Monitoring strategy of COVID-19 vaccination in dialysis patients based on a multiplex immunodot method: The CovidDial study.

INTRODUCTION: COVID-19 vaccine was demonstrated to be effective in dialysis patients, but boosters are mandatory due to a rapid waning of anti-spike antibodies. A vaccination strategy based on immunologic response might be useful to maintain a favorable risk-benefit balance in this vulnerable population. METHODS: CoviDial is an observational prospective study enrolling 121 dialysis patients to receive a 3-dose mRNA-1273 vaccine according to a uniform schedule. At baseline, months 1, 3, 6, 9, and 12, anti-spike antibodies against four epitopes (S1, S2, ECD-S1 + S2, RBD) were monitored with a multiplex immunodot enzymatic assay. Potential correlation between initial serologic response and subsequent COVID-19 infection was then assessed. RESULTS: Overall, 96.2% and 96.8% of patients had anti-RBD antibodies at 3 and 12 months, respectively. All antibodies titers significantly decreased at month 6 compared to month 3. Booster vaccine induced a robust serologic response at month 9, but with a waning 3 months later, particularly for anti-S2 (37.2 ± 3.3 vs. 61.3 ± 3.0, p < 0.0001) and anti-S1 + S2 antibodies (68.4 ± 3.3 vs. 88.4 ± 2.3, p = 0.0015). Fifteen patients were later tested positive for SARS-CoV-2. At month 3, mean titers of anti-RBD, anti-S1 + S2, and anti-S2 antibodies were lower in the subsequent SARS-CoV-2 infected cohort (71.57 ± 9.01 vs. 85.79 ± 2.61, p = 0.0131; 41.07 ± 7.96 vs. 61.68 ± 3.56, p = 0.0237; 13.79 ± 5.03 vs. 39.70 ± 3.86, p = 0.0096; respectively). CONCLUSION: Three doses of mRNA-1273 vaccine induce a robust but time-limited immunologic response in dialysis patients. Lower anti-spike antibodies titers after initial vaccination are associated with a higher risk to subsequently contract SARS-CoV-2, even beyond 6 months.

Effect of freezing, long-term storage, and microwave thawing on the stability of ketorolac tromethamine.

BACKGROUND: Ketorolac tromethamine is a nonsteroidal agent with potent analgesic and moderate antiinflammatory activity. Advance preparation of intravenous solution could be useful to improve quality assurance, time management, and cost-savings of drug delivery. OBJECTIVE: To investigate the effect of freezing, long-term storage, and microwave thawing on the stability of ketorolac tromethamine in dextrose 5% infusion. METHODS: Five polyolefin bags of solution containing ketorolac tromethamine 20 mg per 100 mL of dextrose 5% were frozen for 3 months at -20 degrees C, thawed in a microwave oven with a validated cycle, and stored at 4 degrees C. The concentration of ketorolac was measured by HPLC. Visual inspection and pH measurement were also carried out. RESULTS: No color change or precipitation was observed. Ketorolac was stable for at least 60 days under refrigeration after freeze-thaw. Throughout this period, the lower confidence limit of the estimated regression line of the concentration-time profile remained >90% of the initial concentration, and the pH value decreased slightly without affecting chromatographic parameters. CONCLUSIONS: Within these limits, ketorolac tromethamine in dextrose 5% infusion may be prepared and frozen in advance by a centralized intravenous admixture service, then thawed before use in clinical units.

Effect of the freezing conditions and microwave thawing power on the stability of cefuroxime in dextrose 5% infusion polyolefin bags at 4 degrees C.

BACKGROUND: Intravenous cefuroxime sodium solution could be prepared in advance by a centralized hospital pharmacy service to improve safety and time management. OBJECTIVE: To investigate the effect of freezing and microwave thawing on the solution stability of cefuroxime. METHODS: Cefuroxime 1.5 g in 100 mL of dextrose 5% in polyolefin bags was frozen individually (group A) or in one package (group B) for 98 days at -20 degrees C. The solutions were then thawed using microwaves at 270 (light cycle) or 800 watts (hard cycle) and stored at 4 degrees C. The cefuroxime concentration was measured by HPLC. Visual inspection was performed and pH was measured at that time. Stability of the solution was defined as a concentration remaining superior to 90% of the initial concentration by regression analysis. RESULTS: No color change or precipitation in the solutions was observed. In group A, stability was at least 23 and 21 days after light and hard cycle thawing, respectively. In group B, stability was at least 21 and 18 days, respectively, with the pH increasing without affecting chromatographic parameters. CONCLUSIONS: The optimal conditions for advance preparation of a solution containing cefuroxime 1.5% in dextrose 5% may be freezing of individual containers followed by a light cycle of microwave thawing.

Stability of sufentanil citrate with levobupivacaine HCl in NaCl 0.9% infusion after microwave freeze-thaw treatment.

BACKGROUND: Sufentanil is a powerful central anesthetic and analgesic of the opiate family that can be used with levobupivacaine for epidural administration. Advance preparation of intravenous solution could be useful to improve quality, time management, and cost-savings of drug delivery. OBJECTIVE: To investigate how freezing, long-term storage, and microwave thawing can affect the stability of sufentanil citrate and levobupivacaine HCl in NaCl 0.9% (saline) (w/v) polyvinyl chloride (PVC) bags. METHODS: The stability of 5 bags of solution containing sufentanil 500 microg and levobupivacaine 625 mg per 500 mL of saline solution in PVC bags was studied after freezing for 4 months at -30 degrees C, thawing in a microwave oven with a validated cycle, and storage at 4 degrees C. The concentrations of the drugs were measured by HPLC using a reversed-phase column, a mobile phase consisting of 18% acetonitrile (v/v) in tertabutyl ammonium hydrogen sulfate buffer 0.03 M pH 3.00 +/- 0.05, and UV detection at 235 nm for sufentanil and 260 nm for levobupivacaine. Visual inspection and pH measurement were also performed. RESULTS: No color change or precipitation was observed. Sufentanil and levobupivacaine were stable for at least 70 days at 4 degrees C after freezing and thawing. Throughout this period, the 95% lower confidence limit of the concentration-time profile remained >90% of the initial concentration. During this period, the pH value remained stable. CONCLUSIONS: Within the limits defined here, a mixture of sufentanil citrate and levobupivacaine HCl may be prepared in advance and kept frozen.