Clinical performance of magnetic resonance imaging and biomarkers for prostate cancer diagnosis in men at high genetic risk.

OBJECTIVES: To evaluate different scenarios for the management of early diagnosis of cancer (PCa) in men at high genetic risk, using recently developed blood and urinary molecular biomarkers in combination with clinical information alongside multiparametric magnetic resonance imaging (mpMRI). PATIENTS AND METHODS: A total of 322 patients with a high genetic risk (familial or personal history of cancers or a predisposing germline variant) were included in this study. The primary outcome was the detection rates of PCa (positive biopsy) or clinically significant PCa (biopsy with International Society of Urological Pathology [ISUP] grade >1). Clinical parameters included age, body mass index, ancestry, and germline mutational status, mpMRI, prostate-specific antigen density (PSAD), Prostate Health Index and urinary markers (Prostate Cancer Associated 3, SelectMdx™ and T2:ERG score) were assessed. Sensitivity (Se) and specificity (Sp) for each marker at their recommended cut-off for clinical practice were calculated. Comparison between diagnoses accuracy of each procedure and scenario was computed using mutual information based and direct effect contribution using a supervised Bayesian network approach. RESULTS: A mpMRI Prostate Imaging-Reporting and Data System (PI-RADS) score ≥3 showed higher Se than mpMRI PI-RADS score ≥4 for detection of PCa (82% vs 61%) and for the detection of ISUP grade >1 lesions (96% vs 80%). mpMRI PI-RADS score ≥3 performed better than a PSA level of ≥3 ng/mL (Se 96%, Sp 53% vs Se 91%, Sp 8%) for detection of clinically significant PCa. In case of negative mpMRI results, the supervised Bayesian network approach showed that urinary markers (with the same accuracy for all) and PSAD of ≥0.10 ng/mL/mL were the most useful indicators of decision to biopsy. CONCLUSIONS: We found that screening men at high genetic risk of PCa must be based on mpMRI without pre-screening based on a PSA level of >3 ng/mL, to avoid missing too many ISUP grade >1 tumours and to significantly reduce the number of unnecessary biopsies. However, urinary markers or a PSAD of ≥0.10 ng/mL/mL when mpMRI was negative increased the detection of ISUP grade >1 cancers. We suggest that a baseline mpMRI be discussed for men at high genetic risk from the age of 40 years.

Accuracy of the prostate health index versus the urinary prostate cancer antigen 3 score to predict overall and significant prostate cancer at initial biopsy.

BACKGROUND: It remains unclear whether the Prostate Health Index (PHI) or the urinary Prostate-Cancer Antigen 3 (PCA-3) score is more accurate at screening for prostate cancer (PCa). The aim of this study was to prospectively compare the accuracy of PHI and PCA-3 scores to predict overall and significant PCa in men undergoing an initial prostate biopsy. METHODS: Double-blind assessments of PHI and PCA-3 were conducted by referent physicians in 138 patients who subsequently underwent trans-rectal ultrasound-guided prostate biopsy according to a 12-core scheme. Predictive accuracies of PHI and PCA-3 were assessed using AUC and compared according to the DeLong method. Diagnostic performances with usual cut-off values for positivity (i.e., PHI >40 and PCA-3 >35) were calculated, and odds ratios associated with predicting PCa overall and significant PCa as defined by pathological updated Epstein criteria (i.e., Gleason score ≥7, more than three positive cores, or >50% cancer involvement in any core) were estimated using logistic regression. RESULTS: Prevalences of overall and significant PCa were 44.9% and 28.3%, respectively. PCA-3 (AUC = 0.71) was the most accurate predictor of PCa overall, and significantly outperformed PHI (AUC = 0.65; P = 0.03). However, PHI (AUC = 0.80) remained the most accurate predictor when screening exclusively for significant PCa and significantly outperformed PCA-3 (AUC = 0.55; P = 0.03). Furthermore, PCA-3 >35 had the best accuracy, and positive or negative predictive values when screening for PCa overall whereas these diagnostic performances were greater for PHI >40 when exclusively screening for significant PCa. PHI > 40 combined with PCA-3 > 35 was more specific in both cases. In multivariate analyses, PCA-3 >35 (OR = 5.68; 95%CI = [2.21-14.59]; P < 0.001) was significantly correlated with the presence of PCa overall, but PHI >40 (OR = 9.60; 95%CI = [1.72-91.32]; P = 0.001) was the only independent predictor for detecting significant PCa. CONCLUSIONS: Although PCA-3 score is the best predictor for PCa overall at initial biopsy, our findings strongly indicate that PHI should be used for population-based screening to avoid over-diagnosis of indolent tumors that are unlikely to cause death.

An extension of STARD statements for reporting diagnostic accuracy studies on liver fibrosis tests: the Liver-FibroSTARD standards.

BACKGROUND & AIMS: Chronic liver diseases are highly prevalent and require an accurate evaluation of liver fibrosis to determine patient management. Over the last decade, great effort has been made to develop non-invasive liver fibrosis tests. The ensuing increase of literature is, however, impaired by extensive heterogeneity in the quality of published reports. The Standards for Reporting of Diagnostic Accuracy Studies (STARD), first published in 2003, were developed to improve the quality of research reports on diagnostic studies. We aimed to evaluate STARD statements in the setting of diagnostic studies on non-invasive liver fibrosis tests, and to propose an extended version developed specifically for those studies. METHODS: Eight French experts evaluated STARD statement adequacy in 10 studies on non-invasive liver fibrosis tests and then developed an extended version with a glossary. The new checklist and glossary were independently evaluated by seven international experts. RESULTS: Fourteen of the 25 STARD items were considered only partially adequate for the evaluation of diagnostic studies on non-invasive liver fibrosis tests. Inter-expert agreement was at least very good for 8 STARD items (32%), moderate for 9 (36%), and poor or very poor for 8 (32%). The experts' proposals were developed into the new Liver-FibroSTARD standards including a checklist with 62 items/sub-items and a corresponding comprehensive glossary. New proposals were inserted in the 25 STARD items as a complementary module. Independent evaluation of the Liver-FibroSTARD checklist showed at least very good inter-expert agreement for 39 items/sub-items (63%), moderate agreement for 11 (18%), and poor or very poor agreement for only 12 (19%). CONCLUSIONS: As a supplement of the STARD statements, the Liver-FibroSTARD checklist and its glossary are new tools specifically designed for the evaluation of diagnostic studies about non-invasive liver fibrosis tests.

Comparison of nine blood tests and transient elastography for liver fibrosis in chronic hepatitis C: the ANRS HCEP-23 study.

BACKGROUND & AIMS: Blood tests and transient elastography (Fibroscan™) have been developed as alternatives to liver biopsy. This ANRS HCEP-23 study compared the diagnostic accuracy of nine blood tests and transient elastography (Fibroscan™) to assess liver fibrosis, vs. liver biopsy, in untreated patients with chronic hepatitis C (CHC). METHODS: This was a multicentre prospective independent study in 19 French University hospitals of consecutive adult patients having simultaneous liver biopsy, biochemical blood tests (performed in a centralized laboratory) and Fibroscan™. Two experienced pathologists independently reviewed the liver biopsies (mean length=25±8.4 mm). Performance was assessed using ROC curves corrected by Obuchowski's method. RESULTS: Fibroscan™ was not interpretable in 113 (22%) patients. In the 382 patients having both blood tests and interpretable Fibroscan™, Fibroscan™ performed similarly to the best blood tests for the diagnosis of significant fibrosis and cirrhosis. Obuchowski's measure showed Fibrometer® (0.86), Fibrotest® (0.84), Hepascore® (0.84), and interpretable Fibroscan™ (0.84) to be the most accurate tests. The combination of Fibrotest®, Fibrometer®, or Hepascore® with Fibroscan™ or Apri increases the percentage of well classified patients from 70-73% to 80-83% for significant fibrosis, but for cirrhosis a combination offers no improvement. For the 436 patients having all the blood tests, AUROC's ranged from 0.82 (Fibrometer®) to 0.75 (Hyaluronate) for significant fibrosis, and from 0.89 (Fibrometer® and Hepascore®) to 0.83 (FIB-4) for cirrhosis. CONCLUSIONS: Contrarily to blood tests, performance of Fibroscan™ was reduced due to uninterpretable results. Fibrotest®, interpretable Fibroscan™, Fibrometer®, and Hepascore® perform best and similarly for diagnosis of significant fibrosis and cirrhosis.

Independent validation of the Enhanced Liver Fibrosis (ELF) score in the ANRS HC EP 23 Fibrostar cohort of patients with chronic hepatitis C.

BACKGROUND: The Enhanced Liver Fibrosis (ELF) score combining serum hyaluronan, N-terminal peptide of type III procollagen and tissue inhibitor of metalloproteinase-1, was reported as relevant in predicting liver fibrosis in chronic liver disease and proposed as an alternative to liver biopsy. METHODS: We evaluated the ELF score in a cohort of chronic hepatitis C (CHC) patients included in a multicenter prospective study (ANRS HC EP 23 Fibrostar) using commercial reagents, different from those developed by the manufacturer of the Siemens ELF™ test. RESULTS: In 512 CHC, the ELF score, using ROC curves, showed good predictive performances for severe fibrosis [AUROC=0.82; 95% confidence interval (CI) 0.78-0.86]and for cirrhosis (AUROC=0.85; 95% CI 0.81-0.90), but slightly lower for significant fibrosis (AUROC=0.78; 95% CI 0.74-0.82). The Obuchowski measure (0.81) showed that the ELF score globally performed as a marker of liver fibrosis. The ELF score predicted significant fibrosis (cut-off=9.0) with a sensitivity of 0.86, a specificity of 0.62, a positive predictive value (PPV) of 0.80 and a negative predictive value (NPV) of 0.70. For extensive fibrosis (cut-off=9.33), sensitivity was 0.90, specificity was 0.63, PPV was 0.73 and NPV was 0.85. For cirrhosis (cut-off=9.35), sensitivity was 0.83, specificity was 0.75, PPV was 0.44 and NPV was 0.95. CONCLUSIONS: This study confirms the ELF score performance as an index to predict liver fibrosis or cirrhosis in CHC. The ELF test, using validated reagents, could be added to the health authorities approved non-invasive tests in assessing fibrosis as surrogate to liver biopsy.

[Testosterone assays using non recommended methods lead to misdiagnosis in women]. / Perte d'information diagnostique par utilisation de méthodes non recommandées pour le dosage de la testostérone chez la femme.

French and US endocrine societies recommend using GC-MS or RIA after purification (extraction + chromatography) to assess blood levels of testosterone in women. However, most of laboratories use automatized methods that have to be reserved to measure testosterone levels in men. The aim of this study was to show the consequences of analytical discrepancies of some immunological methods on the diagnostics values of testosterone levels assayed in women. Compared to GC-MS the correlations of the assayed levels varied (Spearman's rank correlation coefficients: 0.935; 0.793; 0.841; 0.852 respectively for RIA Immunotech™ with extraction and chromatographic purification; Testosterone Access-DxI800®; Testosterone Immulite 2000®; Testosterone II Cobas E601®). The testosterone levels allowed an accurate conclusion in 95.2 %; 75.8 %; 77.4 %; 89.8 % of patients, respectively. The agreement with GC-MS results was very good for RIA method (κ=0,840), moderate for DxI800® method (κ=0,414), moderate for Immulite® method (κ=0,467), good for Cobas® method (κ=0,667). Most of discordances are false hypertestosteronemia. The use of non recommended methods may leads to nosological errors (misclassification rates of 10 to 25% with automatized methods) that causes loss of chance in part of female patients.

Performance of 11 biomarkers for liver fibrosis assessment in HIV/HBV co-infected patients.

BACKGROUND/AIMS: The aim of this study was to compare the performance of 11 biochemical scores to estimate liver fibrosis in HIV/HBV co-infection. METHODS: Performance was evaluated using the Receiver Operating Characteristics (ROC) curve method. The Kappa index was used to study overall agreement with liver biopsy results. Interpretative algorithms were established by optimizing sensitivity and specificity and the percentage of correctly classified patients. RESULTS: One hundred and eight patients (F0-F1, n = 47; F2, n = 28; F3, n = 17; F4, n = 16) were considered for the evaluation of serum biomarker performance. The AUROCs of the Fibrotest, Hepascore, Fibrometer, and Zeng's scores ranged from 0.74 to 0.77 for significant fibrosis (> or = F2), from 0.79 to 0.84 for advanced fibrosis (> or = F3) and from 0.87 to 0.92 for cirrhosis (F4). Thresholds defined for each stage of fibrosis were close to those previously published for the Fibrotest and Hepascore. Strict concordance with biopsies correctly classified 50% of the patients. CONCLUSIONS: Fibrotest, Fibrometer, Hepascore, and Zeng's score were the most accurate non-invasive biochemical scores for liver fibrosis assessment in HIV/HBV co-infection. Global performance of biomarkers was not significantly improved by a decision tree combining the results of two biochemical scores.

[Organic and psychiatric intricacy: The complex psychiatric disorder concept, paraclinical investigations]. / Intrications organo-psychiatriques : le concept de troubles psychiatriques complexes, quels examens complémentaires ?

The purpose of this article is to describe complex psychiatric disorders, to recall "minimal classical" explorations in psychiatry, to describe the concept of "complex psychiatric disorders" and to propose a systematized method of exploration. Some organic diseases are well known for their links with psychiatric disorders (manic syndrome and hyperthyroidism, depressive syndrome and corticotropic insufficiency, anxiety disorder and heart disease, etc.). Many other neurological, autoimmune, metabolic, paraneoplastic or endocrine pathologies can have essentially psycho-behavioral manifestations before being neurological or systemic. A large number of factors (nutritional, toxic, immunological, etc.), often ignored, influence the links between organicity and psychiatric pathologies. It is necessary to optimize the medical management of these patients in whom the psychiatric diagnosis masks a curable organo-psychiatric cause.

Severe Congenital Adrenal Hyperplasia Presenting as Bilateral Testicular Tumors and Azoospermia in the Third Decade of Life.

Classic forms of 21-hydroxylase deficiency (21OHD) are usually diagnosed at birth by salt wasting or precocious puberty in male patients. Here we report the case of a 32-year-old male patient who presented with azoospermia and bilateral testicular tumors. He was referred to our endocrine unit after testicular surgery. His gonadotropins were undetectable. Liquid chromatography-tandem mass spectrometry revealed a high serum progesterone level, high 17-hydroxyprogesterone (17OHP) (255 ng/mL), and high levels of 17OHP metabolites, suggesting a classic form of 21OHD. His blood pressure was normal. Molecular analysis showed a homozygous large 21-hydroxylase gene (CYP21A2) conversion. Furthermore, an adrenal CT scan revealed voluminous, heterogeneous bilateral and asymmetric adrenal masses containing calcifications. Our case report illustrates the fact that a classic form of 21OHD can be diagnosed in late adulthood, manifested by azoospermia and large adrenal tumors, associated with elevated 17OHP.

Diagnostic accuracy of the Coopscore© to predict liver fibrosis in human immunodeficiency virus/hepatitis B virus co-infection.

Background Non-invasive methods for assessing liver fibrosis are increasingly used as an alternative to liver biopsy. Recently, a score-based biochemical blood test (Coopscore©) was developed in a cohort of patients chronically infected with hepatitis C virus, showing higher diagnostic performances than Fibrometer®, Fibrotest®, Hepascore® and Fibroscan™. Here, we assess its performance in patients co-infected with the human immunodeficiency virus and hepatitis B virus. Methods Ninety-seven human immunodeficiency virus/hepatitis B virus co-infected patients with liver biopsies were included from a previously described cohort. Histological fibrosis staging using METAVIR criteria was used as the reference. Coopscore©, Fibrotest®, Fibrometer®, Hepascore® and Zeng score were computed and compared with the Coopscore© using the Obuchowski index and area under the receiving operator characteristic curves. Results The distribution of liver fibrosis levels was as follows: F0-F1 ( n = 42), F2 ( n = 25), F3 ( n = 15) and F4 ( n = 15). The Obuchowski index was higher for Coopscore© (0.774) than Fibrometer® (0.668), Hepascore® (0.690) and Zeng scores (0.704) ( P < 0.05), reflecting a better ability to discriminate between fibrosis stages. Similarly, when predicting significant fibrosis (≥F2), the AUROC was significantly greater for the Coopscore© (0.836) than the Hepascore® (0.727) and Zeng scores (0.746), but not for the Fibrotest® (0.778, P = 0.14) or Fibrometer® (0.790, P = 0.19). The Coopscore© did not show a higher capacity than other scores to predict advanced fibrosis (≥F3) or cirrhosis (F4). Conclusions This study supports the diagnostic value of the Coospcore© in fibrosis staging among human immunodeficiency virus/hepatitis B virus co-infected patients, especially to predict significant fibrosis.

A Liquid Chromatography/Tandem Mass Spectometry Profile of 16 Serum Steroids, Including 21-Deoxycortisol and 21-Deoxycorticosterone, for Management of Congenital Adrenal Hyperplasia.

CONTEXT: Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency (CAH21) is most often diagnosed by newborn screening. The classic parameter studied is 17-hydroxy-progesterone, but the positive predictive value for the diagnosis of CAH is low in full-term newborns and even lower in preterm newborns. OBJECTIVE: To evaluate the diagnostic utility of simultaneously quantifying a large number of steroids by using liquid chromatography/tandem mass spectrometry (LC-MS/MS) from a small serum volume in patients with CAH, particularly during the neonatal period. SETTING AND PARTICIPANTS: LC-MS/MS was applied to sera from patients with CAH who had a classic form (n = 48) and rare forms (n = 2) of 21-hydroxylase deficiency, normal preterm (n = 10) and normal full-term (n = 20) neonates, and young patients without CAH (non-CAH; n = 149) but with various other diseases (delayed or advanced puberty, hirsutism, pubarche, adrenarche, simple growth retardation). METHODS: Sixteen steroids (glucocorticoids, mineralocorticoids, androgens, Δ5-steroids) were analyzed in 150 µL of serum by LC-MS/MS. RESULTS: An LC-MS/MS serum steroid profile was developed and validated to provide a reliable etiologic diagnosis of CAH. The serum levels of 17OH-progesterone and 21 deoxycortisol in non-CAH are reported, along with the rarely assayed 21-deoxycorticorticosterone and 11ß hydroxy Δ4-androstenedione, which will aid in the diagnosis of CAH21. In addition, serum levels of mineralocorticoids, androgens, and Δ5-steroids allowed investigation of other forms of CAH. CONCLUSION: This steroid LC-MS/MS approach on a small serum volume is well suited for pediatrics, particularly neonatal medical practice, to aid in the diagnosis and monitoring of various forms of CAH.

Familial Multiplicity of Estrogen Insensitivity Associated With a Loss-of-Function ESR1 Mutation.

Context: Estrogens influence many physiological processes in mammals, including reproduction. Estrogen peripheral actions are mainly mediated through estrogen receptors (ERs) α and ß, encoded by ESR1 and ESR2 genes, respectively. Objective: The study's aim was to describe a family in which 3 members presented with estrogen insensitivity. Design and Setting: Clinical evaluation and genetic and mutational analysis were performed in an academic medical center. Patients and Interventions: An ESR1 mutation was identified in 2 sisters and 1 brother, originating from a consanguineous Algerian family, who did not enter puberty and presented with delayed bone maturation consistent with estrogen insensitivity. The 2 sisters had enlarged multicystic ovaries. Hormonal evaluation as well as genetic and mutational analysis were performed. Results: Hormonal evaluation revealed extremely high plasma 17ß-estradiol (>50-fold normal range) associated with elevated gonadotropin levels (greater than threefold normal range), highly suggestive of estrogen resistance. The 3 affected patients carried a homozygous mutation of a highly conserved arginine 394 for which histidine was substituted through an autosomal recessive mode of transmission. Structural and functional analysis of the mutant ERα revealed strongly reduced transcriptional activity and the inability to securely anchor the activating hormone, estradiol, compared with wild-type ERα. A group of other potential ER activating ligands were tested, but none overcame the estrogen insensitivity in these patients. Conclusion: Description and analysis of this family of patients with mutant ERα provide additional clinical findings toward identification and characterization of what was previously thought to be a highly rare clinical condition.

Direct and indirect evidence for the reversibility of cirrhosis.

The aim of this study was to assess the reversibility of cirrhosis after therapy in a large series of patients with cirrhosis from various etiologies. We performed a retrospective study of 113 patients with biopsy-proven cirrhosis who underwent specific therapy and follow-up biopsies. Two pathologists performed blinded analyses of indirect biochemical and morphological signs of cirrhosis. Fourteen (12.4%) of the 113 cirrhotic patients had biopsy-proven disappearance of cirrhosis, defined as a decrease of 2 or greater in their METAVIR fibrosis score: 8 were related to hepatitis C virus, 3 to hepatitis B virus, and 3 to autoimmune cirrhosis. Necro-inflammatory activity decreased from 2.4 +/- 0.65 to 0.85 +/- 0.9 (P = .004), and fibrosis from 4 to 1.7 +/- 0.61 (P = .001). Prothrombin time (n = 1), platelet count (n = 2), serum albumin level (n = 2), and ultrasound abnormalities (n = 6) normalized in patients who had initial abnormalities. Hyaluronic acid and procollagen type III serum level decreased in all. In the 11 patients with regression of viral cirrhosis, 2 were nonresponders and 9 were responders, including 2 relapsers. The 3 patients with regressive autoimmune cirrhosis were complete responders to immunosupressive therapy. Using repeated liver biopsies, clinicobiochemical, radiologic, and endoscopic tests, we provide evidence for potential reversibility of cirrhosis after long-lasting suppression of the necro-inflammatory activity of liver disease.

[Noninvasive assessment of liver fibrosis in patients with chronic hepatitis virus C]. / Evaluation non invasive de la fibrose hépatique au cours des hépatites chroniques virales C.

Development of liver fibrosis, which leads to cirrhosis, is the principal complication of all chronic liver diseases, regardless of their cause. Knowledge of the existence and severity of fibrosis is important from diagnostic and prognostic viewpoints. Its assessment plays an essential role in the treatment decision and makes it possible to assess the risk of progression to cirrhosis and the onset of its complications. Histologic examination of the liver remains the reference examination for assessing the extent of fibrosis during chronic liver disease. Nonetheless, the number of patients needing assessment, the risks of the punch-biopsy and the cost of this invasive examination have led many to propose other tools to assess fibrosis. Some standard indicators (transaminases, platelets, prothrombin time) have long been recognized as indirect markers of extensive fibrosis. More recently, progress in our knowledge of the mechanisms of liver fibrogenesis have made it possible to identify different peripheral blood components that may be of clinical interest. Thus serum assays of elements of the extracellular matrix, their decay products, or enzymes involved in their metabolism have been proposed as noninvasive indicators. Among these, hyaluronic acid appears the most interesting. For several years, scores have been calculated with algorithms that combine several indicators determined simultaneously to assess fibrosis in patients with hepatitis C and sometimes other chronic liver diseases. The Fibrotest is the best validated and most widely used of these. Finally, Fibroscan is a device for the diagnosis and quantification of hepatic fibrosis, based on the technique of transient elastography. The relative roles of these noninvasive markers and the value of their combinations must still be determined.

Negative predictive value of procalcitonin in medullary thyroid carcinoma.

Calcitonin (CT), the major biochemical marker in medullary thyroid carcinoma (MTC) is prone to in vitro instability and suffers from scarcity of clinical laboratory platforms. Procalcitonin (PCT), the precursor of CT, free of these shortcomings, has been reported as a potential MTC marker. The aim of this study was to assess the negative predictive value (NPV) of PCT as a first-line marker in MTC. 476 serum samples referred to our laboratory for CT measurements were analyzed for PCT. NPVs of PCT were assessed at 3 cut-offs (0.05, 0.10 and 0.15 ng/mL) and the diagnosis of MTC was based on CT levels. PCT and CT levels were correlated (r=0.7554 for CT levels above 10 pg/mL, n=66). Accepting the CT cut-off based on the upper reference limit the NPV of PCT were 98.1% (0.05 ng/mL), 96.3% (0.10 ng/mL) and 95.4% (0.15 ng/mL) respectively. For a CT cut-off of 100 pg/mL the NPVs of PCT were 100% for all PCT thresholds. Serum PCT has a strong NPV and could be a good candidate for a first-line screening test to exclude MTC in patients with suspicious thyroid nodules or suggestive symptoms. Larger prospective studies are necessary to confirm our results.

Values of sperm thiobarbituric acid-reactive substance in fertile men.

BACKGROUND: The objective of this study was to establish for the first time reference levels of sperm malondialdehyde, a stable lipid peroxidation product, in a cohort of fertile men. METHODS: Sperm malondialdehyde, a thiobarbituric acid-reactive substance, was assayed using the 2-thiobarbituric acid method. RESULTS: Sperm malondialdehyde levels, expressed in nM/10(8) spermatozoa, were normally distributed in our cohort of fertile men and averaged 0.0287 +/- 0.0162 (mean +/- S.D.). CONCLUSIONS: Given the impact of lipid peroxidation on spermatozoa and thereby on male fertility, the assay of sperm membrane thiobarbituric acid-reactive substance is clearly of interest. Malondialdehyde levels found in our study form a basis for normal values of sperm thiobarbituric acid-reactive substance observed in the semen of fertile men.