[Discontinuation of Chromium-51 for clinical use: What are the possible alternatives for radiopharmacies and nuclear medicine departments?] / Arrêt de production du chrome-51 (51Cr) a usage clinique : quelles alternatives possibles pour les services de radiopharmacie et de médecine nucléaire ?

OBJECTIVES: Last October, the nuclear medicine departments were informed of the closure of the chromium-51 production line for clinical use. This radionuclide has different diagnostic indications in nephrology and hematology. It was therefore essential to set up alternative exploration protocols to overcome this production stoppage. METHODS: Chromium-51 EDTA has been replaced by technetium-99m DTPA for the determination of glomerular filtration rates. Sodium chromate was substituted by sodium pertechnetate for the determination of globular volumes. A retrospective analysis of the chromium-51 data was performed followed by a prospective study, from January to December 2019 for technetium tracers. RESULTS: One hundred and forty-four patients were included in the study. Forty-two EDTA-51Cr and 30 DTPA-99mTc exams were conducted and compared. There were no significant differences between the methods used to assess renal function (P=0.355). For the determination of blood cell and plasma volumes, 47 tests with 51Cr and 125I and 25 tests with 99mTc and 125I were performed and compared. There were no significant differences in the determination of total (P=0.325) and globular (P=0.148) volumes. CONCLUSIONS: The study carried out shows that there is no significant difference between the results obtained with chromium-51 and technetium tracers. As a result, clinical activity was maintained in good conditions.

Complement activation and adult respiratory distress syndrome during intermittent flow apheresis procedures.

We observed complement (C) activation during intermittent flow apheresis procedures (Haemonetics model 30) in four subjects, two of whom developed adult respiratory distress syndrome (ARDS). Actual C3 conversion during apheresis was illustrated by the finding of significantly elevated C3d levels (p less than 0.05) and of significantly increased alpha-1-antitrypsin/C3 ratios (p less than 0.05) in postapheresis serums. Similarly, marked granulocyte aggregating activity was found in these serums, indicative of the generation of significant amounts of the C-derived anaphylatoxin, C5a or C5a desarginine. A mean decrease of 59.75 percent in neutrophil count during the four procedures suggested sequestration of aggregated granulocytes in the pulmonary vasculature. Moreover, granulocytes activated by apheresis serums induced significant 51Cr leak from cultured human endothelial cells is vitro (p less than 0.001). We conclude that inflammatory C components produced during apheresis procedures may provoke granulocyte aggregation and embolization, leading to plugging of the pulmonary vasculature, and that apheresis-activated granulocytes may induce endothelial cytotoxicity, leading to the capillary leakage syndrome, characteristic of ARDS. Individual variability in C5a generation capacity or alterations in normal C5a clearing mechanisms may account for the low incidence of clinical C activation and true ARDS during apheresis. In these instances, high-dose steroids, which interfere with granulocyte-C interactions, may be beneficial.