Tofacitinib in Patients Hospitalized With Moderate and Severe COVID-19: Not Just Another Kinase Inhibitor.

Background There has been an intense search for pharmacological agents that can complement corticosteroid therapy in the treatment of severe coronavirus disease 2019 (COVID-19). The Janus kinase inhibitor tofacitinib has shown promise in this regard. This study aimed to determine the impact of adding tofacitinib to standard care on the mortality and total duration of hospital stay in severe COVID-19. Methodology This retrospective study compared the mortality and total duration of hospital stay among patients admitted with severe COVID-19 to a designated COVID-19 hospital in south India who had received tofacitinib in addition to standard care versus standard care alone. Medical case records of severe COVID-19 patients were retrieved and screened for inclusion. Categorical variables such as mortality were expressed as proportions and compared using the chi-square test, while continuous variables such as total duration of hospital stay were compared via the independent t-test. The odds ratio (OR) was calculated for the mortality difference between the two groups. P-values ≤0.05 were considered significant. Results Following the initial screening of 250 medical records, 186 patients were included in the final analysis, of whom 103 had received tofacitinib and 83 had received standard care. There was no significant difference in mortality between the two groups (OR = 1.58 (95% confidence interval = 0.71 to 3.51); p = 0.26). The total duration of hospital stay was significantly longer among those in the tofacitinib group (17.14 ± 8.85 days vs. 14.04 ± 5.48 days; p = 0.01). Conclusions Tofacitinib did not improve the clinical outcomes when used to supplement corticosteroids in the treatment of severe COVID-19.

Physio-biochemical characterization of wheat genotypes under temperature stress.

Thermal stress is a major abiotic stress in wheat and is highly complex in mechanism. A large area in northwestern plain zones (NWPZ), which is the wheat bowl of India is affected by heat stress. Climate change also causes an abrupt increase in temperature at different growth stages of wheat. Thus, wiser selection of stress tolerant varieties is an important strategy to combat the climate change effect. The present study aims for physiological and biochemical screening of timely sown NWPZ wheat varieties (WB2, HD3086, DBW88, DPW621-50, DBW17, HD2967 and PBW550) of India for their thermal stress tolerance along with heat tolerant (RAJ3765) and susceptible checks (RAJ4014) at seedling stage. The experiment was conducted in completely randomized design under controlled laboratory condition and heat stress was induced at 37 °C at seedling stage. Later different physio-biochemical traits were studied in both control and stress seedlings. All traits exhibited significant variations among genotypes under heat stress condition. Root and shoot weight, relative water content, chlorophyll content index and chlorophyll fluorescence reduced significantly, whereas membrane leakage, osmotic potential, catalase, ascorbate peroxidase, guaiacol peroxidase, malondialdehyde content and proline content were increased in stress plants. A tolerance matrix was prepared based on stress response of the genotypes for each trait and a final tolerance score was given to each genotype. Based on this tolerance matrix, DBW88 and PBW550 were identified as tolerant, DPW621-50, DBW17 and HD2967 as moderately susceptible and HD3086 and WB2 as susceptible to heat stress. Earlier studies parade that seedling level stress tolerance has high correlation with adult level stress tolerance under field condition in wheat. Hence, this study helps in wiser selection of varieties for sowing in NWPZ based on weather forecast of the location for creating varietal mosaic in context of climate change.

Duplex One-Step RT-qPCR Assays for Simultaneous Detection of Genomic and Subgenomic RNAs of SARS-CoV-2 Variants.

A hallmark of severe acute respiratory syndrome virus (SARS-CoV-2) replication is the discontinuous transcription of open reading frames (ORFs) encoding structural virus proteins. Real-time reverse transcription PCR (RT-qPCR) assays in previous publications used either single or multiplex assays for SARS-CoV-2 genomic RNA detection and a singleplex approach for subgenomic RNA detection. Although multiplex approaches often target multiple genomic RNA segments, an assay that concurrently detects genomic and subgenomic targets has been lacking. To bridge this gap, we developed two duplex one-step RT-qPCR assays that detect SARS-CoV-2 genomic ORF1a and either subgenomic spike or subgenomic ORF3a RNAs. All primers and probes for our assays were designed to bind to variants of SARS-CoV-2. In this study, our assays successfully detected SARS-CoV-2 Washington strain and delta variant isolates at various time points during the course of live virus infection in vitro. The ability to quantify subgenomic SARS-CoV-2 RNA is important, as it may indicate the presence of active replication, particularly in samples collected longitudinally. Furthermore, specific detection of genomic and subgenomic RNAs simultaneously in a single reaction increases assay efficiency, potentially leading to expedited lucidity about viral replication and pathogenesis of any variant of SARS-CoV-2.

Implication of repatriating migrant workers on COVID-19 spread and transportation requirements.

Nationwide lockdown for COVID-19 created an urgent demand for public transportation among migrant workers stranded at different parts of India to return to their native places. Arranging transportation could spike the number of COVID-19 infected cases. Hence, this paper investigates the potential surge in confirmed and active cases of COVID-19 infection and assesses the train and bus fleet size required for the repatriating migrant workers. The expected to repatriate migrant worker population was obtained by forecasting the 2011 census data and comparing it with the information reported in the news media. A modified susceptible-exposed-infected-removed (SEIR) model was proposed to estimate the surge in confirmed and active cases of COVID-19 patients in India's selected states with high outflux of migrants. The developed model considered combinations of different levels of the daily arrival rate of migrant workers, total migrant workers in need of transportation, and the origin of the trip dependent symptomatic cases on arrival. Reducing the daily arrival rate of migrant workers for states with very high outflux of migrants (i.e., Uttar Pradesh and Bihar) can help to lower the surge in confirmed and active cases. Nevertheless, it could create a disparity in the number of days needed to transport all repatriating migrant workers to the home states. Hence, travel arrangements for about 100,000 migrant workers per day to Uttar Pradesh and Bihar, about 50,000 per day to Rajasthan and Madhya Pradesh, 20,000 per day to Maharashtra and less than 20,000 per day to other states of India was recommended.

Quantification and Localization of Protein-RNA Interactions in Patient-Derived Archival Tumor Tissue.

Abnormal post-transcriptional regulation induced by alterations of mRNA-protein interactions is critical during tumorigenesis and cancer progression and is a hallmark of cancer cells. A more thorough understanding is needed to develop treatments and foresee outcomes. Cellular and mouse tumor models are insufficient for vigorous investigation as they lack consistency and translatability to humans. Moreover, to date, studies in human tumor tissue are predominately limited to expression analysis of proteins and mRNA, which do not necessarily provide information about the frequency of mRNA-protein interactions. Here, we demonstrate novel optimization of a method that is based on FISH and proximity ligation techniques to quantify mRNA interactions with RNA-binding proteins relevant for tumorigenesis and cancer progression in archival patient-derived tumor tissue. This method was validated for multiple mRNA-protein pairs in several cellular models and in multiple types of archival human tumor samples. Furthermore, this approach allowed high-throughput analysis of mRNA-protein interactions across a wide range of tumor types and stages through tumor microarrays. This method is quantitative, specific, and sensitive for detecting interactions and their localization at both the individual cell and whole-tissue scales with single interaction sensitivity. This work presents an important tool in investigating post-transcriptional regulation in cancer on a high-throughput scale, with great potential for translatability into any applications where mRNA-protein interactions are of interest. SIGNIFICANCE: This work presents an approach to sensitively, specifically, and quantitatively detect and localize native mRNA and protein interactions for analysis of abnormal post-transcriptional regulation in patient-derived archival tumor samples.

Visualization of early events in mRNA vaccine delivery in non-human primates via PET-CT and near-infrared imaging.

Visualization of the spatio-temporal trafficking of vaccines after their delivery would help evaluate the efficacy of candidate formulations and aid their rational design for preclinical and translational studies. Here, we show that a dual radionuclide-near-infrared probe allows for quantitative, longitudinal and non-invasive monitoring, via positron emission tomography-computed tomography and near-infrared imaging of cynomolgus macaques, of the trafficking dynamics to draining lymph nodes of a model messenger RNA vaccine labelled with the probe. After intramuscular administration of the vaccine to the monkeys, we observed the dynamics of the mRNA vaccine at the injection site and in the draining lymph nodes, performed cellular analyses of the involved tissues using flow cytometry and identified through immunofluorescence that professional antigen-presenting cells are the primary cells containing the injected mRNA and encoding the antigen. This approach may reveal spatio-temporal determinants of vaccine efficacy in preclinical and translational studies employing large mammals.

Proximity Ligation Assays for In Situ Detection of Innate Immune Activation: Focus on In Vitro-Transcribed mRNA.

The characterization of innate immune activation is crucial for vaccine and therapeutic development, including RNA-based vaccines, a promising approach. Current measurement methods quantify type I interferon and inflammatory cytokine production, but they do not allow for the isolation of individual pathways, do not provide kinetic activation or spatial information within tissues, and cannot be translated into clinical studies. Here we demonstrated the use of proximity ligation assays (PLAs) to detect pattern recognition receptor (PRR) activation in cells and in tissue samples. First, we validated PLA's sensitivity and specificity using well-characterized soluble agonists. Next, we characterized PRR activation from in vitro-transcribed (IVT) mRNAs, as well as the effect of sequence and base modifications in vitro. Finally, we established the measurement of PRR activation in tissue sections via PLA upon IVT mRNA intramuscular (i.m.) injection in mice. Overall, our results indicate that PLA is a valuable, versatile, and sensitive tool to monitor PRR activation for vaccine, adjuvant, and therapeutic screening.

In Vitro Transcribed mRNA Vaccines with Programmable Stimulation of Innate Immunity.

In vitro transcribed (IVT) mRNA is an appealing platform for next generation vaccines, as it can be manufactured rapidly at large scale to meet emerging pathogens. However, its performance as a robust vaccine is strengthened by supplemental immune stimulation, which is typically provided by adjuvant formulations that facilitate delivery and stimulate immune responses. Here, we present a strategy for increasing translation of a model IVT mRNA vaccine while simultaneously modulating its immune-stimulatory properties in a programmable fashion, without relying on delivery vehicle formulations. Substitution of uridine with the modified base N1-methylpseudouridine reduces the intrinsic immune stimulation of the IVT mRNA and enhances antigen translation. Tethering adjuvants to naked IVT mRNA through antisense nucleotides boosts the immunostimulatory properties of adjuvants in vitro, without impairing transgene production or adjuvant activity. In vivo, intramuscular injection of tethered IVT mRNA-TLR7 agonists leads to enhanced local immune responses, and to antigen-specific cell-mediated and humoral responses. We believe this system represents a potential platform compatible with any adjuvant of interest to enable specific programmable stimulation of immune responses.

Unifying in vitro and in vivo IVT mRNA expression discrepancies in skeletal muscle via mechanotransduction.

The translational efficiency of an in vitro transcribed (IVT) mRNA was measured upon delivery to primary skeletal muscle cells and to a mouse model system, towards the development of a predictive in vitro assay for the screening and validation of intramuscular mRNA-based vaccines. When IVT mRNA was delivered either naked or complexed with novel aminoglycoside-based delivery vehicles, significant differences in protein expression in vitro and in vivo were observed. We hypothesized that this previously anticipated discrepancy was due to differences in the mechanism of IVT mRNA endosomal entry and release following delivery. To address this, IVT mRNA was fluorescently labeled prior to delivery, to visualize its distribution. Colocalization with endosomal markers indicated that different entry pathways were utilized in vivo and in vitro, depending on the delivery vehicle, resulting in variations in protein expression levels. Since extracellular matrix stiffness (ECM) influences mRNA entry, trafficking and release, the effect of mechanotransduction on mRNA expression was investigated in vitro upon delivery of IVT mRNA alone, and complexed with delivery vehicles to skeletal muscle cells grown on ∼10 kPa hydrogels. This in vitro hydrogel model more accurately recapitulated the results obtained in vivo upon IM injection, indicating that this approach may assist in the characterization of mRNA based vaccines.

Unresolving trismus following third molar surgery: Report of a case of fibrodysplasia ossificans progressiva with review of literature.

BACKGROUND: Trismus is a problem commonly encountered by the dental practitioner. It has a number of potential causes, and its treatment will depend on the cause. However, there are very few reports of trismus due to fibrodysplasia ossificans progressiva (FOP) following third molar surgery. CLINICAL PRESENTATION: FOP is a rare human genetic disorder with characteristic clinical features like progressive formation of extraskeletal bone or heterotopic ossification and congenital malformation of the great toes. CLINICAL SIGNIFICANCE: It is troublesome to the maxillofacial surgeon, that minimal manipulation and minor surgery can induce bone formation in soft tissues of the head and neck region, particularly the masticatory muscles and the temporomandibular joint. This paper presents a case of severe trismus following third molar extraction, intractable by routine treatment methods, which was later diagnosed as FOP.

Epidemiology of Sleep-Disordered Breathing and Heart Failure: What Drives What.

PURPOSE OF REVIEW: The bidirectional relationships that have been demonstrated between heart failure (HF) and central sleep apnea (CSA) demand further exploration with respect to the implications that each condition has for the other. This review discusses the body of literature that has accumulated on these relationships and how CSA and its potential treatment may affect outcomes in patients with CSA. RECENT FINDINGS: Obstructive sleep apnea (OSA) can exacerbate hypertension, type 2 diabetes, obesity, and atherosclerosis, which are known predicates of HF. Conversely, patients with HF more frequently exhibit OSA partly due to respiratory control system instability. These same mechanisms are responsible for the frequent association of HF with CSA with or without a Hunter-Cheyne-Stokes breathing (HCSB) pattern. Just as is the case with OSA, patients with HF complicated by CSA exhibit more severe cardiac dysfunction leading to increased mortality; the increase in severity of HF can in turn worsen the degree of sleep disordered breathing (SDB). Thus, a bidirectional relationship exists between HF and both phenotypes of SDB; moreover, an individual patient may exhibit a combination of these phenotypes. Both types of SDB remain significantly underdiagnosed in patients with HF and hence undertreated. Appropriate screening for, and treatment of, OSA is clearly a significant factor in the comprehensive management of HF, while the relevance of CSA remains controversial. Given the unexpected results of the Treatment of Sleep-Disordered Breathing with Predominant Central Sleep Apnea by Adaptive Servo Ventilation in Patients with Heart Failure trial, it is now of paramount importance that additional analysis of these data be expeditiously reported. It is also critical that ongoing and proposed prospective studies of this issue proceed without delay.

Drug dispensing practices at pharmacies in Bengaluru: A cross-sectional study.

OBJECTIVES: Pharmacists are one of the crucial focal points for health care in the community. They have tremendous outreach to the public as pharmacies are often the first-port-of-call. With the increase of ready-to-use drugs, the main health-related activity of a pharmacist today is to assure the quality of dispensing, a key element to promote rational medicine use. MATERIALS AND METHODS: A cross-sectional study of 200 pharmacies, 100 each in various residential (R) and commercial (C) areas of Bengaluru, was conducted using a prevalidated questionnaire administered to the chief pharmacist or the person-in-charge by the investigators. RESULTS: Dispensing without prescription at pharmacies was 45% of the total dispensing encounters and significantly higher (χ2 = 15.2, P < 0.001, df = 1) in pharmacies of residential areas (46.64%) as compared to commercial areas (43.64%). Analgesics were the most commonly dispensed drugs (90%) without prescription. Only 31% insisted on dispensing full course of antibiotics prescribed and 19% checked for completeness of prescription before dispensing. Although 97% of the pharmacies had a refrigerator, 31% of these did not have power back-up. Only about 50% of the pharmacists were aware of Schedule H. CONCLUSION: This study shows a high proportion of dispensing encounters without prescription, a higher rate of older prescription refills, many irregularities in medication counseling and unsatisfactory storage practices. It also revealed that about half of the pharmacists were unaware of Schedule H and majority of them about current regulations. Hence, regulatory enforcement and educational campaigns are a prerequisite to improve dispenser's knowledge and dispensing practices.

A Modified Coupled Spectrophotometric Method to Detect 2-5 Oligoadenylate Synthetase Activity in Prostate Cell Lines.

BACKGROUND: 2'-5' oligoadenylate synthetases (OAS) are interferon inducible enzymes that polymerizes ATP to 2'-5'-linked oligomers of adenylate (2-5As). As part of the innate immune response, these enzymes are activated by viral double stranded RNA or mRNAs with significant double stranded structure. The 2-5As in turn activate RNaseL that degrade single stranded RNAs. Three distinct forms of OAS exist in human cells (OAS1, 2 and 3) with each form having multiple spliced variants. The OAS enzymes and their spliced variants have different enzyme activities. OAS enzymes also play a significant role in regulating multiple cellular processes such as proliferation and apoptosis. Moreover, Single nucleotide polymorphisms that alter OAS activity are also associated with viral infection, diabetes and cancer. Thus detection of OAS enzyme activity with a simple spectrophotometric method in cells will be important in clinical research. RESULTS: Here we propose a modified coupled spectrophotometric assay to detect 2-5 oligoadenylate synthetase (OAS) enzyme activity in prostate cell lines as a model system. The OAS enzyme from prostate cancer cell lysates was purified using Polyinosinic: polycytidylic acid (poly I:C) bound activated sepharose beads. The activated OAS enzyme eluted from Sepharose beads showed expression of p46 isoform of OAS1, generally considered the most abundant OAS isoform in elutes from DU14 cell line but not in other prostate cell line. In this assay the phosphates generated by the OAS enzymatic reaction is coupled with conversion of the substrate 2-amino-6-mercapto-7-methylpurine ribonucleoside (methylthioguanosine, a guanosine analogue; MESG) to a purine base product, 2-amino-6-mercapto-7-methylpurine and ribose1-phosphate via a catalyst purine nucleoside phosphorylase (phosphorylase) using a commercially available pyrophosphate kit. The absorbance of the purine base product is measured at 360 nm. The higher levels of phosphates detected in DU145 cell line indicates more activity of OAS in this prostate cancer cell line. CONCLUSION: The modified simple method detected OAS enzyme activity with sensitivity and specificity, which could help in detection of OAS enzymes avoiding the laborious and radioactive methods.

Central Sleep Apnea in Kidney Disease.

Sleep is an essential function of life and serves a crucial role in the promotion of health and performance. Poor sleep quality and sleep disorders have been a recurrent finding in patients with chronic kidney disease (CKD). Sleep disorders such as obstructive sleep apnea (OSA) can contribute to hypertension, diabetes, cardiovascular disease, and worsen obesity, all of which are implicated in the etiology of CKD, but CKD itself may lead to OSA. Relationships between CKD/end-stage renal disease (ESRD) and OSA have been the subject of numerous investigations, but central sleep apnea (CSA) also is highly prevalent in CKD/ESRD but remains poorly understood, underdiagnosed, and undertreated in these patients. Emerging literature has implicated CSA as another contributor to morbidity and mortality in CKD/ESRD, and several studies have suggested that CSA treatment is beneficial in improving these outcomes. Patients with CKD/ESRD co-existing with congestive heart failure are particularly prone to CSA, and studies focused on managing CSA in congestive heart failure patients have provided important information concerning how best to manage CSA in kidney disease as well. Adaptive servo-ventilation ultimately may represent the treatment of choice in these patients, although a stepped approach using a variety of therapeutic modalities is recommended.

Solid self microemulsification of Atorvastatin using hydrophilic carriers: a design.

CONTEXT: Atorvastatin has a limited advantage to formulate oral dosage forms. OBJECTIVE: To enhance the solubility of Atorvastatin and to design the suitable solid self-microemulsifying drug delivery systems (S-SMEDDS) Materials and methods: The clear and transparent self-microemulsifying drug delivery system (SMEDDS) were formulated using coconut oil and isopropyl myristate as lipid phases; Tween 80 as surfactant; PEG 400 and glycerin as co-surfactant at 2:1, 3:1, 1:2 and 1:3 ratio. The pseudo ternary phase diagrams were constructed to identify the microemulsion region. The SMEDDS were evaluated for zeta potential, poly dispersity index, globule size, pH, viscosity and drug release. The solid SMEDDS were developed by employing adsorption and melt granulation methods. The S-SMEDDS were evaluated for micromeritics, morphology, solid state property, reconstitution ability, drug release and stability. RESULTS: The micro formulations formed with particle size of 25 nm had shown a 3-folds rise in drug release. The solid SMEDDS had reconstituted to a good microemulsion rapidly in 1-3 min, with a release of 94.62% at the end of 30 min and behaved as immediate releasing capsules. Their shelf-life was found to be 1.3 years. DISCUSSION: The 1:3 ratio SMEDDS had shown more drug release owing to their less particle size. The solid SMEDDS had shown an increased dissolution profiles than atorvastatin. The solid state of the drug had changed in formulation inferring their enhanced solubility. CONCLUSION: The solid form of atorvastatin liquid SMEDDS had been formulated successfully with enhanced shelf life and solubility.

An overview on in situ micronization technique - An emerging novel concept in advanced drug delivery.

The use of drug powders containing micronized drug particles has been increasing in several pharmaceutical dosage forms to overcome the dissolution and bioavailability problems. Most of the newly developed drugs are poorly water soluble which limits dissolution rate and bioavailability. The dissolution rate can be enhanced by micronization of the drug particles. The properties of the micronized drug substance such as particle size, size distribution, shape, surface properties, and agglomeration behaviour and powder flow are affected by the type of micronization technique used. Mechanical communition, spray drying and supercritical fluid (SCF) technology are the most commonly employed techniques for production of micronized drug particles but the characteristics of the resulting drug product cannot be controlled using these techniques. Hence, a newer technique called in situ micronization is developed in order to overcome the limitations associated with the other techniques. This review summarizes the existing knowledge on in situ micronization techniques. The properties of the resulting drug substance obtained by in situ micronization were also compared.

Transmucosal delivery of metformin- a comprehensive study.

Discovered in the 1920s, the biguanide metformin hydrochloride is still the first line drug in the management of Type 2 diabetes mellitus. Metformin hydrochloride is absorbed slowly and incompletely from the gastrointestinal tract. The present research work was undertaken with the aim of developing a fast dissolving film of metformin hydrochloride, suitable for oral trans mucosal administration. Fast dissolving films allow rapid drug dissolution in the oral cavity, ensuring bypass of first pass metabolism resulting in rapid absorption. Films of metformin were prepared by solvent casting method using Hydroxypropyl methylcellulose K15 (HPMC). Six formulations (F1-F6) of metformin hydrochloride were prepared and evaluated for their physical characteristics such as tackiness, thickness, tensile strength, elongation, weight variation, folding endurance, drug content and surface pH. The compatibility of the drug with HPMC was confirmed by FTIR studies. The formulations were subjected to disintegration, in-vitro drug release and the optimised formulation was evaluated for pharmacodynamic studies in diabetic rats. Among the formulations (F1-F6) F4 was found to be the best formulation which contained Hydroxypropyl methyl cellulose K15 at weight ratios of 1:4 and showed excellent film forming characteristics such as disintegration time at 42 sec and percentage drug release of 94.2% within 5 minutes. Pharmacodynamic assessment in diabetes induced rats demonstrated that the fast dissolving films of metformin had a quicker onset of action compared to conventional formulation.

Isolation, structure, and functional elucidation of a modified pentapeptide, cysteine protease inhibitor (CPI-2081) from Streptomyces species 2081 that exhibit inhibitory effect on cancer cell migration.

Cysteine proteases play an important role in cell migration and tumor metastasis. Therefore, their inhibitors are of colossal interest, having potential to be developed as effective antimetastatic drugs for tumor chemotherapy. Traditionally, secondary metabolites from streptomyces show a wide range of diversity with respect to their biological activity and chemical nature. In this article, we have described the characterization of small molecule cysteine protease inhibitor, CPI-2081 (compound 1), a mixture of two novel pentapeptides, compound 1a (736.71 Da), and compound 1b (842.78 Da), isolated from Streptomyces species NCIM2081, following solvent extraction and repeated HPLC based on C18 chemistry, and completely characterized using a variety of both 1D and 2D NMR spectroscopy. Further, it was found that nanomolar concentration of compound 1 is able to inhibit papain hydrolytic activity. Also, compound 1 significantly inhibits tumor cell migration at sub cytotoxic concentration, indicating its remarkable potential to be developed as antimetastatic drug, which will make chemotherapy more localized and specific, thereby minimizing the hazardous side effects on normal tissues.

XMRV infection in patients with prostate cancer: novel serologic assay and correlation with PCR and FISH.

OBJECTIVES: To develop a serum-based assay to detect neutralizing antibodies to the xenotropic murine leukemia virus-related virus (XMRV) retrovirus and to use this assay with polymerase chain reaction and fluorescence in situ hybridization to identify patients with prostate cancer previously exposed to XMRV infection and those who carry XMRV viral sequences in their prostate. METHODS: Patients who had undergone radical prostatectomy were enrolled, and biologic specimens were obtained at surgery. The patients were genotyped for the R462Q RNASEL variant using a TaqMan genotyping assay on DNA from the peripheral blood. A serum assay that detects XMRV neutralizing antibodies was developed and used to determine which patients had serologic evidence of previous infection with XMRV virus. Some of these patients were also tested for the presence of XMRV nucleotide sequences in their prostate using polymerase chain reaction and fluorescence in situ hybridization analysis. RESULTS: At a serum dilution of 1:150, our assay detected 11 (27.5%) of 40 patients with XMRV neutralizing antibodies, including 8 (40%) of 20 with the RNASEL genotype QQ and 3 (15%) of 20 with either the RQ or RR genotype. These results were in complete concordance with 2 other assays (polymerase chain reaction and fluorescence in situ hybridization), which were designed to detect XMRV infection. CONCLUSIONS: XMRV infects some patients with prostate cancer. Neutralizing antibodies against XMRV correlated with 2 independent methods of detecting the virus in the prostate. The antibody response suggests that with clinical serologic assay development, it might be possible to screen patients for XMRV infection. The cases presented in the present report provided biologic samples that can be used for the development of a clinically relevant assay.