Retrospective Clinical Assessment Research Articles

Abstract B020: Targeting the DNA damage response sensor Replication Protein A for first in class cancer therapy

Abstract The DNA Damage Response (DDR) is a DNA repair and cell signaling pathway crucial in maintaining genomic stability. The most successful DDR targeted therapies inhibit the DNA damage sensor, PARP, a protein that recognizes single strand DNA (ssDNA) breaks as well as other DNA secondary structures induced by single strand gaps that can initiate chromosome instability and cell death. Building on the initial clinical success of PARP inhibitors, development of DDR targeted therapeutics has become increasingly popular with the majority of new agents targeting protein kinases downstream of the DNA damage sensors. The clinical outcomes with these therapeutics have not met expectations and thus a new approach to targeting the DDR pathway is needed. NERx Biosciences has developed a novel strategy of targeting the DDR by intervening upstream of the DDR kinases and targeting specific DDR sensors. The human ssDNA binding protein, replication protein A (RPA), is a critical sensor for the DDR, serving to sense ssDNA at replication forks that arise from replication stress (RS) and is a novel target for cancer therapy. We have discovered, developed, and characterized a novel small molecule RPA inhibitor (RPAi) NERx-329 that blocks the RPA-DNA interaction and elicits a state of chemical RPA exhaustion that results in in vivo anticancer activity. Chemical optimization enabled in vitro and in vivo analyses to elucidate mechanism of action, cellular engagement, and therapeutic activity of RPA-targeted agents. Biochemical reconstitution of the ATR signaling pathway shows that NERx-329 disrupts ATR kinase activity, further suggesting a novel mechanism of action driven by RPA inhibition induced replication catastrophe. NERx-329 elicits single agent in vitro anticancer activity across a broad spectrum of cancers and the cellular response suggests existence of a threshold before chemical RPA exhaustion induces cell death. In vivo analysis reveals activity in a series of lung and ovarian PDX models of human cancer. Single agent activity results in a tumor growth delay, which can be enhanced in combination therapy with DDR inhibitors as well as traditional DNA damaging cancer therapeutics. Data demonstrate that tumor growth observed in vivo is a function of NERx329 bioavailability and not development of a specific resistance mechanism. In addition, specific genetic predictors of RPAi sensitivity have been identified and results demonstrate specific genetic alterations increase RPAi activity in vitro and in vivo. NERx-329 represents the first clinically viable agent to target the DDR pathway by disrupting the RPA-DNA interaction and holds potential for significant impact in cancer treatment. This is supported by data from a retrospective clinical assessment of RPA expression to assess treatment outcomes in lung cancer patients, revealing that high RPA expression is a negative prognostic biomarker correlating with worse overall patient survival. NERx 329 offers a novel therapeutic approach for these cancers that are not effectively treated with existing therapeutics. Citation Format: Katherine Pawelczak, Pamela VanderVere-Carozza, Matthew Jordon, Navnath Gavande, John Turchi. Targeting the DNA damage response sensor Replication Protein A for first in class cancer therapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr B020.

Evaluation of the host immune response assay SeptiCyte RAPID for potential triage of COVID-19 patients

Tools for the evaluation of COVID-19 severity would help clinicians with triage decisions, especially the decision whether to admit to ICU. The aim of this study was to evaluate SeptiCyte RAPID, a host immune response assay (Immunexpress, Seattle USA) as a triaging tool for COVID-19 patients requiring hospitalization and potentially ICU care. SeptiCyte RAPID employs a host gene expression signature consisting of the ratio of expression levels of two immune related mRNAs, PLA2G7 and PLAC8, measured from whole blood samples. Blood samples from 146 adult SARS-CoV-2 (+) patients were collected within 48 h of hospital admission in PAXgene blood RNA tubes at Hospital del Mar, Barcelona, Spain, between July 28th and December 1st, 2020. Data on demographics, vital signs, clinical chemistry parameters, radiology, interventions, and SeptiCyte RAPID were collected and analyzed with bioinformatics methods. The performance of SeptiCyte RAPID for COVID-19 severity assessment and ICU admission was evaluated, relative to the comparator of retrospective clinical assessment by the Hospital del Mar clinical care team. In conclusion, SeptiCyte RAPID was able to stratify COVID-19 cases according to clinical severity: critical vs. mild (AUC = 0.93, p < 0.0001), critical vs. moderate (AUC = 0.77, p = 0.002), severe vs. mild (AUC = 0.85, p = 0.0003), severe vs. moderate (AUC = 0.63, p = 0.05). This discrimination was significantly better (by AUC or p-value) than could be achieved by CRP, lactate, creatine, IL-6, or D-dimer. Some of the critical or severe cases had “early” blood draws (before ICU admission; n = 33). For these cases, when compared to moderate and mild cases not in ICU (n = 37), SeptiCyte RAPID had AUC = 0.78 (p = 0.00012). In conclusion, SeptiCyte RAPID was able to stratify COVID-19 cases according to clinical severity as defined by the WHO COVID-19 Clinical Management Living Guidance of January 25th, 2021. Measurements taken early (before a patient is considered for ICU admission) suggest that high SeptiScores could aid in predicting the need for later ICU admission.

Clinical value of full-length tryptophanyl-tRNA synthetase for sepsis detection in critically ill patients — A retrospective clinical assessment

ObjectivesRelated innate immune system activation and diagnostic factors of sepsis are not fully understood. The aim of this study was to analyze the clinical value of full-length tryptophanyl-tRNA synthetase (WRS) induced through inflammatory stimuli for the detection of sepsis and prediction of mortality in critically ill patients. MethodsThis was a retrospective analysis of blood samples collected prospectively from patients in the medical intensive care unit (ICU) at Yonsei University College of Medicine, from March 2015 to June 2018. The ability of WRS to detect sepsis and predict mortality were compared to those of procalcitonin (PCT), C-reactive protein (CRP), and interleukin 6 (IL-6), and with Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores. ResultsA total of 241 study patients were enrolled, of whom 190 (78.8%) had been diagnosed with sepsis on ICU admission. The areas under the receiver operating characteristics curves (AUROCs) for sepsis discrimination with WRS, PCT, CRP, and IL-6 levels, and SOFA and APACHE II scores were 0.864, 0.727, 0.625, 0.651, 0.840, and 0.754, respectively. The prediction of 28-day mortality in patients with sepsis using WRS levels was possible and non-inferior to that with the SOFA score. ConclusionsWRS secreted early in sepsis may be useful not only for the early detection of sepsis, but also for the prediction of mortality in critically ill patients.

Clinical Correlation of a Clostridium difficile Testing Algorithm Reflexing PCR Positive Specimens to Toxin Enzyme Immunoassay (EIA)

BackgroundAn algorithm promoted in the United Kingdom reflexes specimens positive for C. difficile by a nucleic acid amplification test (NAAT) to toxin EIA. Samples positive by NAAT and negative by toxin EIA are reported as “C. difficile could be present (ie, potential C. difficile excretor).” We explored the potential utility of this algorithm to distinguish C. difficile infection (CDI) from colonization compared with retrospective clinical assessment.MethodsLiquid stool specimens (n = 300) from inpatients (or the Emergency Department) submitted to the Cleveland Clinic Microbiology laboratory for C. difficile PCR testing (Cepheid Xpert C. difficile/Epi) with positive results were included in the study. The CDIFF QUICK CHEK COMPLETE GDH/toxin EIA assay (Alere) was performed according to manufacturer’s instructions. The charts of all patients were reviewed by Infectious Diseases physicians blinded to the EIA results. Using the American College of Gastroenterology (ACG) classification system, CDI status was determined to be mild, moderate, severe, or complicated. Patients without significant diarrhea (<3 unformed stools / 24 hours) were considered colonized. Those without documentation of stools were classified as indeterminate. Correlation of clinical assessment with EIA results was assessed.ResultsMost of the PCR positive specimens (75%) were toxin EIA negative. Correlation of clinical assessment with toxin EIA is summarized in the table below. Among patients colonized vs. those with CDI, the percentages with negative toxin EIA results were 80% and 73%, respectively. GDH antigen results were negative for 25 specimens—17 were from patients considered to have CDI. C. difficile PCR positive specimensClinical AssessmentToxin EIA positiveToxin EIA negative(No.)No.Row %No.Row %Indeterminate (11)19.01090.9Colonized (39)820.53179.5CDI (250)6726.818373.2Mild (47)1021.33778.7Moderate (68)2130.94769.1Severe (26)623.12076.9Complicated (109)3027.57972.5Total (300)7625.322474.7Conclusion Toxin EIA performed on samples positive for C. difficile by PCR does not reliably identify patients considered to have CDI with ACG criteria applied. GDH as an initial screen would not have detected 6.8% of patients with CDI.Disclosures S. S. Richter, bioMerieux: Investigator, Research support; BD Diagnostics: Investigator, Research support; Roche: Investigator, Research support; BioFire: Investigator, Research support; OpGen: Investigator, Research support

Development and Retrospective Clinical Assessment of a Patient-Specific Closed-Form Integro-Differential Equation Model of Plasma Dilution.

A closed-form integro-differential equation (IDE) model of plasma dilution (PD) has been derived which represents both the intravenous (IV) infusion of crystalloid and the postinfusion period. Specifically, PD is mathematically represented using a combination of constant ratio, differential, and integral components. Furthermore, this model has successfully been applied to preexisting data, from a prior human study, in which crystalloid was infused for a period of 30 minutes at the beginning of thyroid surgery. Using Euler’s formula and a Laplace transform solution to the IDE, patients could be divided into two distinct groups based on their response to PD during the infusion period. Explicitly, Group 1 patients had an infusion-based PD response which was modeled using an exponentially decaying hyperbolic sine function, whereas Group 2 patients had an infusion-based PD response which was modeled using an exponentially decaying trigonometric sine function. Both Group 1 and Group 2 patients had postinfusion PD responses which were modeled using the same combination of hyperbolic sine and hyperbolic cosine functions. Statistically significant differences, between Groups 1 and 2, were noted with respect to the area under their PD curves during both the infusion and postinfusion periods. Specifically, Group 2 patients exhibited a response to PD which was most likely consistent with a preoperative hypovolemia. Overall, this IDE model of PD appears to be highly “adaptable” and successfully fits clinically-obtained human data on a patient-specific basis, during both the infusion and postinfusion periods. In addition, patient-specific IDE modeling of PD may be a useful adjunct in perioperative fluid management and in assessing clinical volume kinetics, of crystalloid solutions, in real time.

Local paclitaxel induces late lumen enlargement in coronary arteries after balloon angioplasty.

This study investigated p aclitaxel-induced luminal changes following drug-coated balloon (DCB) angioplasty to treat coronary de novo lesions without additional stenting. DCB-mediated local drug delivery reduces late lumen loss in de novo coronary artery lesions. We performed a retrospective clinical assessment based on a pre-specified quantitative coronary angiography (QCA) protocol. QCA was performed for each centre to assess the primary endpoint late lumen changes, i.e. the difference between in-lesion minimal lumen diameter (MLD) at the routine angiographic follow-up as compared to post-procedural in-lesion MLDs. These MLD changes were compared to corresponding reference vessel diameter changes as an intra-patient control. We evaluated 58 consecutive native coronary artery lesions directly after DCB angioplasty and at a routine target follow-up angiography of 4months by QCA. Target lesion MLD increased significantly within the 4.1±2.1month observation period (1.75±0.55 vs. 1.91±0.55mm, p<0.001, diameter stenosis 33.8±12.3 vs. 26.9±13.8%, p<0.001), while there were no changes in non-target reference vessel diameters (2.33±0.60 vs. 2.34±0.61mm, p=ns). A total of 69% of patients showed luminal enlargement whereas 29% had minor luminal loss. Local application of paclitaxel by DCB angioplasty to native coronary arteries after pre-dilatation without major dissection and recoil leads to late lumen increase.

Association analysis between suicidal behaviour and candidate genes of bipolar disorder and schizophrenia

BackgroundThe present study investigated associations between the strongest joint genetic risk variants for bipolar disorder (BD) and schizophrenia (SCZ) and a history of suicide attempt in patients with BD, SCZ and related psychiatric disorders. MethodsA history of suicide attempt was assessed in a sample of 1009 patients with BD, SCZ and related psychosis spectrum disorders, and associations with the joint genetic risk variants for BD and SCZ (rs2239547 (ITIH3/4-region), rs10994359 (ANK3) and rs4765905 (CACNA1C)) were investigated. Previously reported susceptibility loci for suicide attempt in BD were also investigated. Associations were tested by logistic regression with Bonferroni correction for multiple testing. ResultsThe risk allele in rs2239547 (ITIH3/4-region) was significantly associated with a history of suicide attempt (p=0.01) after multiple testing correction (p threshold<0.017). The previous suicide attempt susceptibility loci were only nominally associated, but had the same direction of risk in the replication sample (sign test, p=0.02). LimitationsRelatively small sample size and retrospective clinical assessment. ConclusionsWe detected a novel association between suicide attempt and the ITIH3/4-region in a combined group of patients with BD, SCZ and related psychosis spectrum disorders. This may be useful in understanding molecular mechanisms of suicidal behaviour in severe mental disorders, although replication is warranted.

Motor outcome of dystonic camptocormia treated with pallidal neurostimulation

BackgroundDeep brain stimulation of the internal pallidum (GPi-DBS) is effective for various types of drug-refractory primary dystonias. Rare clinical forms as dystonic camptocormia may profit but available data are scarce. MethodsWe here report on a retrospective clinical assessment of three patients with primary dystonic camptocormia treated with GPi-DBS. ResultsAll three patients showed marked response to bilateral GPi-DBS within days to weeks after surgery which was preserved in the long-term (38–45 months after implantation: mean improvement 82% as rated on the Burke Fahn Marsden Dystonia Rating Scale, 89% in the subitem “trunk”). Two patients developed mild stimulation induced speech problems (stuttering or dysarthria) which resolved with reprogramming or were acceptable in return for the control of dystonic symptoms. ConclusionsThe diagnosis and treatment of camptocormia will continue to require expert knowledge in movement and neuromuscular disorders, but DBS may expand treatment options in this difficult patient population.

Significance of panendoscopy and CT in the follow-up and management of squamous cell carcinoma of the head and neck: A retrospective clinical assessment.

e17003 Background: Treatment of patients with head and neck squamous cell carcinomas (HNSCC) require an evidence-based multidisciplinary approach which varies from medical centres. Panendoscopy has been traditionally used as a routine screening examination tool. We discuss and compare its clinical effectiveness, safety and predictive value in patients with computed tomography (CT) scans in a routine outpatient follow up. Methods: Between 2004-2007, in a retrospective study (204 patients; male:156 (76.5%); female:48 (23.5%))with head and neck cancer, fulfilled all inclusion and exclusion criteria were evaluated at the University Medical Center Hamburg-Eppendorf, Germany. Follow-ups were performed every 2 to 3 months for the first 3 years and every 6 month for the following 2 years. UICC-TNM staging system divided patients into seven categories. Results: The mean age of patients was (male: 59.2±9.3 years; female: 59.5±10.2 years), the highest incidence rate was recorded in the 51 to 60 age group (n = 77). There was a male predominance, with a male/female ratio of 3:1. In comparing normal versus abnormal CT a 12-fold higher frequency of recurrence (odds ratio [OR]; 95% CI: 3.99, 37.51; p&lt;0.001) was interpreted.Additionally, patient anamnesis (OR: 3.33; 95% CI: 1.57, 7.07; p=0.002), clinical investigation (OR: 5.85; 95% CI: 3.01,11.36; p&lt;0.001) and recurrence pattern (OR: 4.82; 95% CI: 2.26,10.32; p&lt;0.001) was observed. Conclusions: In staging / follow-up HNSCC patients, CT-diagnostics also provided similar levels of accuracy as panendoscopy. Panendoscopy in patients with HNSCC was avoided (169 out of 364) when the diagnostic parameters remained satisfactory. Higher patient satisfaction, structural information at a high spatial resolution and comfort was noted in the CT group, indicating a gradual move towards CT diagnostics. For safety-related reasons in particular, we recommend panendoscopy for histological evaluation i.e.in predicting cancer recurrence and progression.

Abundant glial α-synuclein pathology in a case without overt clinical symptoms

Screening of 1,800 brains with alpha-synuclein (alphaS) immunohistochemistry revealed five cases with abundant glial cytoplasmic inclusions (GCIs) within the white matter of the brainstem. Surprisingly, retrospective clinical assessment showed that one of these subjects did not fulfil the currently recommended clinical consensus criteria for the multiple system atrophy (MSA). One of the hallmark lesions of MSA, alphaS-positive GCIs, were widespread and abundant in this atypical case that nonetheless lacked any significant neuronal loss. If the patient had met the clinical criteria for MSA, the neuropathological phenotype would have undeniably confirmed the clinically suggested diagnosis. However, lacking overt clinical signs of MSA, the neuropathological phenotype in this subject is prone to be variably denoted or overlooked. We would therefore like to advise neuropathologists to acknowledge these cases with "occult" alpha-synucleinopathy and to inform the clinicians of such a finding. Whether these cases represent a preclinical stage of MSA or simply a biological coincidence, is yet unknown. The observation of abundant GCIs in an asymptomatic subject is, however, important, because even if these cases are rare in number, their occurrence challenge the current presumption, whereby simply the number of alphaS-positive GCIs mediates the neuronal dysfunction responsible for the clinical symptoms of MSA.

Comparison between jaw bone augmentation by means of a stiff occlusive titanium membrane or an autologous hip graft: a retrospective clinical assessment

Patients in need of bone augmentation procedures can be treated with a traditional hip graft or by neogenesis under a stiff occlusive titanium membrane, custom-fit on the basis of CT-scan data. Eighteen patients treated by means of a hip graft (H) were compared with 11 patients using a full titanium membrane (M) for the rehabilitation of upper jaws. In the H group, 17 patients (62 implants) in the anterior region (Ha) and 14 patients (23 implants) in the posterior region (Hp) were included. In the M group, nine patients (30 implants) in the anterior region (Ma) and seven patients (16 implants) in the posterior region (Mp) were included. In group Ha, the CFR was 13.3% after 14 years compared with group Ma where the CFR was 17.4% after 9 years. In group Hp, the CFR was 22.8% after 16 years compared with group Mp where the CFR was 23.4% after 6 years. The marginal bone loss for group Ha after 20 years was 2.7 mm, for group Ma it was not even 1 mm after 9 years; for group Hp, it was 2.5 mm after 15 years compared with less than 1 mm after 3 years in group Mp. The success rate of alveolar ridge augmentation therapy is lower than in a classical approach. These augmentation procedures, however, show acceptable results. The titanium membrane augmentation leads to less marginal bone loss probably because neo-formed bone has a better chance to adapt its mineralization to occlusal forces encountered. This technique could offer improvement if membrane exposure can be avoided.

α‐Synuclein pathology does not predict extrapyramidal symptoms or dementia

Intracytoplasmic aggregation of alpha-synuclein protein as Lewy bodies in the brainstem neurons is diagnostic for Parkinson's disease, whereas if this process also occurs in the cortical neurons, it is considered pathognomonic for dementia with Lewy bodies. However, the link between alpha-synuclein incorporation into inclusions, neuronal dysfunction, and clinical symptoms needs to be clarified. Another important issue of the pathogenetic puzzle is to understand where alpha-synuclein pathology begins and how it progresses in the brain. To study this, we collected all cases from autopsy material (N = 904) that had alpha-synuclein pathology in the dorsal motor nucleus of vagus, substantia nigra, and/or basal forebrain nuclei. In this way, our study has a unique design because the selection of material is entirely based on the presence of alpha-synuclein pathology regardless of clinical phenotype. Retrospective clinical assessment then showed that only 32 (30%) of 106 alpha-synuclein-positive cases were diagnosed with a neurodegenerative disorder. The distribution or load of alpha-synuclein pathology did not permit a dependable postmortem diagnosis of extrapyramidal symptoms or cognitive impairment. Some neurologically unimpaired cases had a reasonable burden of alpha-synuclein pathology in both brainstem and cortical areas, suggesting that alpha-synuclein-positive structures are not definite markers of neuronal dysfunction.

A new modified technique for harvest of calcaneal bone grafts in surgery on the foot and ankle.

Reported sites for retrieval of cancellous bone for grafts include the iliac crest, greater trochanter, proximal tibia, and distal tibia. A new lateral technique for retrieval of cancellous bone from the calcaneus is evaluated through anatomic review, quantitative analysis, and retrospective clinical assessment. Of 22 patients managed with this technique over a 2-year period, 17 returned for an evaluation by questionnaire, physical examination, and radiographic follow-up at an average of 7 months after surgery (range, 4-16 months). Complaints/complications were minor: three had minor incisional symptoms, five had medial heel pain (3 caused by plantar fasciitis), and one had unchanged preoperative heel pain secondary to clubfoot deformity. Compared with more extensive bone-grafting procedures, this procedure offers the advantages of bone harvested under local anesthesia using a readily accessible ipsilateral extremity and producing minor complications.

Long-term monitoring of renal transplant patients by a CUSUM test on serum creatinine.

A retrospective clinical assessment of kidney function change was performed on 38 kidney transplant patients over a median follow-up period of 128 weeks. Full records of the patients' course were available to the clinician, while only the serum creatinine series of each patient was supplied to the computer on which a bilateral CUSUM test was implemented. The frequency of change assessed by the clinician was 146 out of 2,688 patient-weeks. The computer identified the function changes with 84.9% sensitivity and 94.3% specificity and the function deteriorations attributed to rejection with 88.9% sensitivity and 97.2% specificity. Thus we suggest an efficient long-term monitoring of the graft function with this simple and reliable statistical technique.