Banff Histopathological Consensus Criteria for Preimplantation Kidney Biopsies.

The Banff working group on preimplantation biopsy was established to develop consensus criteria (best practice guidelines) for the interpretation of preimplantation kidney biopsies. Digitally scanned slides were used (i) to evaluate interobserver variability of histopathologic findings, comparing frozen sections with formalin-fixed, paraffin-embedded tissue of wedge and needle core biopsies, and (ii) to correlate consensus histopathologic findings with graft outcome in a cohort of biopsies from international medical centers. Intraclass correlations (ICCs) and univariable and multivariable statistical analyses were performed. Good to fair reproducibility was observed in semiquantitative scores for percentage of glomerulosclerosis, arterial intimal fibrosis and interstitial fibrosis on frozen wedge biopsies. Evaluation of frozen wedge and core biopsies was comparable for number of glomeruli, but needle biopsies showed worse ICCs for glomerulosclerosis, interstitial fibrosis and tubular atrophy. A consensus evaluation form is provided to help standardize the reporting of histopathologic lesions in donor biopsies. It should be recognized that histologic parameters may not correlate with graft outcome in studies based on organs deemed to be acceptable after careful clinical assessment. Significant limitations remain in the assessment of implantation biopsies.

The Banff 2015 Kidney Meeting Report: Current Challenges in Rejection Classification and Prospects for Adopting Molecular Pathology.

The XIII Banff meeting, held in conjunction the Canadian Society of Transplantation in Vancouver, Canada, reviewed the clinical impact of updates of C4d-negative antibody-mediated rejection (ABMR) from the 2013 meeting, reports from active Banff Working Groups, the relationships of donor-specific antibody tests (anti-HLA and non-HLA) with transplant histopathology, and questions of molecular transplant diagnostics. The use of transcriptome gene sets, their resultant diagnostic classifiers, or common key genes to supplement the diagnosis and classification of rejection requires further consensus agreement and validation in biopsies. Newly introduced concepts include the i-IFTA score, comprising inflammation within areas of fibrosis and atrophy and acceptance of transplant arteriolopathy within the descriptions of chronic active T cell-mediated rejection (TCMR) or chronic ABMR. The pattern of mixed TCMR and ABMR was increasingly recognized. This report also includes improved definitions of TCMR and ABMR in pancreas transplants with specification of vascular lesions and prospects for defining a vascularized composite allograft rejection classification. The goal of the Banff process is ongoing integration of advances in histologic, serologic, and molecular diagnostic techniques to produce a consensus-based reporting system that offers precise composite scores, accurate routine diagnostics, and applicability to next-generation clinical trials.

Banff 2013 meeting report: inclusion of c4d-negative antibody-mediated rejection and antibody-associated arterial lesions.

The 12th Banff Conference on Allograft Pathology was held in Comandatuba, Brazil, from August 19-23, 2013, and was preceded by a 2-day Latin American Symposium on Transplant Immunobiology and Immunopathology. The meeting was highlighted by the presentation of the findings of several working groups formed at the 2009 and 2011 Banff meetings to: (1) establish consensus criteria for diagnosing antibody-mediated rejection (ABMR) in the presence and absence of detectable C4d deposition; (2) develop consensus definitions and thresholds for glomerulitis (g score) and chronic glomerulopathy (cg score), associated with improved inter-observer agreement and correlation with clinical, molecular and serological data; (3) determine whether isolated lesions of intimal arteritis ("isolated v") represent acute rejection similar to intimal arteritis in the presence of tubulointerstitial inflammation; (4) compare different methodologies for evaluating interstitial fibrosis and for performing/evaluating implantation biopsies of renal allografts with regard to reproducibility and prediction of subsequent graft function; and (5) define clinically and prognostically significant morphologic criteria for subclassifying polyoma virus nephropathy. The key outcome of the 2013 conference is defining criteria for diagnosis of C4d-negative ABMR and respective modification of the Banff classification. In addition, three new Banff Working Groups were initiated.

Banff '09 meeting report: antibody mediated graft deterioration and implementation of Banff working groups.

The 10th Banff Conference on Allograft Pathology was held in Banff, Canada from August 9 to 14, 2009. A total of 263 transplant clinicians, pathologists, surgeons, immunologists and researchers discussed several aspects of solid organ transplants with a special focus on antibody mediated graft injury. The willingness of the Banff process to adapt continuously in response to new research and improve potential weaknesses, led to the implementation of six working groups on the following areas: isolated v-lesion, fibrosis scoring, glomerular lesions, molecular pathology, polyomavirus nephropathy and quality assurance. Banff working groups will conduct multicenter trials to evaluate the clinical relevance, practical feasibility and reproducibility of potential changes to the Banff classification. There were also sessions on quality improvement in biopsy reading and utilization of virtual microscopy for maintaining competence in transplant biopsy interpretation. In addition, compelling molecular research data led to the discussion of incorporation of omics-technologies and discovery of new tissue markers with the goal of combining histopathology and molecular parameters within the Banff working classification in the near future.

Focal C4d+ in renal allografts is associated with the presence of donor-specific antibodies and decreased allograft survival.

Diffuse peritubular capillary C4d deposition in renal allograft biopsies is associated with donor-specific antibodies (DSA) and graft failure. The significance of focal C4d+ is unclear. We reviewed 368 biopsies from 301 patients performed for renal dysfunction or proteinuria over 5 years. Diffuse C4d+, focal C4d+ and C4d- detected by immunofluorescence occurred in 9.5%, 20.9% and 69.4% of biopsies, respectively. Patients were similar in gender, age, cause of renal disease, donor source, HLA mismatch, serum creatinine at baseline and interval from transplantation to biopsy. Diffuse and focal C4d+ were associated with acute cellular rejection (p < 0.001). Transplant glomerulopathy was associated with diffuse C4d+. DSA at the time of biopsy, were positive in 79.3% of diffusely C4d+ patients, 68.8% of those with focal C4d+ (p = 0.27) and 9.9% of patients with C4d- (p < 0.001, compared to either the focal or diffuse groups, respectively). Allograft survival at 40 months was lower in diffuse C4d+ compared to the C4d- group (p = 0.014), but not when compared to the focal C4d+ group. There was a clear trend toward worse graft survival in patients with focal C4d+ in this time interval, but focal C4d+ compared to both diffuse C4d+ and C4d-groups was not statistically significant (p = 0.08).

NFATc1 promotes prostate tumorigenesis and overcomes PTEN loss-induced senescence.

Despite recent insights into prostate cancer (PCa)-associated genetic changes, full understanding of prostate tumorigenesis remains elusive owing to complexity of interactions among various cell types and soluble factors present in prostate tissue. We found the upregulation of nuclear factor of activated T cells c1 (NFATc1) in human PCa and cultured PCa cells, but not in normal prostates and non-tumorigenic prostate cells. To understand the role of NFATc1 in prostate tumorigenesis in situ, we temporally and spatially controlled the activation of NFATc1 in mouse prostate and showed that such activation resulted in prostatic adenocarcinoma with features similar to those seen in human PCa. Our results indicate that the activation of a single transcription factor, NFATc1 in prostatic luminal epithelium to PCa can affect expression of diverse factors in both cells harboring the genetic changes and in neighboring cells through microenvironmental alterations. In addition to the activation of oncogenes c-MYC and STAT3 in tumor cells, a number of cytokines and growth factors, such as IL1ß, IL6 and SPP1 (osteopontin, a key biomarker for PCa), were upregulated in NFATc1-induced PCa, establishing a tumorigenic microenvironment involving both NFATc1 positive and negative cells for prostate tumorigenesis. To further characterize interactions between genes involved in prostate tumorigenesis, we generated mice with both NFATc1 activation and Pten inactivation in prostate. We showed that NFATc1 activation led to acceleration of Pten null-driven prostate tumorigenesis by overcoming the PTEN loss-induced cellular senescence through inhibition of p21 activation. This study provides direct in vivo evidence of an oncogenic role of NFATc1 in prostate tumorigenesis and reveals multiple functions of NFATc1 in activating oncogenes, in inducing proinflammatory cytokines, in oncogene addiction, and in overcoming cellular senescence, which suggests calcineurin-NFAT signaling as a potential target in preventing PCa.

Cyclooxygenase-2 is overexpressed in human cervical cancer.

Multiple lines of evidence suggest that cyclooxygenase-2 (COX-2) is an important target for preventing epithelial malignancies. Little is known, however, about the expression of COX-2 in gynecological malignancies. By immunoblot analysis, COX-2 was detected in 12 of 13 cases of cervical cancer but was undetectable in normal cervical tissue. Immunohistochemistry revealed COX-2 in malignant epithelial cells. COX-2 was also expressed in cervical intraepithelial neoplasia. The mechanism by which COX-2 is up-regulated in cervical cancer is unknown. Because the epidermal growth factor (EGF) receptor is commonly overexpressed in cervical cancer, we investigated whether EGF could induce COX-2 in cultured human cervical carcinoma cells. Treatment with EGF markedly induced COX-2 protein, COX-2 mRNA, and stimulated COX-2 promoter activity. The induction of COX-2 by EGF was suppressed by inhibitors of tyrosine kinase activity, phosphatidylinositol 3-kinase, mitogen-activated protein kinase kinase, and p38 mitogen-activated protein kinase. Moreover, overexpressing dominant-negative forms of extracellular signal-regulated kinase 1, c-Jun NH2-terminal kinase, p38, and c-Jun blocked EGF-mediated induction of COX-2 promoter activity. Taken together, these findings suggest that deregulation of the EGF receptor signaling pathway may lead to enhanced COX-2 expression in cervical cancer.

Primitive neuroectodermal tumor of the kidney--another enigma: a pathologic, immunohistochemical, and molecular diagnostic study.

Primitive neuroectodermal tumor (PNET), the second most common type of sarcoma in the first two decades of life, rarely presents as an organ-based neoplasm. Rather, it is seen typically in the soft tissues of the chest wall and paraspinal region. We report a case of primary PNET of the kidney in a 17-year-old girl who presented with abdominal pain, hematuria, and an abdominal mass. Nodules and sheets of monotonous-appearing primitive round cells and the formation of rosettes focally were the principal microscopic features. The tumor cells were uniformly immunoreactive for vimentin, cytokeratin, neuron-specific enolase, and 013 (CD99). In addition, the characteristic translocation of PNET and Ewing sarcoma, t(11;22)(q24;q12), was detected by polymerase chain reaction (PCR). Eight previous examples of renal PNET have been reported in the literature in the past 2 years, but only three of these cases have had complete immunohistochemical evaluation with the demonstration of 013 positivity. To our knowledge the present case is the only one to date demonstrating the recurrent translocation t(11;22)(q24;q12) by PCR. Assuming that the previous cases in the literature are bona fide examples of PNET, the kidney may be another site of predilection for this usual soft-tissue neoplasm. We are once again confronted with the dilemma about the nature of the progenitor cell.

Detection of integrins in formalin-fixed, paraffin-embedded tissues.

Integrins are heterodimeric transmembrane receptors, which are expressed in many cells. In vitro experiments have demonstrated that integrins may be important in tumor progression and organ development. The functions of integrins were previously studied in cell cultures and their tissue expression was detected by immunofluorescence or immunoperoxidase in frozen sections. The purpose of this study was to determine the optimal conditions for detection of integrins in formalin-fixed, paraffin-embedded tissues. We utilized microwave heating and enzyme digestion in routinely processed, surgically removed tissues. Our results demonstrate that integrins can be reliably detected in archival material. This approach will facilitate further investigation of the role played by integrins in human malignancies and in developmental processes.

Nodular glomerulosclerosis secondary to mu heavy chain deposits.

mu heavy chain deposition disease is very rare. We report the first case of glomerulonephritis in a woman without evidence of hematopoietic malignancy. Nodular glomerulosclerosis and monotypic mu heavy chain mesangial deposits were identified by immunofluorescence without kappa or lambda deposits. Electron microscopy showed fibrillar mesangial deposits of 16-18 nm in diameter. Serum immunoglobulins, cryoglobulins, serum immunoelectrophoresis, and immunofixation, bone marrow biopsy, and Bence Jones proteins in urine were negative. The patient has stable renal disease and is free of malignancy 6 years after the initial occurrence of proteinuria.

Osteopontin expression in ovarian carcinomas and tumors of low malignant potential (LMP).

Expression of osteopontin (OPN) by ovarian tumors is not known. Neoplasms arising from the ovarian epithelium are distinguished in adenocarcinomas and borderline tumors (LMPs), which overall have a favorable prognosis even with omental implants. Tissues from primary ovarian tumors and their metastases from 30 patients (16 LMPs and 14 adenocarcinomas) were evaluated for OPN expression by immunohistochemistry, Western blotting, and in situ hybridization. OPN was weak or absent in 93% of ovarian adenocarcinomas or their metastases. In contrast, 81.5% of the LMPs and 50% of omental and lymph node implants were OPN positive (P < .028). Histological type, grade, or clinical stage did not correlate with OPN expression. Expression of OPN primarily by ovarian neoplasms with favorable prognosis is an intriguing new finding of potential importance in the pathogenesis of ovarian LMPs.

In situ localization of parathyroid hormone-like protein and mRNA in intraepithelial neoplasia and invasive carcinoma of the uterine cervix.

Parathyroid-like protein (PLP), or parathyroid hormone-related peptide, is a well-recognized mediator of paraneoplastic hypercalcemia (humoral hypercalcemia of malignancy syndrome). In this study we examined the expression of PLP by 40 invasive squamous cell carcinomas (SCCs) of the cervix and selected carcinomas of nonsquamous histology. Using a polyclonal antibody to human PLP, 93% of SCCs, including two tumors from patients with humoral hypercalcemia of malignancy syndrome, showed moderate to strong cytoplasmic immunoperoxidase staining for PLP. The strongest staining often was observed in areas of invasion associated with stromal desmoplasia. The small number of weak or negatively stained SCCs were all poorly differentiated tumors. Although native uninvolved squamous epithelium showed weak to moderate staining of the superficial layers, there was variable or full-thickness immunostaining in areas of dysplasia. Normal endocervical glands and stroma as well as cervical adenocarcinomas and neuroendocrine carcinomas were negative. In situ hybridization studies showed abundant PLP mRNA within SCC in patients with hypercalcemia. However, PLP mRNA was of relatively low abundance in tumors of normocalcemic patients. Ultrastructural studies showed cytoplasmic, membrane-bound, granular inclusions in tumor cells from the hypercalcemic patients. Our data suggest that increased PLP gene transcription contributes to the increased production of PLP and the pathogenesis of humoral hypercalcemia of malignancy syndrome.

Expression of alpha(v)beta3 integrin is less frequent in ovarian epithelial tumors of low malignant potential in contrast to ovarian carcinomas.

Ovarian tumors of low malignant potential (LMPs) histologically lack invasion and have excellent prognosis in contrast to invasive carcinomas. Integrins are heterodimeric adhesion molecules thought to play a role in cell migration and tumor progression. The alpha(v)beta3 integrin in particular mediates melanoma invasion in vitro and promotes neoplastic angiogenesis, facilitating breast cancer metastasis. In addition, alpha(v)beta3 expression has been detected in ovarian cancer cell lines and in a limited number of human ovarian cancer samples. The distribution pattern of this integrin in LMPs is not known. We examined tissue sections from 19 LMPs and 31 ovarian carcinomas for alpha(v)beta3, in addition to alpha5beta1 and alpha2beta1 integrins, which have been shown to be expressed in ovarian cancer cell lines. Variable immunoreactivities of alpha5beta1 and alpha2beta1 were detected in both LMPs and ovarian carcinomas. Most (74.2%) ovarian carcinomas were alpha(v)beta3 positive, whereas only 36.8% of LMPs were positive, which is statistically significant (P = .009). These results establish the distribution pattern of alpha2beta1, alpha5beta1, and alpha(v)beta3 integrins in LMPs. The biological significance of the less frequent expression of alpha(v)beta3 in LMPs compared with carcinomas of the ovary needs further elucidation.

Matrix metalloproteinase-1 and -3 in breast cancer: correlation with progesterone receptors and other clinicopathologic features.

Although matrix metalloproteinases (MMPs) are implicated in breast cancer progression, the contribution of MMP-1 and MMP-3 to this process, has not been thoroughly investigated. Matrix metalloproteinases (MMPs) are important at several points during multistage neoplastic progression. Immunohistochemistry (Strept-ABC-HRP method) and in situ hybridization were performed to detect MMP-1, MMM-3 proteins, and MMP-3 mRNA, respectively, in 77 infiltrative breast carcinomas. MMP-1, MMP-3 protein, and MMP-3 mRNA detection were analyzed in parallel with clinicopathologic features (menopausal status, histological type, nuclear and histological grade, stage) and the immunohistochemical reactivity of estrogen (ER), progesterone (PR) receptors, and c-erbB-2 oncoprotein in breast carcinomas. Statistical analysis was performed using the multiple linear regression test. Immunoreactivity for MMP-1 and MMP-3 was observed in 59 of 77 (77%) and 22 of 77 (28.5%) breast carcinomas and was evaluated separately in cancer cells and in stromal fibroblasts. MMP-3 mRNA was detected in 72 of 77 (93.5%) carcinomas exclusively in stromal cells within the tumors or in the marginal portion of tumors. MMP-1 protein immunoreactivity in stromal fibroblasts but not in cancer cells showed a statistically significant correlation with tumor stage (P=.04). MMP-1 reactivity either in stromal or in cancer cells showed a statistically significant inverse correlation with PR expression (P=.04 and P=.04, respectively). MMP-3 protein immunoreactivity in cancer or stromal cells and MMP-3 mRNA expression was not associated with the clinicopathologic features studied. MMP-3 mRNA was detected more often in ductal carcinomas. These results indicate that MMP-1 may contribute to breast cancer invasiveness. Furthermore, they suggest differential functions for MMP-1 and MMP-3 in breast cancer progression.

Molecular analysis of malignant triton tumors.

Triton tumors are rare variants of malignant peripheral nerve sheath tumor (MPNST) with muscle differentiation, often seen in patients with neurofibromatosis 1 (NF1). Individuals affected with NF1 harbor mutations in the NF1 tumor suppressor gene and develop neurofibromas and MPNSTs. The NF1 gene is expressed in Schwann cells and its expression is lost in schwannian neoplasms, suggesting a role in malignant development. Separately, there is evidence that p53 suppressor gene mutations are involved in MPNSTs. To determine the role of the NF1 and p53 genes in the development of the malignant Triton tumor we examined 2 such tumors, 1 from a 3-year-old boy without clinical manifestations of NF1 and another from a 24-year-old man with NF1. Histological analysis of these tumors showed both neural and muscle differentiation with S-100 and desmin immunoreactivity, respectively. Reverse transcribed RNA polymerase chain reaction (RT-PCR) of NF1 mRNA showed NF1 expression in the sporadic tumor. Strong nuclear immunoreactivity for p53 was observed throughout the malignant population in both tumors. This was confirmed by loss of heterozygosity for p53 in the non-NF1 patient, suggesting that p53 is involved in both hereditary and sporadic Triton tumors. The finding of preserved NF1 gene expression in the non-NF1-related Triton tumor suggests that different genetic events predispose to the development of this rare neoplasm in sporadic cases.

Myocardial extramedullary hematopoiesis following myocardial infarction.

Extramedullary hematopoiesis (EMH) usually accompanies a chronic hematologic disease in adults or prematurity in neonates. We observed a striking case of EMH in the explanted heart of a 13-year-old boy who underwent transplantation after extensive myocardial infarction. The florid myeloid proliferation raised the possibility of a leukemic process. To our knowledge, extensive myocardial EMH subsequent to myocardial infarction has not been previously reported. Possible mechanisms underlying EMH in the myocardium are presented.

North American opossum Didelphis virginiana as a fetal nephrotoxicity model: histologic and ultrastructural assessment of uranyl nitrate (UN)-induced damage.

We have used our opossum model of fetal nephrotoxicity to investigate uranyl nitrate-induced morphologic changes in the developing kidney. The present study establishes a renal dose response curve for the uranyl nitrate (UN). We find that pups treated with nonlethal doses of UN do not demonstrate growth retardation compared to saline-treated controls. The kidneys of UN-treated pups are heavier than the control animals, an effect less apparent the longer the pups are followed. A low dose of 60 mg/kg of UN administered to small pups causes slight histologic derangement but nevertheless more change than the same dose administered to larger more mature pups. Using a dose of 100 mg/kg of UN that effectively causes nonfatal renal disruption, we examined the kidneys from 4 to 42 days following injection. We find that tubular dilation and epithelial necrosis starts soon after treatment (day 4) and reaches its maximum during the second and third week (11 and 22 days). Architectural restoration appears complete by the end of the third week. By electron microscopy, UN induces sequential structural damage with loss of proximal tubule brush border, epithelial necrosis with intact basement membranes and regeneration at 4, 11, and 22 days. Residual tubular mitochondrial damage is present at 42 days in spite of histologically normal tubules. No apparent lesions are seen in glomeruli. Fibroblastic interstitial proliferation in UN-treated kidneys at 11 days is not followed by appreciable fibrosis when assessed at 22 and 42 days. As the structural changes caused by 100 mg/ml UN administration in fetal opossum kidneys are reversible, this is a useful model to study the molecular mediators responsible for this form of renal damage and repair.

Recurrent ovarian tumor with low malignant potential and cardiac metastasis.

BACKGROUND: Up to 20% of ovarian epithelial tumors are classified as being of low malignant potential. Most of these low malignant potential tumors are detected at an early stage and have an excellent prognosis. This is a report of a woman with cardiac metastasis from an ovarian low malignant potential tumor. CASE: This case describes a 53-year-old woman who presented with congestive heart failure and was found to have a recurrent stage III ovarian tumor of low malignant potential. A transesophageal echocardiogram revealed compression of the inferior vena cava and a mass encompassing the right atrium. Findings at autopsy confirmed a low malignant potential ovarian tumor thrombus involving the inferior vena cava and right atrium. CONCLUSION: Ovarian low malignant potential tumors can metastasize in an aggressive manner. A transesophageal echocardiogram may be useful when the diagnosis of cardiac tumor thrombus is considered.

Integrin alpha V beta 3 expression by bone-residing breast cancer metastases.

Breast cancer metastasis to bone is a multistep process requiring attachment of tumor cells to the bone and bone marrow environment. The precise adhesion molecules involved in skeletal homing of breast cancer to bone are unknown but likely include integrins. We investigated the expression of vitronectin receptor (alpha V beta 3) by breast cancer cells residing in bone because this heterodimer mediates osteoclast-bone recognition. We used immunohistochemistry and in situ hybridization in a systematic study of 22 bone biopsies containing breast cancer metastases and available samples of corresponding primary tumors and normal breast and compared alpha V beta 3, alpha 2 beta 1, and alpha B beta 5 integrin expression. The results showed that alpha V beta 3 was strongly expressed by normal breast epithelium and was decreased in some and strongly expressed in other primary invasive breast carcinomas. In contrast, this integrin heterodimer was abundant in all breast cancer cells metastatic to bone. In situ hybridization revealed high levels of steady-state mRNA corresponding to sites of protein expression; alpha 2 beta 1 was weakly expressed in both primary and metastatic tumors, and alpha V beta 5 was not detected. Our results showed an overexpression of alpha V beta 3 by bone-residing breast cancer cells and suggest either subclonal selection of alpha V beta 3-expressing tumor cell populations or upregulation of alpha V beta 3 in the bone microenvironment.

MMP-3 mRNA and MMP-3 and MMP-1 proteins in bladder cancer: a comparison with clinicopathologic features and survival.

Matrix metalloproteinases (MMPs) are proteolytic enzymes important at several points during multistep neoplastic progression. Although MMP-1 and MMP-3 have been implicated in the progression of various human cancers, their expression in bladder cancer has not been addressed. Immunohistochemistry (Strept-ABC-HRP method) and in situ hybridization were performed to detect MMP-1 protein, MMP-3 protein, and MMP-3 mRNA, respectively, in 59 transitional cell bladder carcinomas. To assess the role of these MMPs in bladder cancer, their expression was evaluated in relation to known clinicopathologic parameters and patients' disease-free and overall survival. Immunoreactivity for MMP-1 and MMP-3 proteins was observed in the cytoplasm of cancer cells in 30.5% and 24% of samples, respectively. Transcripts for MMP-3 mRNA were localized in stromal cells in 71.2% of cases and in cancer cells in 49% of cases. MMP-1 immunoreactivity demonstrated a statistically significant association with deeply invasive and grade III tumors versus superficial and lower grade tumors. MMP-3 protein immunoreactivity and MMP-3 mRNA immunolocalization did not associate with the parameters studied. However, MMP-3 mRNA localization in stromal cells demonstrated a borderline association with poor patients' disease-free and overall survival. In conclusion, the authors' results demonstrate a differential expression between MMP-1 and MMP-3 in bladder cancer; MMP-1 appears to participate in invasiveness and possibly in loss of differentiation in urothelial carcinomas in contrast to MMP-3.