Absolute emission intensities of the gamma rays from the decay of 224Ra and 212Pb progenies and the half-life of the 212 Pb decay.

Absolute gamma-ray emission intensities for 36 characteristic gamma rays from the decay of 224Ra, 212Pb, and their progeny were determined by measuring sources calibrated for activity by means of primary methods based on well-defined high-purity germanium (HPGe) detectors at both NIST and NPL. Results from the two laboratories agree with recent data evaluations, except for gamma rays with low emission intensities. The decay schemes have been re-balanced based on the new results. In addition, the half-life for 212Pb was measured using several HPGe detectors, ionization chambers, and a well-type NaI(Tl) detector.

Determination of the Terbium-152 half-life from mass-separated samples from CERN-ISOLDE and assessment of the radionuclide purity.

Terbium-152 is one of four terbium radioisotopes that together form a potential theranostic toolbox for the personalised treatment of tumours. As 152 Tb decay by positron emission it can be utilised for diagnostics by positron emission tomography. For use in radiopharmaceuticals and for activity measurements by an activity calibrator a high radionuclide purity of the material and an accurate and precise knowledge of the half-life is required. Mass-separation and radiochemical purification provide a production route of high purity 152Tb. In the current work, two mass-separated samples from the CERN-ISOLDE facility have been assayed at the National Physical Laboratory to investigate the radionuclide purity. These samples have been used to perform four measurements of the half-life by three independent techniques: high-purity germanium gamma-ray spectrometry, ionisation chamber measurements and liquid scintillation counting. From the four measurement campaigns a half-life of 17.8784(95) h has been determined. The reported half-life shows a significant difference to the currently evaluated half-life (ζ-score = 3.77), with a relative difference of 2.2 % and an order of magnitude improvement in the precision. This work also shows that under controlled conditions the combination of mass-separation and radiochemical separation can provide high-purity 152Tb.

Long-Term Biochemical Control of a Prospective Cohort of Prostate Cancer Patients Treated With Interstitial Brachytherapy Versus Radical Prostatectomy.

AIMS: To report long-term oncological outcomes of men treated prospectively as part of the American College of Surgeons Oncology Group phase III Surgical Prostatectomy Versus Interstitial Radiation Intervention Trial (SPIRIT) at our institution. MATERIALS AND METHODS: In 2003-2004, patients eligible for SPRIT attended a multidisciplinary educational session, following which they could choose radical prostatectomy, low dose rate brachytherapy (LDR-BT) or randomisation to SPIRIT. Biochemical failure was determined by the accepted definitions of a prostate-specific antigen (PSA) level ≥0.2 ng/ml after radical prostatectomy and the Phoenix definition of PSA ≥2 ng/ml above the nadir after LDR-BT. A sensitivity analysis, using a PSA >0.5 ng/ml to define biochemical failure after LDR-BT and a threshold PSA ≥0.2 ng/ml, was carried out to test the robustness of the results. To account for the competing risk of death, Gray's test was used to test the equality of the cumulative incidence function of biochemical failure between treatment groups. The Kaplan-Meier method was used to estimate overall survival and prostate cancer-specific survival. A P-value ≤0.05 was considered statistically significant. RESULTS: Of 156 patients, 100 received LDR-BT (15 after randomisation) and 56 underwent radical prostatectomy (15 after randomisation). The median follow-up was 12.6 and 14.7 years for LDR-BT and radical prostatectomy, respectively. The median age was 60 years; the median pre-treatment PSA was 5.5 (interquartile range 4.3-7.1). No significant differences in patient characteristics were found between groups. Two patients received adjuvant radiotherapy after radical prostatectomy. The cumulative incidence function of biochemical failure was 0%, 1.1% and 2.4% at 5, 10 and 15 years, respectively, in the LDR-BT arm versus 8.5%, 15.8% and 15.8% in the radical prostatectomy arm (P < 0.001). These results were consistent when varying the definition of biochemical failure defined as PSA ≥0.5 ng/ml (P = 0.01). At 15 years, overall survival was higher in patients treated with radical prostatectomy compared with those treated with LDR-BT; however, no statistical difference was found in prostate cancer-specific survival. CONCLUSION: In low-risk prostate cancer patients, LDR-BT offers excellent long-term oncological outcomes comparable with radical prostatectomy, in addition to the previously reported advantage for LDR-BT in urinary and sexual quality of life domains and patient satisfaction.

Comparative Effectiveness of Behavioral Interventions to Prevent or Delay Dementia: One-Year Partner Outcomes.

BACKGROUND/OBJECTIVE: Various behavioral interventions are recommended to combat the distress experienced by caregivers of those with cognitive decline, but their comparative effectiveness is poorly understood. DESIGN/SETTING: Caregivers in a comparative intervention study randomly had 1 of 5 possible interventions suppressed while receiving the other four. Caregivers in a full clinical program received all 5 intervention components. Care partner outcomes in the study group were compared to participants enrolled in a full clinical program. PARTICIPANTS: Two hundred and seventy-two dyads of persons with amnestic mild cognitive impairment (pwMCI) and care partners enrolled in the comparative intervention study. 265 dyads participated in the full clinical program. INTERVENTION: Behavioral intervention components included: memory compensation training, computerized cognitive training, yoga, support group, and wellness education. Each was administered for 10 sessions over 2 weeks. MEASUREMENTS: A longitudinal mixed-effect regression model was used to analyze the effects of the interventions on partner burden, quality of life (QoL), mood, anxiety, and self-efficacy at 12 months follow-up. RESULTS: At 12 months, withholding wellness education or yoga had a significantly negative impact on partner anxiety compared to partners in the clinical program (ES=0.55 and 0.44, respectively). Although not statistically significant, withholding yoga had a negative impact on partner burden and mood compared to partners in the full clinical program (ES=0.32 and 0.36, respectively). CONCLUSION: Our results support the benefits of wellness education and yoga for improving partner's burden, mood, and anxiety at one year. Our findings are the first to provide an exploration of the impact of multicomponent interventions in care partners of pwMCI.

A Phase II trial of 8 weeks of degarelix for prostate volume reduction: Efficacy and hormonal recovery.

PURPOSE: The purpose of this study was to determine the efficacy of 8 weeks of degarelix for prostate downsizing before interstitial brachytherapy. We also report associated toxicity and the time course of endocrine recovery over the following 12 months. METHODS AND MATERIALS: Fifty patients were accrued to an open-label Phase II clinical trial (www.clinicaltrials.gov ID NCT01446991). Baseline prostate transrectal ultrasound (TRUS) was performed on all patients followed by degarelix administration and a repeat TRUS at Week 8. Brachytherapy was performed within 4 weeks of the 8-week TRUS for all patients who achieved suitable downsizing. RESULTS: The median prostate volume was reduced from 65.0 cc (interquartile range [IQR]: 55.2-80.0 cc) to 48.2 cc at 8 weeks (IQR: 41.2-59.3 cc), representing a median decrease of 26.2% (IQR: 21-31%). Functional recovery of testosterone within an age-adjusted normal range occurred at a median of 34.1 weeks (IQR: 28.2-44.5 weeks) from the date of the final injection. Despite this recovery, follicle-stimulating hormone and luteinizing hormone levels remained abnormally elevated throughout 12 months. Quality-of-life implications are discussed. CONCLUSIONS: Degarelix is effective for prostate downsizing before prostate brachytherapy with a median volume decrease of 26.2% by 8 weeks. Despite the short course of treatment and eventual testosterone recovery, follicle-stimulating hormone and luteinizing hormone remain elevated beyond 12 months. Further investigation with randomized comparisons to other hormonal agents is warranted.

Chronic implantation of cuff electrodes on the pelvic nerve in rats is well tolerated and does not compromise afferent or efferent fibre functionality.

OBJECTIVE: Neuromodulation of autonomic nerve activity to regulate physiological processes is an emerging field. Vagal stimulation has received most attention whereas the potential of modulate visceral function by targeting autonomic nerves within the abdominal cavity remains under-exploited. Surgery to locate intra-abdominal targets is inherently more stressful than for peripheral nerves. Electrode leads risk becoming entrapped by intestines and loss of functionality in the nerve-target organ connection could result from electrode migration or twisting. Since nociceptor afferents are intermingled with similar-sized visceral autonomic fibres, stimulation may induce pain. In anaesthetised rats high frequency stimulation of the pelvic nerve can suppress urinary voiding but it is not known how conscious animals would react to this procedure. Our objective therefore was to determine how rats tolerated chronic implantation of cuff electrodes on the pelvic nerve, whether nerve stimulation would be aversive and whether nerve-bladder functionality would be compromised. APPROACH: We carried out a preliminary de-risking study to investigate how conscious rats tolerated chronic implantation of electrodes on the pelvic nerve, their responsiveness to intermittent high frequency stimulation and whether functionality of the nerve-bladder connection became compromised. MAIN RESULTS: Implantation of cuff electrodes was well-tolerated. The normal diurnal pattern of urinary voiding was not disrupted. Pelvic nerve stimulation (up to 4 mA, 3 kHz) for 30 min periods evoked mild alerting at stimulus onset but no signs of pain. Stimulation evoked a modest (<0.5 °C) increase in nerve temperature but the functional integrity of the nerve-bladder connection, reflected by contraction of the detrusor muscle in response to 10 Hz nerve stimulation, was not compromised. SIGNIFICANCE: Chronic implantation of cuff electrodes on the pelvic nerve was found to be a well-tolerated procedure in rats and high frequency stimulation did not lead to loss of nerve functionality. Pelvic nerve stimulation has development potential for normalizing voiding dysfunction in conscious rats.

A comparison of electronic and manual fracture risk assessment tools in screening elderly male US veterans at risk for osteoporosis.

This study compares four screening tools in their ability to predict osteoporosis. We found that there was no significant difference between the tools. These results provide support for the use of automated screening tools which work in conjunction with the electronic medical record and help improve screening rates for osteoporosis. INTRODUCTION: The purpose of this study is to compare the performance of four fracture risk assessment tools (FRATs) in identifying osteoporosis by bone mineral density (BMD) T-score: Veterans Affairs Fracture Absolute Risk Assessment Tool (VA-FARA), World Health Organization's Fracture Risk Assessment Tool (FRAX), electronic FRAX (e-FRAX), and Osteoporosis Self-Assessment Screening Tool (OST). METHODS: We performed a cross-sectional analysis of all patients enrolled in the VA Salt Lake City bone health team (BHT) who had completed a DXA scan between February 1, 2012, and February 1, 2013. DXA scan results were obtained by chart abstraction. For calculation of FRAX, osteoporosis risk factors were obtained from a screening questionnaire completed prior to DXA. For VA-FARA and e-FRAX, risk factors were derived from the electronic medical record (EMR). Clinical risk scores were calculated and compared against the gold standard of DXA-based osteoporosis. Sensitivity, specificity, and predictive values were calculated. Receiver operator characteristic (ROC) curves were plotted, and areas under the curve (AUC) were compared. RESULTS: A cohort of 463 patients met eligibility criteria (mean age 80.4 years). One hundred twelve patients (24%) had osteoporosis as defined by DXA T-score ≤-2.5. Sensitivity, specificity, and predictive values were calculated. ROC statistics were compared and did not reach statistical significance difference between FRATs in identifying DXA-based osteoporosis. CONCLUSIONS: Our study suggests that all FRATs tested perform similarly in identifying osteoporosis among elderly, primarily Caucasian, male veterans. If these electronic screening methods perform similarly for fracture outcomes, they could replace manual FRAX and thus improve efficiency in identifying individuals who should be sent for DXA scan.

Use of magnetic resonance imaging in low-dose-rate and high-dose-rate prostate brachytherapy from diagnosis to treatment assessment: Defining the knowledge gaps, technical challenges, and barriers to implementation.

MRI is rapidly evolving as an imaging tool in both low-dose-rate and high-dose-rate brachytherapy for prostate cancer. The ability of MRI to identify intraprostatic tumors and reduce uncertainties in the workflow process should enable a more accurate and precise radiation delivery approach while simultaneously improving the quality assurance process. The ability to identify functional anatomic structures adjacent to the prostate cancer could reduce or eliminate some of the more common side effects of the treatment. However, MRI is complex, and collaborative efforts and future research are required to address the current knowledge gaps, technical challenges, and barriers to widespread the implementation of MRI-assisted and MRI-guided prostate brachytherapy.

Transperineal biopsies of MRI-detected aggressive index lesions in low- and intermediate-risk prostate cancer patients: Implications for treatment decision.

PURPOSE: Multiparametric MRI (mpMRI) has a potential role for the identification of aggressive cancer that can be targeted for biopsy. We report the incidence and severity of discordant information between the pathology found on the transrectal ultrasound (TRUS)-guided biopsy and the mpMRI findings in patients with favorable or intermediate-risk prostate cancer referred for brachytherapy. METHODS AND MATERIALS: From March 2014 to September 2015, 10/44 consecutive patients with low- or intermediate-risk prostate cancer referred for brachytherapy presented an aggressive lesion on mpMRI and underwent an MRI-TRUS fusion-guided transperineal biopsy of the index lesion. RESULTS: A median of two intraprostatic lesions were detected by mpMRI for each patient. Three patients had bilateral disease, and seven had unilateral disease on mpMRI. The median number of cores obtained by MRI-TRUS-guided fusion of the index lesion was 3 (range 2-4). As a result of the re-evaluation consequent to additional information becoming available after the transperineal biopsy, upgrading of Gleason score occurred in 8 of the 10 patients, which changed the risk group in 9 patients. These changes resulted in modification of the proposed treatment in 8 patients. CONCLUSIONS: MpMRI-US fusion-targeted biopsy sampling allows detection and characterization of otherwise undetected aggressive disease, often placing men in higher risk groups and altering the treatment approach.

Stereotactic Ablative Radiotherapy Versus Low Dose Rate Brachytherapy or External Beam Radiotherapy: Propensity Score Matched Analyses of Canadian Data.

AIMS: To compare biochemical failure-free survival (BFFS) and overall survival for prostate cancer treated with stereotactic ablative radiotherapy (SABR), low dose rate (LDR) brachytherapy or external beam radiotherapy (EBRT) using a large Canadian multi-institutional database. MATERIALS AND METHODS: Patients with low risk localised prostate cancer treated with SABR, LDR or EBRT and no androgen deprivation therapy were selected. Propensity score matching was used to create two sets of matched cohorts with LDR and EBRT serving as control groups. Kaplan-Meier survival analysis and Cox proportional hazards regression were used to compare differences in BFFS and overall survival between treatment groups. RESULTS: The pre-matched cohort contained 602 patients; the median follow-up was >5.0 years. There were no significant differences in BFFS before or after matching for SABR versus LDR but the prostate-specific antigen (PSA) nadir was lower after LDR. For the SABR versus EBRT, SABR had a BFFS trend before matching (P = 0.08), which became significant after matching (P < 0.001). CONCLUSIONS: Using the Genitourinary Radiation Oncologists of Canada Prostate Cancer Risk Stratification database, low risk prostate cancer patients receiving SABR had similar BFFS compared with patients receiving LDR but better BFFS than EBRT patients. Further comparative studies of efficacy, quality of life and economic outcomes using a broader risk of patients are warranted.

Urodynamic function during sleep-like brain states in urethane anesthetized rats.

The aim was to investigate urodynamic parameters and functional excitability of the periaqueductal gray matter (PAG) during changes in sleep-like brain states in urethane anesthetized rats. Simultaneous recordings of detrusor pressure, external urethral sphincter (EUS) electromyogram (EMG), cortical electroencephalogram (EEG), and single-unit activity in the PAG were made during repeated voiding induced by continuous infusion of saline into the bladder. The EEG cycled between synchronized, high-amplitude slow wave activity (SWA) and desynchronized low-amplitude fast activity similar to slow wave and 'activated' sleep-like brain states. During (SWA, 0.5-1.5 Hz synchronized oscillation of the EEG waveform) voiding became more irregular than in the 'activated' brain state (2-5 Hz low-amplitude desynchronized EEG waveform) and detrusor void pressure threshold, void volume threshold and the duration of bursting activity in the external urethral sphincter EMG were raised. The spontaneous firing rate of 23/52 neurons recorded within the caudal PAG and adjacent tegmentum was linked to the EEG state, with the majority of responsive cells (92%) firing more slowly during SWA. Almost a quarter of the cells recorded (12/52) showed phasic changes in firing rate that were linked to the occurrence of voids. Inhibition (n=6), excitation (n=4) or excitation/inhibition (n=2) was seen. The spontaneous firing rate of 83% of the micturition-responsive cells was sensitive to changes in EEG state. In nine of the 12 responsive cells (75%) the responses were reduced during SWA. We propose that during different sleep-like brain states changes in urodynamic properties occur which may be linked to changing excitability of the micturition circuitry in the periaqueductal gray.

Effects of UV irradiation in a continuous turbulent flow UV reactor on microbiological and sensory characteristics of cow's milk.

The dairy industry under current pasteurization conditions (15 s at 72°C) and sanitary standards achieves a safe product with excellent quality. In an ever-competitive market there is still a need to improve product quality and extend shelf life of dairy products to increase competitiveness and open up new markets. In an attempt to test the effect of UV irradiation on microbiota of fluid milk, a continuous flow UV system at 254 nm was used to treat 3.5 and 2% fat milk at two UV doses (880 and 1,760 J liter(-1)). Milk was obtained from three processors, and two lots from each processor were assessed. To assess the impact on the most descriptive native microbiota in pasteurized milk after UV illumination, the product was held at two storage temperatures (4 and 7°C) and tested weekly for 5 weeks for aerobic plate counts (psychrotrophic and mesophilic bacteria), laboratory pasteurization counts, aerobic sporeformers, coliform organisms, and titratable acidity. Microbial counts for all tested microorganisms were lower in UV-treated milk when compared with control throughout storage at 4 and 7°C in both 3.5 and 2% fat milk. Sensory analysis indicated that there is a sensory defect associated with UV treatment at the wavelength used.

Undetectable sensitive serum thyroglobulin (<0.1 ng/ml) in 163 patients with follicular cell-derived thyroid cancer: results of rhTSH stimulation and neck ultrasonography and long-term biochemical and clinical follow-up.

CONTEXT: Surveillance of patients with differentiated thyroid cancer (DTC) is achieved using serum thyroglobulin (Tg), neck ultrasonography (US), and recombinant human TSH (rhTSH)-stimulated Tg (Tg-stim). OBJECTIVE: Our primary aim was to assess the utility of rhTSH Tg-stim in patients with suppressed Tg (Tg-supp) below 0.1 ng/ml using a sensitive assay. Our secondary aims were to assess the utility of US and to summarize the profile of subsequent Tg-supp measures. DESIGN: This is a retrospective study conducted at two sites of an academic institution. PATIENTS: A total of 163 patients status after thyroidectomy and radioactive iodine treatment who had Tg-supp below 0.1 ng/ml and rhTSH Tg-stim within 60 d of each other were included. RESULTS: After rhTSH stimulation, Tg remained below 0.1 ng/ml in 94 (58%) and increased to 0.1-0.5 in 56 (34%), more than 0.5-2.0 in nine (6%), and above 2.0 ng/ml in four (2%) patients. Serial Tg-supp levels were obtained in 138 patients followed over a median of 3.6 yr. Neck US were performed on 153 patients; suspicious exams had fine-needle aspiration (FNA). All positive FNA were identified around the time of the initial rhTSH test. Six of seven recurrences were detected by US (Tg-stim >2.0 ng/ml in one, 0.8 in one and ≤ 0.5 in four). One stage IV patient had undetectable Tg-stim. CONCLUSION: In patients with DTC whose T(4)-suppressed serum Tg is below 0.1 ng/ml, long-term monitoring with annual Tg-supp and periodic neck US are adequate to detect recurrences. In our experience, rhTSH testing does not change management and is not needed in this group of patients.

A comparison of high definition-image enhanced colonoscopy and standard white-light colonoscopy for colorectal polyp detection.

BACKGROUND AND STUDY AIMS: Colonoscopy is widely used to detect and remove precancerous polyps, but fails to detect some polyps. Recent studies evaluating different image-enhanced methods have revealed conflicting results. The efficacy of colonoscopy imaging with simultaneous use of commercially available improvements, including high definition narrow band imaging (HD-NBI), and monochromatic charge-coupled device (CCD) video, was compared with a widely used standard definition white light (SDWL) colonoscopy system for detecting colorectal polyps. The primary aim was to determine whether the combination of image-enhanced colonoscopy systems resulted in fewer missed polyps compared with conventional colonoscopy. PATIENTS AND METHODS: In a randomized controlled trial (Clinicaltrials.gov. study number NCT00825292) patients having routine screening and surveillance underwent tandem colonoscopies with SDWL and image-enhanced (HD-NBI) colonoscopy. The main outcome measurement was the per-polyp false-negative ("miss") rate. Secondary outcomes were adenoma miss rate, and per-patient polyp and adenoma miss rates. RESULTS: 100 patients were randomized and 96 were included in the analysis. In total, 177 polyps were detected; of these, 72 (41 %) were adenomatous. Polyp and adenoma miss rates for SDWL colonoscopy were 57 % (60/105) and 49 % (19/39); those for image-enhanced colonoscopy were 31 % (22/72) and 27 % (9/33) (P = 0.005 and P = 0.036 for polyps and adenomas, respectively). Image-enhanced and SDWL approaches had similar per-patient miss rates for polyps (6/35 vs. 9/32, P = 0.27) and adenomas (4/22 vs. 8/20, P = 0.11). CONCLUSIONS: Utilization of multiple recent improvements in image-enhanced colonoscopy was associated with a reduced miss rate for all polyps and for adenomatous polyps. It is not known which individual feature or combination of image-enhancement features led to the improvement.

Association of surgeon with surgical site infection after liver transplantation.

Surgical site infection (SSI) after liver transplantation has been associated with increased risk of allograft loss and death. Identification of modifiable risk factors for these infections is imperative. To our knowledge, intraoperative practices associated with transplant surgeons have not been assessed as a risk factor. A retrospective cohort study of risk factors for SSI after 1036 first liver transplantations completed by seven surgeons at a single center between 2003 and 2008 was undertaken. Cox proportional hazards models were used to evaluate the association between surgeons and SSIs. SSIs were identified in 166 of 1036 patients (16%). Single variable analysis showed strong evidence of an association between surgeon and SSI (p = 0.0007); the estimated cumulative incidence of SSI ranged from 7% to 24%. This result was consistent in multivariable analysis adjusting for potentially confounding variables (p = 0.002). The occurrence of organ-space or deep SSI varied significantly among surgeons in both single variable analysis (p = 0.005) and multivariable analysis (p = 0.006). These findings provide evidence that differences in the surgical practices of individual surgeons are associated with risk for SSI after liver transplantation. Identification of specific surgical practices associated with risk of SSI is warranted.

The role of brachytherapy in the definitive management of prostate cancer.

Over the past two decades, brachytherapy has played an ever expanding role in the definitive radiotherapy of prostate cancer. Brachytherapy surpasses external beam radiotherapy in its ability to deliver intense intraprostatic dose escalation. Although initially low dose rate permanent seed brachytherapy was favored for favorable risk prostate cancers, and high dose rate temporary brachytherapy for intermediate and advanced disease, both types of brachytherapy now have a place across all the risk groups of localized prostate cancer. This article will review indications and patient selection, planning and technical aspects, toxicity and efficacy for both low and high dose rate prostate brachytherapy.

SNCA, MAPT, and GSK3B in Parkinson disease: a gene-gene interaction study.

BACKGROUND AND PURPOSE: Recent evidence suggests that variation in the SNCA, MAPT, and GSK3B genes interacts in affecting risk for Parkinson disease (PD). In the current study, we attempt to validate previously published findings, evaluating gene-gene interactions between SNCA, MAPT, and GSK3B in association with PD. METHODS: Three Caucasian PD patient-control series from the United States, Ireland, and Norway (combined n = 1020 patients and 1095 controls) were genotyped for SNCA rs356219, MAPT H1/H2-discriminating SNP rs1052553, and GSK3B rs334558 and rs6438552. RESULTS: Our findings indicate that as previously reported, the SNCA rs356219-G allele and MAPT rs1052553 (H1 haplotype) were both associated with an increased risk of PD, whilst contrary to previous reports, GSK3B variants were not. No pair-wise interaction was observed between SNCA, MAPT, and GSK3B; the risk effects of SNCA rs356219-G and MAPT rs1052553-H1 were seen in a similar manner across genotypes of other variants, with no evidence suggesting synergistic, antagonistic, or deferential effects. CONCLUSIONS: In the Caucasian patient-control series examined, risk for PD was influenced by variation in SNCA and MAPT but not GSK3B. Additionally, those three genes did not interact in determining disease risk.

TMEM106B regulates progranulin levels and the penetrance of FTLD in GRN mutation carriers.

OBJECTIVES: To determine whether TMEM106B single nucleotide polymorphisms (SNPs) are associated with frontotemporal lobar degeneration (FTLD) in patients with and without mutations in progranulin (GRN) and to determine whether TMEM106B modulates GRN expression. METHODS: We performed a case-control study of 3 SNPs in TMEM106B in 482 patients with clinical and 80 patients with pathologic FTLD-TAR DNA-binding protein 43 without GRN mutations, 78 patients with FTLD with GRN mutations, and 822 controls. Association analysis of TMEM106B with GRN plasma levels was performed in 1,013 controls and TMEM106B and GRN mRNA expression levels were correlated in peripheral blood samples from 33 patients with FTLD and 150 controls. RESULTS: In our complete FTLD patient cohort, nominal significance was identified for 2 TMEM106B SNPs (top SNP rs1990622, p(allelic) = 0.036). However, the most significant association with risk of FTLD was observed in the subgroup of GRN mutation carriers compared to controls (corrected p(allelic) = 0.0009), where there was a highly significant decrease in the frequency of homozygote carriers of the minor alleles of all TMEM106B SNPs (top SNP rs1990622, CC genotype frequency 2.6% vs 19.1%, corrected p(recessive) = 0.009). We further identified a significant association of TMEM106B SNPs with plasma GRN levels in controls (top SNP rs1990622, corrected p = 0.002) and in peripheral blood samples a highly significant correlation was observed between TMEM106B and GRN mRNA expression in patients with FTLD (r = -0.63, p = 7.7 × 10(-5)) and controls (r = -0.49, p = 2.2 × 10(-10)). CONCLUSIONS: In our study, TMEM106B SNPs significantly reduced the disease penetrance in patients with GRN mutations, potentially by modulating GRN levels. These findings hold promise for the development of future protective therapies for FTLD.