Ten years of specialized adult care for phenylketonuria – a single-centre experience

Abstract

BackgroundSpecialized adult care of phenylketonuria (PKU) patients is of increasing importance. Adult outpatient clinics for inherited errors of metabolism can help to achieve this task, but experience is limited. Ten years after establishment of a coordinated transition process and specialised adult care for inherited metabolic diseases, adult PKU care was evaluated with respect to metabolic control, therapy satisfaction, life satisfaction, sociodemographic data, economical welfare as well as pregnancy outcome.MethodsAll PKU patients transferred from paediatric to adult care between 2005 and 2015 were identified. A retrospective data analysis and a cross-sectional survey in a sub-cohort of 30 patients including a questionnaire for assessing quality of life (FLZm) were performed as a single-centre investigation at the metabolic department of the University Hospital Leipzig, Germany. For statistical analysis, Mann-Whitney-U-test, t-test for independent samples, ANOVA and chi square test were used as appropriate.Results96 PKU patients (56 females/40 males; median age 32 years, range 18–62) were included. In the last 3-year period, 81 % of the transferred patients still kept contact to the adult care centre. Metabolic control was stable over the evaluation period and dried blood phenylalanine concentrations mostly remained within the therapeutic range (median 673.0 μmol/l, range 213.0–1381.1). Sociodemographic data, economical welfare and life satisfaction data were comparable to data from the general population. However, differences could be revealed when splitting the cohort according to time of diagnosis and to management during childhood. 83 % of the PKU adults were satisfied with the transition process and current adult care. 25 completed pregnancies were supervised; three newborns, born after unplanned pregnancy, showed characteristic symptoms of maternal PKU syndrome.ConclusionsContinuous care for adult PKU patients in a specialized outpatient clinic is successful, leading to good to satisfactory metabolic control and social outcomes. Uninterrupted good metabolic treatment throughout childhood and adolescence positively influences educational, professional and economic success in later life. Further effort in specialized paediatric and adult metabolic care is needed to prevent loss of follow-up and to support the recommended life-long treatment and/or care.

The neurological and psychological phenotype of adult patients with early‐treated phenylketonuria: A systematic review

“…However, the impact of dietary management on QoL was comparable between patients with classical and mild PKU, possibly reflecting dietary relaxation during adulthood . In another study, patients on a restricted diet reported higher scores of general life‐satisfaction than both an off‐diet patient group and a reference sample . Moreover, some data suggest that returning to a strict diet after discontinuation for at least 3 months can significantly improve the subjective well‐being of patients, according to evaluation with the Psychological General Well‐Being Index …”

“…In the first study, patients with PKU, 96% of whom were on a restricted diet, achieved lower levels of academic achievement, specifically for graduation at senior high school level, compared with the general population . The second study found that educational attainment was only lower in patients with PKU whose treatment was interrupted (for at least 4 years starting at the age of 7‐14 years), while patients who had been continuously treated until the end of adolescence demonstrated comparable education status to the census population . Nevertheless, income was comparable between patients with PKU and the census population, regardless of therapy interruption …”

“…It is not clear at this stage what proportion of adults with ETPKU suffer from these residual effects, or to what extent they affect their lives. Recent population‐based surveys suggest that the majority of adults with ETPKU are, in fact, functioning well in society …”

Organic acidurias in adults: late complications and management

“…Presymptomatically diagnosed and treated individuals often remain asymptomatic until adolescence/adulthood. In many countries, however, there is still a need to establish a transition from pediatric to adult health care and long-term care to prevent a drop-out of medical care and to support lifelong compliance analogous to other inborn metabolic diseases (Mutze et al 2011;Mutze et al 2016). Although metabolic crisis occur rarely in adulthood, prolonged fasting and catabolic stress should be avoided life-long to prevent metabolic decompensations (Feinstein and O'Brien 2003)byor al or intravenous carbohydrate supply (4-6 g/kg BW/d) and if necessary additional carnitine supplementation (50-100 mg/ kg BW/d).…”

Hyperphenylalaninemia Correlated with Global Decrease of Antioxidant Genes Expression in White Blood Cells of Adult Patients with Phenylketonuria

“…However, evidences suggest that high plasma Phe concentrations can cause neurological and psychological disorders in adulthood (Waisbren et al 2007;ten Hoedt et al 2011;Sharman et al 2012;Bilder et al 2013;Okano and Nagasaka 2013;Weglage et al 2013). Thus, maintaining a Phe-restricted diet in adult PKU patients is still debated (Demirkol et al 2011;ten Hoedt et al 2011;Trefz et al 2011;Hanley 2013;Mutze et al 2016). Several hypotheses about the pathophysiology of brain injury in PKU have been discussed but the mechanisms remain unclear and seem to be multifactorial (Bone et al 2012).…”