Key Points Loss-of-function ALG8 and ALG9 variants were enriched in polycystic kidney/liver groups and International Classification of Diseases–coded cystic individuals in population cohorts. The ALG8 and ALG9 kidney phenotypes were usually mild to moderate, and lower eGFR or kidney failure was rare. ALG8 pathogenic variants sometimes resulted in severe polycystic liver disease. Background Autosomal dominant polycystic kidney disease (ADPKD) is a common, inherited nephropathy often resulting in kidney failure. It is genetically heterogeneous; along with the major genes, PKD1 and PKD2 , at least eight others have been suggested. ALG8 pathogenic variants have been associated with autosomal dominant polycystic liver disease and implicated in ADPKD, while ALG9 has been suggested as an ADPKD gene, but details of the phenotypes and penetrance are unclear. Methods We screened >3900 families with cystic kidneys and/or livers using global approaches to detect ALG8 or ALG9 pathogenic variants. In addition, population cohorts with sequence data (Genomics England 100K Genomics Project, UK Biobank, and Mayo Clinic Biobank [MCBB]) were screened for ALG8 / ALG9 pathogenic variants. Results Multicenter screening of individuals with polycystic kidney and/or liver disease identified 51 (1.3%) ALG8 (7 multiplex) and 23 (0.6%) ALG9 (5 multiplex) families—frequencies that were approximately 10× and approximately 24× greater than nonpolycystic kidney disease controls. Analysis of individuals with polycystic kidney disease phenotypes in 100K Genomics Project, UK Biobank, and MCBB identified nine ALG8 (0.39%) and nine ALG9 (0.39%) families, an enriched frequency over controls. Two individuals had PKD1 and ALG8 pathogenic changes. Eighty-nine percent of individuals with ALG8 mutations with imaging in the entire MCBB had kidney cysts (50%, >10 cysts), with greater median kidney and liver cyst numbers than controls. For ALG9, 78% had kidney cysts (27%, >10 cysts). Individuals with ALG8 mutations typically had mild cystic kidneys with limited enlargement. Liver cysts were common (71%), with enlarged livers (>2L) found in 11 of 62 patients, although surgical intervention was rare. The ALG9 kidney phenotype was also of mild cystic kidneys, but enlarged livers were rare; for both genes, CKD or kidney failure were rare. Conclusions ALG8 and ALG9 are defined as cystic kidney/liver genes but with limited penetrance for lower eGFR.
Potential Role of Inflammation-Promoting Biliary Microbiome in Primary Sclerosing Cholangitis and Cholangiocarcinoma
Background: Primary sclerosing cholangitis (PSC) is a major risk factor for cholangiocarcinoma (CCA). We investigated biliary and fecal microbiota to determine whether specific microbes in the bile or stool are associated with PSC or CCA. Methods: Bile was obtained from 32 patients with PSC, 23 with CCA with PSC, 26 with CCA without PSC, and 17 controls. Over 90% of bile samples were from patients with perihilar CCA. Stool was obtained from 31 patients with PSC (11 were matched to bile), 16 with CCA with PSC (10 matched to bile), and 11 with CCA without PSC (6 matched to bile). Microbiota composition was assessed using 16SrRNA-marker-based sequencing and was compared between groups. Results: Bile has a unique microbiota distinguished from negative DNA controls and stool. Increased species richness and abundance of Fusobacteria correlated with duration of PSC and characterized the biliary microbiota in CCA. Stool microbiota composition showed no significant differences between groups. Conclusions: We identified a unique microbial signature in the bile of patients with increased duration of PSC or with CCA, suggesting a role for microbiota-driven inflammation in the pathogenesis and or progression to perihilar CCA. Further studies are needed to test this hypothesis.
The value of genotypic and imaging information to predict functional and structural outcomes in ADPKD
BACKGROUND A treatment option for autosomal dominant polycystic kidney disease (ADPKD) has highlighted the need to identify rapidly progressive patients. Kidney size/age and genotype have predictive power for renal outcomes, but their relative and additive value, plus associated trajectories of disease progression, are not well defined. METHODS The value of genotypic and/or kidney imaging data (Mayo Imaging Class; MIC) to predict the time to functional (end-stage kidney disease [ESKD] or decline in estimated glomerular filtration rate [eGFR]) or structural (increase in height-adjusted total kidney volume [htTKV]) outcomes were evaluated in a Mayo Clinic PKD1/PKD2 population, and eGFR and htTKV trajectories from 20–65 years of age were modeled and independently validated in similarly defined CRISP and HALT PKD patients. RESULTS Both genotypic and imaging groups strongly predicted ESKD and eGFR endpoints, with genotype improving the imaging predictions and vice versa; a multivariate model had strong discriminatory power (C-index = 0.845). However, imaging but not genotypic groups predicted htTKV growth, although more severe genotypic and imaging groups had larger kidneys at a young age. The trajectory of eGFR decline was linear from baseline in the most severe genotypic and imaging groups, but it was curvilinear in milder groups. Imaging class trajectories differentiated htTKV growth rates; severe classes had rapid early growth and large kidneys, but growth later slowed. CONCLUSION The value of imaging, genotypic, and combined data to identify rapidly progressive patients was demonstrated, and reference values for clinical trials were provided. Our data indicate that differences in kidney growth rates before adulthood significantly define patients with severe disease. FUNDING NIDDK grants: Mayo DK058816 and DK090728; CRISP DK056943, DK056956, DK056957, and DK056961; and HALT PKD DK062410, DK062408, DK062402, DK082230, DK062411, and DK062401.
Effect of Statins on the Risk of Extrahepatic Cholangiocarcinoma
Background and Aims Statins have been proven to be cytotoxic to human cholangiocarcinoma cells by inhibiting cell division and inducing apoptosis. We aimed to determine the effect of statin use on the risk of cancer development and survival in patients with extrahepatic cholangiocarcinoma (ECC), including perihilar cholangiocarcinoma (pCCA) and distal cholangiocarcinoma (dCCA). Approach and Results A total of 394 patients with ECC and hyperlipidemia who received care at Mayo Clinic Rochester between 2005 and 2015 were matched by age, sex, race, ethnicity, and residency to 788 controls with hyperlipidemia. Clinical and outcome data were abstracted. The odds ratios (ORs) for risk and hazard ratios for outcomes were calculated. The mean age and standard deviation (SD) for cases and controls was 65.6 years (13.8). The number of statin users in cases and controls was 73 (19%) and 403 (51%), respectively. Hepatitis C virus infection (OR, 15.84; 95% confidence interval [CI], 4.06‐61.87; P < 0.001) was the most significant risk factor for pCCA followed by inflammatory bowel disease and cirrhosis, whereas other liver disease, including biliary stone disease (OR, 4.06; CI, 2.24‐7.36; P < 0.001), was the only significant risk factor for dCCA. Statin use was associated with significantly reduced risk for all ECC (OR, 0.22; CI, 0.16‐0.29) as well as for the subtypes pCCA (OR, 0.3; CI, 0.21‐0.41) and dCCA (OR, 0.06; CI, 0.03‐0.14), all P < 0.0001. Moderate‐intensity dosage was found to decrease the risk of ECC (OR, 0.48; CI, 0.34‐0.67; P < 0.001). Comparing statin ever users to nonusers, patients with dCCA who used statins had significantly overall better survival (hazard ratio = 0.53; CI, 0.29‐0.97; P = 0.04). Conclusions This case‐control study suggests that statins decrease the risk of ECC and may improve survival in patients with dCCA. Additional validation studies are warranted.
Extramedullary Hematopoiesis in the Absence of Myeloproliferative Neoplasm: Mayo Clinic Case Series of 309 Patients
Abstract Background : Extramedullary hematopoiesis (EMH) implies the production of erythroid and myeloid progenitor cells outside of the bone marrow. EMH in adults is typically seen in patients with myeloproliferative neoplasms (MPN). The current study examines the Mayo Clinic experience with EMH cited in the absence of MPN. The objectives were to describe associated conditions and involved sites and identify "idiopathic" cases and review their management and long-term outcome. Methods : After approval by the Mayo Clinic institutional review board, institutional databases were screened through the Mayo Clinic Advanced Cohort Explorer (ACE) Tool, in order to identify patients with EMH. We performed a retrospective database review of all identified patients between 1975 and 2018. Demographic, biochemical, genetic, radiological and pathological data were collected and reviewed. Results : ACE identified 1,933 cases of "EMH". Extensive review confirmed the absence of associated MPN in 336 cases. Among these, 27 cases involved pathology remarks during tissue biopsy for liver transplant and were excluded from further analysis. The most frequent associated conditions in the remaining 309 cases included myelodysplastic syndromes (n=41; 13%), acute myeloid leukemia (n=28; 9%), hemolytic anemia (n=24; 8%), thalassemia (n=22; 7%), non-Hodgkin's lymphoma (n=19; 6%), immune thrombocytopenic purpura (n=17; 6%), metastatic cancer (n=17; 6%), plasma cell neoplasms (n=12; 4%) and a spectrum of other hematologic and non-hematologic conditions, including chronic lymphocytic leukemia, natural killer cell disorders, Hodgkin's lymphoma and Hemophagocytic lymphohistiocytosis. in 12 (4%) cases, no overt associated condition was evident and the cases were accordingly assigned "idiopathic". The most frequent involved sites included spleen (n=162), liver (n=78) and lymph nodes (n=20). A diagnosis of "idiopathic" EMH was established in 12 (4%) patients (median age 71 years, range 23-78; 50% females). Most of these cases presented with non-specific symptoms including abdominal and back pain and the EMH was an incidental discovery (Table 1). Involved sites included 4 pre-sacral, 3 para-spinal, 2 spleen and one each retroperitoneal, pleural-based chest mass and right upper lobe lung mass. All cases were evaluated with imaging studies and diagnosis was subsequently confirmed by pathology review. Past medical history was non-contributory. Complete blood counts were normal in 7 cases, showed anemia in 4 cases and were not available in one case (Table 1). The median follow-up time since the discovery of EMH was 7 years (range 2-20). None of the patients showed evidence of any malignancy, including MPN or other hematologic disorders, either at presentation or during follow-up. Nine (75%) of the 12 patients were managed conservatively; the two patients with splenic EMH underwent splenectomy and one patient had surgical excision of the EMH mass in order to prevent compression of the ureter. The FUO in the patient with splenic EMH resolved with splenectomy. Conclusions : We present the largest experience in EMH without associated MPN, in adults. We describe associated conditions and elaborate further on "idiopathic" EMH (n=12), which often represented an incidental discovery during evaluation of unrelated symptoms. None of the patients with idiopathic EMH harbored occult malignancies or subsequently developed MPN or other myeloid malignancies. Our observations do not support undertaking extensive investigations targeting MPN or other malignancies in idiopathic EMH and simple monitoring might be adequate. Disclosures No relevant conflicts of interest to declare.
Serum Erythropoietin Levels in Essential Thrombocythemia: Phenotypic and Prognostic Correlates
Abstract Background: Subnormal serum erythropoietin (EPO) level is widely accepted as a minor diagnostic criterion for polycythemia vera (PV) and has retained its value in the revised 2016 World Health Organization (WHO) classification scheme of myeloid neoplasms (Blood. 2016;127:2391). While over 80% of PV patients exhibit subnormal EPO values (Haematologica. 2004;89:1194), very little is known about the incidence, phenotypic connotation, or prognostic significance of serum EPO levels in essential thrombocythemia (ET). Methods: Study patients were recruited from the Mayo Clinic, Rochester, MN, USA. Diagnosis of ET was in strict accordance with the 2016 WHO criteria (Blood. 2016;127:2391) and only patients with EPO measurements at diagnosis or during their chronic phase were considered under the following provisions: i) no evidence of myelofibrotic or leukemic transformation; ii) no treatment with cytoreductive agents at the time of sample collection (and for those with EPO sampling at diagnosis, no prior exposure to cytoreductive therapy); iii) no hemoglobin levels below sex-adjusted values for anemia; and iv) systematic exclusion of all cases of masked PV. Serum erythropoietin levels were measured using Mayo-verified standard immune-enzymatic assay consistent with CLIA requirements with reference range between 4-21 mIU/mL. Standard statistical methods and time-to-event curves prepared using the Kaplan-Meier method were used to compare EPO-stratified groups. The JMP® Pro 13.0.0 software package was used for all analyses (SAS Institute, Cary, NC, USA). Results: Among 177 informative ET patients (median age 51 years, range 18-88; 71% females), median serum EPO concentrations were 5.2 mIU/mL (range <1-25) overall and 2.6 mIU/mL (range <1-3.9) and 7.2 mIU/mL (range 4-25) in those with subnormal versus normal/above normal EPO levels, respectively (p<0.0001). The majority of EPO measurements were at the time or within one year of diagnosis (67%), with the remainder obtained at referral or during the chronic clinical course. Risk stratification disclosed low, intermediate, and high risk status in 45%, 33% and 23% of patients, respectively, with no appreciable differences between EPO-stratified subsets. Subnormal serum EPO levels clustered clinically with JAK2 mutations (95% vs 60%; p<0.0001), higher hemoglobin (median 14.7 vs 13.8 g/dl, range: 12.1-17.8 vs 12-17.1; p<0.0001) and leukocyte counts (median 9.7 vs 8.2 x 109/l, range: 4-28.1 vs 3.9-22; p=0.0001), and arterial thrombosis after diagnosis (13% vs 5%; p=0.04). In addition, all three documented conversions to PV (p=0.01) and none of the six fibrotic progressions (p=0.02) occurred in patients with subnormal serum EPO levels (Table 1). While serum EPO level had no bearing on overall survival data (p=0.41) (Figure 1A), subnormal circulating EPO concentrations were significantly associated with superior myelofibrosis-free survival (p=0.02) (Figure 1B) but conversely, inferior polycythemia-free survival (p=0.03) (Figure 1C). Conclusions: We conclude that subnormal serum EPO levels are relatively frequent in ET, cluster with disease features that are reminiscent of polycythemia vera, and might be associated with a lower risk of fibrotic progression. Disclosures No relevant conflicts of interest to declare.
45 The Role of the Biliary and Gut Microbiome in the Progression of Cholangiocarcinoma and Primary Sclerosing Cholangitis
INTRODUCTION: Primary sclerosing cholangitis (PSC) is a chronic, fibroinflammatory, cholestatic liver disease of unknown etiopathogenesis which is recognized as a major risk factor for cholangiocarcinoma (CCA). We aimed to investigate the roles of the biliary and intestinal microflora in the inflammatory process of PSC and to determine if the microflora is associated with progression to CCA. METHODS: We studied the bile and stool microbiomes in samples obtained from patients with PSC (31 stool and 35 bile samples), sporadic CCA (11 stool and 26 bile samples), and PSC coexisting with CCA (16 stool and bile 17 samples). Control bile was obtained from patients with cholelithiasis or choledocholithiasis (n = 17). DNA extraction was followed by amplification and high-throughput next generation sequencing (MiSeq) of the 16S rDNA (V3-V5) region to identify the microbiota present. We performed: 1. analysis of the stool microbiome between PSC and CCA patients; 2. analysis of the biliary microbiome in PSC and CCA patients; 3. comparison of the biliary microbiome collected before and after biliary stent placement. RESULTS: Although bile samples from study patients had significantly lower sequencing depths than stool, their sequencing depths were much higher than bile from negative controls. The microbiomes of stool and bile samples from the same patients were significantly correlated ( P = 0.022). CCA bile samples had significant difference of alpha diversity from control bile samples with less Streptococcaceae and Desulfovibrionaceae (FDR < 10%) than PSC whereas no significant change of stool microbiome was identified between CCA and PSC. Fusobacterium and Gemella were correlated to PSC duration. An increased abundance of Fusobacteria after stent placement was revealed. Fusobacteria, which is inflammation-promoting, was also increased with the number of stents in the bile duct. CONCLUSION: Our study suggests that the bile microbiome is potentially a more distinctive biomarker than the stool microbiome for PSC and CCA development. There is increased inhabitance of inflammation-promoting bacteria in the bile of CCA patients and after biliary stent placement. Increased PSC duration also increases the microbial burden in the bile, which may also promote CCA development. We further detected specific bile microbes statistically associated with CCA or stent presence in the bile ducts, which raises the possibility of their role in the CCA progression or stent obstruction. Additional analyses with more samples are needed.
GALAD Score for Hepatocellular Carcinoma Detection in Comparison with Liver Ultrasound and Proposal of GALADUS Score
Abstract Background: The GALAD score is a serum biomarker–based model that predicts the probability of having hepatocellular carcinoma (HCC) in patients with chronic liver disease. We aimed to assess the performance of the GALAD score in comparison with liver ultrasound for detection of HCC. Methods: A single-center cohort of 111 HCC patients and 180 controls with cirrhosis or chronic hepatitis B and a multicenter cohort of 233 early HCC and 412 cirrhosis patients from the Early Detection Research Network (EDRN) phase II HCC Study were analyzed. Results: The area under the ROC curve (AUC) of the GALAD score for HCC detection was 0.95 [95% confidence interval (CI), 0.93–97], which was higher than the AUC of ultrasound (0.82, P <0.01). At a cutoff of −0.76, the GALAD score had a sensitivity of 91% and a specificity of 85% for HCC detection. The AUC of the GALAD score for early-stage HCC detection remained high at 0.92 (95% CI, 0.88–0.96; cutoff −1.18, sensitivity 92%, specificity 79%). The AUC of the GALAD score for HCC detection was 0.88 (95% CI, 0.85–0.91) in the EDRN cohort. The combination of GALAD and ultrasound (GALADUS score) further improved the performance of the GALAD score in the single-center cohort, achieving an AUC of 0.98 (95% CI, 0.96–0.99; cutoff −0.18, sensitivity 95%, specificity 91%). Conclusions: The performance of the GALAD score was superior to ultrasound for HCC detection. The GALADUS score further enhanced the performance of the GALAD score. Impact: The GALAD score was validated in the United States.
JAK2 exon 12 mutated polycythemia vera: Mayo‐Careggi MPN Alliance study of 33 consecutive cases and comparison with JAK2V617F mutated disease