The detection of isochromosome i(12p) in malignant germ cell tumours and tumours with somatic malignant transformation by the use of quantitative real-time polymerase chain reaction.

AIMS: Malignant germ cell tumours (GCTs) of the testis are rare neoplasms, but the most common solid malignancies in young men. World Health Organization guidelines divide GCTs into five types, for which numerous immunohistochemical markers allow exact histological subtyping in the majority of cases. In contrast, a germ cell origin is often hard to prove in metastatic GCTs that have developed so-called somatic malignant transformation. A high percentage, up to 89%, of GCTs are characterised by the appearance of isochromosome 12p [i(12p)]. Fluorescence in-situ hybridisation has been the most common diagnostic method for the detection of i(12p) so far, but has the disadvantages of being time-consuming, demanding, and not being a stand-alone method. The aim of the present study was to establish a quantitative real-time polymerase chain reaction assay as an independent method for detecting i(12p) and regional amplifications of the short arm of chromosome 12 by using DNA extracted from formalin-fixed paraffin-embedded tissue. METHODS AND RESULTS: A cut-off value to distinguish between the presence and absence of i(12p) was established in a control set consisting of 36 tumour-free samples. In a training set of 149 GCT samples, i(12p) was detectable in 133 tumours (89%), but not in 16 tumours (11%). In a test set containing 27 primary and metastatic GCTs, all 16 tumours with metastatic spread and/or somatic malignant transformation were successfully identified by the detection of i(12p). CONCLUSION: In summary, the qPCR assay presented here can help to identify, further characterise and assign a large proportion of histologically inconclusive malignancies to a GCT origin.

Management of Germ Cell Tumours of the Testes in Adult Patients: German Clinical Practice Guideline, PART II - Recommendations for the Treatment of Advanced, Recurrent, and Refractory Disease and Extragonadal and Sex Cord/Stromal Tumours and for the Management of Follow-Up, Toxicity, Quality of Life, Palliative Care, and Supportive Therapy.

OBJECTIVES: We developed the first German evidence- and consensus-based clinical guideline on diagnosis, treatment, and follow-up of germ cell tumours (GCT) of the testes in adult patients. We present the guideline content in 2 separate publications. The present second part summarizes therecommendations for the treatment of advanced disease stages and for the management of follow-up and late effects. MATERIALS AND METHODS: An interdisciplinary panel of 42 experts including 1 patient representative developed the guideline content. Clinical recommendations and statements were based on scientific evidence and expert consensus. For this purpose, evidence tables for several review questions, which were based on systematic literature searches (last search in March 2018), were provided. Thirty-one experts, who were entitled to vote, rated the final clinical recommendations and statements. RESULTS: Here we present the treatment recommendations separately for patients with metastatic seminoma and non-seminomatous GCT (stages IIA/B and IIC/III), for restaging and treatment of residual masses, and for relapsed and refractory disease stages. The recommendations also cover extragonadal and sex cord/stromal tumours, the management of follow-up and toxicity, quality-of-life aspects, palliative care, and supportive therapy. CONCLUSION: Physicians and other medical service providers who are involved in the diagnostics, treatment, and follow-up of GCT (all stages, outpatient and inpatient care as well as rehabilitation) are the users of the present guideline. The guideline also comprises quality indicators for measuring the implementation of the guideline recommendations in routine clinical care; these data will be presented in a future publication.

Management of Germ Cell Tumours of the Testis in Adult Patients. German Clinical Practice Guideline Part I: Epidemiology, Classification, Diagnosis, Prognosis, Fertility Preservation, and Treatment Recommendations for Localized Stages.

INTRODUCTION: This is the first German evidence- and consensus-based clinical guideline on diagnosis, treatment, and follow-up on germ cell tumours (GCTs) of the testis in adult patients. We present the guideline content in two publications. Part I covers the topic's background, methods, epidemiology, classification systems, diagnostics, prognosis, and treatment recommendations for the localized stages. METHODS: An interdisciplinary panel of 42 experts including 1 patient representative developed the guideline content. Clinical recommendations and statements were based on scientific evidence and expert consensus. For this purpose, evidence tables for several review questions, which were based on systematic literature searches (last search was in March 2018) were provided. Thirty-one experts entitled to vote, rated the final clinical recommendations and statements. RESULTS: We provide 161 clinical recommendations and statements. We present information on the quality of cancer care and epidemiology and give recommendations for staging and classification as well as for diagnostic procedures. The diagnostic recommendations encompass measures for assessing the primary tumour as well as procedures for the detection of metastases. One chapter addresses prognostic factors. In part I, we separately present the treatment recommendations for germ cell neoplasia in situ, and the organ-confined stages (clinical stage I) of both seminoma and nonseminoma. CONCLUSION: Although GCT is a rare tumour entity with excellent survival rates for the localized stages, its management requires an interdisciplinary approach, including several clinical experts. Quality of care is highly related to institutional expertise and can be reassured by established online-based second-opinion boards. There are very few studies on diagnostics with good level of evidence. Treatment of metastatic GCTs must be tailored to the risk according to the International Germ Cell Cancer Collaboration Group classification after careful diagnostic evaluation. An interdisciplinary approach as well as the referral of selected patients to centres with proven experience can help achieve favourable clinical outcomes.

Valproic acid inhibits the proliferation of cancer cells by re-expressing cyclin D2.

In this study, primary murine prostate cancer (PCa) cells were derived using the well-established TRAMP model. These PCa cells were treated with the histone deacetylase inhibitor, valproic acid (VPA), and we demonstrated that VPA treatment has an antimigrative, antiinvasive and antiproliferative effect on PCa cells. Using microarray analyses, we discovered several candidate genes that could contribute to the cellular effects we observed. In this study, we could demonstrate that VPA treatment of PCa cells causes the re-expression of cyclin D2, a known regulator that is frequently lost in PCa as we could show using immunohistochemical analyses on PCa specimens. We demonstrate that VPA specifically induces the re-expression of cyclin D2, one of the highly conserved D-type cyclin family members, in several cancer cell lines with weak or no cyclin D2 expression. Interestingly, VPA treatment had no effect in fibroblasts, which typically have high basal levels of cyclin D2 expression. The re-expression of cyclin D2 observed in PCa cells is activated by increased histone acetylation in the promoter region of the Ccnd2 gene and represents one underlying molecular mechanism of VPA treatment that inhibits the proliferation of cancer cells. Altogether, our results confirm that VPA is an anticancer therapeutic drug for the treatment of tumors with epigenetically repressed cyclin D2 expression.

A TNF-regulated recombinatorial macrophage immune receptor implicated in granuloma formation in tuberculosis.

Macrophages play a central role in host defense against mycobacterial infection and anti- TNF therapy is associated with granuloma disorganization and reactivation of tuberculosis in humans. Here, we provide evidence for the presence of a T cell receptor (TCR) αß based recombinatorial immune receptor in subpopulations of human and mouse monocytes and macrophages. In vitro, we find that the macrophage-TCRαß induces the release of CCL2 and modulates phagocytosis. TNF blockade suppresses macrophage-TCRαß expression. Infection of macrophages from healthy individuals with mycobacteria triggers formation of clusters that express restricted TCR Vß repertoires. In vivo, TCRαß bearing macrophages abundantly accumulate at the inner host-pathogen contact zone of caseous granulomas from patients with lung tuberculosis. In chimeric mouse models, deletion of the variable macrophage-TCRαß or TNF is associated with structurally compromised granulomas of pulmonary tuberculosis even in the presence of intact T cells. These results uncover a TNF-regulated recombinatorial immune receptor in monocytes/macrophages and demonstrate its implication in granuloma formation in tuberculosis.

Amyloid precursor protein is a biomarker for transformed human pluripotent stem cells.

Increasing evidence suggests an important function of the ß-amyloid precursor protein (APP) in malignant disease in humans; however, the biological basis for this evidence is not well understood at present. To understand the role of APP in transformed pluripotent stem cells, we studied its expression levels in human testicular germ cell tumors using patient tissues, model cell lines, and an established xenograft mouse model. In the present study, we demonstrate the cooperative expression of APP with prominent pluripotency-related genes such as Sox2, NANOG, and POU5F1 (Oct3/4). The closest homologue family member, APLP2, showed no correlation to these stem cell factors. In addition, treatment with histone deacetylase (HDAC) inhibitors suppressed the levels of APP and stem cell markers. Loss of pluripotency, either spontaneously or as a consequence of treatment with an HDAC inhibitor, was accompanied by decreased APP protein levels both in vitro and in vivo. These observations suggest that APP represents a novel and specific biomarker in human transformed pluripotent stem cells that can be selectively modulated by HDAC inhibitors.

Embryo implantation failure and other reproductive defects in Ube2q1-deficient female mice.

The ubiquitination process is indispensable for proteome regulation. Three classes of ubiquitin (Ub)-related proteins can be distinguished: E1, E2 and E3. Proteins from the E2 class are responsible for the transfer of Ubls from E1 to the target protein. For this activity, interaction with class E3 ligases is usually required. Ub-conjugating enzyme E2Q 1 (UBE2Q1) belongs to the E2 class of Ub-related enzymes and is demonstrated to be involved in the regulation of membrane B4GALT1 protein. Here, we demonstrate that human UBE2Q1 and mouse Ube2q1 are widely expressed and highly conserved genes. To elucidate the function of UBE2Q1 protein, we generated knockout mouse model. No overt phenotype was detected in UBE2Q1-deficient males, but in mutant females, pleiotropic reproductive defects were observed including altered oestrus cycle, abnormal sexual behaviour and reduced offspring care. Moreover, in the uterus of mutant females, significantly increased embryonic lethality and decreased implantation capacity of homozygous mutant embryos were noticed. We found that Ube2q1 is not expressed in the uterus of non-pregnant females but its expression is up-regulated during pregnancy. Taken together, Ube2q1 is involved in different aspects of female fertility.

13-year-old tuberous sclerosis patient with renal cell carcinoma associated with multiple renal angiomyolipomas developing multifocal micronodular pneumocyte hyperplasia.

BACKGROUND: The autosomal dominant tumor syndrome tuberous sclerosis complex is caused by the mutated TSC1 gene, hamartin, and the TSC2 gene, tuberin. Patients with this complex develop typical cutaneus symptoms such as peau chagrin or angiofibromas of the skin as well as other lesions such as astrocytomas in the brain and lymphangioleiomyomatosis in the lung. Only a few tuberous sclerosis patients have been described who showed a multifocal micronodular pneumocyte hyperplasia of the lung. Another benign tumor which often occurs together with tuberous sclerosis is the angiomyolipoma of the kidney. Furthermore, an increased incidence of renal cell carcinoma in connection with tuberous sclerosis has also been proven. CASE PRESENTATION: We report a 13-year-old white girl with epilepsy and hypopigmented skin lesions. Radiological studies demonstrated the typical cortical tubers leading to the diagnosis of tuberous sclerosis. In the following examinations a large number of angiomyolipomas were found in both kidneys. One lesion showed an increasing size and tumor like aspects in magnetic resonance imaging. The pathological examination of the following tumorectomy demonstrated an unclassified renal cell carcinoma. Four months postoperatively, a follow-up computer tomography revealed multiple bilateral pulmonary nodules. To exclude lung metastases of the renal cell carcinoma, multiple open-lung biopsies were performed. CONCLUSION: Here we report a diagnostically challenging case of a 13-year-old patient with tuberous sclerosis and angiomyolipomas of the kidney who developed an unclassified renal cell carcinoma as well as multifocal micronodular pneumocyte hyperplasia.

Blastomatoid pulmonary carcinosarcoma: report of a case with a review of the literature.

BACKGROUND: Pulmonary carcinosarcoma is a biphasic tumour with an unfavourable prognosis. The differential diagnosis includes pulmonary blastoma and is often challenging. CASE PRESENTATION: We here describe a case of blastomatoid pulmonary carcinosarcoma in a 58-year-old patient, who underwent surgical resection. Histopathological examination revealed immature glandular epithelium resembling high-grade fetal adenocarcinoma expressing epithelial markers and membranous beta-catenin, and blastomatoid spindle cells with partial rhabdomyosarcoma-like differentiation. Both elements expressed p53, MDM2, and cyclin-dependent kinase 4 (CDK4), but not thyroid-transcription factor 1 (TTF-1). Mutation analysis of KRAS, EGFR, and beta-catenin revealed no mutations. Comparative genomic hybridization detected +1q, +6p, +6q24qter, +8q, +11q12q14, +11q23qter, +12q12q21, +12q24qter, +17q, +20q, -5q14q23, -9p13pter, -13q21q21, and amplifications at 12q14q21, 15q24qter, 20q11q12. CONCLUSION: The observed molecular and cytogenetic findings may provide additional tools for the differential diagnosis of biphasic pulmonary neoplasms. Furthermore, TP53, MDM2, CDK4, and PTPN1 may be involved in tumourigenesis.

[Diagnostic problems in testicular tumours in consultant pathology : A practical guide]. / Diagnostische Probleme bei Hodentumoren in der Konsiliarpathologie : Ein praktischer Leitfaden.

The great variety of pathological patterns in germ cell tumours, especially in yolk sac tumours but also the possibility of somatic-type malignancies, can complicate daily diagnosis. For the correct diagnosis, knowledge of morphological aspects and additional immunohistochemical staining can be helpful. Also, rare entities like sex cord stromal tumours, tumours of testicular adnexa or mesenchymal tumours of the spermatic cord can be diagnostically challenging.

Histone deacetylase inhibitor valproic acid inhibits cancer cell proliferation via down-regulation of the alzheimer amyloid precursor protein.

The beta-amyloid precursor protein (APP) represents a type I transmembrane glycoprotein that is ubiquitously expressed. In the brain, it is a key player in the molecular pathogenesis of Alzheimer disease. Its physiological function is however less well understood. Previous studies showed that APP is up-regulated in prostate, colon, pancreatic tumor, and oral squamous cell carcinoma. In this study, we show that APP has an essential role in growth control of pancreatic and colon cancer. Abundant APP staining was found in human pancreatic adenocarcinoma and colon cancer tissue. Interestingly, treating pancreatic and colon cancer cells with valproic acid (VPA, 2-propylpentanoic acid), a known histone deacetylase (HDAC) inhibitor, leads to up-regulation of GRP78, an endoplasmic reticulum chaperone immunoglobulin-binding protein. GRP78 is involved in APP maturation and inhibition of tumor cell growth by down-regulation of APP and secreted soluble APPalpha. Trichostatin A, a pan-HDAC inhibitor, also lowered APP and increased GRP78 levels. In contrast, treating cells with valpromide, a VPA derivative lacking HDAC inhibitory properties, had no effect on APP levels. VPA did not modify the level of epidermal growth factor receptor, another type I transmembrane protein, and APLP2, a member of the APP family, demonstrating the specificity of the VPA effect on APP. Small interfering RNA-mediated knockdown of APP also resulted in significantly decreased cell growth. Based on these observations, the data suggest that APP down-regulation via HDAC inhibition provides a novel mechanism for pancreatic and colon cancer therapy.

Unicentric castleman's disease located in the lower extremity: a case report.

BACKGROUND: Castleman's disease is a rare form of localized lymph node hyperplasia of uncertain etiology. Although the mediastinum is the most common site of involvement, rare cases occurring in lymph node bearing tissue of other localization have been reported, including only a few intramuscular cases. Unicentric and multicentric Castleman's disease are being distinguished, the latter harboring an unfavorable prognosis. CASE PRESENTATION: Here, we present a case of unicentric Castleman's disease in a 37-year-old woman without associated neoplastic, autoimmune or infectious diseases. The lesion was located in the femoral region of the right lower extremity and surgically resected after radiographic workup and excisional biopsy examinations. The tumor comprised lymphoid tissue with numerous germinal centers with central fibrosis, onion-skinning and rich interfollicular vascularization. CD23-positive follicular dendritic cells were detected in the germinal centers and numerous CD138-positive plasma cells in interfollicular areas. The diagnosis of mixed cellularity type Castleman's disease was established and the patient recovered well. CONCLUSIONS: In conclusion, the differential diagnosis of Castleman's disease should be considered when evaluating a sharply demarcated, hypervascularized lymphatic tumor located in the extremities. However, the developmental etiology of Castleman's disease remains to be further examined.

Sertoli-Leydig cell tumour in a 13-year-old girl.

Sertoli-Leydig cell tumours account for less than 0.2% of ovarian malignancies. We describe the case of a Sertoli-Leydig cell tumour in a 13-year-old girl who presented with symptoms of hyperandrogenism. We give an overview over current literature and discuss options of therapy of rare Sertoli-Leydig cell tumours.

TLR3 gene polymorphisms and liver disease manifestations in chronic hepatitis C.

Phenotypes of liver disease due to chronic hepatitis C virus (HCV) infection show a wide range of variations in terms of histological manifestations and the clinical outcome. Sensing of viral double-stranded RNA (dsRNA) by Toll-like receptor 3 (TLR3) is likely involved in early pathogen detection and the host response to viral infection. This study analyzed epidemiological and clinical data from a total of 137 patients with chronic HCV infection with regard to two polymorphic positions within the TLR3 gene: rs5743305 (T/A) is located within the promoter region and might affect transcriptional activity, rs3775291 (C/T) is a non-synonymous single nucleotide polymorphism (SNP) located within exon 4 and the variant receptor has been shown to be functionally impaired. TLR3 promoter and the exon 4 variations were not found to be associated with TLR3 gene expression in peripheral blood mononuclear cells (PBMCs). In the liver, however, a tendency of higher TLR3 gene expression was found for exon 4 TT genotypes. Both variations were not found to be associated with clinical parameters of chronic disease. On the other hand, an analysis of the TLR3 exon 4 genotype distribution with respect to HCV subtype revealed an absence of TT genotype among HCV subtype 1a infected individuals. This study thus failed to reveal any association of the two SNPs under investigation with clinical parameters of chronic hepatitis C. However, data argue for a functional relevance of the exon 4 SNP in terms of conferring a different susceptibility towards HCV subtype infection.

Leupaxin, a novel coactivator of the androgen receptor, is expressed in prostate cancer and plays a role in adhesion and invasion of prostate carcinoma cells.

In the present study, we demonstrate that leupaxin mRNA is overexpressed in prostate cancer (PCa) as compared with normal prostate tissue by using cDNA arrays and quantitative RT-PCR analyses. Moderate to strong expression of leupaxin protein was detected in approximately 22% of the PCa tissue sections analyzed, and leupaxin expression intensities were found to be significantly correlated with Gleason patterns/scores. In addition, different leupaxin expression levels were observed in PCa cell lines, and at the subcellular level, leupaxin was usually localized in focal adhesion sites. Furthermore, mutational analysis and transfection experiments of LNCaP cells using different green fluorescent protein-leupaxin constructs demonstrated that leupaxin contains functional nuclear export signals in its LD3 and LD4 motifs, thus shuttling between the cytoplasm and the nucleus. We could also demonstrate for the first time that leupaxin interacts with the androgen receptor in a ligand-dependent manner and serves as a transcriptional activator of this hormone receptor in PCa cells. Down-regulation of leupaxin expression using RNA interference in LNCaP cells resulted in a high rate of morphological changes, detachment, spontaneous apoptosis, and a reduction of prostate-specific antigen secretion. In contrast, knockdown of leupaxin expression in androgen-independent PC-3 and DU 145 cells induced a significant decrease of both the invasive capacity and motility. Our results therefore indicate that leupaxin could serve as a potential progression marker for a subset of PCa and may represent a novel coactivator of the androgen receptor. Leupaxin could function as a putative target for therapeutic interventions of a subset of advanced PCa.

Cyclopamine treatment of full-blown Hh/Ptch-associated RMS partially inhibits Hh/Ptch signaling, but not tumor growth.

Mutations in the Hedgehog (Hh) receptor Patched (Ptch) are responsible for a variety of tumors, which show ligand-independent stimulation of the Hh/Ptch signaling cascade. Cyclopamine is an alkaloid of the corn lily Veratrum californicum, which blocks activity of the pathway by inhibition of Smoothened (Smo), the signal transduction partner of Ptch. This results in growth inhibition of Hh/Ptch-dependent tumor cells in vitro, of subcutaneous xenografts as well as of precancerous lesions in Ptch(+/-) mice. However, the evidence that treatment with cyclopamine is an effective anti-cancer therapy against full-blown tumors is sparse. Here, we have investigated the responsiveness of full-blown Hh/Ptch-associated rhabdomyosarcoma (RMS) to this drug. Hh pathway activity and proliferation of cultured primary RMS cells was inhibited by cyclopamine. Hh signaling was also partially suppressed by the drug in RMS in vivo, but cyclopamine treatment did not result in stable disease or tumor regression. It also did not affect proliferation, apoptosis or the differentiation status of RMS. This was in contrast to anti-proliferative effects on tumor growth caused by doxorubicin, an anthracycline routinely used in therapy of human RMS. In summary, our data indicate that there must be additional factors that render full-blown Hh/Ptch-associated RMS insensitive against anti-proliferative effects of cyclopamine in vivo.

Immunohistochemical staining of plastic (methyl-methacrylate)-embedded bone marrow biopsies applying the biotin-free tyramide signal amplification system.

Immunohistochemistry of trephine bone marrow biopsies plays a prominent role in diagnostic assessment of a broad spectrum of non-neoplastic and neoplastic hematologic and metastatic diseases. We tested the quality of immunohistochemical stainings in sections of methyl-methacrylate-embedded core biopsies prepared according to the so-called Hannover-method of cold polymerization using the novel biotin-free tyramide signal amplification system in comparison to the alkaline phosphatase-conjugated "EnVision" method. Examining a large panel of immunohistochemical markers, the amplification system proved to be a highly sensitive technique substantially superior to the EnVision-AP method in reliably detecting the antigenic determinants of the target cells and referred to the intensity of immunoprecipitations.

The relevance of estrogen receptor-beta expression to the antiproliferative effects observed with histone deacetylase inhibitors and phytoestrogens in prostate cancer treatment.

In the prostate, estrogen receptor beta (ERbeta), the preferred receptor for phytoestrogens, has features of a tumor suppressor. To investigate the mechanisms underlying the beneficial effects on prostate cancer of histone deacetylase inhibitor valproic acid (VPA) and phytoestrogen tectorigenin, we analyzed the expression of ERbeta after tectorigenin or VPA treatment. For further functional analysis, we knocked down ERbeta expression by RNA interference. LNCaP prostate cancer cells were treated with 5 mmol/L VPA or 100 micromol/L tectorigenin and transfected with small interfering RNA (siRNA) against ERbeta. Control transfections were done with luciferase (LUC) siRNA. Expression of ERbeta was assessed by Western blot. mRNA expression was quantitated by real-time reverse transcription-PCR. Expression of ERbeta mRNA and protein markedly increased after VPA or tectorigenin treatment. When ERbeta was knocked down by siRNA, the expression of prostate-derived Ets factor, prostate-specific antigen, prostate cancer-specific indicator gene DD3(PCA3), insulin-like growth factor-1 receptor, the catalytic subunit of the telomerase, and ERalpha was up-regulated and the tectorigenin effects were abrogated. ERbeta levels were diminished in prostate cancer and loss of ERbeta was associated with proliferation. Here, we show that siRNA-mediated knockdown of ERbeta increases the expression of genes highly relevant to tumor cell proliferation. In addition, we show that one prominent result of treatment with VPA or tectorigenin is the up-regulation of ERbeta resulting in antiproliferative effects. Thus, these drugs, by restoring the regulatory function of ERbeta in tumor cells, could become useful in the intervention of prostate cancer.

Use of monoclonal antibodies to assess expression of anaphylatoxin receptors in tubular epithelial cells of human, murine and rat kidneys.

To assess published evidence of anaphylatoxin receptor expression in renal tubular epithelial cells, monoclonal antibodies (mAbs) against human, mouse and rat receptors for C5a and C3a (C5aR, C3aR) were raised using receptor-expressing transfectants as immunogens. Applying these reagents in immunohistochemistry, we observed that mAbs with reactivities against three distinct epitopes of human C5aR N-terminus recognized tissue macrophages but not at all renal tubular epithelial cells. These findings were surprising, as strong tubular staining had been previously demonstrated by mAbs raised against a synthetic N-terminal C5aR peptide. To extend our study to mammalian kidneys, renal specimens from normal rats as well as LPS-treated Balb/c and MRL/lpr mice, which suffered from lupus-type nephritis, were examined. Similar to humans, mAbs against murine or rat C5aR strongly recognized infiltrating leukocytes in situ whereas tubular epithelial cells remained negative. As a mAb has been previously used to document C3aR expression in renal tubular epithelial cells, kidney specimens were examined using newly established mAbs against different epitopes of human, murine and rat C3aR. In contrast to published evidence, C3aR was detectable exclusively in interstitial leukocytes but not in epithelial tubular cells of normal and diseased tissues. Taken together, our findings question a direct involvement of tubular epithelial cells in anaphylatoxin-mediated renal inflammation. Furthermore, as we demonstrate in the case of anaphylatoxin receptors, cross-reactivities of mAbs may constitute as yet underestimated pitfalls in immunohistochemical antigen detection.