Alternative approaches to the therapeutic drug monitoring of prophylactic posaconazole in haematology patients.

OBJECTIVE: The intention of the study was to assess whether a unique daily specimen is adequate for prophylactic posaconazole TDM in haematology patients and if bioassay and HPLC produce similar results and could be equally used in clinical setting. METHOD: Serum specimens from thirty haematology patients were collected at the end of the first and second week of treatment, just before the morning dose, 2 and 6 to 8hours afterwards. Levels were measured by bioassay in 157 specimens and additionally by HPLC in 51 of them. RESULTS: Bioassay levels were correlated inter and intra daily, with no statistical difference between them, irrespective of the timing. The same was true for HPLC measurements. There was no statistical difference between bioassay (median: 1.60mg/L, interquartile range: 0.60-2.30) and HPLC levels (median: 1.16mg/L, interquartile range: 0.56-1.72), while they were significantly correlated. CONCLUSION: In clinically stable haematology patients, a random specimen on any day after steady state serum concentrations have been achieved is probably adequate in order to monitor posaconazole levels. In the case of monotherapy, a bioassay is an acceptable alternative to HPLC.

Long term cryostorage of UC blood units: ability of the integral segment to confirm both identity and hematopoietic potential.

BACKGROUND: With the maturation of UC blood banking, cord blood (CB) units stored for years prior to use in transplantation present a new set of issues in clinical transplantation, including interval improvements in immune typing and confirmation of product identity and viability. A preliminary analysis of the transplants supported by the St Louis Cord Blood Bank, looking for an impact of length of CB storage time and transplant outcome was performed. We evaluated the utility of an integral segment containing an aliquot of cryopreserved product that has been exposed to the same post-processing storage conditions as the unit as a quality control tool for CB banking. METHODS: Engraftment and survival following unrelated donor UC blood transplant were evaluated based on length of CB product storage at the St Louis Cord Blood Bank. A strategy of routine testing of the contiguous segment for high-resolution HLA typing (also confirming identity) and CFU analysis was tested in 283 consecutive CB searches. Comparison between CB unit and contiguous segment viability and hematopoietic potential was performed on 30 research CB units that had been stored up to 5 years. RESULTS: There was no statistical difference in engraftment or survival following unrelated donor cord blood transplant employing units banked < 1 year or > 3 years. Confirmatory HLA typing, CFU and viability testing was successfully performed from the same segment as part of a strategy for product release evaluation. When comparing the segment with its corresponding CB unit, the total colony-forming units (CFU) measured in the two was similar (P = 0.51, paired t-test). Three research units purposely sabotaged by an overnight thaw and refreeze had no CFU growth, but viability as measured by Trypan was still 68-98%. DISCUSSION: No deterioration of hematopoietic potential has been detected with storage up to 5 years. The contiguous segment CFU is representative of the product, and thus is a useful tool for quality control and confirmation of product viability. Viability, as measured by Trypan blue dye exclusion may be falsely reassuring.

A simple and reliable procedure for cord blood banking, processing, and freezing: St Louis and Ohio Cord Blood Bank experiences.

BACKGROUND: In UC blood banking, volume and RBC reduction of the collected UC blood allows more efficient long-term storage and decreases infusion-related hemolysis and DMSO toxicity. However, high cell yields are imperative. At the St Louis Cord Blood Bank, we have systematically addressed processing/freezing and have developed a simple processing/freezing procedure. METHOD: The methodology is a modification of the hetastarch sedimentation and volume reduction approach of Rubinstein at the New York Placental Blood Program. Cord blood is mixed with a 1:5 v/v ratio of hetastarch. The product is incubated for 45 min in an inverted position in a refrigerated centrifuge (4 degrees C), and then is spun for 5 min at 50 g. RBC concentrate is drained from the bottom. The volume drained is calculated to remove 80% of RBC. The UC blood unit is then resuspended and spun for 13 min at 420 g. Plasma is expressed from the top. RESULTS: A final product volume of 27 mL (range 16-58 mL) was obtained from an original 50-200 mL of UC blood collected. The average yield of total nucleated cells pre- and post-processing was 90% for the first 4055 UC blood units banked. Pre- and post-processing CFU and CD34 yields were tested in a cohort and were similarly conserved. With a processing time of 3 h for a single cord, this process is time efficient and lends itself well to processing several units at the same time. The technique has been exported to other laboratories with similar yields. DISCUSSION: This simple methodology results in reliable yields and is well suited to larger scale banking.

Aspergillus antigen testing in bone marrow transplant recipients.

AIMS: To assess the clinical usefulness of a commercial aspergillus antigen enzyme linked immunosorbent assay (ELISA) in the diagnosis of invasive aspergillosis (IA) in bone marrow transplant recipients, and to compare it with a commercial latex agglutination (LA) test. METHODS: In total, 2026 serum samples from 104 bone marrow transplant recipients were tested. These comprised 67 sera from seven patients who had died with confirmed IA, 268 sera from nine patients who had died with suspected IA, and 1691 sera from 88 patients with no clinical, radiological, or microbiological signs of IA. RESULTS: The ELISA was more sensitive than the LA test. All patients who were ELISA positive were also LA positive, and a positive LA result never preceded a positive ELISA. Twelve of 16 patients with confirmed or suspected IA were ELISA positive on two or more occasions, compared with 10 of 15 who were LA positive. ELISA was positive before LA in five patients (range, 2-14 days), and became positive on the same day in the remainder. Aspergillus antigen was detected by ELISA a median of 15 days before death (range, 4-233). Clinical and/or radiological evidence of IA was noted in all patients, and a positive ELISA was never the sole criterion for introduction of antifungal treatment. Two samples (one from each of two patients without IA) gave false positive results. CONCLUSIONS: The aspergillus ELISA is a specific indicator of invasive aspergillosis if the criterion of two positive samples is required to confirm the diagnosis. However, the test is insufficiently sensitive to diagnose aspergillosis before other symptoms or signs are apparent, and hence is unlikely to lead to earlier initiation of antifungal treatment. It is therefore unsuitable for screening of asymptomatic patients at risk of invasive aspergillosis, but does have a useful role in confirming the diagnosis in symptomatic patients.

Multiple dose pharmacokinetics of an oral solution of itraconazole in patients receiving chemotherapy for acute myeloid leukaemia.

The multiple dose pharmacokinetics of a solution of itraconazole given orally were measured in an open study of 20 patients undergoing remission induction chemotherapy for acute myeloid leukaemia. Patients were given itraconazole 5 mg/kg od, 2.5 mg/kg bd, 2.5 mg/kg od or 1.25 mg/kg bd. The mean daily dose of itraconazole was 407 mg for patients receiving 5 mg/kg/day and 148 mg in patients receiving 2.5 mg/kg/day. Mean concentrations of 493 and 495 micrograms/L were achieved on day 8 in patients who received 5 mg/kg/d od or 2.5 mg/kg bd itraconazole respectively. However, mean concentrations were significantly lower for those who received 2.5 mg/kg od itraconazole being 110 micrograms/L on day 8. Mean areas under the serum-concentration time curves were also markedly higher in patients receiving 5 mg/kg/day than in those receiving 2.5 mg/kg/day itraconazole and were 22,382 and 5615 micrograms.h/L on day 15 respectively. These findings suggest that the serum concentrations attained with an oral solution of 5 mg/kg itraconazole either once daily or in two divided doses are suitable for antifungal prophylaxis in patients receiving chemotherapy for acute myeloid leukaemia.

Multiple dose pharmacokinetics of an oral solution of itraconazole in autologous bone marrow transplant recipients.

The pharmacokinetics of itraconazole oral solution were measured in seven patients receiving chemotherapy followed by autologous bone marrow transplantation for leukaemia or lymphoma. Patients received 5 mg/kg/day itraconazole either as a once or twice daily dose. Drug concentrations reached steady state by day 15, in both groups. The mean pre-dose itraconazole serum concentration at hour 0, day 8 was 385 ng/mL in the od group and 394 ng/mL in the bd group, rising to 762 and 845 ng/mL by day 15, respectively. The mean AUCs for 0-24 h on day 8, 15 and 22 were 17,310 and 13,302 ng/mL/h, 24,476 and 25,154 and 22,621 and 21,423, for the od and bd groups, respectively. Thus serum concentrations of itraconazole suitable for antifungal prophylaxis can be attained in neutropenic patients, with the administration of an oral solution in a dosage of 5 mg/kg as either an od or bd schedule, following pre-autograft high-dose cytotoxic chemotherapy.

Effect of methotrexate on the germination and growth of Aspergillus fumigatus and Aspergillus flavus strains.

Methotrexate at concentrations of greater than or equal to 10(-5) M caused a significant reduction in the rate of germ tube formation of spores of Aspergillus fumigatus, but not of Aspergillus flavus, after 7 h incubation. At 10(-3) M the drug caused a significant reduction in germ tube elongation of A. fumigatus and A. flavus strains during the first 7 h of germination. After 18 h incubation, drug concentrations of greater than or equal to 4 x 10(-4) M produced greater than 80% reduction in growth of all strains tested. Potentiation of the antifungal effect against A. fumigatus was detected in tests in which methotrexate at 10(-4) M was used in combination with amphotericin B at 5 x 10(-7) M.

Sisomicin in surgical infections. Laboratory and clinical studies.

A clinical and bacteriological study to evaluate the effectiveness and toxicity of sisomicin in the treatment of surgical infections is described. Fifteen patients received i.m. injections of 150 or 225 mg/day for seven days. The daily doses was divided into three applications. The mean serum levels at the first hour were 5.26 +/- 2.41 microgram/ml and at the seventh hour 1.0 +/- 1.19 microgram/ml. Similar values were determined on the seventh day of treatment with sisomicin: 6.36 +/- 2.36 microgram/ml one hour, 1.17 +/- 1.67 microgram/ml seven hours after i.m. injection. All the microorganisms isolated had MICs below the sisomicin levels measured. The clinical results were assessed as "excellent" in 11 patients. Therapeutic results were considered as "fair" in three patients. The clinical conditions of one patient affected by osteomyelitis following osteosynthesis of the femur was not improved by treatment. No side effects were observed.