Publications by authors named "Danja Schulenburg-Brand"

4 Publications

  • Page 1 of 1

Performance of laboratory tests used to measure blood phenylalanine for the monitoring of patients with phenylketonuria.

J Inherit Metab Dis 2020 03 2;43(2):179-188. Epub 2019 Oct 2.

Biochemical Sciences, Viapath, Guys & St Thomas' NHSFT, London, UK.

Analysis of blood phenylalanine is central to the monitoring of patients with phenylketonuria (PKU) and age-related phenylalanine target treatment-ranges (0-12 years; 120-360 μmol/L, and >12 years; 120-600 μmol/L) are recommended in order to prevent adverse neurological outcomes. These target treatment-ranges are based upon plasma phenylalanine concentrations. However, patients are routinely monitored using dried bloodspot (DBS) specimens due to the convenience of collection. Significant differences exist between phenylalanine concentrations in plasma and DBS, with phenylalanine concentrations in DBS specimens analyzed by flow-injection analysis tandem mass spectrometry reported to be 18% to 28% lower than paired plasma concentrations analyzed using ion-exchange chromatography. DBS specimens with phenylalanine concentrations of 360 and 600 μmol/L, at the critical upper-target treatment-range thresholds would be plasma equivalents of 461 and 768 μmol/L, respectively, when a reported difference of 28% is taken into account. Furthermore, analytical test imprecision and bias in conjunction with pre-analytical factors such as volume and quality of blood applied to filter paper collection devices to produce DBS specimens affect the final test results. Reporting of inaccurate patient results when comparing DBS results to target treatment-ranges based on plasma concentrations, together with inter-laboratory imprecision could have a significant impact on patient management resulting in inappropriate dietary change and potentially adverse patient outcomes. This review is intended to provide perspective on the issues related to the measurement of phenylalanine in blood specimens and to provide direction for the future needs of PKU patients to ensure reliable monitoring of metabolic control using the target treatment-ranges.
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http://dx.doi.org/10.1002/jimd.12163DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7957320PMC
March 2020

An Audit of the Use of Gonadorelin Analogues to Prevent Recurrent Acute Symptoms in Patients with Acute Porphyria in the United Kingdom.

JIMD Rep 2017 21;36:99-107. Epub 2017 Feb 21.

Department of Medical Biochemistry and Immunology, University Hospital of Wales, Cardiff, CF14 4XW, UK.

Severe recurrent acute attacks of porphyria have traditionally been treated with either prophylactic human haemin or gonadorelin analogues (GnA) in females. Evidence on the most effective treatment for this patient subgroup is lacking. This audit surveyed the use of prophylactic GnA in the UK.Twenty female patients (who experienced between 2 and 45 acute attacks of porphyria requiring hospitalisation and treatment with human haemin prior to GnA prophylaxis) were included in the audit. Data was retrospectively collected based on patient history and case review.Twenty three treatment courses were given lasting a median period of 12 months. Monthly subcutaneous Goserelin was most commonly used. In three patients in whom timing with the menstrual cycle was not considered, an acute attack occurred after initiation of the first dose. The majority of patients experienced oestrogen deficiency symptoms during treatment. Fifty percent of the prescribed courses of GnA resulted in a degree of clinical benefit. This successfully treated group experienced between 3 and 20 acute attacks prior to and between 0 and 6 acute attacks during GnA treatment.The audit revealed large variation in practice in the United Kingdom regarding indication, duration of treatment, specific drug used and management of side effects. In view of the limited treatment options available for this cohort and the mixed outcome successes reported, we believe it is reasonable for porphyria specialists to continue offering GnA treatment to women with severe recurrent debilitating acute attacks of porphyria associated with the menstrual cycle, and we propose best practice guidelines to standardise management.
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http://dx.doi.org/10.1007/8904_2017_2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5680288PMC
February 2017

The cutaneous porphyrias.

Dermatol Clin 2014 Jul 5;32(3):369-84, ix. Epub 2014 May 5.

Department of Medical Biochemistry and Immunology, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK; Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Heath Park, Cardiff, Wales CF14 4XN, UK.

The porphyrias are a group of mainly inherited disorders of heme biosynthesis where accumulation of porphyrins and/or porphyrin precursors gives rise to 2 types of clinical presentation: cutaneous photosensitivity and/or acute neurovisceral attacks. The cutaneous porphyrias present with either bullous skin fragility or nonbullous acute photosensitivity. This review discusses the epidemiology, pathogenesis, clinical presentation, laboratory diagnosis, complications, and current approach to porphyria management. Although focusing mainly on their dermatological aspects, the article also covers the management of acute porphyria, which by virtue of its association with variegate porphyria and hereditary coproporphyria, may become the responsibility of the clinical dermatologist.
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http://dx.doi.org/10.1016/j.det.2014.03.001DOI Listing
July 2014

The impact of local guidelines on the tumour marker requesting patterns of a General Surgery Department.

Ann Clin Biochem 2013 Sep 4;50(Pt 5):438-42. Epub 2013 Jul 4.

Department of Medical Biochemistry and Immunology, University Hospital of Wales, Cardiff, UK.

Background: The inappropriate use of tumour markers (TMs) is a common problem. The aim of this audit was to evaluate the impact of local guidelines on the TM requesting patterns of a General Surgery Department.

Methods: CA 125, CA 19-9, CA15-3, CEA, AFP and HCG requests from all hospital surgical locations were audited over two periods of eight months before and after the implementation of local requesting guidelines.

Results: Postintervention, total TM requests decreased by 32% while patient requests decreased by 9.8%. Single TM requesting increased and requests for panels containing four or more TMs decreased from 279 to 60 requests (78% reduction).

Conclusion: Interdepartmental collaboration and the implementation of local guidelines have resulted in a change in requesting behaviour, most notably a reduction in multiple TM panel requests.
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http://dx.doi.org/10.1177/0004563213479942DOI Listing
September 2013
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