Comparison of the reliability of Gram-negative and Gram-positive flags of the Sysmex UF-5000 with manual Gram stain and urine culture results.

OBJECTIVES: Recently, the fully automated flow cytometry-based UF-5000 (Sysmex Corboration, Kobe, Japan) urine sediment analyzer was developed providing bacteria (BACT) info flags for more accurate bacterial discrimination of urinary tract infections (UTIs). This study aimed to compare the reliability of the UF-5000 BACT-info flags with manual Gram stain and urine culture as the gold standard method. METHODS: A total of 344 urine samples were analyzed on the UF-5000 and compared with manual microscopic Gram stain and urine cultures. Agreement was assessed by Cohen's kappa (κ) analysis. The Youden index was used to determine the optimal BACT and white blood cell (WBC) cut-off points for discriminating positive and negative urine cultures. RESULTS: Overall 98/344 (28.5%) samples were urine culture positive at a cut-off of ≥105 CFU/mL. "Gram-negative?" UF-5000 BACT-Info flags showed a better concordance of 25/40 (62.5%) with urine culture compared to Gram stain with 30/50 (60%). The results for UF-5000 discrimination of Gram-positive and Gram-negative microorganisms demonstrated a substantial (κ = 0.78) and fair (κ = 0.40) agreement with urine culture. Optimal cut-off points detecting positive urine cultures were 135 BACT/µL (sensitivity [SE]: 92.1%, specificity [SP]: 85.4%, positive predictive value [PPV]: 71%, negative predictive value [NPV]: 96%) and 23 WBC/µL (SE: 73.5%, SP: 84.1%, PPV: 65%, NPV: 89%). CONCLUSIONS: The UF-5000 analyzer (Sysmex) is a reliable diagnostic tool for UTI screening. The displayed BACT-Info flags allow a quick diagnostic orientation for the clinician. However, the authors suggest verifying the automated Gram categories with urine culture.

Cell-free DNA analysis reveals POLR1D-mediated resistance to bevacizumab in colorectal cancer.

BACKGROUND: Bevacizumab, a monoclonal antibody against soluble VEGFA, is an approved and commonly administered anti-angiogenic drug in patients with metastasized colorectal cancer (mCRC). The survival benefit of anti-VEGF therapy in mCRC patients is limited to a few months, and acquired resistance mechanisms are largely unknown. Here, we employed whole-genome sequencing of plasma DNA to evaluate the tumor genome of patients undergoing treatment with bevacizumab to determine novel aberrations associated with resistance. METHODS: Using longitudinal plasma analyses, we studied the evolution of tumor genomes in a mCRC cohort (n = 150) and conducted analyses of CRC cases from The Cancer Genome Atlas (TCGA) database (n = 619) to identify associations between genomic aberrations and clinical features. We employed whole-genome sequencing to identify the most frequently occurring focal somatic copy number alterations (SCNAs). Using the TCGA data as a comparative and supporting dataset, we defined the minimally amplified overlapping region and studied the mechanistic consequences of copy number gain of the involved genes in this segment. In addition, we established an in vitro cell model and conducted downstream gene expression and cell viability assays to confirm our findings from the patient dataset. RESULTS: We observed a recurrent focal amplification (8.7% of cases) on chromosome 13q12.2. Analysis of CRC cases from the TCGA database suggested that this amplicon is associated with more advanced stages. We confirmed that this 13q12.2 amplicon frequently emerges later during the clinical course of disease. After defining the minimally amplified region, we observed that the amplification and expression of one gene, POLR1D, impacted cell proliferation and resulted in upregulation of VEGFA, an important regulator of angiogenesis which has been implicated in the resistance to bevacizumab treatment. In fact, in several patients, we observed the emergence of this 13q12.2 amplicon under bevacizumab treatment, which was invariably associated with therapy resistance. CONCLUSIONS: Non-invasive analyses of cell-free DNA from patients undergoing treatment with bevacizumab enabled the tracking of evolving tumor genomes and helped identify a recurrent focal SCNA of clinical relevance. Here, we describe a novel resistance mechanism against a widely applied treatment in patients with mCRC which will impact the clinical management of patients.

The diagnostic role of BAP1 in serous effusions.

The aim of this study was to analyze the diagnostic role of BAP1 in effusion cytology. Effusions (n = 258), consisting of 53 malignant mesotheliomas and 205 other cancers, the majority carcinomas (62 breast, 60 ovarian, 31 lung, 51 carcinomas of other origin, 1 melanoma), were analyzed for BAP1 expression using immunohistochemistry. BAP1 was lost in 46 (87%) mesotheliomas compared with 4 (2%) of 205 other cancers (P < .001), resulting in sensitivity and specificity of 87% and 98%, respectively. There was no significant difference between peritoneal (n = 14) and pleural (n = 39) mesotheliomas. The 4 carcinomas with loss of BAP1 included 1 ovarian, 1 breast, 1 uterine cervical, and 1 gastric carcinoma. The present study supports the role of BAP1 as a highly sensitive and specific marker for malignant mesothelioma in serous effusions and argues for inclusion of this test in all specimens in which this diagnosis is considered.

The diagnostic role of PTEN and ARID1A in serous effusions.

The aim of this study was to analyze the diagnostic role of PTEN and ARID1A in effusion cytology. Effusions (n = 279), consisting of 226 carcinomas (70 ovarian, 64 breast, 36 lung, and 15 uterine corpus carcinomas; 41 carcinomas of other origin) and 53 malignant mesotheliomas, were analyzed for PTEN and ARID1A expression using immunohistochemistry. PTEN was preserved in 166 (59%) tumors, partially lost in 38 (14%), and absent in 75 (27%), with lower expression in malignant mesotheliomas compared to carcinomas, though not significantly (p = 0.084). ARID1A was preserved in 243 (88%) tumors, partially lost in 18 (6%), and absent in 18 (6%). The majority of tumors with absent ARID1A were ovarian carcinomas, predominantly of clear cell or low-grade serous type. Reactive mesothelial cells in carcinoma specimens were uniformly positive for both proteins. ARID1A mutation analysis showed no mutations in eight analyzed specimens negative by immunohistochemistry. Loss of PTEN and ARID1A expression is highly specific for malignancy in effusion pathology. Loss of PTEN is not informative of organ of origin, whereas absence of ARID1A should raise suspicion of an ovarian primary.

CD133+ cells in pulmonary arterial hypertension.

Circulating mononuclear cells may play an important role for the vascular remodelling in pulmonary arterial hypertension (PAH), but studies addressing multiple progenitor populations are rare and inconsistent.We used a comprehensive fluorescence-activated cell sorting analysis of circulating mononuclear cells in 20 PAH patients and 20 age- and sex-matched controls, and additionally analysed CD133(+) cells in the lung tissue of five PAH transplant recipients and five healthy controls (donor lungs).PAH patients were characterised by increased numbers of circulating CD133(+) cells and lymphopenia as compared with control. In PAH, CD133(+) subpopulations positive for CD117 or CD45 were significantly increased, whereas CD133(+)CD309(+), CD133(+)CXCR2(+) and CD133(+)CD31(+) cells were decreased. In CD133(+) cells, SOX2, Nanog, Ki67 and CXCR4 were not detected, but Oct3/4 mRNA was present in both PAH and controls. In the lung tissue, CD133(+) cells included three main populations: type 2 pneumocytes, monocytes and undifferentiated cells without significant differences between PAH and controls.In conclusion, circulating CD133(+) progenitor cells are elevated in PAH and consist of phenotypically different subpopulations that may be up- or downregulated. This may explain the inconsistent results in the literature. CD133(+) type 2 pneumocytes in the lung tissue are not associated with circulating CD133(+) mononuclear cells.

Adiponectin attenuates osteolysis in aseptic loosening of total hip replacements.

Joint replacements have a longer durability in patients with high serum levels of adiponectin (APN) than in patients with low levels. We aimed to characterize the unknown pathophysiological effects of APN on wear particle-induced inflammation, apoptosis and osteolysis. Immunohistochemistry was performed to detect APN, its receptors and apoptosis in patients with and without aseptic loosening. Additionally, APN knockout mouse studies and pharmacological intervention of APN were performed in an established calvarial mouse model. Osteolysis and inflammation were quantified by histomorphometry and microcomputed tomography, apoptosis by immunohistochemistry and TUNEL assay. In a cell culture model, human monocyte-derived macrophages were incubated with or without metal wear debris particles and partially treated with APN. Expression of APN, AdipoR1 and calreticulin in specimens from patients with aseptic loosening were significantly higher than in patients without aseptic loosening. Administration of APN in mice significantly reduced wear particle-induced inflammation, osteolysis and the number of caspase-3-positive macrophages. The cell culture model showed that APN leads to significantly lower values of TNF-α. These findings support a prominent role of APN in the development of particle-induced osteolysis and APN may be therapeutically useful in patients with aseptic loosening.

Growth patterns of lung metastases from sarcoma: prognostic and surgical implications from histology.

OBJECTIVES: Pulmonary metastasectomy is firmly established in the multidisciplinary management of patients with advanced sarcomas. While the number of metastases, completeness of resection, disease-free interval and grading of the primary sarcoma are well established prognostic factors in metastatic surgery, histological parameters are not widely evaluated. The objective of the present study was to evaluate the prognostic impact of intrapulmonary growth patterns of sarcoma metastases. METHODS: We retrospectively analysed the clinicopathological characteristics of 52 sarcoma patients who underwent surgical resection of lung metastases at our centre from January 2006 to January 2009. The histological growth characteristics of all 261 metastases have been categorized and published previously. 'Interstitial growth' was defined as a diffuse spread of the sarcoma cells into the alveolar septae at the transition of the metastasis to the normal lung tissue and was found to be prognostic. 'Pleural penetration' was defined as the infiltration and destruction of all visceral pleural layers by the tumour and was found to be a risk factor for local recurrence. RESULTS: The median post-metastasectomy overall survival was 50.3 months, and the corresponding 5-year survival rate was 44.7%. Age >55 years at metastasectomy (P = 0.02), the presence of interstitial growth (P = 0.008), size of the largest metastasis >35 mm (P = 0.023) and the presence of tumour recurrence at any site after metastasectomy (P < 0.001) were identified as risk factors for death. Pleural penetration (P = 0.007) and size of the metastasis >5 mm were found to be risk factors for local intrapulmonary recurrence. CONCLUSIONS: Interstitial tumour growth, which is easily detected by light microscopy, can serve as a strong predictor of survival following pulmonary metastasectomy in sarcoma patients. Obvious pleural infiltration indicates the need for larger margins.

Growth patterns of lung metastases from sarcomas.

Complete resection of pulmonary metastases from sarcomas is an established method of treatment. While resection margins are well described for primary sarcoma lesions, minimal knowledge is available about margins and factors influencing local tumour control in the lung. The objective of the present study was to describe intrapulmonary patterns of growth for sarcoma metastases as a basis for planning resections. From January 2006 to January 2009, we retrospectively analysed 261 resected pulmonary sarcoma metastases from 52 patients. All metastases were reviewed for histological characteristics and resection margins. Metastases characterised by a solid, well-defined tumour mass were found in 127 of 261 metastases (48.7%). Interstitial spread (39.8%), vascular infiltration (20.7%), satellite nodules (16.1%) and lymphangitic spread (10.7%) were identified as aggressive histological growth characteristics. Forty-five of 52 patients (86.5%) had metastases with a mitotic index of 10 or more per 10 HPF, underlining their high-grade malignant potential. The following characteristics of aggressive intrapulmonary growth were highly correlated with each other: interstitial growth and lymphangitic spread (p = 0.002), interstitial growth and vascular infiltration (p < 0.001), vascular infiltration and satellite nodules (p = 0.009), interstitial growth and pleural invasion (p = 0.004); by contrast, the presence of a fibrous pseudocapsule (17.2%) was not associated with aggressive growth patterns. Almost half of all pulmonary sarcoma metastases could be identified with aggressive patterns of local growth, and only 17.2% are surrounded by a pseudocapsule which might allow safe resection margins.

Integrin-linked kinase, phosphorylated AKT and the prognosis of malignant pleural mesothelioma.

OBJECTIVE: Integrin-linked kinase (ILK) is a cell membrane-bound molecule implicated in the metastatic progression of many tumour types. It phosphorylates the downstream target AKT (phosphorylated AKT, pAKT), and, by doing this, it activates anti-apoptotic pathways. We have recently shown ILK expression in malignant pleural mesothelioma (MPM). To determine whether ILK expression in MPM is connected with pAKT expression, and whether ILK and pAKT expression have any influence on the patient's prognosis, we correlated ILK and pAKT expression, as assessed by immunohistochemistry, with disease-related survival in a retrospective cohort of 80 MPM patients. MATERIAL AND METHODS: The paraffin specimens of 80 MPM cases treated from 1990 to 2006 (52 surgical cases, 28 conservative cases) have been retrieved from the archive. The median (range) patients' age was 62 (28-83 years) years; the male-to-female ratio was 3:1. Fifty percent of the patients had an epitheloid subtype. The samples have been stained with anti-ILK as well as with anti-pAKT and scored by two independent pathologists. Intensity of ILK and pAKT expression has been correlated with disease-related survival. RESULTS: In total, 73 of 80 (91%) MPM samples expressed ILK; 65 of 74 (88%) MPM samples expressed pAKT. Comparing the 5-year disease-related survival according to ILK or pAKT expression, no statistically significant difference could be found between ILK and pAKT expressing or non-expressing patients. However, in the subgroup of conservatively treated MPM patients, those with strong ILK expression had a longer 5-year disease-related survival (p < 0.0001). In total, the only prognostic factor across all ILK, pAKT and therapy subgroups was the histological subtype (p = 0.01). The prognostic significance of the histological subtype has been confirmed in multivariate analysis (p = 0.005). CONCLUSION: The expression of ILK in MPM is connected with the expression of the downstream target pAKT, but neither ILK nor pAKT expression has a measurable influence on the patient's prognosis, except for certain subgroups of MPM. However, to shed light on the true prognostic impact of ILK and pAKT expression in MPM, prospective trials are needed.

Safety distance in the resection of colorectal lung metastases: a prospective evaluation of satellite tumor cells with immunohistochemistry.

OBJECTIVE: After complete pulmonary metastasectomy of colorectal lung metastases, tumor recurrence at the site of former resection develops in some patients. Well-described risk factors for local recurrence in the lung include incomplete resection and aerogenous spread of floating cancer cell clusters. The aim of this study was to describe the distribution and frequency of satellite cancer cells or clusters in resected tissue to deduce recommendations for safety margins in the future. METHODS: Seventeen colorectal metastases from 10 patients were processed. Evaluation for pattern of growth, satellite cancer cells, and inflammatory reaction at the surface of the metastases was performed on 102 sections with CDX2 and cytokeratin 20 stains. The distance between the surface of the nodule and the satellite cancer cell was measured for each satellite and statistically evaluated. RESULTS: As a pattern of growth, interstitial spread, inflammatory reaction, and lymphangitic spread were observed in 41.2%, 35.3%, and 23.5%, respectively. A total of 205 satellite cancer cells were identified in 16 of 17 metastases with a mean distance to the nodule of 0.99 ± 0.85 mm (range, 0.06-6.43 mm). The percentages of satellite tumor cells that are likely to be found within 1.59 mm, 3.43 mm, and 7.4 mm around the nodule are 68.27%, 95.5%, and 99.73%, respectively. CONCLUSIONS: Satellite tumor cells, a potential source for local recurrence, are found in a high number around colorectal lung metastases. As a standard of care, a safety distance of 3 mm for small metastases and 8 to 10 mm for larger metastases must be maintained around the lesion to prevent local recurrence.

Senescence in cells in aseptic loosening after total hip replacement.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The purpose of the current study was to evaluate cellular senescence of macrophages and giant cells in patients with aseptic hip loosening by determination of SA-ß-Gal (SA-ß-galactosidase), a reliable and frequently used indicator of cellular senescence. The level of senescence in capsule and interface membranes was significantly higher in patients with aseptic loosening in comparison to specimens from patients without aseptic loosening. Using Spearman's rank correlation, we found that the expression of SA-ß-Gal in giant cells (p=0.002) and macrophages (p=0.050) in the interface membranes correlates significantly with the degree of polyethylene debris. We speculate that the induction of DNA damage by wear particles is responsible for premature senescence. Consequently, we conclude that the form of senescence observed in this study is a "stress-induced senescence".

Prognostic impact of plasminogen activator inhibitor type 1 expression in bladder cancer.

BACKGROUND: Recent studies have demonstrated a poor prognosis for patients who have altered expression of plasminogen activator inhibitor type 1 (PAI-1) in several cancer types. The objective of the current study was to investigate the prognostic impact of PAI-1 on patients with transitional cell carcinoma (TCC) of the urinary bladder. METHODS: PAI-1 expression was quantified using real-time polymerase chain reaction in 91 TCCs and in 6 normal tissue specimens. PAI-1 concentrations were analyzed by enzyme-linked immunoadsorbent assay in plasma from 104 patients and 10 controls and in urine from 244 patients and 74 controls. PAI-1 expression was evaluated immunohistochemically in paraffin-embedded tissues (94 tumor samples and 10 adjacent normal tissue samples). The results were analyzed in relation to clinical features and follow-up. RESULTS: Significantly higher PAI-1 levels were detected in tissue and plasma samples, but not in urine, from patients with bladder cancer compared with controls (P=.001 and P=.008, respectively). Elevated gene expression and plasma protein concentrations were independent of tumor stage and grade. Immunostaining revealed a subgroup of patients with single tumor cells that strongly expressed PAI-1. These patients' survival was significantly shorter, and their clinical presentation was correlated significantly with lymph node-positive disease. CONCLUSIONS: PAI-1 gene expression in tissues and plasma protein levels were elevated in patients with TCC compared with controls. PAI-1 gene or protein expression was not associated with the clinical characteristics of bladder TCC. Although the assessment of PAI-1 expression in plasma or urine may not serve as an independent predictor of prognosis in patients with TCC, the immunohistochemical detection of single PAI-1-positive cells may serve as a predictor of survival and a possible indicator of metastasis.

Overexpression of the drug resistance-associated protein metallothionein does not correlate with response of sarcomas to isolated limb perfusion treatment.

BACKGROUND AND OBJECTIVES: Hyperthermic isolated limb perfusion with TNF-alpha and melphalan (HILP-TM) achieves high response rates in sarcomas. Melphalan resistance was previously reported to be associated with overexpression of metallothioneins (MTs). Objective of this study was to investigate the influence of MT expression on tumor responses in HILP-TM-treated soft tissue (STSs) and bone sarcomas (BS). METHODS: In primary biopsies of 41 HILP-TM-treated sarcomas (37 STSs and 4 BS), MT expression was assessed by an immunoreactive score. The pathologic response to HILP-TM was quantified in the corresponding tumor resection specimens. We studied the association of MT-IRS between histological regression (responder >90%, or non-responder

The prognostic value of cadherin switch in bladder cancer.

Loss of E-cadherin expression and gain of N-cadherin expression ('cadherin switch') is shown to be characteristic in epithelial to mesenchymal transition (EMT), a mechanism associated with cancer progression. Furthermore, the prognostic role of P-cadherin in different cancers is controversial. The aim of this study was to evaluate the prognostic significance of 'cadherin switch' on the gene expression level in bladder cancer. Frozen tissue samples of 181 bladder cancer patients and 7 control individuals were analyzed by quantitative real-time PCR. Kaplan-Meier log-rank test and Cox univariate and multivariate analysis were performed to assess the prognostic relevance of gene expression of E-, N- and P-cadherin. Cox univariate analysis revealed that the decrease of E-cadherin and the gain of N-cadherin gene expression are risk factors for cancer-related death (P=0.087, P=0.005, respectively). Fourteen percent (13/92) of muscle-invasive bladder cancers were N-cadherin- negative. These patients had a significantly poorer prognosis than those with N-cadherin-positive muscle-invasive tumors (P=0.024). P-cadherin gene expression proved to be a significant independent prognostic factor for both cancer-specific and recurrence-free survival (P=0.011, P=0.036). The characteristic 'cadherin switch' between low- and high-stage tumors that we observed and the prognostic significance of E-, N- and P-cadherin suggests the importance of these markers in bladder cancer progression. The poor patient prognosis in N-cadherin-negative muscle-invasive tumors indicates an alternative, N-cadherin-independent way in bladder cancer progression.

Immunoreactivity of integrin-linked kinase in primary non-small-cell lung cancer and survival after curative resection.

OBJECTIVE: Increased immunoreactivity of integrin-linked kinase (ILK) in the primary tumour is an adverse prognostic factor in a variety of preclinical and clinical models of human cancer. Here, we investigate the relationship between ILK immunoreactivity in primary non-small-cell lung cancer (NSCLC) and the survival after curative lung resection. METHODS: Tumour specimens of 138 radically operated NSCLC patients have been retrieved from the pathology archive, mounted in tissue microarrays and immunostained against ILK. The immunoreactivity against ILK has been graded in a semi-quantitative manner (negative or 1-3 positive) by two observers blinded to any patient data, and correlated to the survival data. RESULTS: In total, 88 of 138 tumours (64%) showed an ILK immunoreactivity, which varied significantly between various histological subtypes as it ranged from 46% (squamous cell carcinoma (SCC)) to 79% (adenocarcinoma) (p=0.019). The 5-year cancer-related survival of ILK-positive SCC patients was at 42 + or - 10% versus 72 + or - 9% significantly shorter than in ILK-negative patients (p=0.011). In addition, the recurrence-free survival (RFS) of ILK-positive SCC patients was also significantly shorter than of ILK-negative patients (38 + or - 10% vs 60 + or - 10%) (p=0.005). In multivariate analysis, ILK expression was a significant prognostic factor for RFS in squamous cell carcinoma (p=0.018), but not in adenocarcinoma or in the rare histology group. CONCLUSIONS: Primary NSCLC tumours show a variable ILK immunoreactivity, dependent on the histological subtype. In SCC, ILK immunoreactivity is a significantly adverse prognostic factor.

Matrix metalloproteinase-7 as a marker of metastasis and predictor of poor survival in bladder cancer.

Matrix metalloproteinases (MMPs) play an important role in tumor progression and metastasis. Here, we investigated the prognostic relevance of MMP-7 in urinary bladder cancer. MMP-7 gene expression was measured in tissue samples of 101 patients using quantitative real-time PCR. Circulating MMP-7 serum levels of 98 individuals (79 patients and 19 controls) were analyzed by enzyme-linked immunosorbent assay. The results were compared with the clinical follow-up data, performing Kaplan-Meier log-rank test as well as univariate and multivariate Cox analysis. In representative cases, immunohistochemical analysis for MMP-7 was performed. We detected significantly elevated MMP-7 levels both in tissue and serum samples of patients with metastatic disease (P = 0.001 and P = 0.002). Multivariate analysis revealed that high MMP-7 tissue expression and serum concentration are stage- and grade-independent predictors of both metastasis-free (hazard ratio [HR] = 3.80, 95% confidence interval [CI], 1.29-11.23, P = 0.016, and HR = 2.53, 95% CI, 1.01-6.37, P = 0.048) and disease-specific survival (HR = 1.89, 95% CI, 1.00-3.55, P = 0.050 and HR = 1.95, 95% CI, 1.03-3.71, P = 0.041). Based on these findings, we conclude that MMP-7 is a promising marker to detect present and to predict future metastasis. Serum MMP-7 analysis provides information about the risk of metastasis before surgery which could help to optimize therapeutic procedures. Furthermore, high MMP-7 tissue and/or serum levels could identify patients most likely to benefit from early adjuvant chemotherapy.

A female soccer player with recurrent haemoptysis and iron deficiency anaemia: idiopathic pulmonary haemosiderosis (IPH)-case report and literature review.

A 19-year-old woman presented with repeated episodes of haemoptysis and shortness of breath. Blood tests revealed iron deficiency anaemia and chest imaging studies showed bilateral lung opacities. In further laboratory tests and technical examination including bronchoalveolar lavage and transbronchial lung biopsy, pulmonary embolism, cardiac disease, and pulmonary vasculitis due to autoimmune disease were ruled out. Finally, a diagnosis of idiopathic pulmonary haemosiderosis (IPH) was made in January 2008. The patient was treated with prednisone, azathioprine, and oral iron supplementation. Subsequently, the patient's condition and haemoglobin value improved notably. In May 2009, the patient was in full disease remission including a normal blood count and normal iron parameters. IPH is a rare cause of diffuse alveolar haemorrhage of unknown origin. It occurs most frequently in children and adolescents and typically presents with recurrent haemoptysis due to alveolar bleeding. However, pulmonary signs and symptoms often are obscure in children. In these cases iron deficiency anaemia is the prominent clinical finding. The purpose of this case report is to increase awareness of IPH as a possible cause of recurrent haemoptysis and anaemia.

Tartrate-resistant acid phosphatase 5b and C-terminal telopeptides of type I collagen as markers for diagnosis of aseptic loosening after total hip replacement.

INTRODUCTION: Plain radiography, bone scintigraphy, digital subtraction arthrography and various other techniques can be used to evaluate loosening of hip replacements. These methods are associated with radiation exposure and some of them have an increased morbidity. Furthermore, in some cases the results are not conclusive. METHOD: The osteoclast biomarkers tartrate-resistant acid phosphatase 5b (TRAP 5b) and C-terminal telopeptides of type I collagen (CTX) in serum taken from 12 patients with aseptic loosening were measured. Serum samples from 24 other patients, 12 with an intact arthroplasty and 12 without any kind of joint replacement, served as control groups. RESULTS: The serum level of CTX was increased in comparison to the control groups, but the differences were not significant. In contrast, the increase in TRAP 5b in patients with aseptic loosening was highly significant (P < 0.001). A TRAP 5b value of 3.365 U/L was determined as a cut-off value, giving a sensitivity of 83.3% and specificity of 91.7% to differentiate the patients with aseptic loosening from those with an intact arthroplasty. Measurement of serum TRAP 5b may be a clinically relevant assay for monitoring patients after arthroplasty.

ERCC1 expression in aseptic loosening after total hip replacement.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The purpose of the current study was to evaluate the DNA damage repair capacity of macrophages in patients with aseptic hip loosening by determination of ERCC1. Moreover, we wanted to elucidate if the potency of the DNA-repair mechanisms correlates with the survival of joint implants. For this purpose we compared the immunohistochemical ERCC1 expression in capsules and interface membranes of patients with loosening of a hip replacement in the first 10 years after implantation with those in patients with late loosening. In analogy with ERCC1 studies on cancer in humans we calculated the semi-quantitative H-score by multiplying the staining intensity with the proportion score of positive stained macrophages. The level of ERCC1 reaction in the specimens taken from patients with early aseptic loosening (mean H-score 0.57) was clearly lower in comparison with those from patients undergoing exchange hip arthroplasty later than 10 years after surgery (mean H-score 2.24). We determined an H-score for ERCC1 expression of 1 as a cutoff point giving a sensitivity and specificity of 100% for identification of early aseptic loosening after less than 10 years. In summary, lower levels of ERCC1 were found in patients with early aseptic loosening compared to patients with aseptic loosening later than 10 years.