Citations

Abstract Objective.—To assess laboratory performance, use, and limitations in the joint College of American Pathologists and American College of Medical Genetics proficiency testing program for laboratories performing cytogenetic tests based on fluorescence in situ hybridization (FISH). Data Sources.—Eight proficiency surveys dealing with FISH detection of microdeletions or microduplications, aneuploidy in interphase cells, gene amplification, and neoplasm-specific translocations. Participating laboratories used their own DNA probes (commercial or home-brew), hybridization methods, and analytic criteria to answer clinical questions about cases represented by slides included in the survey materials. They also described their test results according to the International System for Human Cytogenetic Nomenclature (ISCN) and answered supplementary questions relating to their experience with the subject test systems. Data Extraction.—In addition to evaluating diagnostic accuracy, we evaluated survey use, laboratory experience, variation in methodologic approach, and the practicality of using ISCN nomenclature for describing test results. Synthesis and Conclusions.—With the exception of one challenge, at least 80% of the participants reached the correct diagnostic conclusion. In the sole exception, there was still a consensus of 91.7% of participants with the same (albeit erroneous) diagnostic conclusion. The overall outstanding performance of participating laboratories clearly shows the reliability of current FISH methods. Despite the fact that a large number of laboratories reported little or no experience with the specific test systems, the overwhelming majority performed very well. This result shows that the program's strategy of targeting classes of abnormalities (vs a single abnormality associated with a specific disease) did not put at a disadvantage participants who did not routinely perform all of the potential tests in the class. The extraordinary variation in ISCN descriptions submitted by participants showed that the existing system for human cytogenetic nomenclature is not suitable for facile communication of FISH test results.

Abstract Objective. —To assemble and interpret karyotype data provided as part of the College of American Pathologists/American College of Medical Genetics Cytogenetics Proficiency Testing Program. Data Sources, Extraction, and Synthesis. —The Cytogenetics Resource Committee requested data on all cells analyzed in a 1994 whole-blood specimen challenge. In that study, 287 participating laboratories analyzed a total of 14297 cells derived from a sample drawn from an adult donor with Turner syndrome. This individual had previously been found to have mosaicism, including cell lines with X structural anomalies along with monosomy X, making this an excellent challenge for a multicenter cytogenetic survey. Results and Conclusions. —Analysis of the data from this extensive study revealed mosaicism of up to 10 different sex chromosome complements involving the X chromosome with and without a small ring X or a derivative X chromosome. In the routine cytogenetic analysis performed by the participating laboratories, cell lines observed, in decreasing order of prevalence, included 45,X (n = 8357 cells), 46,X,r(X) (n = 3597), 46,X,der( X )t( X ;X) (n = 2237), 46,XX (n = 93), 47,X,r(X),r(X) (n = 5), 47,X,der( X )t( X ;X),der( X )t( X ;X) (n = 3), 47,XX,r(X) (n = 2), and one observation each of 47,XX,der( X )t( X ;X), 47,X,der( X )t( X ;X),r(X), and 47,XXX. Our molecular cytogenetic data, as well as detailed analysis of G-banded chromosomes, suggest the nomenclature for these 2 abnormal X chromosomes as r(X)(p11.3q21.3) and der( X )t( X ;X)(p11.3;q21.3), and we discuss models for the concomitant formation of these 2 entities. Both the degree of analysis and the extensive mosaicism that was discovered in this study are exceptional, and similar reported cases as well as possible mechanisms for the observed X chromosome instability are reviewed.

Filarial worms cause multiple debilitating diseases in millions of people worldwide, including river blindness. Currently available drugs reduce transmission by killing larvae (microfilariae), but there are no effective cures targeting the adult parasites (macrofilaricides) which survive and reproduce in the host for very long periods. To identify effective macrofilaricides, we carried out phenotypic screening of a library of 2121 approved drugs for clinical use against adult Brugia pahangi and prioritized the hits for further studies by integrating those results with a computational prioritization of drugs and associated targets. This resulted in the identification of 18 hits with anti-macrofilaricidal activity, of which two classes, azoles and aspartic protease inhibitors, were further expanded upon. Follow up screening against Onchocerca spp. (adult Onchocerca ochengi and pre-adult O. volvulus) confirmed activity for 13 drugs (the majority having IC50 < 10 μM), and a counter screen of a subset against L. loa microfilariae showed the potential to identify selective drugs that prevent adverse events when co-infected individuals are treated. Stage specific activity was also observed. Many of these drugs are amenable to structural optimization, and also have known canonical targets, making them promising candidates for further optimization that can lead to identifying and characterizing novel anti-macrofilarial drugs.

PURPOSE This trial assessed the utility of applying tumor DNA sequencing to treatment selection for patients with advanced, refractory cancer and somatic mutations in one of four signaling pathways by comparing the efficacy of four study regimens that were either matched to the patient's aberrant pathway (experimental arm) or not matched to that pathway (control arm). MATERIALS AND METHODS Adult patients with an actionable mutation of interest were randomly assigned 2:1 to receive either (1) a study regimen identified to target the aberrant pathway found in their tumor (veliparib with temozolomide or adavosertib with carboplatin [DNA repair pathway], everolimus [PI3K pathway], or trametinib [RAS/RAF/MEK pathway]), or (2) one of the same four regimens, but chosen from among those not targeting that pathway. RESULTS Among 49 patients treated in the experimental arm, the objective response rate was 2% (95% CI, 0% to 10.9%). One of 20 patients (5%) in the experimental trametinib cohort had a partial response. There were no responses in the other cohorts. Although patients and physicians were blinded to the sequencing and random assignment results, a higher pretreatment dropout rate was observed in the control arm (22%) compared with the experimental arm (6%; P = .038), suggesting that some patients may have had prior tumor mutation profiling performed that led to a lack of participation in the control arm. CONCLUSION Further investigation, better annotation of predictive biomarkers, and the development of more effective agents are necessary to inform treatment decisions in an era of precision cancer medicine. Increasing prevalence of tumor mutation profiling and preference for targeted therapy make it difficult to use a randomized phase II design to evaluate targeted therapy efficacy in an advanced disease setting.

ObjectivesTo quantify the bias of shear wave speed (SWS) measurements between different commercial ultrasonic shear elasticity systems and a magnetic resonance elastography (MRE) system in elastic and viscoelastic phantoms.MethodsTwo elastic phantoms, representing healthy through fibrotic liver, were measured with 5 different ultrasound platforms, and 3 viscoelastic phantoms, representing healthy through fibrotic liver tissue, were measured with 12 different ultrasound platforms. Measurements were performed with different systems at different sites, at 3 focal depths, and with different appraisers. The SWS bias across the systems was quantified as a function of the system, site, focal depth, and appraiser. A single MRE research system was also used to characterize these phantoms using discrete frequencies from 60 to 500 Hz.ResultsThe SWS from different systems had mean difference 95% confidence intervals of ±0.145 m/s (±9.6%) across both elastic phantoms and ± 0.340 m/s (±15.3%) across the viscoelastic phantoms. The focal depth and appraiser were less significant sources of SWS variability than the system and site. Magnetic resonance elastography best matched the ultrasonic SWS in the viscoelastic phantoms using a 140 Hz source but had a − 0.27 ± 0.027‐m/s (−12.2% ± 1.2%) bias when using the clinically implemented 60‐Hz vibration source.ConclusionsShear wave speed reconstruction across different manufacturer systems is more consistent in elastic than viscoelastic phantoms, with a mean difference bias of < ±10% in all cases. Magnetic resonance elastographic measurements in the elastic and viscoelastic phantoms best match the ultrasound systems with a 140‐Hz excitation but have a significant negative bias operating at 60 Hz. This study establishes a foundation for meaningful comparison of SWS measurements made with different platforms.

Abstract Background Mycobacterium septicum is a rapidly growing non-tuberculous mycobacterium. It is a ubiquitous organism capable of causing infections in both healthy and immunocompromised individuals. Only a few cases have been reported to date, and standard therapeutic regimens, and optimal treatment duration have not been defined. Methods We conducted a retrospective chart review of all patients seen at Mayo Clinic in Rochester, MN from July 2014 to March 2020 from whom Mycobacterium septicum was isolated in culture by our clinical microbiology laboratory. Results There were 12 patients identified with M. septicum infection – 7 males and 5 females. The average age was 67 years, with an age range of 48 to 80 years. Seven of 12 isolates obtained were from sputum samples. Only one patient was on immunosuppressive medication. Three cases were considered clinically significant infections for which directed anti-mycobacterial therapy was instituted. In two of these three cases, co-infection with Mycobacterium avium complex (MAC) was seen. Underlying structural lung disease was present in the two cases of pulmonary infections. Peritoneal dialysis catheter-related peritonitis was seen in the third case. All the isolates were susceptible to amikacin, ciprofloxacin, imipenem, linezolid, moxifloxacin, and trimethoprim-sulfamethoxazole (TMP-SMX). The isolates were resistant to clarithromycin and doxycycline. Patient Characteristics, Associated M. septicum Illness, and Therapy Provided Antimicrobial Susceptibility Profiles of the Mycobacterium septicum Isolates, MIC (mcg/mL) and Interpretation Patient Demographics and Specimen Source of Mycobacerium septicum Isolates Conclusion M. septicum is an unusual cause of non-tuberculous mycobacterial infection. The presence of a foreign body may increase the risk of infection. Individuals with underlying structural lung disease are also likely to be at increased risk of developing pulmonary infection. Generalized treatment recommendations are limited by the lack of prospective controlled trials; hence, optimal antibiotic regimen and treatment duration have not been firmly established. Susceptibility testing should be performed to guide treatment selection, but the use of combination therapy with potentially empiric agents like amikacin, ciprofloxacin, imipenem, linezolid, moxifloxacin, and TMP-SMX as demonstrated in this small study, can be considered. A high rate of macrolide resistance was noted in our study. Disclosures All Authors: No reported disclosures

Abstract Background Blastomycosis has historically been a difficult diagnosis to establish, often initially misdiagnosed as bacterial pneumonia. Serologic assays and polymerase chain reaction (PCR) tests are available, but their performance is not well defined. The objective of this study was to characterize their performance. Methods Subjects were identified via chart review of patients diagnosed with blastomycosis from 2005 to 2020. A definitive diagnosis was based on fungal culture, histopathology, or cytology. Performance characteristics of the Blastomyces antibody enzyme linked immunosorbent assay (ELISA), immunodiffusion (ID), complement fixation (CF), urine and serum antigen ELISAs, and PCR were evaluated in patients with confirmed blastomycosis. Data on patient demographics, location of disease, and mortality was also collected. Results We identified 193 patients with blastomycosis. The mean age was 51.8 years (range, 11-84) and 73.6% of patients were male. 42.5% resided in Minnesota, 18.1% in Wisconsin, and 12.9% in Iowa. Diagnosis was based on culture in 142 (73.2%) or histopathology/cytology in 67 (34.7%) patients. Granulomatous inflammation was present in 73.1% (38/52) while 21.2% (41/193) had evidence of extrapulmonary dissemination. The antibody, ID, and CF assays were positive in 43.5% (37/85), 35.1% (33/94) and 20.5% (8/39) of patients, respectively. Sensitivity of Blastomyces PCR was 40% (4/10) in sputum and 75% (21/28) in bronchoalveolar lavage (BAL) fluid. Blastomyces urine and serum antigen tests were positive in 68% (34/50) and 50% (9/18) of cases, respectively, while the urine antigen was positive in 63.6% (7/11) of disseminated cases. Patients had a positive Histoplasma urine antigen test in 54.1% (20/37) and Aspergillus galactomannan in BAL in 34.8% (8/23) of cases. Serum beta-D-glucan test was positive in 16.7% (2/12). 90-day mortality was 21/193 (10.9%) and median time from diagnosis to death was 18 days. Conclusion In this cohort, Blastomyces urine antigen was the most sensitive noninvasive test, with similar performance in pulmonary and disseminated disease. However, its utility is limited by poor specificity due to cross-reactivity. Blastomyces PCR from BAL fluid demonstrated the highest sensitivity. Blastomyces antibody, ID, and CF had poor sensitivity. Disclosures All Authors: No reported disclosures

Purpose: The purpose of this retrospective cohort study was to report the outcomes of high AC/A ratio accommodative esotropia (AET) among children. Methods: The medical records of all children <19 years diagnosed with accommodative esotropia and a high AC/A ratio while residing in Olmsted County, Minnesota, from January 1, 1975, through December 31, 2004, were retrospectively reviewed. Results: A total of 512 patients were diagnosed with AET during the 30-year study period, of which 395 (77.1%) had fully accommodative ET, 117 (22.8%) had partially accommodative ET and 106 (20.5%) had a high AC/A ratio. Of the 93 (87.7 %) high AC/A patients managed with bifocals, 50 (53.8 %) discontinued their use after a mean of 58.7 (range: 5.6–229) months. The Kaplan–Meier rate of discontinuing bifocals was 24.5% at 3 years, 36.4% at 5 years, and 61.4% at 10 years. Patients who discontinued bifocals were more likely to have had strabismus surgery (44% vs 18.6%, p = 0.009) than those who did not discontinue bifocals. The high AC/A patients managed with bifocals achieved similar stereoacuity outcomes to those who did not wear bifocals ( p = 0.65) and were no more likely to require surgery ( p = 0.13). Conclusion: Among this cohort of children with accommodative esotropia and a high AC/A ratio, bifocal use was discontinued in the majority of children within 10 years, and more commonly among those who underwent strabismus surgery. The use of bifocals was not associated with a higher likelihood of undergoing surgery or enhanced stereopsis compared to those who did not use them.