A178 ELUCIDATING THE ROLE OF THE LEUCINE-RICH REPEAT KINASE 2 G2019S MUTATION IN CROHN’S DISEASE PATHOGENESIS USING A CITROBACTER RODENTIUM INFECTIOUS COLITIS MODEL

Background

Associations have been found linking certain LRRK2 kinase domain gain-of-function variants, such as G2019S, to the development of Crohn’s disease and Parkinson’s disease, yet their exact roles in pathogenesis remains elusive. LRRK2 is most robustly expressed in circulating and tissue-resident immune cells, such as neutrophils, lymphocytes, and macrophages. Myeloid cells deficient in LRRK2 exhibit defective antimicrobial responses, such as reduced production of reactive oxygen species in response to microbial stimuli and reduced bactericidal activity in response to infection. As an enteric colitis-inducing extracellular pathogen, Citrobacter rodentium can help us better understand the consequences of LRRK2 kinase hyperactivity on intestinal inflammation by correlating pathogen burden with key host response parameters over the course of infection.

Purpose

To investigate the effects of the Crohn’s and Parkinson’s disease-associated Lrrk2 G2019S hyper-kinase mutation on pathogen burden and colonic inflammation in the context of C. rodentium-induced infectious colitis.

Method

Wild-type and Lrrk2 G2019S mutant mice (7-8 weeks old) were fasted for 4 hours then infected with 1 x 10⁸ CFU of C. rodentium in a 3% NaHCO₃ solution by oral gavage. Body weight, faecal pathogen burden, and faecal lipocalin-2 (Lcn2) concentrations were measured at 2, 4, 7, 9, 10, 12, and 14 days post-infection (DPI). Systemic pathogen burden (as measured in the mesenteric lymph nodes and spleen), colon length, colonic inflammatory gene expression, and histopathological scoring were assessed at 7, 10, and 14 DPI.

Result(s)

While G2019S mice exhibited marginally higher C. rodentium loads at certain timepoints, no significant differences were found in overall pathogen burden or pathogen clearance rates between genotypes over the first 14 days of infection. Faecal pathogen load peaked at 7-9 DPI in both WT and G2019S mice, which correlated with detectable levels of C. rodentium in the mesenteric lymph nodes and spleens of some mice at 7 DPI. Lcn2 secretion and the expression of inflammatory and antimicrobial genes of interest were induced robustly over the course of infection. They peaked and ebbed at timepoints correlating well with pathogen burden; however, no significant differences were observed between WT and G2019S mutant mice at the various timepoints assessed.

Conclusion(s)

Mice expressing the G2019S Lrrk2 mutation exhibit neither defective pathogen control nor deleterious hyperinflammation – compared to WT mice – when infected with C. rodentium. Further research will aim to investigate the role of this Lrrk2 variant in additional models of intestinal inflammation.

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CCC, CIHR

Disclosure of Interest

None Declared

Functional Precision Medicine Provides Clinical Benefit in Advanced Aggressive Hematologic Cancers and Identifies Exceptional Responders

Personalized medicine aims to match the right drug with the right patient by using specific features of the individual patient's tumor. However, current strategies of personalized therapy matching provide treatment opportunities for less than 10% of patients with cancer. A promising method may be drug profiling of patient biopsy specimens with single-cell resolution to directly quantify drug effects. We prospectively tested an image-based single-cell functional precision medicine (scFPM) approach to guide treatments in 143 patients with advanced aggressive hematologic cancers. Fifty-six patients (39%) were treated according to scFPM results. At a median follow-up of 23.9 months, 30 patients (54%) demonstrated a clinical benefit of more than 1.3-fold enhanced progression-free survival compared with their previous therapy. Twelve patients (40% of responders) experienced exceptional responses lasting three times longer than expected for their respective disease. We conclude that therapy matching by scFPM is clinically feasible and effective in advanced aggressive hematologic cancers. SIGNIFICANCE: This is the first precision medicine trial using a functional assay to instruct n-of-one therapies in oncology. It illustrates that for patients lacking standard therapies, high-content assay-based scFPM can have a significant value in clinical therapy guidance based on functional dependencies of each patient's cancer.See related commentary by Letai, p. 290.This article is highlighted in the In This Issue feature, p. 275.

Transformed mucosa-associated lymphoid tissue lymphomas: A single institution retrospective study including polymerase chain reaction-based clonality analysis

Given the lack of consistent data regarding the clinico-pathological features and clonal lymphomagenesis of patients with mucosa-associated lymphoid tissue (MALT) lymphoma and histological transformation (HT), we have systematically analysed 379 patients (32% gastric, 68% extra-gastric; median follow-up 52 months) diagnosed with HT at the Medical University Vienna 1999-2017, and reassessed tissues of identified patients by polymerase chain reaction (PCR)-based clonality analysis. HT was documented in 12/379 patients (3·2%) and occurred at a median time of 22 months (range; 6-202 months) after diagnosis of MALT lymphoma. By PCR-based clonality analysis, we detected a clear-cut clonal relationship of MALT lymphoma and diffuse large B-cell lymphoma (DLBCL) in 8 of 11 analysed cases proving that the large majority of DLBCL following MALT lymphoma are clonally-related and constitute a real transformation. Interestingly, HT occurred within the first 2·5 years after diagnosis in patients with clonal relationship, whereas time to aggressive lymphoma was longer in patients identified as clonally-unrelated (most likely secondary) lymphoma (82-202 months), suggesting that HT is an early event in this disease. Survival of patients with HT was poor with 6/12 dying at 1·5-33 months after HT, however, patients with localized gastric transformation had a superior outcome with only 1/6 dying due to progression of lymphoma.

[Ecchymosis as the presenting manifestation of Wilson disease: A case report]

INTRODUCTION

The presence of a psychiatric disorder during the course of an organic disease is a common cause of delayed diagnosis.

CASE REPORT

We report a 16-year-old girl who was admitted with thrombocytopenia and had a two-year history of neuropsychiatric disorder which was attributed to a difficult family situation. Neurological examination showed a frontal lobe disorder and extrapyramidal manifestations. The thrombocytopenia was attributed to liver cirrhosis. These neurological and hepatic injuries were consistent with a metabolic disease, most likely Wilson disease. This was supported by the presence of a corneal Kayser-Fleischer ring and a decreased ceruloplasmin concentration. An urgent liver transplantation was required due to worsening neurological symptoms.

CONCLUSION

Wilson disease is a rare genetic disease caused by copper toxicity. It is characterized by combined hepatic and neurologic damage to varying degrees and can develop at any age. Urgent treatment is required, but the diagnosis may be delayed by prevailing psychiatric symptoms.

Extravasation of Pt-based chemotherapeutics – bioimaging of their distribution in resectates using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

Spatially resolved quantification of platinum distribution in patients that exhibited extravasation was feasible up to 4 weeks upon drug application.

Evaluation of the intraoperative specimens of the thoracic and abdominal aorta

BACKGROUND

Little is known about the histological patterns of acute and chronic aortic pathology with regard to medial degeneration, atherosclerosis and aortitis as well as their distribution in different age groups. The aim of the study was to evaluate histopathological findings of intraoperatively gained aortic specimens with regard to the incidence of medial degeneration, atherosclerosis and aortitis.

METHODS

Intraoperatively gained aortic specimens were evaluated in 151 patients including 83 (55%) aortic aneurysms (65 thoracic, 18 abdominal) and 68 (45%) acute type A aortic dissections. Histological stainings used were hematoxylin and eosin, Van Gieson as well as alcian blue. Patients were stratified according to above and below 65 years of age. High grade medial degeneration represented pooling of mucoid material in the whole aortic wall. High grade atherosclerosis represented severe intimal fibrosis, massive accumulation of macrophages and foam cells or massive calcification of the aortic wall.

RESULTS

Medial degeneration was diagnosed in 106 (70%) patients including 55 (52%) aortic aneurysms and 51 (48%) acute type A aortic dissections. High grade medial degeneration was found in 50% of patients with thoracic aortic aneurysms < 65 years of age vs. 44% in patients ≥ 65 years of age (p = 0.64) and in 36% of patients with thoracic aortic dissections < 65 years of age vs. 14% in patients ≥ 65 years of age (p = 0.07). Atherosclerosis was diagnosed in 71 (47%) patients including 46 (65%) aortic aneurysms and 25 (35%) aortic dissections. High grade atherosclerosis was found in 23% of patients with thoracic aneurysms < 65 years of age vs. 36% in patients ≥ 65 years of age (p = 0.24) and in 13% of patients with aortic dissections < 65 years of age vs. 52% in patients ≥ 65 years of age (p < 0.001). Aortitis was rare (n = 2).

CONCLUSIONS

Medial degeneration was the most frequent diagnosis in this series of aortic specimens. Medial degeneration was equally common in patients above and below 65 years of age. However in cases with acute type A aortic dissections, high grade atherosclerosis was the leading histopathological diagnosis in patients older than 65 years. Acute type A aortic dissections seem to have different underlying pathologies in different age groups.

Aortitis requiring aortic repair associated with glaucoma, thyroiditis, glaucoma, and neuropathy: case report

Aortitis may be due to infectious and non-infectious causes. We observed aortitis, associated with glaucoma, thyroiditis, pericarditis, pleural effusion and neuropathy in a 63-years old woman. Despite antibiotic therapy, inflammatory signs persisted and resolved only after initiation of glucocorticoid therapy. Increasing aortic ectasia necessitated resection of the ascending aorta and implantation of a Vascutek 30 mm prosthesis. Histologically a granulomatous aortitis was diagnosed. Since all other possible causes were excluded, an immunological mechanism of the aortitis is suspected and possible triggering factors are discussed.

A 3,500-gram leiomyoma of the bladder: case report on a 3-year follow-up after surgical enucleation

We report on a unique-sized large leiomyoma of the bladder wall in a male patient. After open surgical intervention all symptoms resolved spontaneously and no relapse occurred within a 3-year follow-up period. In conclusion, for symptomatic leiomyoma of the bladder surgical intervention should be considered as an early treatment option since it is associated with low morbidity, a high cure rate for this type of tumor and an immediate relief of urological symptoms.

Keratinocytes express the CD146 (Muc18/S-endo) antigen in tissue culture and during inflammatory skin diseases

The CD146 (or MUC18/MEL-CAM) antigen is a cell adhesion molecule of the immunoglobulin superfamily. Besides in melanoma, expression of CD146 antigen has been demonstrated in breast epithelia and hair follicles. We studied its expression by human keratinocytes in culture as well as in neoplastic and inflammatory skin diseases. Staining of primary cultured keratinocytes revealed expression of CD146 on the cell membrane, preferentially on cell-cell contact sites. Western blot analysis of keratinocytes detected a band of approximately 113 kDa, corresponding to the CD146 protein. In contrast to primary keratinocytes, neither CD146 protein nor mRNA expression was found in the keratinocyte-derived cell lines A431 and HaCaT. Treatment of keratinocytes with the proinflammatory cytokines interleukin-1 and interleukin-6, tumor necrosis factor-alpha, and interferon-gamma, resulted in no change of CD146 expression and incubation with phorbol 12-myristate 13-acetate led to a reduction of CD146 on keratinocytes. By contrast, when culturing keratinocytes in medium devoid of growth supplements, a distinct upregulation was observed as compared with culture in fully supplemented medium. In normal human epidermis expression of the CD146 antigen was not detectable. It was strongly upregulated, however, on suprabasal keratinocytes in psoriasis, in lichen planus, in the epidermis overlying skin neoplasms, and in viral warts. In squamous cell carcinomas and basal cell carcinomas only a minority of tumor cells expressed CD146. Our findings suggest that the CD146 antigen represents an activation marker of keratinocytes and may be involved in cutaneous inflammatory tissue reaction.

Twelve prostate biopsies detect significant cancer volumes (> 0.5 mL)

OBJECTIVES

To compare, in a retrospective study, pathological specimens of prostate cancer detected in additional areas of a 12-core biopsy with tumours detected using traditional sextant biopsy.

PATIENTS AND METHODS

The study included 27 patients who had undergone radical prostatectomy (RP) for prostate cancer. Prostatectomy specimens of cancers detected using standard sextant biopsies were compared with those detected using six additional core biopsies. The RP specimens were analysed for cancer volume, Gleason score, tumour grade (Mostofi) and pathological stage.

RESULTS

Of the 27 patients, six (29%) had cancer detected in the extra six biopsy cores which would have otherwise have been undetected using sextant biopsy. Only two insignificant cancers were detected. The mean Gleason score was 6.1 for cancer detected by the sextant or 12-core method (P = 0.907); the mean grade (Mostofi) was 2.1 and 2. 33, respectively (P = 0.29). The final tumour stage in the 21 patients undergoing sextant biopsy was pT2 in 13 and pT3 in eight, compared with six pT2 tumours in the six patients diagnosed using extra biopsies. The mean (median, range) tumour volume was 5.7 (3.5, 0.312-23.75) mL for cancers detected on sextant biopsy and 1.99 (1. 85, 0.4-3.6) mL in the six cancers detected using extra cores (P = 0. 0138).

CONCLUSION

The detection of prostate cancer was increased using extra biopsy cores. There was a significant difference in tumour volume but not in Gleason score, Mostofi grade or final pathological tumour stage between tumours diagnosed using 12 cores and those detected on sextant biopsy.

Comparison of different telepathology solutions for primary frozen section diagnostic

In a retrospective study on a set of 125 cases we compared the following three telepathology solutions for primary frozen section diagnosis: ATM-TP (connection via ATM), TPS 1.0 (connection via LAN) and TELEMIC (connection via Internet), which represent different concepts of telepathological procedures. A set of 125 routine frozen sections (breast) was selected from the Charité cases of the year 1999. Four experienced pathologists diagnosed retrospectively all of these cases using the ATM-TP and TPS systems and 53 of them with the TELEMIC system. Using the ATM-TP we recorded no false positive (0%), 4 false negative (3.2%) and 4 deferred (3.2%) cases. Using the TPS we recorded no false positive (0%), 4 false negative (3.2%) and 4 deferred (3.2%) cases. Using the TELEMIC we recorded in 53 cases no false positive (0%), no false negative (0%) and 16 deferred (30.2%) cases. The average time of 2.2 minutes per case using ATM-TP is also short enough for routine frozen section diagnostic. This is also true for the TPS system with 7.2 minutes per case.

Comparative study of two different TRUS-guided sextant biopsy techniques in detecting prostate cancer in one biopsy session

OBJECTIVE

The aim of this study was to compare a transrectal ultrasound (TRUS)-guided sextant biopsy technique, which puts more emphasis on the apical region of the prostate where most prostate carcinomas (PCs) develop, with the standard sextant biopsy technique.

METHODS

A total of 280 patients with suspected PC were included in this analysis. Twelve biopsy cores were obtained from all patients. Six biopsy cores were taken within a lateral parasagittal plane from each lobe at the apex, middle and basis, with an angle of approximately 45 degrees (technique A), and 6 further biopsy cores were taken from the left to the right lateral margin always penetrating the prostate in the apex with the same angle (socalled fan-shaped technique, technique B). Technique A predominantly samples in the sagittal and technique B samples more in the transversal plane with emphasis on the apical region where most PCs develop. The sensitivity in detecting PCs for both techniques was calculated and correlated to the serum prostate-specific antigen (PSA) levels.

RESULTS

A total of 72 PCs (25.7%) were diagnosed. We subsequently performed subgroup analysis depending on the serum PSA levels: in patients with a PSA of </=10 ng/ml (n = 27) technique A has a PC sensitivity of 88.8% (p = 0.037) and technique B 96.2% (p = 0.326) as compared to our reference standard of 100% by sampling 12 biopsy cores in the same prostate. The number of positive biopsy cores using technique B was superior in 12 cases as compared to 3 cases with technique A (p = 0.04). In 12 patients the number of positive biopsy cores was identically. In patients with a PSA of >10 ng/ml (n = 45) technique A has a PC sensitivity of 93.3% (p = 0.083) and technique B 88.8% (p = 0.023) as compared to our reference standard. The number of positive core biopsies using technique A was superior in 14 cases as compared to 12 with technique B (p = 0.154). In 19 patients the number of positive biopsies was identical.

CONCLUSION

Our data suggest that in patients with PSA of </=10 ng/ml technique B bring significant benefit with regard to the number of positive core biopsies, as well as an enhanced PC detection rate which is near the 12-core biopsy. Due to the fact that technique B samples more in the apical region where most cancers develop, it should be performed in suspected early stage cancers of the prostate (PSA</=10 ng/ml).

Fatal familial insomnia: a new Austrian family

We present clinical, pathological and molecular features of the first Austrian family with fatal familial insomnia. Detailed clinical data are available in five patients and autopsy in four patients. Age at onset of disease ranged between 20 and 60 years, and disease duration between 8 and 20 months. Severe loss of weight was an early symptom in all five patients. Four patients developed insomnia and/or autonomic dysfunction, and all five patients developed motor abnormalities. Analysis of the prion protein (PrP) gene revealed the codon 178 point mutation and methionine homozygosity at position 129. In all brains, neuropathology showed widespread cortical astrogliosis, widespread brainstem nuclei and tract degeneration, and olivary 'pseudohypertrophy' with vacuolated neurons, in addition to neuropathological features described previously, such as thalamic and olivary degeneration. Western blotting of one brain and immunocytochemistry in four brains revealed quantitative and regional dissociation between PrP(res)(the protease resistant form of PrP) deposition and histopathology. In the cerebellar cortex of one patient, PrP(res) deposits were prominent in the molecular layer and displayed a peculiar patchy and strip-like pattern with perpendicular orientation to the surface. In another patient, a single vacuolated neuron in the inferior olivary nuclei contained prominent intravacuolar granular PrP(res) deposits, resembling changes of brainstem neurons in bovine spongiform encephalopathy.

A simplified method for monitoring heparin therapy at the bedside: the activated whole blood clotting time

Twelve patients receiving heparin during hemodialysis had coagulation parameters monitored using the whole blood clotting time (WBCT), activated partial thromboplastin time (APTT), plasma heparin levels and activated whole blood clotting time (AWBCT). The AWBCT, performed with a battery-powered portable incubator/timer, correlated with both the corresponding WBCT and the plasma heparin levels. However, the correlation between the AWBCT and the APTT was quite poor. This assay is simply performed, inexpensive, and reproducible. It is recommended as an excellent method for monitoring heparin therapy.