Comparison between free β subunit of human chorionic gonadotropin (hCG) and total hCG assays in adults with testicular cancer.

Objectives: We tested the hypothesis that the free-β subunit (βhCG) is diagnostically more sensitive with total hCG assays (hCGt) not detecting all tumours secreting βhCG. The effects of sex, age, and renal failure were investigated as secondary objectives.

Methods: We compared βhCG with hCGt in 204 testicular cancer patients (99 seminomas, 105 non-seminonatous germ cell tumours).

Evaluation of the Atellica TnIH cardiac troponin I assay and assessment of biological equivalence.

Objectives: We evaluated the analytical performance characteristics and the biological equivalence of the Atellica TnIH assay.

Methods: Precision, detection capability, linearity, and sex specific 99 percentiles were determined . Classification of patients relative to the 99 percentiles was used to assess biological equivalence.

How comparable are total human chorionic gonadotropin (hCGt) tumour markers assays?

Background Total human chorionic gonadotropin (hCGt) tumour marker testing is regarded as an "off label" application for most commercial methods. We compared four assays in patients with a hCGt tumour marker request. We hypothesised that regression slopes would be altered and that outliers would be more common with tumour marker than with pregnancy samples if the detection of malignancy associated hCG molecular forms differed amongst assays.

Comparison of Freelite™ and N Latex serum free light chain assays in subjects with end stage kidney disease on haemodialysis.

Background: Quantification of serum free light chains (FLC) is important in the diagnosis of plasma cell diseases where an abnormal kappa:lambda ratio infers a population of monoclonal plasma cells. The Freelite™ and N Latex assays have been validated in populations without kidney disease but there is a paucity of data relating to the use of these assays in end stage kidney disease (ESKD). The aim of the study was to compare FLC assay performance in ESKD patients on haemodialysis.

Combined light chain immunofixation to detect monoclonal gammopathy: a comparison to standard electrophoresis in serum and urine.

Background: The purpose of this study was to evaluate a combined κ and λ light chain immunofixation (CLIF) as a screening tool to detect monoclonal immunoglobulins in serum and urine. A secondary aim was to investigate the impact on workflow and reagent utilisation of a systematic implementation of CLIF in addition to routine protein electrophoresis (PE) on all samples.

Methods: Light chain antisera (κ and λ) were mixed in a 1:1 ratio and loaded in the same sequence as the PE to create a superimposable image.

Investigation of cholesterol bias due to a matrix effect of external quality assurance samples: how true is your cholesterol method?

Background: Comparability of cholesterol measurement is clinically required and external quality assurance (EQA) programmes are important to verify the trueness of routine methods.

Methods: We developed a gas chromatography-isotope dilution mass spectrometry (GC-IDMS) total cholesterol assay to investigate the cause of a suspected matrix-related negative bias with the Beckman Coulter enzymatic method discovered in an EQA programme. The GC-IDMS method was calibrated with certified reference material and verified against a secondary reference method.

Evaluation of the N Latex FLC free light chain assay on the Siemens BN analyser: precision, agreement, linearity and variation between reagent lots.

Background: The clinical utility of serum κ and λ free light chains (FLC) for the diagnosis and prognosis of plasma cell proliferative disorders is well established. We assessed the analytical performance of the N Latex FLC assays and compared it with the Freelite™ assays.

Methods: Analytical precision was assessed according to the CLSI EP5-A2 protocol.

Differential expression of pyloric atresia in junctional epidermolysis bullosa with ITGB4 mutations suggests that pyloric atresia is due to factors other than the mutations and not predictive of a poor outcome: three novel mutations and a review of the literature.

Junctional epidermolysis bullosa with pyloric atresia (JEB-PA) is an autosomal recessive blistering disease including lethal and non-lethal variants due to mutations in ITGB4 and ITGA6. It is unclear whether PA is caused directly by the mutations in these genes or by other factors. Skin biopsies from patients with JEB were processed for immunofluorescence mapping.

Review of collagen VII sequence variants found in Australasian patients with dystrophic epidermolysis bullosa reveals nine novel COL7A1 variants.

Background: Dystrophic epidermolysis bullosa (DEB) is an inherited skin fragility disorder where blistering occurs in the sub-lamina densa zone at the level of anchoring fibrils (AFs) of the dermo-epidermal junction. Both autosomal dominant (DDEB) and recessive (RDEB) result from mutations in the type VII collagen gene (COL7A1).

Objective: The purpose of this study was to understand the genotype-phenotype correlation in Australian patients with DEB.

Transient elevation of the tumor markers CA 15-3 and CASA as markers of interstitial lung disease rather than underlying malignancy in dermatomyositis sine myositis.

A 37-year-old woman with severe interstitial lung disease associated with dermatomyositis sine myositis is reported. A thoracoscopic lung biopsy revealed organizing diffuse alveolar damage. Significantly elevated serum levels of the tumor markers CA 15-3 and CASA (cancer-associated serum antigen) were detected, but no evidence of an underlying malignancy (including breast and ovarian) was found on serial clinical and radiologic examinations.

Epidermolysis bullosa simplex Dowling-Meara due to an arginine to cysteine substitution in exon 1 of keratin 14.

Epidermolysis bullosa simplex (EBS) is a blistering disorder affecting the basal layer of the epidermis usually inherited in an autosomal dominant fashion. Most cases are caused by mutations in the genes encoding keratin 5 (K5) and keratin 14 (K14) and are characterized by cytolysis within the basal layer of the epidermis. We report a patient manifesting the Dowling-Meara variant of EBS in whom we characterized a cytosine to thymine transition at codon 125 (R125C) in K14.