Fertility-preserving myeloablative conditioning using single-dose CD117 antibody-drug conjugate in a rhesus gene therapy model.

Hematopoietic stem cell (HSC) gene therapy has curative potential; however, its use is limited by the morbidity and mortality associated with current chemotherapy-based conditioning. Targeted conditioning using antibody-drug conjugates (ADC) holds promise for reduced toxicity in HSC gene therapy. Here we test the ability of an antibody-drug conjugate targeting CD117 (CD117-ADC) to enable engraftment in a non-human primate lentiviral gene therapy model of hemoglobinopathies. Following single-dose CD117-ADC, a >99% depletion of bone marrow CD34 + CD90 + CD45RA- cells without lymphocyte reduction is observed, which results are not inferior to multi-day myeloablative busulfan conditioning. CD117-ADC, similarly to busulfan, allows efficient engraftment, gene marking, and vector-derived fetal hemoglobin induction. Importantly, ADC treatment is associated with minimal toxicity, and CD117-ADC-conditioned animals maintain fertility. In contrast, busulfan treatment commonly causes severe toxicities and infertility in humans. Thus, the myeloablative capacity of single-dose CD117-ADC is sufficient for efficient engraftment of gene-modified HSCs while preserving fertility and reducing adverse effects related to toxicity in non-human primates. This targeted conditioning approach thus provides the proof-of-principle to improve risk-benefit ratio in a variety of HSC-based gene therapy products in humans.

Integration of CD34+CD117dim population signature improves the prognosis prediction of acute myeloid leukemia.

BACKGROUND: Acute Myeloid Leukemia (AML) is a hematological cancer characterized by heterogeneous hematopoietic cells. Through the use of multidimensional sequencing technologies, we previously identified a distinct myeloblast population, CD34+CD117dim, the proportion of which was strongly associated with the clinical outcome in t (8;21) AML. In this study, we explored the potential value of the CD34+CD117dim population signature (117DPS) in AML stratification. METHODS: Based on the CD34+CD117dim gene signature, the least absolute shrinkage and selection operator (LASSO) Cox regression analysis was performed to construct the 117DPS model using the gene expression data from Gene Expression Omnibus (GEO) database (GSE37642-GPL96 was used as training cohort; GSE37642-GPL570, GSE12417-GPL96, GSE12417-GPL570 and GSE106291 were used as validation cohorts). In addition, the RNA-seq data from The Cancer Genome Atlas (TCGA)-LAML and Beat AML projects of de-novo AML patients were also analyzed as validation cohorts. The differences of clinical features and tumor-infiltrating lymphocytes were further explored between the high-risk score group and low-risk score group. RESULTS: The high-risk group of the 117DPS model exhibited worse overall survival than the low-risk group in both training and validation cohorts. Immune signaling pathways were significantly activated in the high-risk group. Patients with high-risk score had a distinct pattern of infiltrating immune cells, which were closely related to clinical outcome. CONCLUSION: The 117DPS model established in our study may serve as a potentially valuable tool for predicting clinical outcome of patients with AML.

Tissue-Specific Molecular Markers and Heterogeneity in Type 2 Innate Lymphoid Cells.

Innate lymphoid cells (ILCs) are the most recently described group of lymphoid subpopulations. These tissue-resident cells display a heterogeneity resembling that observed on different groups of T cells, hence their categorization as cytotoxic NK cells and helper ILCs type 1, 2 and 3. Each one of these groups is highly diverse and expresses different markers in a context-dependent manner. Type 2 innate lymphoid cells (ILC2s) are activated in response to helminth parasites and regulate the immune response. They are involved in the etiology of diseases associated with allergic responses as well as in the maintenance of tissue homeostasis. Markers associated with their identification differ depending on the tissue and model used, making the study and understanding of these cells a cumbersome task. This review compiles evidence for the heterogeneity of ILC2s as well as discussion and analyses of molecular markers associated with their identity, function, tissue-dependent expression, and how these markers contribute to the interaction of ILC2s with specific microenvironments to maintain homeostasis or respond to pathogenic challenges.

Hypersensitivity response has negligible impact on Hematopoietic Stem Cells.

Immune cells are generated from hematopoietic stem cells (HSCs) in the bone marrow (BM). Immune stimulation can rapidly activate HSCs out of their quiescent state to accelerate the generation of immune cells. HSCs' activation follows various viral or bacterial stimuli, and we sought to investigate the hypersensitivity immune response. Surprisingly, the Ova-induced hypersensitivity peritonitis model finds no significant changes in BM HSCs. HSC markers cKIT, SCA1, CD48, CD150, and the Fgd5-mCherry reporter showed no significant difference from control. Functionally, hypersensitivity did not alter HSCs' potency, as assayed by transplantation. We further characterized the possible impact of hypersensitivity using RNA-sequencing of HSCs, finding minor changes at the transcriptome level. Moreover, hypersensitivity induced no significant change in the proliferative state of HSCs. Therefore, this study suggests that, in contrast to other immune stimuli, hypersensitivity has no impact on HSCs.

Oncogenic KIT Modulates Type I IFN-Mediated Antitumor Immunity in GIST.

Type I IFNs are implicated in tumor immunogenicity and response to systemic therapy, but their interaction with oncogene signaling is not well understood. Here, we studied oncogenic KIT, which drives gastrointestinal stromal tumor (GIST), the most common sarcoma. Using mouse models of GIST, we found that KIT inhibition reduced type I IFN production and signaling, which downregulated tumor MHC class I expression. Absence of type I IFN signaling increased tumor size, in part due to CD8+ T-cell impairment. Oncogenic KIT was required for GIST type I IFN signal transduction via STAT1. In human GIST cell lines and surgical specimens, type I IFN signaling contributed to human lymphocyte antigen class I expression and correlated with tumor immunogenicity. Augmenting the type I IFN response partially compensated for the immunosuppressive effects of KIT inhibition. Thus, KIT signaling contributes to type I IFN signaling, whereas KIT inhibition attenuates tumor immunogenicity and is partly rescued by innate immune stimulation.See related Spotlight on p. 489.

Routine KIT p.D816V screening identifies clonal mast cell disease in patients with Hymenoptera allergy regularly missed using baseline tryptase levels alone.

BACKGROUND: Clonal mast cell disorders and elevated basal serum tryptase (BST) levels with unknown cause(s) are associated with severe Hymenoptera venom-triggered anaphylaxis (HVA). However, some individuals with clonal disease have a normal BST level (<11.4 ng/mL). OBJECTIVE: Our aim was to evaluate whether screening for KIT p.D816V in the blood is a useful clinical tool to risk-stratify patients with venom allergy. METHODS: We prospectively recruited 374 patients with Hymenoptera allergy and no overt signs of mastocytosis who were referred to our center during the years 2018 and 2019. KIT p.D816V was determined in their peripheral blood by quantitative PCR, and tryptase genotyping was performed by droplet digital PCR. RESULTS: In all, 351 patients (93.9%) had normal levels of BST, and KIT p.D816V was detected in 8% of patients (28 of 351), predominantly in patients with the most severe Mueller grade IV anaphylaxis (18.2% [24 of 132] vs 1.8% in patients with lower grades [4 of 88 with grade III and 0 of 131 with other grades]; P < .001). In grade IV patients with a normal BST level, KIT p.D816V was associated with more severe symptoms, including a significantly higher frequency of loss of consciousness (58.3% [14 of 24] vs 34.3% [37 of 108]; P = .03) and absence of skin symptoms (41.7% [10 of 24] vs 15.7% [17 of 108]; P = .004). Among patients with a normal BST level, KIT p.D816V (OR = 10.25 [95% CI = 3.75-36.14]; P < .0001) was the major risk factor associated with severe HVA. Hereditary α-tryptasemia (HαT) due to increased germline copies of TPSAB1 encoding α-tryptase was the most common cause (65.2% [15 of 23]) of elevated BST level in patients with HVA, and together with KIT p.D816V, it accounted for 90% of BST level elevations (20 of 23) in patients with HVA. CONCLUSION: These results indicate that routine KIT p.D816V screening identifies clonal disease in high-risk patients with HVA who are regularly missed when BST level is used alone.

Activated M1 macrophages suppress c-kit expression via TNF-α-mediated upregulation of miR-222 in Neonatal Necrotizing Enterocolitis.

BACKGROUND: Activation of intestinal macrophages is implicated in the pathogenesis of neonatal necrotizing enterocolitis (NEC), yet its precise mechanisms remain unclear. OBJECTIVE: The purpose of this study is to investigate the role of macrophages and TNF-α via an inflammatory MicroRNA in NEC. MATERIALS AND METHODS: Immunofluorescence (IF) staining of CD68, iNOS, and Arg-1 was employed to identify phenotypes of macrophage in the intestines of NEC infants and NEC mice. Expression of TNF-α, c-kit, and miR-222 was evaluated by qRT-PCR, Western blot, and immunochemical staining from the tissue samples. RESULTS: Large number of M1 macrophage infiltration was found in the NEC intestines. Expression of CD68, iNOS, and TNF-α were significantly increased, while c-kit was decreased distinctly in the NEC group. In the early phase of NEC mouse model, inhibition of M1 macrophages reduced the incidence of NEC and intestinal inflammation. We found that TNF-α upregulated the expression of miRNA-222 and inhibited the expression of c-kit. Conversely, such decrease of c-kit expression could be reversed by miR-222 antagonists. Furtherly, dual-luciferase assay confirmed that c-kit can be inhibited by miR-222 directly. CONCLUSION: Macrophages activation in NEC intestine results in an increased inflammatory response and TNF-α production, accompanied with miR-222 upregulation and c-kit suppression. Modulations of M1 macrophages, TNF-α or miR-222 may be potential therapeutic targets for NEC treatment.

CD117/c-kit defines a prostate CSC-like subpopulation driving progression and TKI resistance.

Cancer stem-like cells (CSCs) are associated with cancer progression, metastasis, and recurrence, and may also represent a subset of circulating tumor cells (CTCs). In our prior study, CTCs in advanced prostate cancer patients were found to express CD117/c-kit in a liquid biopsy. Whether CD117 expression played an active or passive role in the aggressiveness and migration of these CTCs remained an open question. In this study, we show that CD117 expression in prostate cancer patients is associated with decreased overall and progression-free survival and that activation and phosphorylation of CD117 increases in prostate cancer patients with higher Gleason grades. To determine how CD117 expression and activation by its ligand stem cell factor (SCF, kit ligand, steel factor) alter prostate cancer aggressiveness, we used C4-2 and PC3-mm human prostate cancer cells, which contain a CD117+ subpopulation. We demonstrate that CD117+ cells display increased proliferation and migration. In prostaspheres, CD117 expression enhances sphere formation. In both 2D and 3D cultures, stemness marker gene expression is higher in CD117+ cells. Using xenograft limiting dilution assays and serial tumor initiation assays, we show that CD117+ cells represent a CSC population. Combined, these data indicate that CD117 expression potentially promotes tumor initiation and metastasis. Further, in cell lines, CD117 activation by SCF promotes faster proliferation and invasiveness, while blocking CD117 activation with tyrosine kinase inhibitors (TKIs) decreased progression in a context-dependent manner. We demonstrate that CD117 expression and activation drives prostate cancer aggressiveness through the CSC phenotype and TKI resistance.

A new monoclonal antibody that blocks dimerisation and inhibits c-kit mutation-driven tumour growth.

PURPOSE: Imatinib, a small-molecule tyrosine kinase inhibitor, has shown good clinical activity by inhibiting adenosine triphosphate (ATP) binding to the receptor. Unfortunately, majority of patients eventually develop drug resistance, which limits the long-term benefits of the tyrosine kinase inhibitors and poses a significant challenge in the clinical management of GIST. The aim of our study was to explore the feasibility of blocking KIT dimerisation upstream of the phosphorylation in imatinib-resistant GIST. METHOD: KITMAb was prepared using hybridoma technique. The biological function of KITMAb was examined in KIT-dimer-expressing cells constructed by transfecting with liposomes using enzyme linked immunosorbent assay (ELISA), immunohistochemistry, western blot, MTT, Annexin V/FITC, and flow cytometry assay, respectively. RESULTS: KIT-dimer was expressed in 293 cells transfected with c-kit mutated-type pcDNA3.1. Treatment of KIT-dimer-expressing cells with the KITMAb significantly decreased the expression of both KIT-dimer and other phosphorylated proteins of KIT downstream signalling pathway. Furthermore, KITMAb slowed down cell growth and reduced the proportion of cells in the proliferative phase (S + G2-M). Finally, we also found that KITMAb treatment accelerated cell apoptosis. These results indicate that KITMAb strongly inhibits KIT receptor dimerisation-mediated signalling pathway and cell growth responses in vitro. CONCLUSIONS: We demonstrate c-kit mutation-driven KIT auto-dimerisation prior to tyrosine kinase phosphorylation as same as the procedure in ligand-dependent signalling pathway and describe a monoclonal antibody, KITMAb, with strong affinity to the dimerisation domain of KIT that blocks the important step in both the KIT signalling pathways. Further, the results suggest that treatment with KITMAb may be potentially therapeutic in imatinib-resistant GIST.

Anti-CD117 immunotherapy to eliminate hematopoietic and leukemia stem cells.

Precise replacement of diseased or dysfunctional organs is the goal of regenerative medicine and has appeared to be a distant goal for a long time. In the field of hematopoietic stem cell transplantation, this goal is now becoming tangible as gene-editing technologies and novel conditioning agents are entering the clinical arena. Targeted immunologic depletion of hematopoietic stem cells (HSCs), which are at the very root of the hematopoietic system, will enable more selective and potentially more effective hematopoietic stem cell transplantation in patients with hematological diseases. In contrast to current conditioning regimes based on ionizing radiation and chemotherapy, immunologic conditioning will spare mature hematopoietic cells and cause substantially less inflammation and unspecific collateral damage to other organs. Biological agents that target the stem cell antigen CD117 are the frontrunners for this purpose and have exhibited preclinical activity in depletion of healthy HSCs. The value of anti-CD117 antibodies as conditioning agents is currently being evaluated in early clinical trials. Whereas mild, antibody-based immunologic conditioning concepts might be appropriate for benign hematological disorders in which incomplete replacement of diseased cells is sufficient, higher efficacy will be required for treatment and elimination of hematologic stem cell malignancies such as acute myeloid leukemia and myelodysplastic syndrome. Antibody-drug conjugates, bispecific T-cell engaging and activating antibodies (TEAs), or chimeric antigen receptor (CAR) T cells might offer increased efficacy compared with naked antibodies and yet higher tolerability and safety compared with current genotoxic conditioning approaches. Here, we summarize the current state regarding immunologic conditioning concepts for the treatment of HSC disorders and outline potential future developments.

CD33 Delineates Two Functionally Distinct NK Cell Populations Divergent in Cytokine Production and Antibody-Mediated Cellular Cytotoxicity.

The generation and expansion of functionally competent NK cells in vitro is of great interest for their application in immunotherapy of cancer. Since CD33 constitutes a promising target for immunotherapy of myeloid malignancies, NK cells expressing a CD33-specific chimeric antigen receptor (CAR) were generated. Unexpectedly, we noted that CD33-CAR NK cells could not be efficiently expanded in vitro due to a fratricide-like process in which CD33-CAR NK cells killed other CD33-CAR NK cells that had upregulated CD33 in culture. This upregulation was dependent on the stimulation protocol and encompassed up to 50% of NK cells including CD56dim NK cells that do generally not express CD33 in vivo. RNAseq analysis revealed that upregulation of CD33+ NK cells was accompanied by a unique transcriptional signature combining features of canonical CD56bright (CD117high, CD16low) and CD56dim NK cells (high expression of granzyme B and perforin). CD33+ NK cells exhibited significantly higher mobilization of cytotoxic granula and comparable levels of cytotoxicity against different leukemic target cells compared to the CD33- subset. Moreover, CD33+ NK cells showed superior production of IFNγ and TNFα, whereas CD33- NK cells exerted increased antibody-dependent cellular cytotoxicity (ADCC). In summary, the study delineates a novel functional divergence between NK cell subsets upon in vitro stimulation that is marked by CD33 expression. By choosing suitable stimulation protocols, it is possible to preferentially generate CD33+ NK cells combining efficient target cell killing and cytokine production, or alternatively CD33- NK cells, which produce less cytokines but are more efficient in antibody-dependent applications.

Evaluation of Mast Cell Density using CD117 antibody and Microvessel Density Using CD34 Antibody in Different Grades of Oral Squamous Cell Carcinoma.

OBJECTIVE: To compare mast cell and microvessel densities among histologic grades of oral squamous cell carcinoma. SETTING: Armed Forces Institute of Pathology. MATERIALS AND METHODS: A total of 60 specimens of OSCC comprising 20 each of well, moderately and poorly differentiated were evaluated. Immunohistochemical analysis was performed to measure MCD and MVD by applying monoclonal CD117 antibody and monoclonal CD34 antibody, on formalin fixed and paraffin embedded sections. ANOVA and Post Hoc Tukey test was employed to assess the densities and to compare the differences between different grades of OSCC. A p-value.

Effect of Tussilago farfara L. Polysaccharides on the Content of Hematopoietic Stem Cells (CD117+34+) in the Bone Marrow of Mice Treated with Cyclophosphamide.

Myelotoxicity is a serious side effect of anticancer drugs. The search for drugs that can reduce the hematological complications of chemotherapy through modulation of hematopoietic stem cells is an urgent task of oncopharmacology. In the present study we showed that administration of Tussilago farfara L. polysaccharides to C57BL/6 mice treated with cyclophosphamide can increase the number of hematopoietic stem cells (CD117+34+) in the bone marrow.

Mast Cells in Alveolar Septa of COVID-19 Patients: A Pathogenic Pathway That May Link Interstitial Edema to Immunothrombosis.

It is currently believed that innate immunity is unable to prevent the spread of SARS-CoV-2 from the upper airways to the alveoli of high-risk groups of patients. SARS-CoV-2 replication in ACE-2-expressing pneumocytes can drive the diffuse alveolar injury through the cytokine storm and immunothrombosis by upregulating the transcription of chemokine/cytokines, unlike several other respiratory viruses. Here we report histopathology data obtained in post-mortem lung biopsies of COVID-19, showing the increased density of perivascular and septal mast cells (MCs) and IL-4-expressing cells (n = 6), in contrast to the numbers found in pandemic H1N1-induced pneumonia (n = 10) or Control specimens (n = 10). Noteworthy, COVID-19 lung biopsies showed a higher density of CD117+ cells, suggesting that c-kit positive MCs progenitors were recruited earlier to the alveolar septa. These findings suggest that MC proliferation/differentiation in the alveolar septa might be harnessed by the shift toward IL-4 expression in the inflamed alveolar septa. Future studies may clarify whether the fibrin-dependent generation of the hyaline membrane, processes that require the diffusion of procoagulative plasma factors into the alveolar lumen and the endothelial dysfunction, are preceded by MC-driven formation of interstitial edema in the alveolar septa.

Isolation and enrichment of melanocytes from human corneal limbus using CD117 (c-Kit) as selection marker.

Limbal melanocytes (LM) are located in the basal epithelial layer of the corneoscleral limbus and interact with adjacent limbal epithelial progenitor cells. The exploration of their biological role in the maintenance of the limbal stem cell niche has been limited by the difficulty of LM isolation and cultivation. Here, we report on a facile protocol for the efficient isolation and enrichment of pure populations of human LMs by fluorescence-activated cell sorting (FACS) using antibodies raised against the cell surface marker CD117 (c-Kit). The enriched LMs retain self-renewal capacity and sustained melanin production, and are suitable to study the potential of LMs in stem cell-based corneal tissue engineering.

An Inverse Relationship Between c-Kit/CD117 and mTOR Confers NK Cell Dysregulation Late After Severe Injury.

Major trauma-induced tissue injury causes a dysregulation of the immune system. Severe systemic inflammation occurs early after the insult. Later on, an enhanced risk for life-threatening opportunistic infections develops that culminates at the end of the first week after trauma. CD56bright Natural killer (NK) cells play a key role in the defense against infection due to their rapid release of Interferon (IFN) γ in response to Interleukin (IL) 12. NK cells are impaired in IFN-γ synthesis after severe injury due to a disturbed IL-12/IFN-γ axis. Thereby, a circulating factor mediates extrinsic suppression of NK cells. Yet unknown cell-intrinsic mechanisms manifest by day 8 after trauma and render NK cells unresponsive to stimulatory cytokines. In the present study, we investigated the origin of such late NK cell-intrinsic suppression after major trauma. Peripheral blood mononuclear cells (PBMC) were isolated from patients 8 day after severe injury and from healthy control subjects and were stimulated with inactivated Staphylococcus aureus. The expression of diverse cytokine receptors, intracellular signaling molecules, and the secretion of IFN-γ by CD56bright NK cells were examined. After stimulation with S. aureus, NK cells from patients expressed enhanced levels of c-kit/CD117 that inversely correlated with IFN-γ synthesis and IL-12 receptor (IL-12R) ß2 expression. Supplementation with IL-15 and inhibition of the transforming growth factor receptor (TGF-ßR) I reduced CD117 expression and increased the level of IL-12Rß2 and IFN-γ. NK cells from patients showed reduced phosphorylation of mammalian target of rapamycin (mTOR). Addition of IL-15 at least partly restored mTOR phosphorylation and increased IL-12Rß2 expression. The reduced mTOR phosphorylation after severe injury was cell-intrinsic as it was not induced by serum factors. Inhibition of mTOR in purified NK cells from healthy donors by rapamycin decreased the synthesis of IFN-γ. Thus, impaired mTOR phosphorylation in response to a microbial challenge contributes to the cell-intrinsic mechanisms that underlie NK cell dysregulation after trauma. Restoration of the mTOR phosphorylation capacity along with inhibition of the TGF-ßRI signaling in NK cells after severe injury might improve the immune defense against opportunistic infections.

Development and characterization of a fully human antibody targeting SCF/c-kit signaling.

CD117/c-kit, a tyrosine kinase receptor, plays a critical role in hematopoiesis, pigmentation, and fertility. The overexpression and activation of c-kit are thought to promote tumor growth and have been reported in various cancers, including leukemia, glioblastoma and mastocytosis. To disrupt the SCF/c-kit signaling axis in cancer, we generated a c-kit antagonist human antibody (NN2101) that binds to domain 2/3 of c-kit. This completely blocked the SCF-mediated phosphorylation of c-kit and inhibited TF-1 cell proliferation, erythroleukemia. In addition, the examination of binding affinity using surface plasmon resonance (SPR) assay showed that NN2101 can bind to c-kit of monkeys (KD = 2.92 × 10-10 M), rats (KD = 1.68 × 10-6 M), mice (KD = 11.5 × 10-9 M), and humans (KD = 2.83 × 10-12 M). We showed that NN2101 does not cause antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The immunogenicity of NN2101 was similar to that of bevacizumab. Furthermore, the crystal structure of NN2101 Fab was determined and the structure of NN2101 Fab:c-kit complex was modeled. Structural information, as well as mutagenesis results, revealed that NN2101 can bind to the SCF-binding regions of c-kit. Collectively, we generated a c-kit neutralizing human antibody (NN2101) for the treatment of erythroleukemia and characterized its biophysical properties. NN2101 can potentially be used as a therapeutic antibody to treat different cancers.

Reduction of circulating innate lymphoid cell progenitors results in impaired cytokine production by innate lymphoid cells in patients with lupus nephritis.

BACKGROUND: Innate lymphoid cells (ILCs) play an essential role in maintaining homeostasis; however, they can also cause chronic inflammation and autoimmune disease. This study aimed to identify the role of ILCs in the pathogenesis of lupus nephritis (LN). METHODS: The percentage of ILCs within the peripheral blood mononuclear cell (PBMC) population and urine of patients with LN (n = 16), healthy controls (HC; n = 8), and disease controls (ANCA-associated vasculitis (AAV; n = 6), IgA nephropathy (IgAN; n = 9), and other glomerular diseases (n = 5)) was determined by flow cytometry analysis. In addition, ILCs were sorted and cultured with plasma from LN patients or HC to elucidate whether the reduced population of CD117+ ILCs observed in LN was due to changes in the ILC progenitor population. RESULTS: The percentage of total ILCs and CD117+ ILCs in LN was significantly lower than that in HC. The percentage of cytokine-secreting ILCs was also lower in LN; however, when the disease stabilized, cytokine production was restored to levels similar to those in HC. The increase in the number of exhausted ILCs (cells unable to secrete cytokines) correlated positively with disease activity. When CD117+ ILCs were cultured with LN plasma, the number of CD117+ ILCs fell, but that of other ILC subsets increased. CONCLUSIONS: The percentage of CD117+ ILCs and the capacity of ILCs to secrete cytokines fell as LN severity increased, suggesting that an inflammatory environment of LN induces persistent differentiation and exhaustion of ILCs.

Stem Cell Factor Receptor Immunoexpression in Adolescent Varicocele.

PURPOSE: Stem cell factor receptor (c-kit) plays a crucial role in regulating proliferation and survival of germ cells. The aim of this study was to find the correlation between the number of c-kit positive germ cells, testicular asymmetry and histological grade in varicocele affected testis samples of adolescents. MATERIALS AND METHODS: Twenty testicular biopsy samples of adolescents affected by varicocele and eight normal control testes were included. The relationship between percentage of testicular asymmetry, number of tubular c-kit positive germ cells and severity of spermatogenic failure was assessed. RESULTS: The mean (SD; median) histological grade for spermatogenic failure in controls was 1.37(0.52; 1), while in the varicocele group, it was 2.70(1.08; 3) (P = .0052). Mean(SD; median) number c-kit positive germ cells in the control group were 20.1(2.52; 20), while in the varicocele group it was 12.35(7.16; 12.5) (P = .0059). Spearman test documented a significant positive correlation between percentage of hypotrophy and histological grade of spermatogenic failure (r = 0.5544 , 95% CI: 0.1345 to 0.8055, P = .0112) but a negative correlation with the number of c-kit positive cells (r = - 0.5871, 95% CI: - 0.8219 to -0.1817, P = .0065). Moreover, a significant negative correlation was found between grade of histological changes and number of c-kit positive germ cells (P < .0001). CONCLUSION: A significant correlation between hypotrophy, histological lesions and c-kit positive germ cells exists in varicocele testes. This finding suggests a possible role for c-kit in the pathogenesis of germ cell impairment in varicocele. Histological changes and lack of c-kit germ cells were also noted in testes not displaying hypotrophy. We believe that reliable markers should be found as better predictors of testicular function in adolescent with varicocele.

Clinic-pathological aspect of gastro-intestinal stromal tumors at tertiary care Hospital India / Aspecto clínico e patológico dos tumores estromais gastrointestinais em hospital terciário da Índia

Abstract Background This study defines the disease profile in south Indian population and determine the clinic-pathological aspects of Gastro-Intestinal Stromal Tumors. Method In this prospective study patients diagnosed of gastrointestinal stromal tumors were taken thorough clinical examination and a database of Anthropometric details and clinical details were analyzed. Pathological data included tumor size, presence or absence necrosis, mitotic counts, immunohistochemistry for CD-117, CD-34. Results There were 44 patients with confirmed diagnosis of gastro-intestinal stromal tumor. The highest incidence was found in the 6th decade. The most common symptoms were abdominal pain and gastrointestinal bleed. Stomach was most frequent site for gastro-intestinal stromal tumors. Immunochemistry for CD-117 was positive in 93.18% cases. Majority of tumors (79.5%) had pure spindle cell morphology and mitotic activity showed that 34% of the GISTs were of the high risk group. Forty two patients were suggestive of surgery as the primary treatment after presentation. Conclusion Abdominal pain was the most common presenting complaint. Majority of the tumors aroused from the stomach. The majority of the tumors had pure spindle cell morphology and 93% of the tumors were CD-117 positive. A significant relationship between tumor size, tumor necrosis and mitotic activity with large tumors having necrosis and high mitotic rate having high risk of malignancy, was observed. Surgical resection is considered mainstay of treatment of gastro-intestinal stromal tumor. Imatinib therapy should be given to patients in moderate to severe risk categories.

Resumo Justificativa Este estudo define o perfil da doença na população do sul da Índia e determina os aspectos clínicos e patológicos dos tumores estromais gastrointestinais. Método Neste estudo prospectivo, os pacientes diagnosticados com tumor estromal gastrointestinl foram submetidos a um exame clínico completo, e uma série de dados dos pacientes, incluindo detalhes antropométricos e clínicos, foram analisados. Os dados patológicos incluíram tamanho do tumor, presença ou ausência de necrose, contagem mitótica e imuno-histoquímica para CD-117, CD-34. Resultados Havia 44 pacientes com diagnóstico confirmado de tumor estromal gastrointestinal. A maior incidência foi encontrada na 6ª década de vida. Os sintomas mais comuns foram dor abdominal e sangramento gastrointestinal. O estômago foi o local mais frequente para tumores estromais gastrointestinais. A imuno-histoquímica para CD-117 foi positiva em 93,18% dos casos. A maioria dos tumores (79,5%) apresentava morfologia pura de células fusiformes e a atividade mitótica mostrou que 34% dos GISTs pertenciam ao grupo de alto risco. Quarenta e dois pacientes receberam indicação para cirurgia como tratamento primário após a apresentação. Conclusão A dor abdominal foi a queixa mais comum. A maioria dos tumores afetava o estômago, apresentava morfologia pura de células fusiformes e 93% eram CD-117 positivos. Foi observada uma relação significativa entre o tamanho do tumor, a necrose tumoral e a atividade mitótica, com os tumores grandes apresentando necrose e alta taxa mitótica com alto risco de malignidade. A ressecção cirúrgica é considerada o principal tratamento do tumor estromal gastrointestinal. A terapia com imatinibe deve ser administrada a pacientes em categoria de risco de moderadas a grave.