Ferritin nanoconjugates guide trastuzumab brain delivery to promote an antitumor response in murine HER2 + breast cancer brain metastasis.

Brain metastasis (BM) represents a clinical challenge for patients with advanced HER2 + breast cancer (BC). The monoclonal anti-HER2 antibody trastuzumab (TZ) improves survival of BC patients, but it has low central nervous system penetrance, being ineffective in treating BM. Previous studies showed that ferritin nanoparticles (HFn) may cross the blood brain barrier (BBB) through binding to the transferrin receptor 1 (TfR1). However, whether this has efficacy in promoting the trans-BBB delivery of TZ and combating BC BM was not studied yet. Here, we investigated the potential of HFn to drive TZ brain delivery and promote a targeted antitumor response in a murine model of BC BM established by stereotaxic injection of engineered BC cells overexpressing human HER2. HFn were covalently conjugated with TZ to obtain a nanoconjugate endowed with HER2 and TfR1 targeting specificity (H-TZ). H-TZ efficiently achieved TZ brain delivery upon intraperitoneal injection and triggered stable targeting of cancer cells. Treatment with H-TZ plus docetaxel significantly reduced tumor growth and shaped a protective brain microenvironment by engaging macrophage activation toward cancer cells. H-TZ-based treatment also avoided TZ-associated cardiotoxicity by preventing drug accumulation in the heart and did not induce any other major side effects when combined with docetaxel. These results provided in vivo demonstration of the pharmacological potential of H-TZ, able to tackle BC BM in combination with docetaxel. Indeed, upon systemic administration, the nanoconjugate guides TZ brain accumulation, reduces BM growth and limits side effects in off-target organs, thus showing promise for the management of HER2 + BC metastatic to the brain.

Case Report: Ileo-Ileal Intussusception Secondary to Inflammatory Fibroid Polyp: A Rare Cause of Intestinal Obstruction.

Introduction: Intussusception is a telescoping of a bowel segment into another and it can be a surgical urgency. Most adult intussusceptions arise from a lead point which can be benign or malignant. For this reason, intussusception in adults should undergo surgery. Here we describe a case of ileal inflammatory fibroid polyp (IFP), presenting with ileo-ileal intussusception and obstruction. Case report: A 54-year-old Caucasian woman presented for acute abdominal pain. A radiography and a CT of the abdomen were performed, which showed signs of occlusion due to an ileo-ileal intussusception. An urgent laparoscopy was performed, the intussusception was extracorporeally reduced, the ileal segment involved was resected, and an ileo-ileal anastomosis was performed. The intussusception seemed to be caused by a 3-cm intra-mural lesion. Discussion: Intussusception is a surgical concern. While most cases are idiopathic in children, 90% of adult intussusceptions are caused by underlying diseases. Therefore, intussusception in adults should undergo surgery. Radiology is necessary for the diagnosis: the CT scan helps localizing the lesion and shows pathognomonic signs. This case report analyzes an intussusception caused by an inflammatory fibroid polyp. Accurate diagnosis of IFP is only possible with histopathological examination, helped by immunohistochemistry. The differential diagnosis is important because some lesions are malignant. Conclusion: We reported a case of intussusception caused by an IFP. The diagnosis was made with a CT scan together with intraoperative findings and histopathological examination, which excluded potential differential diagnoses. The patient underwent an explorative laparoscopy, with an ileal resection and anastomosis. Due to the risk of malignancy, surgery is mandatory.

SARS-CoV-2 in the knee joint: a cadaver study.

OBJECTIVES: Despite the considerable research efforts being made to learn more about COVID-19, little is known about the presence of SARS-CoV-2 genetic material in biological fluids other than respiratory droplets, blood, and feces. The aim of this post-mortem study was to assess the presence of SARS-CoV-2 RNA in the knee synovial fluid, synovial tissue, and bone tissue of COVID-19 patients in order to discover whether the joint is a possible route of transmission during orthopaedic surgical procedures, and clarify the possible role of SARS-CoV-2 as a directly arthritogenic virus. METHODS: Post-mortem synovial fluid, synovial tissue and bone tissue samples were collected from the knees of five patients who died of COVID-19 in our hospital between September and October 2020, and analysed for the presence of SARS-CoV-2 using a commercial real-time polymerase chain reaction (RT-PCR) panel. Quantitative RT-PCR was used to test post-mortem nasopharyngeal swabs of all of the patients. RESULTS: No SARS-CoV-2 RNA was detected in any of the knee samples, despite the positivity of the throat swab. CONCLUSIONS: Our findings indicate that SARS-CoV-2 was not detected in knee synovial fluid, synovial membrane or bone. This makes it unlikely that these are potential sources of contagion, and suggests that SARS-CoV-2 is not directly arthritogenic.

Neuroinflammation, body temperature and behavioural changes in CD1 male mice undergoing acute restraint stress: An exploratory study.

BACKGROUND: Animal models used to study pathologies requiring rehabilitation therapy, such as cardiovascular and neurologic disorders or oncologic disease, must be as refined and translationally relevant as possible. Sometimes, however, experimental procedures such as those involving restraint may generate undesired effects which may act as a source of bias. However, the extent to which potentially confounding effects derive from such routine procedures is currently unknown. Our study was therefore aimed at exploring possible undesirable effects of acute restraint stress, whereby animals were exposed to a brightly lit enclosed chamber (R&L) similar to those that are commonly used for substance injection. We hypothesised that this would induce a range of unwanted physiological alterations [such as neuroinflammatory response and changes in body weight and in brown adipose tissue (BAT)] and behavioural modification, and that these might be mitigated via the use of non-aversive handling methods: Tunnel Handling (NAH-T) and Mechanoceptive Handling (NAH-M)) as compared to standard Tail Handling (TH). METHODS: Two indicators of physiological alterations and three potentially stress sensitive behavioural parameters were assessed. Physiological alterations were recorded via body weight changes and assessing the temperature of Brown Adipose Tissue (BAT) using infra-red thermography (IRT), and at the end of the experiment we determined the concentration of cytokines CXCL12 and CCL2 in bone marrow (BM) and activated microglia in the brain. Nest complexity scoring, automated home-cage behaviour analysis (HCS) and Elevated Plus Maze testing (EPM) were used to detect any behavioural alterations. Recordings were made before and after a 15-minute period of R&L in groups of mice handled via TH, NAH-T or NAH-M. RESULTS: BAT temperature significantly decreased in all handling groups following R&L regardless of handling method. There was a difference, at the limit of significance (p = 0.06), in CXCL12 BM content among groups. CXCL12 content in BM of NAH-T animals was similar to that found in Sentinels, the less stressed group of animals. After R&L, mice undergoing NAH-T and NAH-M showed improved body-weight maintenance compared to those exposed to TH. Mice handled via NAH-M spent a significantly longer time on the open arms of the EPM. The HCS results showed that in all mice, regardless of handling method, R&L resulted in a significant reduction in walking and rearing, but not in total distance travelled. All mice also groomed more. No difference among the groups was found in Nest Score, in CCL2 BM content or in brain activated microglia. CONCLUSIONS: Stress induced by a common restraint procedure caused metabolic and behavioural changes that might increase the risk of unexpected bias. In particular, the significant decrease in BAT temperature could affect the important metabolic pathways controlled by this tissue. R&L lowered the normal frequency of walking and rearing, increased grooming and probably carried a risk of low-grade neuro-inflammation. Some of the observed alterations can be mitigated by Non-aversive handlings.

Atypical primary hyperparathyroidism due to parathyroid lipoadenoma: a case report.

Parathyroid lipoadenoma is a very rare cause of primary hyperparathyroidism. Preoperative imaging techniques often fail to detect such lesions, and even during surgery they can be misinterpreted just as fat tissue. A 62-year-old woman clinically monitored for primary hyperparathyroidism, with hypertension and a left nephrectomy for hydrouretheronephrosis caused by recurrent kidney stones. A neck ultrasound showed a nodule consistent with left parathyroid of 9 × 5 mm, which was not confirmed on single-photon-emission computed tomography/computed tomography (CT) scan. On surgery, a voluminous lesion with adipose appearance and texture was removed. Frozen sections and intraoperative parathyroid hormone (PTH) confirmed such lesion to be a parathyroid lipoadenoma. Parathyroid lipoadenomas are difficult to localize preoperatively. Sometimes they can be seen by ultrasound scan as hyperechoich lesion, but scintigraphy and CT often fail to identify them. Only the awareness of such lesions and the use of intraoperative PTH can avoid unnecessary extensive cervical exploration.

Thyroid metastasis from adenoid cystic carcinoma of the lung: a case report and literature review.

Both adenoid cystic carcinoma (ACC) and thyroid metastasis are quite peculiar clinical presentations. ACC is a malignant salivary gland-type tumour mostly found in the head and neck district, but that can arise from different organs. Due to its rarity, it can pose problems in the diagnostic and therapeutic management. A 72-year-old woman presented for a persistent non-productive cough. A computed tomography showed a lung mass. She underwent lung surgery, and the lesion was an ACC primitive of the lung. She developed hoarseness and ultrasound and cytology confirmed metastatic involvement of left thyroid lobe from ACC. A total thyroidectomy was performed, followed by radiotherapy. The present case highlights the need to be aware of possible metastatic thyroid localization of ACC originating in lower airways. This is a very rare event, and clinical and cytological findings must be carefully examined. It represents an opportunity to consider the current knowledge about ACC metastasis to thyroid.

Anti-MAdCAM-1-Conjugated Nanocarriers Delivering Quantum Dots Enable Specific Imaging of Inflammatory Bowel Disease.

PURPOSE: Assessment of inflammatory bowel disease (IBD) currently relies on aspecific clinical signs of bowel inflammation. Specific imaging of the diseased bowel regions is still lacking. Here, we investigate mucosal addressin cell adhesion molecule 1 (MAdCAM-1) as a reliable and specific endothelial target for engineered nanoparticles delivering imaging agents to obtain an exact mapping of diseased bowel foci. MATERIALS AND METHODS: We generated a nanodevice composed of PLGA-PEG coupled with anti-MAdCAM-1 antibody half-chains and loaded with quantum dots (P@QD-MdC NPs). Bowel localization and systemic biodistribution of the nanoconjugate were analyzed upon injection in a murine model of chronic IBD obtained through repeated administration of dextran sulfate sodium salt. Specificity for diseased bowel regions was also assessed ex vivo in human specimens from patients with IBD. Potential for development as contrast agent in magnetic resonance imaging was assessed by preliminary study on animal model. RESULTS: Synthesized nanoparticles revealed good stability and monodispersity. Molecular targeting properties were analyzed in vitro in a cell culture model. Upon intravenous injection, P@QD-MdC NPs were localized in the bowel of colitic mice, with enhanced accumulation at 24 h post-injection compared to untargeted nanoparticles (p<0.05). Nanoparticles injection did not induce histologic lesions in non-target organs. Ex vivo exposure of human bowel specimens to P@QD-MdC NPs revealed specific recognition of the diseased regions vs uninvolved tracts (p<0.0001). After loading with appropriate contrast agent, the nanoparticles enabled localized contrast enhancement of bowel mucosa in the rectum of treated mice. CONCLUSION: P@QD-MdC NPs efficiently detected bowel inflammation foci, accurately following the expression pattern of MAdCAM-1. Fine-tuning of this nanoconjugate with appropriate imaging agents offers a promising non-invasive tool for specific IBD diagnosis.

Liver histopathology in severe COVID 19 respiratory failure is suggestive of vascular alterations.

SARS2-CoV-2 breakout in Italy caused a huge number of severely ill patients with a serious increase in mortality. Although lungs seem to be the main target of the infection, very few information are available about liver involvement, possibly evocating a systemic disease. Post-mortem wedge liver biopsies from 48 patients died from severe pulmonary COVID-19 disease with respiratory failure were collected from two main hospitals in northern Italy. No patient had clinical symptoms of liver disease or signs of liver failure before and during hospitalization; for each of them liver function tests were available. All liver samples showed minimal inflammation features. Histological pictures compatible with vascular alterations were observed, characterized by increase in number of portal vein branches associated with lumen massive dilatation, partial or complete luminal thrombosis of portal and sinusoidal vessels, fibrosis of portal tract, focally markedly enlarged and fibrotic. SARS-CoV-2 was found in 15 of 22 samples tested by in situ hybridization method. Our preliminary results confirm the clinical impression that liver failure is not a main concern and this organ is not the target of significant inflammatory damage. Histopathological findings are highly suggestive for marked derangement of intrahepatic blood vessel network secondary to systemic changes induced by virus that could target not only lung parenchyma but also cardiovascular system, coagulation cascade and endothelial layer of blood vessels. It still remains unclear if the mentioned changes are directly related to virus infection or if SARS-CoV-2 triggers a series of reactions leading to striking vascular alterations.

Pulmonary post-mortem findings in a series of COVID-19 cases from northern Italy: a two-centre descriptive study.

BACKGROUND: COVID-19 is characterised by respiratory symptoms, which deteriorate into respiratory failure in a substantial proportion of cases, requiring intensive care in up to a third of patients admitted to hospital. Analysis of the pathological features in the lung tissues of patients who have died with COVID-19 could help us to understand the disease pathogenesis and clinical outcomes. METHODS: We systematically analysed lung tissue samples from 38 patients who died from COVID-19 in two hospitals in northern Italy between Feb 29 and March 24, 2020. The most representative areas identified at macroscopic examination were selected, and tissue blocks (median seven, range five to nine) were taken from each lung and fixed in 10% buffered formalin for at least 48 h. Tissues were assessed with use of haematoxylin and eosin staining, immunohistochemical staining for inflammatory infiltrate and cellular components (including staining with antibodies against CD68, CD3, CD45, CD61, TTF1, p40, and Ki-67), and electron microscopy to identify virion localisation. FINDINGS: All cases showed features of the exudative and proliferative phases of diffuse alveolar damage, which included capillary congestion (in all cases), necrosis of pneumocytes (in all cases), hyaline membranes (in 33 cases), interstitial and intra-alveolar oedema (in 37 cases), type 2 pneumocyte hyperplasia (in all cases), squamous metaplasia with atypia (in 21 cases), and platelet-fibrin thrombi (in 33 cases). The inflammatory infiltrate, observed in all cases, was largely composed of macrophages in the alveolar lumina (in 24 cases) and lymphocytes in the interstitium (in 31 cases). Electron microscopy revealed that viral particles were predominantly located in the pneumocytes. INTERPRETATION: The predominant pattern of lung lesions in patients with COVID-19 patients is diffuse alveolar damage, as described in patients infected with severe acute respiratory syndrome and Middle East respiratory syndrome coronaviruses. Hyaline membrane formation and pneumocyte atypical hyperplasia are frequent. Importantly, the presence of platelet-fibrin thrombi in small arterial vessels is consistent with coagulopathy, which appears to be common in patients with COVID-19 and should be one of the main targets of therapy. FUNDING: None.

Clinical relevance of the left brachiocephalic vein anatomy for vascular access in dialysis patients.

INTRODUCTION: Most hemodialysis patients start renal replacement therapy with a central venous catheter (CVC). The left internal jugular vein (LIJV) is the second-choice vein for CVC positioning, after the right IJV. However, to reach the right atrium, the CVC must pass through the left brachiocephalic vein (LBV), which also drains blood from the left arm through the subclavian vein. The purpose of this study is to describe how the anatomy of the central venous system and in particular that of the LBV affects vascular access in hemodialysis patients. MATERIALS AND METHODS: Three-dimensional (3D) virtual model reconstructions of the central thoracic veins of three hemodialysis patients were obtained from contrast-enhanced computed tomography scans acquired in the venous phase. The images were exported as DICOM files and loaded on open-source software for visualizing and analyzing the medical imaging (3D Slicer, Windows version 4.8.1). RESULTS: As expected, the 3D reconstructions showed that the LBV has a tortuous path with three main angulations that could be associated with external compression and stenosis. These could determine the difficulties and increased risks of venous injury during CVC placement, and an increased risk of medium to long-term catheter-associated vein thrombosis and stenosis. CONCLUSIONS: The anatomical features of the LBV indicate that the path of a CVC from the LIJV to the right atrium is tortuous and can easily be complicated by vein injury, negatively affecting the creation of future arterio-venous vascular accesses in the left arm.

A refinement approach in a mouse model of rehabilitation research. Analgesia strategy, reduction approach and infrared thermography in spinal cord injury.

The principles of Refinement, Replacement and Reduction (3R's) should be taken into account when animals must be used for scientific purpose. Here, a Reduction / Refinement approach was applied to the procedure of spinal cord injury (SCI), an animal model used in rehabilitation medicine research, in order to improve the quality of experiments, avoiding unnecessary suffering. The aims of this investigation were 1- to assess acute surgical pain in mice subjected to SCI, 2- to compare the efficacy of commonly used analgesia (three buprenorphine subcutaneous injection in 48 hours, 0,15 mg/kg each) with a combination of opioid and NSAID (one subcutaneous injection of 5 mg/kg carprofen before surgery followed by three buprenorphine subcutaneous injection in 48 hours, 0,15 mg/kg each) and 3- to test if Infrared Thermography (IRT) could be a potential new Refinement method to easily assess thermoregulation, an important metabolic parameter. Finally, we aimed to achieve these goals without recruiting animals on purpose, but using mice already scheduled for studies on SCI. By using behaviours analysis, we found that, despite being commonly used, buprenorphine does not completely relieve acute surgical pain, whereas the combination of buprenorphine and carprofen significantly decreases pain signs by 80%. IRT technology turned out to be a very useful Refinement tool being a non invasive methods to measure animal temperature, particularly useful when rectal probe cannot be used, as in the case of SCI. We could find that temperatures constantly and significantly increased until 7 days after surgery and then slowly decreased and, finally, we could observe that in the buprenorphine and carprofen treated group, temperatures were statistically lower than in the buprenorphine-alone treated mice. To our knowledge this is the first work providing an analgesic Refinement and a description of thermoregulatory response using the IRT technology, in mice subjected to SCI.

Impaired testicular signaling of vitamin A and vitamin K contributes to the aberrant composition of the extracellular matrix in idiopathic germ cell aplasia.

OBJECTIVE: To study pathogenic features of the somatic testicular microenvironment associated with idiopathic germ cell aplasia. DESIGN: Cross-sectional study. SETTING: Tertiary referral center for reproductive medicine. PATIENT(S): Testicular specimens from men with idiopathic nonobstructive azoospermia (iNOA) prospectively submitted to microdissection testicular sperm extraction. Of 20 specimens used for histology, 10 were also available for proteomic analysis. Primary Sertoli cells with normal karyotype and phenotype were also used. INTERVENTION(S): Patients with iNOA were dichotomized according to a positive versus negative sperm retrieval at microdissection testicular sperm extraction, and on the isolated extracellular matrix (ECM) the proteomic analysis was performed. MAIN OUTCOME MEASURE(S): Proteomic analysis of the ECM from testicular specimens with positive versus negative sperm retrieval. Gene ontology enrichment was used to identify upstream regulators based on the 11 deregulated ECM proteins, which were validated by immunohistochemistry and quantitative polymerase chain reaction. Continuous variables were expressed as medians and interquartile range. RESULT(S): Germ cell aplasia was characterized by an increased signaling of the retinoic acid in Sertoli cells and associated with decreased expression of the basal membrane markers nidogen-2 and heparan sulfate proteoglycan-2. Decreased levels of the interstitial matrisome-associated factor IX and its regulator VKORC1 were, instead, coupled with decreased signaling of vitamin K in Leydig cells. An altered expression of a further eight ECM proteins was also found, including laminin-4 and laminin-5. Peripheral levels of the two vitamins were within the reference range in the two cohorts of iNOA men. CONCLUSION(S): We identified the pathogenetic signature of the somatic human testicular microenvironment, providing two vitamin-related mechanistic insights related to the molecular determinants of the idiopathic germ cell aplasia.

Leiomyomatosis peritonealis disseminata: A case report of recurrent presentation and literature review.

INTRODUCTION: Leiomyomatosis peritonealis disseminata (LPD) is an uncommon disease featured by the presence of multiple nodules of smooth muscle cells scattered in the abdominal cavity. To date only about 150 cases have been reported in literature. We report a case of recurrent LPD after laparotomy. CASE PRESENTATION: In March 2016 a 36-year-old female, with a history of multiple previous laparoscopic myomectomies, consulted her gynaecologist complaining abdominal pain; a MRI was performed and reported multiple pelvic masses, subsequently excised during laparotomy. The patient refused a total hysterectomy with bilateral salpingo-oopherectomy so a close follow-up was recommended. In November 2017 when a new MRI revealed recurrency of the disease, a second laparotomy is performed and all visible nodules are excised. The histological exam confirms LPD diagnosis. On follow-up after three months the patients is completely asymptomatic. DISCUSSION: Differential diagnosis of LPD is challenging due to its similarity to carcinomatosis and to other benign abdominal disorders. Malignant transformation is rare, but it may occur, so a close follow-up is necessary. Even if there is no consensus regarding the treatment, hormonal therapy is probably the best first line approach, while surgery should be the second choice. CONCLUSIONS: LPD is an uncommon but potentially severe disease. In our opinion larger studies are necessary to improve our diagnostic effectiveness and to define the best therapeutic strategy.

Inhibition of Fibroblast Activation Protein Restores a Balanced Extracellular Matrix and Reduces Fibrosis in Crohn's Disease Strictures Ex Vivo.

Background: Crohn's disease (CD) is a chronic bowel inflammation that ultimately leads to fibrosis, for which medical therapy is currently unavailable. Fibrotic strictures in CD are characterized by excessive extracellular matrix (ECM) deposition, altered balance between matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), and overexpression of fibroblast activation protein (FAP), a marker of active fibroblasts. Here we investigated the role of FAP-targeted therapy in ECM remodeling in CD strictures ex vivo. Methods: Bowel specimens were obtained from stenotic and nonstenotic ileal segments from 30 patients with fibrostenotic CD undergoing surgery. FAP expression was evaluated in isolated mucosal myofibroblasts by immunoblotting and flow cytometry. Bowel tissue cultures were treated with anti-FAP antibody, and soluble collagen, TIMP-1, and MMPs were measured in tissue culture supernatants by immunoblotting. Anti-FAP-treated myofibroblasts were analyzed for TIMP-1 expression by immunoblotting, for migratory potential by wound healing assay, and for apoptosis by Annexin V staining. Results: Myofibroblasts from stenotic CD mucosa showed upregulation of FAP expression when compared with nonstenotic mucosa. Treatment of stenotic tissues with anti-FAP antibody induced a dose-dependent decrease in collagen production, particularly affecting type I collagen. The treatment also reduced TIMP-1 production in CD strictures, without altering MMP-3 and MMP-12 secretion. Accordingly, anti-FAP treatment inhibited TIMP-1 expression in stenotic CD myofibroblasts and enhanced myofibroblast migration without affecting survival. Conclusions: FAP inhibition reduced type I collagen and TIMP-1 production by CD strictures ex vivo without compromising uninvolved bowel areas. These results suggest that targeting FAP could reconstitute ECM homeostasis in fibrostenotic CD.

Remitting infections due to community-acquired Panton-Valentine leukocidin-producing Staphylococcus aureus in the Milan area.

One of the most important Staphylococcus aureus virulence factors is Panton-Valentine leukocidin (PVL). We describe an outbreak of recurrent cutaneous PVL infections in different members of three family clusters. Molecular investigations were performed to confirm the presence of the mecA and PVL genes and to assign the SCCmec type, sequence type (ST) and clonal relatedness. A strain of PVL-producing methicillin-resistant S. aureus (MRSA) was responsible for infection in two related families (A and B), and a third family (C) was infected with PVL-producing methicillin-sensitive S. aureus (MSSA). Molecular investigations revealed the same clone of community-acquired (CA)-MRSA, PVL positive ST8, and SCCmec IV in families A and B and CA-MSSA PVL positive ST15 in family C. S. aureus PVL may give rise to recurrent uncontrolled infections that are difficult to eradicate, and close family contacts are at high risk for transmission.

Anti-Mullerian Hormone-to-Testosterone Ratio is Predictive of Positive Sperm Retrieval in Men with Idiopathic Non-Obstructive Azoospermia.

The lack of clinically-reliable biomarkers makes impossible to predict sperm retrieval outcomes at testicular sperm extraction (TESE) in men with non-obstructive azoospermia (NOA), resulting in up to 50% of unnecessary surgical interventions. Clinical data, hormonal profile and histological classification of testis parenchyma from 47 white-Caucasian idiopathic NOA (iNOA) men submitted to microdissection TESE (microTESE) were analyzed. Logistic regression analyses tested potential clinical predictors of positive sperm retrieval. The predictive accuracy of all variables was evaluated using the receiver operating characteristic-derived area under the curve, and the clinical net benefit estimated by a decision-curve analysis (DCA). Overall, 23 (49%) and 24 (51%) patients were classified as positive and negative sperm retrievals at microTESE. While circulating hormones associated to a condition of primary hypogonadism did not predict sperm retrieval, levels of anti-Mullerian hormone (AMH) and the ratio AMH-to-total Testosterone (AMH/tT) achieved independent predictor status for sperm retrieval at microTESE, with a predictive accuracy of 93% and 95%. Using cutoff values of <4.62 ng/ml for AMH and <1.02 for AMH/tT, positive sperm retrieval was predicted in all individuals, with 19 men out of 47 potentially spared from surgery. DCA findings demonstrated clinical net benefit using AMH and AMH/tT for patient selection at microTESE.