Preclinical evaluation of a TEX101 protein ELISA test for the differential diagnosis of male infertility

BACKGROUND: TEX101 is a cell membrane protein exclusively expressed by testicular germ cells and shed into seminal plasma. We previously verified human TEX101 as a biomarker for the differential diagnosis of azoospermia, and developed a first-of-its-kind TEX101 ELISA. To demonstrate the clinical utility of TEX101, in this work we aimed at evaluating ELISA performance in a large population of fertile, subfertile, and infertile men. METHODS: Mass spectrometry, size-exclusion chromatography, ultracentrifugation, and immunohistochemistry were used to characterize TEX101 protein as an analyte in seminal plasma. Using the optimized protocol for seminal plasma pretreatment, TEX101 was measured by ELISA in 805 seminal plasma samples. RESULTS: We demonstrated that TEX101 was present in seminal plasma mostly in a free soluble form and that its small fraction was associated with seminal microvesicles. TEX101 median values were estimated in healthy, fertile pre-vasectomy men (5436 ng/mL, N = 64) and in patients with unexplained infertility (4967 ng/mL, N = 277), oligospermia (450 ng/mL, N = 270), and azoospermia (0.5 ng/mL, N = 137). Fertile post-vasectomy men (N = 57) and patients with Sertoli cell-only syndrome (N = 13) and obstructive azoospermia (N = 36) had undetectable levels of TEX101 (≤0.5 ng/mL). A cut-off value of 0.9 ng/mL provided 100% sensitivity at 100% specificity for distinguishing pre- and post-vasectomy men. The combination of a concentration of TEX101 > 0.9 ng/mL and epididymis-specific protein ECM1 > 2.3 μg/mL provided 81% sensitivity at 100% specificity for differentiating between non-obstructive and obstructive azoospermia, thus eliminating the majority of diagnostic testicular biopsies. In addition, a cut-off value of ≥0.6 ng/mL provided 73% sensitivity at 64% specificity for predicting sperm or spermatid retrieval in patients with non-obstructive azoospermia. CONCLUSIONS: We demonstrated the clinical utility of TEX101 ELISA as a test to evaluate vasectomy success, to stratify azoospermia forms, and to better select patients for sperm retrieval. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12916-017-0817-5) contains supplementary material, which is available to authorized users

Immunohistochemical study of cutaneous nerves in the emu

The distribution and chemical content of cutaneous nerves in 3- to 13-day-old emu chicks (Dromaius novaehollandiae) were examined by using double-labelling immunohistochemistry. Seven different subpopulations of cutaneous nerves were identified based on their neurochemistry. No intraepidermal nerve fibres were found. However, axons were located within the dermis and were often associated with blood vessels, pennamotor muscles and feather follicles or innervated Herbst corpuscles. Both similarities and differences exist between subpopulations of cutaneous nerves in the emu and volant birds. As in volant birds, a subpopulation of cutaneous axons innervates the superficial skin layers and contains immunoreactivity to both substance P and calcitonin gene-related peptide (CGRP). This suggests that the neuropeptide content of these presumptive free nerve endings is conserved throughout the evolution of birds. In contrast, Herbst corpuscles in the emu are innervated by axons that contain immunoreactivity for CGRP or neuropeptide Y (NPY) but that lack the calbindin D-28k immunoreactivity found in fibres innervating Herbst corpuscles of volant birds. Herbst corpuscles therefore may have a different chemical content in a flightless species from that in volant birds

Iliopsoas bursitis and pseudogout of the knee mimicking L2-L3 radiculopathy: case report and review of the literature.

We report the case of a 74-year-old woman who presented with acute-onset right groin pain irradiating to the thigh anteriorly after having suffered for a few weeks from slight knee pain. As a CT scan showed multiple herniated intervertebral discs and spinal stenosis at the L3-L4 level, she was referred to a neurosurgical unit with the tentative diagnosis of L2-L3 radicular pain. Investigations (MR, myelography with CT scan) showed severe acquired lumbar canal stenosis. Decompression surgery was finally postponed because of the patient's serious cardiac medical history and she was referred to us for conservative treatment. She was found to have iliopsoas bursitis with chondrocalcinosis of the knee. Local steroid injections of the two sites abolished her symptoms. We draw attention to the possible pitfalls that the radiographic appearance and one of the multiple clinical presentations of this unrare pathology may represent. Whenever a patient comes walking with crutches, avoids putting weight on his or her leg, and radicular pain is suspected, we advise consideration of other extra-spinal causes for the pain