatitis were retrieved.

RESULTS

Out of 20 cases of granulomatous prostatitis, we encountered 12 cases of non-specific granulomatous prostatitis, two cases of xanthogranulomatous prostatitis, two cases of tuberculous prostatitis, two cases of malakoplakia prostate and one case each of granulomatous prostatitis associated with adenocarcinoma prostate and post-surgical palisading granuloma. The diagnosis was made by histopathological examination of Trucut biopsy, transuretheral resection of prostate chips or retropubic prostatectomy specimen. In all the cases, granulomatous prostatitis was an incidental finding.

CONCLUSIONS

Non-specific granulomatous prostatitis is the most common type of granulomatous prostatitis. Despite tuberculosis being very common in India, granulomatous prostatitis associated with tuberculosis is not common. Distinction between non-specific and infectious granulomatous prostatitis is important for therapeutic reasons.

Nonspecific (idiopathic) granulomatous prostatitis associated with low-grade prostatic adenocarcinoma

Nonspecific granulomatous prostatitis (NSGP) is uncommon and may simulate carcinoma both clinically and microscopically. Concurrent NSGP and prostatic adenocarcinoma is rare. To our knowledge this association has been documented once and it was only rarely mentioned in two large series of NSGP. We describe a 67-year-old man who presented with a history of prostatism of 1 month's duration. Suprapubic prostatectomy revealed NSGP associated with nodular hyperplasia and low-grade prostatic adenocarcinoma. The pathologist should be aware of the rare association of NSGP and prostatic adenocarcinoma. Wide sampling of the prostatectomy specimens with NSGP is mandatory to exclude an occult prostatic adenocarcinoma.

Immunohistochemistry in diagnostic surgical pathology of the prostate

Immunohistochemistry (IHC) can play an important role in diagnostic surgical pathology of the prostate. Basal cell markers, such as the 34betaE12 antibody and antibodies directed against cytokeratin 5 and 6 or p63, are very useful for demonstration of basal cells as their presence argues against a diagnosis of invasive prostatic carcinoma (PC). However, several benign mimickers of PC, including atrophy, atypical adenomatous hyperplasia (AAH), nephrogenic adenoma, and mesonephric hyperplasia, can stain negatively with these markers, and thus, a negative basal cell marker immunostain alone does not exclude a diagnosis of benignancy. Although there are examples in the literature of high grade PC that stain focally with some of the basal cell markers, these cases are usually readily diagnosed based on H&E appearances and are unlikely to be confused with these benign mimickers. Alpha-methylacyl-coenzyme-A racemase (AMACR) is a sensitive marker of PC (except for a few uncommon variants: atrophic, foamy gland, and pseudohyperplastic variants), and its detection by immunohistochemical staining in atypical prostatic lesions can be very useful in confirming an impression of adenocarcinoma. AMACR expression can also be identified in high grade prostatic intraepithelial neoplasia (PIN), prostatic atrophy, AAH, and benign prostatic glands, and accordingly, a diagnosis of PC should not be based solely on a positive AMACR immunostain, especially when the luminal staining is weak and/or noncircumferential. The use of AMACR/basal cell antibody cocktails has been found to greatly facilitate the distinction between PC and its benign mimickers, especially when only limited tissue is available for staining. Prostate specific antigen (PSA) and prostate specific acid phosphatase (PSAP) are both quite sensitive and fairly specific markers of PC (there are a few nonprostatic tumors that can express one or both), and are both very helpful in establishing or confirming the diagnosis of PC when the differential diagnosis includes other tumors that can involve the prostate such as urinary bladder urothelial carcinoma. 34betaE12, p63, thrombomodulin, and uroplakin III are additional urothelial associated markers useful in this differential diagnosis. CDX2 and villin are useful markers to diagnostically separate colonic adenocarcinoma from PC. AMACR positivity and negative basal cell marker reactions are useful to confirm the presence of residual PC after hormonal or radiation therapy. Pan-cytokeratin, PSA, and PSAP can also highlight subtle infiltrates of PC with hormonal or radiation therapy effect. PSA and PSAP immunohistochemical stains are valuable in confirming metastatic carcinoma as being of prostatic origin and should always be utilized in the diagnostic evaluation of metastatic adenocarcinoma of unknown primary origin in males.

CD4 and CD8 T-lymphocyte recognition of prostate specific antigen in granulomatous prostatitis

In order to develop immunotherapies for prostate cancer, many groups are exploring vaccination strategies to induce an immune response against prostate specific antigen (PSA). To determine if T-cell recognition of PSA might be a feature of a naturally occurring human disease, we have studied patients with prostatitis, a poorly understood clinical syndrome of men in which there is evidence that an immune response directed against the prostate may be occurring. We wished to determine if a T-cell response to PSA might be occurring in these patients. We generated long-term T-cell lines from peripheral blood mononuclear cells (PBMC) of one patient with granulomatous prostatitis using purified PSA as an antigen. Several CD4+ and CD8+ TcR alpha/beta+ T-cell lines were selected for PSA reactivity as measured by at least a threefold increase in IFN-gamma secretion in response to PSA presented by irradiated autologous PBMC. CD4 and CD8 T-cell lines recognized PSA in the context of HLA-DRbeta1*1501 and HLA-B*0702, respectively. The specificity and HLA restriction of the lines was confirmed using EBV-B cell lines infected with a recombinant PSA-expressing vaccinia virus and also engineered to express PSA by retroviral transfection. HLA-matched targets infected by control vector as well as HLA-mismatched PSA-expressing targets did not induce the response. The data demonstrate that PSA-specific T cells are present in the PBMC of this patient with granulomatous prostatitis, who may be manifesting naturally the type of immune response directed at the prostate that is the goal of prostate cancer immunotherapy. However, the Class I-restricted epitope has not yet been demonstrated to be expressed on the surface of prostate cancer cells. To our knowledge, this is the first demonstration of HLA-DRB1*1501- or HLA-B*0702-restricted responses to PSA and extends the number of HLA molecules accommodating the use of PSA antigen as a candidate vaccine for prostate cancer immunotherapy.