CASE REPORT: We described a patient with ET whose disease evolved into MDS with fibrosis and complex karyotype after 15 years of stable disease. She was asymptomatic and was on hydroxyurea (HU) treatment until recently when she presented with worsening anaemia. Physical examination showed mild splenomegaly. Full blood picture showed leukoerythroblastic picture with presence of 3% circulating blasts and background of dysplastic features such as hypogranular cytoplasm and nuclear hyposegmentation of neutrophils. The bone marrow aspiration was haemodiluted but revealed presence of 6% blast cells, trilineage dysplasia and predominant erythroid precursors (60%). Trephine biopsy showed no excess of blast cells and normal quantity of erythroid precursors, but there was increased in fibrosis (WHO grade 2) and presence of dysmegakaryopoeisis such as nuclear hypolobation, multinucleation and micromegakaryocytes. Cytogenetic study showed complex karyotype; monosomy of chromosome 2, chromosome 5, chromosome 18 and presence of a marker chromosome (42~44, XX,-2,-5,-18,+mar). Fluorescence in situ hybridisation (FISH) showed 5q deletion (CSF1R and EGR1).
CONCLUSION: The findings were consistent with transformation of ET to MDS with fibrosis and complex karyotype. ET progression to MDS is considered rare. The presence of complex karyotype and fibrosis in MDS are associated with unfavourable outcome.
METHODS: This prospective study included a derivation cohort before validation in multiple international cohorts. The derivation cohort was a cross-sectional, multicentre study of patients aged 18 years or older, scheduled to have a liver biopsy for suspicion of NAFLD at seven tertiary care liver centres in England. This was a prespecified secondary outcome of a study for which the primary endpoints have already been reported. Liver stiffness measurement (LSM) by vibration-controlled transient elastography and controlled attenuation parameter (CAP) measured by FibroScan device were combined with aspartate aminotransferase (AST), alanine aminotransferase (ALT), or AST:ALT ratio. To identify those patients with NASH, an elevated NAS, and significant fibrosis, the best fitting multivariable logistic regression model was identified and internally validated using boot-strapping. Score calibration and discrimination performance were determined in both the derivation dataset in England, and seven independent international (France, USA, China, Malaysia, Turkey) histologically confirmed cohorts of patients with NAFLD (external validation cohorts). This study is registered with ClinicalTrials.gov, number NCT01985009.
FINDINGS: Between March 20, 2014, and Jan 17, 2017, 350 patients with suspected NAFLD attending liver clinics in England were prospectively enrolled in the derivation cohort. The most predictive model combined LSM, CAP, and AST, and was designated FAST (FibroScan-AST). Performance was satisfactory in the derivation dataset (C-statistic 0·80, 95% CI 0·76-0·85) and was well calibrated. In external validation cohorts, calibration of the score was satisfactory and discrimination was good across the full range of validation cohorts (C-statistic range 0·74-0·95, 0·85; 95% CI 0·83-0·87 in the pooled external validation patients' cohort; n=1026). Cutoff was 0·35 for sensitivity of 0·90 or greater and 0·67 for specificity of 0·90 or greater in the derivation cohort, leading to a positive predictive value (PPV) of 0·83 (84/101) and a negative predictive value (NPV) of 0·85 (93/110). In the external validation cohorts, PPV ranged from 0·33 to 0·81 and NPV from 0·73 to 1·0.
INTERPRETATION: The FAST score provides an efficient way to non-invasively identify patients at risk of progressive NASH for clinical trials or treatments when they become available, and thereby reduce unnecessary liver biopsy in patients unlikely to have significant disease.
FUNDING: Echosens and UK National Institute for Health Research.