[About a case of macro-FSH analytical interference]. / Une grosse FSH qui trompe énormément : à propos d'un cas de macro-FSH.

An 18-year-old woman was referred by her GP to the endocrinology department of the University Hospital of Bordeaux on suspicion of premature ovarian failure because of a disorder of the menstrual cycle and pathological results of biological exploration of the gonadotropic axis. Repeatedly-found elevated concentrations of FSH contrasted with a normal concentration of LH leading to a hypothesis of ovarian failure. However, different investigations favoured an analytical interference. The presence of heterophilic antibodies or anti-mouse antibodies (HAMA) was unlikely but, finally, a complex combining FSH and autoantibody (called macro-FSH) was evidenced.

[What to do in the event of a suspicion of analytical interference during an immunoassay?] / Conduite à tenir devant une suspicion d'interférence analytique lors d'un immunodosage.

Identifying analytical interference is a challenge for the medical biologist in providing advice to the prescriber. Indeed, these analytical interferences often have deleterious consequences on the care of patients. Understanding their mechanisms and mastering corrective procedures is essential to limit these management errors. Faced with the many questions from clinicians in current practice, we propose an algorithm for managing a sample when interference is suspected.

Immunotherapy-induced hypothyroidism A report of melanoma treated by ipilimumab and nivolumab.

We report the case of a patient treated by ipilimumab and nivolumab for a metastatic melanoma. After a mild clinical thyroiditis and a transient biological hyperthyroidism she rapidly demonstrated a peripheral hypothyroidism with appearance of antibodies against thyroperoxidase and thyroglobulin.

Prognostic Biomarkers Used for Localised Prostate Cancer Management: A Systematic Review.

CONTEXT: Prostate cancer stratification is based on tumour size, pretreatment PSA level, and Gleason score, but it remains imperfect. Current research focuses on the discovery and validation of novel prognostic biomarkers to improve the identification of patients at risk of aggressive cancer or of tumour relapse. OBJECTIVE: This systematic review by the Intergroupe Coopérateur Francophone de Recherche en Onco-urologie (ICFuro) analysed new evidence on the analytical validity and clinical validity and utility of six prognostic biomarkers (PHI, 4Kscore, MiPS, GPS, Prolaris, Decipher). EVIDENCE ACQUISITION: All available data for the six biomarkers published between January 2002 and April 2015 were systematically searched and reviewed. The main endpoints were aggressive prostate cancer prediction, additional value compared to classical prognostic parameters, and clinical benefit for patients with localised prostate cancer. EVIDENCE SYNTHESIS: The preanalytical and analytical validations were heterogeneous for all tests and often not adequate for the molecular signatures. Each biomarker was studied for specific indications (candidates for a first or second biopsy, and potential candidates for active surveillance, radical prostatectomy, or adjuvant treatment) for which the level of evidence (LOE) was variable. PHI and 4Kscore were the biomarkers with the highest LOE for discriminating aggressive and indolent tumours in different indications. CONCLUSIONS: Blood biomarkers (PHI and 4Kscore) have the highest LOE for the prediction of more aggressive prostate cancer and could help clinicians to manage patients with localised prostate cancer. The other biomarkers show a potential prognostic value; however, they should be evaluated in additional studies to confirm their clinical validity. PATIENT SUMMARY: We reviewed studies assessing the value of six prognostic biomarkers for prostate cancer. On the basis of the available evidence, some biomarkers could help in discriminating between aggressive and non-aggressive tumours with an additional value compared to the prognostic parameters currently used by clinicians.

No compensatory lung growth after resection in a one-year follow-up cohort of patients with lung cancer.

BACKGROUND: As compensatory lung growth after lung resection has been studied in animals of various ages and in one case report in a young adult, it has not been studied in a cohort of adults operated for lung cancer. METHODS: A prospective study including patients with lung cancer was conducted over two years. Parenchymal mass was calculated using computed tomography before (M0) and at 3 and 12 months (M3 and M12) after surgery. Respiratory function was estimated by plethysmography and CO/NO lung transfer (DLCO and DLNO). Pulmonary capillary blood volume (Vc) and membrane conductance for CO (DmCO) were calculated. Insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) plasma concentrations were measured simultaneously. RESULTS: Forty-nine patients underwent a pneumonectomy (N=12) or a lobectomy (N=37) thirty two completed the protocol. Among all patients, from M3 to M12 the masses of the operated lungs (239±58 to 238±72 g in the lobectomy group) and of the non-operated lungs (393±84 to 377±68 g) did not change. Adjusted by the alveolar volume (VA), DLNO/VA decreased transiently by 7% at M3, returning towards the M0 value at M12. Both Vc and DmCO increased slightly between M3 and M12. IGF-1 and IGFBP-3 concentrations did not change at M3, IGF-1 decreased significantly from M3 to M12. CONCLUSIONS: Compensatory lung growth did not occur over one year after lung surgery. The lung function data could suggest a slight recruitment or distension of capillaries owing to the likely hemodynamic alterations. An angiogenesis process is unlikely.

[The level of evidence for the use of biomarkers in the early detection of prostate cancer]. / Les niveaux de preuve des biomarqueurs utilisés pour la détection précoce des cancers de la prostate.

To systematically review the evidence for the use of PSA and other biomarkers in the early detection of prostate cancer, we searched PubMed for clinical trials and studies assessing PSA and other biomarkers in the early detection of prostate cancer, published between 2000 and May 2013 that included >200 subjects. The level of evidence (LOE) for clinical utility was evaluated using the tumor marker utility grading system. A total of 84 publications, corresponding to 70 trials and studies were selected for inclusion in this review. We attributed a level of evidence (LoE) of IA to PSA for early PCa detection, but we do not recommend its use in mass screening. Emerging biomarkers were assessed in prospective case-control and cohort studies: PCA3 (n=3); kallikreins (n=3); [-2]proPSA (n=5); fusion oncogenes (n=2). These studies used biopsy results for prostate cancer to determine specificity and sensitivity, but they did not assess the effect on PCa mortality. The LoE attributed was III-C. PSA can be used for early prostate cancer detection but mass screening is not recommended. Studies on other biomarkers suggest that they could be used, individually or in combination, to improve the selection of patients with elevated PSA levels for biopsy, but RCTs assessing their impact on prostate cancer management and mortality are needed. A better use of available tests is possible for men at risk in order to maximize the risk-benefit ratio.

Hypercalcemia and elevated concentration of vitamin D: A case report too easy to be true.

BACKGROUND: Endogenous (heterophile, human anti-animal …) antibodies are a known cause of interference in immunoassays. CASE REPORT: A patient with hypercalcemia and low PTH levels was investigated. The serum 25OH vitamin D (25OHD) concentration was above the analytical range of the automated analyser (>150ng/mL) but serum dilutions were not linear. A myeloma-related monoclonal peak of immunoglobulin G (30g/L) was found. RESULTS: Alternative 25OHD assays (RIA, automated analysers, mass spectrometry) all found concentrations <25ng/mL. NabTM columns (Thermo Scientific) eliminated the endogenous immunoglobulin from the serum thus allowing the initial analyser to provide correct results. DISCUSSION AND CONCLUSION: The potentially misleading point was that the apparent very high 25OHD levels were concomitant with hypercalcemia and low PTH levels thus mimicking vitamin D intoxication. Identifying assay interferences requires clinical awareness but, when suspected, one should be aware that technical tools or alternate assays are available to correct some interferences, including monoclonal immunoglobulins.

Aldosterone determination: comparison of a RIA assay and a CLIA assay.

OBJECTIVE: To extend knowledge about the clinical performances of a new chemiluminescent immunoassay (CLIA) for aldosterone set up in available analysers. DESIGN AND PATIENTS: We compared the results of a RIA assay to those of a CLIA assay in 198 serum and 80 urine samples from patients in endocrine and hypertension departments. Furthermore, for serum samples the concordance of results for postural tests was analysed. RESULTS: RIA and CLIA aldosterone serum concentration was linearly correlated with a slope of 0.988 and an intercept of 70.4pmol/L. The variations of aldosterone serum concentration obtained with the two assays during postural tests were very consistent. There was no significant difference of aldosterone concentrations after thawing with the CLIA assay. RIA and CLIA aldosterone urine concentrations were linearly correlated with a slope of 0.787 and an intercept of -2.64nmol/L. Omitting the preservative boric acid from urine samples did not modify aldosterone concentration at least up to 48h after collection. CONCLUSION: The RIA and CLIA assays were well correlated for the most useful serum samples. It is well suited to circumvent isotopic assays with the throughput of available analysers.

Impact of the reference values on the clinically-relevant cut-offs. The example of cortisol testing in children.

BACKGROUND: After modification of our routine cortisol assay, we questioned the reference ranges for basal and stimulated cortisol plasma concentration in children. METHODS: We retrospectively addressed the relevance of using the manufacturer's normal reference range for basal cortisol and investigated its response to glucagon-betaxolol testing. RESULTS: Basal morning cortisol was 260 (98-604) nmol/L [manufacturer's normal range (185-624) nmol/L: 26% subjects had "low" basal cortisol]. Upon testing cortisol increased to 502 (117-856) nmol/L. If a recently described 100% specificity threshold (403 nmol/L) is used it would amount to 31% adrenal insufficient children in apparently unaffected children. Basal and stimulated cortisol obtained with our prior radioimmunoassay (RIA) in a sub-group of subjects were lower: 411 (187-1061) and 770 (329-1542) nmol/L. Using the 403 nmol/L threshold with the radioimmunoassay would result in only 5% adrenal insufficient children. CONCLUSIONS: This shows again that laboratories have to advertise the need to establish reference values for given populations, both for basal or stimulated hormone levels. Failure to apply this rule will elicit false-positive and more critically, false-negative results.

Thyroxin overdose due to rheumatoid factor interferences in thyroid-stimulating hormone assays.

BACKGROUND: Immunoassays are susceptible to interferences by anti-hormone antibodies, heterophilic antibodies or rheumatoid factor (RF). METHODS: We report a case of levothyroxin overdose because of gross overestimation of thyroid-stimulating hormone (TSH) by chemiluminescent and IRMA assays. Alternate assays were performed and heterophilic antibodies blocking tubes were used. RESULTS: Analytical investigations revealed: i) non-linear concentrations of TSH after serum dilutions, ii) decreased TSH concentrations after removal of heterophilic antibodies, iii) appropriately decreased TSH concentrations in alternate TSH assays and iv) identification of increased concentrations of RF. CONCLUSIONS: The presence of RF may be responsible for false determination of TSH concentrations preventing monitoring of TSH.

The chronic oral administration of arginine aspartate decreases secretion of IGF-1 and IGFBP-3 in healthy volunteers.

To investigate the effect of chronic oral arginine aspartate on the growth hormone (GH), GH-releasing hormone (GHRH), insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) secretions in healthy volunteers. Twenty-three healthy non-athlete volunteer males were administered arginine aspartate (30 g) orally once daily at 21:00 h for 21 consecutive days. Subjects were hospitalized on days 0, 1, 3, 5, 7, 14 and 21 of treatment. At each hospitalization, concentrations of GHRH, GH, IGF-1 and IGFBP-3 were measured over 4 h after arginine aspartate intake. GH, IGF-1 and IGFBP-3 concentrations were also determined over 12 h at days 0, 1 and 21. Compared with day 1, 4 h GH levels dropped at day 5 and subsequently rose to levels not significantly different from initial ones. The latter was substantiated by 12 h GH levels that did not significantly change from days 1 to 21. GHRH levels were not statistically different, although there was a trend in median values that seemed to inversely mirror those of GH. This dynamic over the course of the study for GH and GHRH was accompanied by a general decrease in IGF-1 and IGFBP-3. In healthy volunteers, a chronic oral treatment with 30 g/day arginine aspartate is followed by a decrease in IGF-1 and IGFBP-3 secretions.

Do intrinsic factor antibodies assays provide univocal answers in Biermer's disease?

The objective of the study is to evaluate the concordance of four assays for antibodies against intrinsic factor (IF-Ab). Sixty-two sera were tested with one competitive automated and three manual noncompetitive assays. Thirty-five percent patients had discordant results with at least one of the four assays. However, any method uncovered patients with proven Biermer's disease missed by the others assays. The observed discordance partly explains the poor sensitivity of IF-Ab in studies using a single assay.

Chronic atrial fibrillation ablation impact on endocrine and mechanical cardiac functions.

AIMS: Assess the impact of persistent/permanent atrial fibrillation (AF) ablation on endocrine and mechanical cardiac functions. METHODS AND RESULTS: In all, 43 patients (40 males, 53 +/- 12 years) undergoing persistent/permanent AF ablation had atrial (ANP) and brain natriuretic peptide (BNP) measurements before day 1, 3, and 3 months after ablation. In the same period of time transthoracic echocardiography was performed. With a mean radiofrequency delivery of 98 +/- 29 min, sinus rhythm (SR) was restored in 30 patients (70%) without DC shock. ANP decreased significantly (P < 0.001) with restoration of SR and then increased until day 3 post ablation without reaching the level observed during AF. At 3 months, ANP was significantly lower than day 3 reaching normal value in 28 (65%) patients and being <7 pg/mL in 4 (9%). The BNP followed the same trend with normal BNP level in 23 (53%) patients at 3 months. Identifiable atrial filling waves on the pulsed Doppler transmitral recordings performed between day 2 and day 4 after the procedure were seen in 18 patients (42%). At 3 months, 39 (95%) of the patients with SR during echocardiography had a significant A wave. CONCLUSION: SR following persistent/permanent AF ablation is associated with a dramatic decrease in natriuretic peptides. At 3 months, despite relatively extensive atrial ablation, endocrine and mechanical cardiac functions are significantly improved.

Effects of Helicobacter pylori infection on gut appetite peptide (leptin, ghrelin) expression in elderly inpatients.

The aim of the study was to investigate the relationship between gastritis and leptin and ghrelin in elderly patients. Patients older than 75 years undergoing an endoscopy were included. We reported data on nutritional status and Helicobacter pylori infection diagnosis (serology, 13C-urea breath test, culture, histology, and polymerase chain reaction on gastric biopsies). Gastric messenger RNA expression of leptin and ghrelin were quantified by real-time polymerase chain reaction. Sixty-two patients were included (84.7 +/- 5.2 years). H. pylori infection was associated with decreased gastric expression of leptin (p = .021), ghrelin (p =.002), and plasma ghrelin levels (p = .018). Atrophy was associated with decreased gastric leptin (p = .007) and ghrelin (p = .02). H. pylori infection correlated negatively with patient energy intake (r = -0.36; p = .001) and body mass index (r = -0.34; p = .018). The negative association between ghrelin and H. pylori infection may be related to a higher prevalence of atrophy and raises the possibility that H. pylori may be contributing to undernutrition in some older people.

131I in blood samples: a danger for professionals? A problem for immunoassays?

OBJECTIVE: Our objective was to investigate the safety of radioactive blood samples from patients receiving 131I and whether the radioactivity affects the validity of assays. METHODS: First, the activity of samples from patients given 131I was measured by 3 methods and compared with the upper threshold. Then, pilot sera were spiked with 131I, and possible interference was investigated using 2 immunoradiometric assays. RESULTS: The activity of 13 of the 15 samples was below the European limit; the other 2 samples were from patients with reduced renal clearance rates. No differences in thyroglobulin level or thyroid-stimulating hormone level were found between sera that were spiked with 131I and sera that were not. CONCLUSION: These blood samples are safe because they contain negligible activity, and the use of radioimmunoassays or immunoradiometric assays on them produces reliable results.

Human bone marrow endothelial cells: a new identified source of B-type natriuretic peptide.

B-type natriuretic peptide (BNP) is a hormone mainly secreted by cardiac ventricle myocytes and which is increased in cardiac diseases. Moreover, BNP expression has been shown in various cell/tissue types. Six different human endothelial cell (EC) culture models arising from macro and microcirculation either primary cultures or cell lines were cultured and screened for BNP presence and secretion. All cell types expressed BNP mRNA while only the ECs arising from bone marrow stromal compartment secreted high amounts of BNP protein. This report is the first to identify ECs as a new source of BNP. However, BNP secretion is limited to a particular EC type.