Adult macrophage activation syndrome-haemophagocytic lymphohistiocytosis: 'of plasma exchange and immunosuppressive escalation strategies' - a single centre reflection.

OBJECTIVE: In the context of systemic autoimmunity, that is systemic lupus erythematosus (SLE) or adult-onset Still's disease (AOSD), secondary haemophagocytic lymphohistiocytosis (HLH; also referred to as macrophage activation syndrome (MAS) or more recently MAS-HLH) is a rare and potentially life-threatening complication. Pathophysiological hallmarks are aberrant macrophage and T cell hyperactivation and a systemic cytokine flare, which generate a sepsis-like, tissue-damaging, cytopenic phenotype. Unfortunately, for adult MAS-HLH we lack standardized treatment protocols that go beyond high-dose corticosteroids. Consequently, outcome data are scarce on steroid refractory cases. Aside from protocols based on treatment with calcineurin inhibitors, etoposide, cyclophosphamide and anti-IL-1, favourable outcomes have been reported with the use of intravenous immunoglobulin (IvIG) and plasma exchange (PE). METHODS: Here we report a retrospective series of steroid refractory MAS-HLH, the associated therapeutic regimes and outcomes. RESULTS: In this single-centre experience, 6/8 steroid refractory patients survived (median follow-up: 54.4 (interquartile range: 23.3-113.3) weeks). All were initially treated with PE, which induced partial response in 5/8 patients. Yet, all patients required escalation of immunosuppressive therapies. One case of MAS-HLH in new-onset AOSD had to be escalated to etoposide, whereas most SLE-associated MAS-HLH patients responded well to cyclophosphamide. Relapses occurred in 2/8 cases. CONCLUSION: Together, early use of PE is at most a supportive measure, not a promising monotherapy of adult MAS-HLH. In refractory cases, conventional cytoreductive therapies (i.e. cyclophosphamide and etoposide) constitute potent and reliable rescue approaches, whereas IvIG, anti-thymoglobulin, and biologic agents appear to be less effective.

Autopsy of a cadaver containing strontium-89-chloride.

An autopsy was performed on a patient who died after receiving 89Sr-chloride for treatment of bone pain from metastatic prostate carcinoma. Coordination between nuclear medicine physicians, radiation safety division personnel and pathologists resulted in minimal radiation exposure and the acquisition of dosimetry data.

PET versus SPECT for determining myocardial tissue viability using fluorine-18-fluorodeoxyglucose.

The U.S. Food and Drug Administration regulates the manufacture and distribution of 18F-FDG. Acquisition and use of this radiopharmaceutical for myocardial imaging at our institution required approval by our Institutional Review Board. Our initial objective was to present a scientific validation for use of this radiopharmaceutical in adjudicating the "viable versus scarred myocardium question," using either a PET scanner or a gamma camera equipped with 511-keV collimators. We believe that our nuclear medicine colleagues who find themselves in a similar business/legal situation regarding the acquisition and use of 18F-FDG will find this review useful. We reviewed the literature to document the efficacy of 18F-FDG, in general, in assessing myocardial viability. We then did a literature-based comparison of PET scanner methodology versus modified gamma camera methodology for imaging 18F-FDG emissions. Imaging 18F-FDG with a modified gamma camera appears to be an effective alternative to imaging with a standard PET camera for assessing myocardial viability.

Tl-201 scintigraphy in multivessel exercise-induced variant angina.

A 53-year-old man presented for evaluation of nocturnal chest pain, consistent with angina pectoris. An exercise stress test reproduced his symptoms, however, exercise electrocardiograms were nondiagnostic. An exercise-thallium perfusion study confirmed vasospasm as the cause. This knowledge guided subsequent successful medical therapy.

False-positive result of a captopril-enhanced radionuclide renogram in a child secondary to dehydration.

PURPOSE: Renovascular hypertension is an unusual cause of elevated mean arterial pressure in children. When suspected, angiotensin-converting enzyme inhibitor-enhanced renal scintigraphy is usually one of the initial studies done to evaluate patients. The accuracy of this test depends not only on patient selection but also on technical factors involved in performing the study. We report a case of a false-positive angiotensin-converting enzyme inhibitor-enhanced radionuclide renogram in a 5-year-old boy with hypertension. METHODS: Angiotensin-converting enzyme inhibitor-enhanced renal scintigraphy was performed and the result was interpreted as positive for bilateral renovascular disease. A review of the anesthesia record from the study revealed that the patient was hypotensive. A repeated study with adequate hydration and blood pressure stability was then done. RESULTS: The result of the second examination was interpreted as normal, without evidence of abnormal renovascular physiology. CONCLUSIONS: The cause of the initial false-positive result was determined to be dehydration with secondary hypotension. Dehydration, with secondary hypotension, can cause a diminished glomerular filtration rate and mimic bilateral renovascular physiology on angiotensin-converting enzyme inhibitor-enhanced renal scans.