Qualitative detection of desmopressin in plasma by liquid chromatography-tandem mass spectrometry

This work describes a liquid chromatography-electrospray tandem mass spectrometry method for detection of desmopressin in human plasma in the low femtomolar range. Desmopressin is a synthetic analogue of the antidiuretic hormone arginine vasopressin and it might be used by athletes as a masking agent in the framework of blood passport controls. Therefore, it was recently added by the World Anti-Doping Agency to the list of prohibited substances in sport as a masking agent. Mass spectrometry characterization of desmopressin was performed with a high-resolution Orbitrap-based mass spectrometer. Detection of the peptide in the biological matrix was achieved using a triple-quadrupole instrument with an electrospray ionization interface after protein precipitation, weak cation solid-phase extraction and high performance liquid chromatography separation with an octadecyl reverse-phase column. Identification of desmopressin was performed using three product ions, m/z 328.0, m/z 120.0, and m/z 214.0, from the parent ion, m/z 535.5. The extraction efficiency of the method at the limit of detection was estimated as 40% (n = 10), the ion suppression as 5% (n = 10), and the limit of detection was 50 pg/ml (signal-to-noise ratio greater than 3). The selectivity of the method was verified against several endogenous and synthetic desmopressin-related peptides. The performance and the applicability of the method were tested by analysis of clinical samples after administration of desmopressin via intravenous, oral, and intranasal routes. Only after intravenous administration could desmopressin be successfully detected

Myeloma of the central nervous system: report of a single center case series

Background: Neurologic manifestations often complicate the course of multiple myeloma, but direct involvement of the central nervous system (CNS) is rare. Objective: To describe the clinical course, neurological symptoms, laboratory findings and imaging of patients with CNS myeloma. This additional information may contribute to better recognition and more effective management of this complication in the future. Methods: We retrospectively identified 6 MM patients with CNS involvement diagnosed at our centre between April 2003 and April 2009. The clinical, biochemical and imaging data were collected and compared with previously reported cases. Results: At time of diagnosis of CNS myeloma, 3 patients had progressive disease and 3 were in good partial remission. The presenting symptoms included diplopia, vision loss, extremity weakness and paresis. All cases showed one or more features of aggressive disease at diagnosis, including high tumour burden, plasmablastic morphology and high-risk cytogenetic abnormalities. Prognosis was poor with a median survival of 4.8 months. Conclusion: CNS myeloma should be considered in patients with aggressive MM and unexplained neurological symptoms. The prognosis is poor despite intensive therapy

Dexamethasone-induced catatonia in a patient with multiple myeloma

Catatonia is a complex neuropsychiatric syndrome, caused by different underlying metabolic, neurologic, psychiatric and toxic conditions. Although catatonia is often associated with psychiatric disorders such as schizophrenia or depression, in about 20 to 39% of the patients a somatic illness is found. Unfortunately, this diagnosis is often missed although catatonia is characterized by a specific symptom complex. We report a case of acute catatonia with psychotic features in a patient with multiple myeloma (MM), caused by systemic use of dexamethasone. Physicians should be aware of possible psychiatric side effects when prescribing high doses of dexamethasone. Further, MM patients on corticosteroids should be closely monitored for mild psychological and/or psychiatric symptoms since they may be predictive for the onset of catatonia

Acquired hemophilia: a case report and review of the literature

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies against clotting factor VIII (FVIII). FVIII autoantibody is characterized as polyclonal immunoglobulin G directed against the FVIII procoagulant activity. This disease occurs most commonly in the elderly population and with preponderance of men in nonpregnancy-related AHA. There are well-established clinical associations with AHA such as malignancy, other autoimmune diseases and pregnancy. However, up to 50% of reported cases remain idiopathic. The clinical manifestation of AHA includes mostly spontaneous hemorrhages into skin, muscles and soft tissues, or mucous membranes. AHA should be suspected when a patient with no previous history of bleeding presents with bleeding and an unexplained prolonged activated partial thromboplastin time. The diagnosis is confirmed in the laboratory by the subsequent identification of reduced FVIII levels and FVIII inhibitor titration. There is a high mortality, making prompt diagnosis and treatment vitally important. The principles of treatment consist in controlling the bleeding and eradicating the inhibitor. Because of the overall high relapse rate (15-33%), it is also recommended to follow up these patients. The review summarizes what is currently known about the epidemiology, pathogenesis, clinical features, diagnosis, treatment and prognosis of AHA and starts with a case report