Quantification of the flux of tyrosine pathway metabolites during nitisinone treatment of Alkaptonuria.

Nitisinone decreases homogentisic acid (HGA) in Alkaptonuria (AKU) by inhibiting the tyrosine metabolic pathway in humans. The effect of different daily doses of nitisinone on circulating and 24 h urinary excretion of phenylalanine (PA), tyrosine (TYR), hydroxyphenylpyruvate (HPPA), hydroxyphenyllactate (HPLA) and HGA in patients with AKU was studied over a four week period. Forty AKU patients, randomised into five groups of eight patients, received doses of 1, 2, 4 or 8 mg of nitisinone daily, or no drug (control). Metabolites were analysed by tandem mass spectrometry in 24 h urine and serum samples collected before and after nitisinone. Serum metabolites were corrected for total body water and the sum of 24 hr urine plus total body water metabolites of PA, TYR, HPPA, HPLA and HGA were determined. Body weight and urine urea were used to check on stability of diet and metabolism over the 4 weeks of study. The sum of quantities of urine metabolites (PA, TYR, HPPA, HPLA and HGA) were similar pre- and post-nitisinone. The sum of total body water metabolites were significantly higher post-nitisinone (p < 0.0001) at all doses. Similarly, combined 24 hr urine:total body water ratios for all analytes were significantly higher post-nitisinone, compared with pre-nitisinone baseline for all doses (p = 0.0002 - p < 0.0001). Significantly higher concentrations of metabolites from the tyrosine metabolic pathway were observed in a dose dependant manner following treatment with nitisinone and we speculate that, for the first time, experimental evidence of the metabolite pool that would otherwise be directed towards pigment formation, has been unmasked.

Data on items of AKUSSI in Alkaptonuria collected over three years from the United Kingdom National Alkaptonuria Centre and the impact of nitisinone.

Alkaptonuria is a rare genetic disorder characterized by a high level of circulating (and urine) homogentisic acid (HGA), which contributes to ochronosis when it is deposited in connective tissue as a pigmented polymer. In an observational study carried out by National AKU Centre (NAC) in Liverpool, a total of thirty-nine AKU patients attended yearly visits in varying numbers. At each visit a mixture of clinical, joint and spinal assessments were carried out and the results calculated to yield an AKUSSI (Alkaptonuria Severity Score Index), see "Nitisinone arrests ochronosis and decreases rate of progression of Alkaptonuria: evaluation of the effect of nitisinone in the United Kingdom National Alkaptonuria Centre" (Ranganath at el., 2018). The aim of this data article is to produce visual representation of the change in the components of AKUSSI over 3 years, through radar charts. The metabolic effect of nitisinone is shown through box plots.

Nitisinone arrests ochronosis and decreases rate of progression of Alkaptonuria: Evaluation of the effect of nitisinone in the United Kingdom National Alkaptonuria Centre.

QUESTION: Does Nitisinone prevent the clinical progression of the Alkaptonuria? FINDINGS: In this observational study on 39 patients, 2 mg of daily nitisinone inhibited ochronosis and significantly slowed the progression of AKU over a three-year period. MEANING: Nitisinone is a beneficial therapy in Alkaptonuria. BACKGROUND: Nitisinone decreases homogentisic acid (HGA), but has not been shown to modify progression of Alkaptonuria (AKU). METHODS: Thirty-nine AKU patients attended the National AKU Centre (NAC) in Liverpool for assessments and treatment. Nitisinone was commenced at V1 or baseline. Thirty nine, 34 and 22 AKU patients completed 1, 2 and 3 years of monitoring respectively (V2, V3 and V4) in the VAR group. Seventeen patients also attended a pre-baseline visit (V0) in the VAR group. Within the 39 patients, a subgroup of the same ten patients attended V0, V1, V2, V3 and V4 visits constituting the SAME Group. Severity of AKU was assessed by calculation of the AKU Severity Score Index (AKUSSI) allowing comparison between the pre-nitisinone and the nitisinone treatment phases. RESULTS: The ALL (sum of clinical, joint and spine AKUSSI features) AKUSSI rate of change of scores/patient/month, in the SAME group, was significantly lower at two (0.32 ±â€¯0.19) and three (0.15 ±â€¯0.13) years post-nitisinone when compared to pre-nitisinone (0.65 ±â€¯0.15) (p < .01 for both comparisons). Similarly, the ALL AKUSSI rate of change of scores/patient/month, in the VAR group, was significantly lower at one (0.16 ±â€¯0.08) and three (0.19 ±â€¯0.06) years post-nitisinone when compared to pre-nitisinone (0.59 ±â€¯0.13) (p < .01 for both comparisons). Combined ear and ocular ochronosis rate of change of scores/patient/month was significantly lower at one, two and three year's post-nitisinone in both VAR and SAME groups compared with pre-nitisinone (p < .05). CONCLUSION: This is the first indication that a 2 mg dose of nitisinone slows down the clinical progression of AKU. Combined ocular and ear ochronosis progression was arrested by nitisinone.

Immunohistochemical hENT1 expression as a prognostic biomarker in patients with resected pancreatic ductal adenocarcinoma undergoing adjuvant gemcitabine-based chemotherapy.

BACKGROUND: Human equilibrative nucleoside transporters (hENTs) are transmembranous proteins that facilitate the uptake of nucleosides and nucleoside analogues, such as gemcitabine, into the cell. The abundance of hENT1 transporters in resected pancreatic ductal adenocarcinoma (PDAC) might make hENT1 a potential biomarker of response to adjuvant chemotherapy. The aim of this study was to see whether hENT1 expression, as determined by immunohistochemistry, was a suitable predictive marker for subsequent treatment with gemcitabine-based adjuvant chemotherapy. METHODS: A systematic review was performed, searching databases from January 1997 to January 2016. Articles pertaining to hENT1 immunohistochemical analysis in resected PDAC specimens from patients who subsequently underwent adjuvant gemcitabine-based chemotherapy were identified. Eligible studies were required to contain survival data, reporting specifically overall survival (OS) and disease-free survival (DFS) with associated hazard ratios (HRs) stratified by hENT1 status. RESULTS: Of 42 articles reviewed, eight were suitable for review, with seven selected for quantitative meta-analysis. The total number of patients included in the meta-analysis was 770 (405 hENT1-negative, 365 hENT1-positive). Immunohistochemically detected hENT1 expression was significantly associated with both prolonged DFS (HR 0·58, 95 per cent c.i. 0·42 to 0·79) and OS (HR 0·52, 0·38 to 0·72) in patients receiving adjuvant gemcitabine but not those having fluoropyrimidine-based adjuvant therapy. CONCLUSION: Expression of hENT1 is a suitable prognostic biomarker in patients undergoing adjuvant gemcitabine-based chemotherapy.

The 5-year outcome of patients having incomplete colonoscopy.

AIM: Incomplete colonoscopy indicated for the detection of neoplasia occurs in 2-23% of patients, but there is little information on the long-term outcome of such patients. METHOD: All patients who underwent colonoscopy over 5 years at the Royal Liverpool University Hospital with a follow-up of up to 5 years were identified. RESULTS: The risk of colorectal cancer (CRC) was 2.9% (312/10 580) for all patients undergoing colonoscopy. For a failed colonoscopy, the risk was five-fold higher [14.3% (99/693)]. The mean age of the patients was 61 years and 58% were female. Following incomplete colonoscopy the risk of finding additional CRC, advanced colonic neoplasia and extracolonic neoplasia on subsequent investigation was 6.2%, 3.2% and 1.9%. The diagnostic yield on subsequent investigation for CRC or colonic polyps was 7% for repeat colonoscopy, 13.4% for computed tomography colonography, 10.3% for standard computed tomography and 1.8% for barium enema. In the 363 patients who were not offered a subsequent investigation, there was no further instance of CRC or CRC-related mortality over a 36-month period. CONCLUSION: Although the risk of CRC is higher in patients who have had a failed colonoscopy, a protocol approach of subsequent investigation should not replace clinical assessment on whether another test is necessary in the light of the good outcome of patients who were not subsequently investigated.

The role of ultrasound in the management of patients with occult groin hernias.

INTRODUCTION: Groin ultrasound scanning is commonly used to examine patients with obscure groin pain or swelling. A recent study has shown ultrasound has a poor positive predictive value (PPV) in diagnosing groin hernias although earlier studies reported PPV values as high as 100%. Our aims were to calculate ultrasound's accuracy in diagnosing occult groin hernias in symptomatic patients and assess how management of these patients is affected by ultrasound result. METHODS: We retrospectively analysed 375 symptomatic adult patients, who between February 2008 and March 2010, had ultrasound to diagnose groin hernias when clinical examination was inconclusive. Patients were identified on a prospective radiology database and all groin ultrasounds were performed by either one consultant radiologist or one radiographer. RESULTS: Ultrasound was positive in 199 patients, of which 118 underwent surgery. Using operative findings as the gold standard, ultrasound's PPV for groin hernias was 70% (95% CI: 62-78%). Ultrasound was equivocal in 42 patients of which hernias were diagnosed in 7 of the 10 who had surgery. Ultrasound was negative in 151 patients of which none were later diagnosed with hernias during 3 years' median follow-up. CONCLUSION: Ultrasound is poor in diagnosing occult groin hernias with a PPV of 70% suggesting a 30% chance of negative groin exploration. The equivocal ultrasound group requires careful follow-up as a considerable number were later diagnosed with hernia. The absence of subsequent hernia diagnosis in the negative ultrasound group suggests it may be a useful rule-out test to exclude occult groin hernias in symptomatic patients.