Lipid formulations of amphotericin B preserve and stabilize renal function in HSCT recipients

The current study assessed renal function based on medical records in adult hematopoietic stem cell transplant (HSCT) recipients with proven or probable invasive fungal infection (IFI) transplanted between 1995 and 2000. We confirm that amphotericin B deoxycholate (AmB-d) is nephrotoxic in a large percentage of HSCT recipients. Due to nephrotoxicity, defined as serum creatinine (SCr) >2.5 mg/dl or a 100% increase in SCr from baseline, 88% of patients treated with AmB-d were switched to a lipid formulation of amphotericin B (LFAB). In total, 53% of patients initiated on AmB-d were switched within the first week of therapy. Significantly more patients (70.6%) treated with AmB-d experienced a 100% increase in SCr from baseline compared to patients treated with either AmBisome (44.4%) or Abelcet (41.2%). A Cox Proportional Hazards Model revealed that, compared to patients initiated on AmBisome or Abelcet, the risk of nephrotoxicity (RR=1.5 vs AmBisome; RR=1.7 vs Abelcet), dialysis (RR=2.4 vs AmBisome; RR=1.4 vs Abelcet), and death (RR=2.0 vs AmBisome; RR=1.1 vs Abelcet) were all increased for patients initiated on AmB-d. Study results suggest that renal function improves and mortality declines when an LFAB is given to HSCT patients as initial therapy rather than as second-line therapy, the current practice.

Immunological and clinical effects of post-transplant G-CSF versus placebo in T-cell replete allogeneic blood transplant patients: Results from a randomized double-blind study

BACKGROUND

Immunological and clinical effects of post-transplant growth factor administration have not been well studied. This report describes the outcome and immune functions of a total of 50 HLA-matched related donor allogeneic blood stem-cell transplantation patients who received post-transplant G-CSF (10 microg/kg) or placebo.

METHODS

Immune status, including number of lymphocyte subsets and their functions, and serum immunoglobulin levels and clinical status--including GvHD, rate of relapse, event-free survival, and overall survival--were determined in the patients enrolled in this study.

RESULTS

Twenty-eight patients survived 1 year after transplant, and 15 patients had available results to compare immune function by randomization assignment. At 12 months post-transplant, immune parameters in G-CSF versus placebo groups showed no statistically significant differences in number of circulating lymphocyte subsets CD3, CD4, CD8, CD19 and CD56 in the two groups. There was no significant (NS) difference in immunoglobulin IgG, IgA and IgM levels, NK or LAK cell-mediated cytotoxicity levels, and mitogen-induced proliferation between post-transplant G-CSF and placebo group. In addition, the analyses of immune parameters at earlier time-points on Days 28, 100, 180, and 270 revealed that, except for LAK cytotoxicity at Day 100, there was no differences between the two groups. Fourteen of 26 patients are alive in the G-CSF arm and nine of 24 in the placebo arm. Median follow-up of surviving patients is 43 months. Four year overall and event-free survival in the G-CSF and the placebo group were 53% and 35% (NS), and 44% and 36% (NS) respectively. Bacterial or fungal infections were the cause of six of 12 deaths in the G-CSF arm (all bacterial) and of four of 15 deaths in the placebo arm (two deaths from Aspergillus) (P=0.26). Two patients relapsed in the G-CSF arm and three in the placebo arm. Four year cumulative incidences of relapse were 8% versus 13% in G-CSF versus placebo arms, respectively, (NS). Chronic GvHD developed in 14 of 19 100-day survivors after G-CSF (11 extensive stage), and in 17 of 20 (14 extensive stage) in the placebo arm. The 4-year cumulative incidence of chronic GvHD was 56% [95% confidence interval (CI) 24-88%] after G-CSF and 71% (95% CI 48-94%) after placebo; this difference was not statistically significant (log rank P=0.41).

CONCLUSION

In summary, there were no significant immunological or alterations in clinical benefit of post-transplant G-CSF administration in T-replete allotransplant recipients.

Isolation and flow cytometric analysis of T-cell-depleted CD34+ PBPCs

BACKGROUND

To extend allogeneic HPC transplantation to a greater range of patients, the use of partially matched related donors is under development. Because of the inherently higher degree of histoincompatibility in such transplants, there is increased risk of GVHD as well as of graft failure. Ex vivo depletion of donor-derived T-lymphocytes from PBPCs is one of the most effective methods of preventing GVHD. Thus far, individual centers have used custom-developed procedures to deplete the graft of T cells that are responsible for alloreactivity, often employing relatively impure, nonstandardized reagents such as soybean agglutinin and complement. In addition, with improved methods of T-cell depletion, it has been difficult to accurately assess the number of T cells remaining. Because different centers have used different protocols to assay T cells, it has been difficult to reproduce and validate the results between institutions, and this has limited direct comparison of data between centers.

STUDY DESIGN AND METHODS

A standardized approach for T-cell depletion was developed by using a Good Manufacturing Practice-manufactured magnetic cell separator (Isolex 300i, Nexell Therapeutics) and commercially available OKT3 antibody. T-cell depletion was performed on PBPCs from six haploidentical donors.

RESULTS

CD34+ cell recovery was 47 percent (range, 31-63%) with a median purity of 94 percent (range, 75-99%) and median T-cell log depletion of 4.72 (range, 3.90-5.83). Because this high degree of depletion makes it challenging to accurately quantitate the remaining T cells, two highly sensitive flow cytometric protocols were developed, each of which accurately detects T cells with a sensitivity of 2 per 10,000 (0.02%). The purified CD34+ cells administered to the patients (dose range, 6.13-13.50 x 10(6)/kg) provided rapid neutrophil and platelet engraftment.

CONCLUSION

With the Isolex 300i and a MoAb directed against T cells, a high degree of T-cell depletion is obtained. Sensitive, accurate, and reproducible assays have now been developed for T-cell enumeration in these highly purified cell populations.

Restriction fragment length polymorphism analysis of Mycobacterium avium isolates from animal and human sources

Restriction fragment length polymorphism (RFLP) analysis using probes derived from the insertion sequences IS901, IS1245 and IS1311, was carried out on Mycobacterium avium isolates obtained from 18 human patients, 44 deer, 14 pigs and five cattle in the Republic of Ireland. Forty-two of the cervine isolates and two of the bovine isolates contained IS901, while this insertion sequence was absent from all of the human and porcine isolates. RFLP analysis with IS901 probe differentiated the 44 field isolates which contained this element into three types. All of the IS901-positive isolates had a characteristic three-band IS1245 hybridisation pattern and a characteristic single-band IS1311 hybridisation pattern. The IS901-negative isolates exhibited highly polymorphic IS1245 and IS1311 hybridisation patterns which differentiated the human and porcine isolates into a wide diversity of strain types.

Antileukemia activity of a natural killer cell line against human leukemias

We describe here the in vitro and in vivo antileukemia activity of a recently described natural killer (NK) cell line (NK-92), which has features of human activated NK cells. The cytotoxic activity of rhIL2-dependent cultured NK-92 cells against primary patient-derived leukemic target cells [12 acute myelogenous leukemias (AMLs), 7 T acute lymphoblastic leukemias (T-ALLs), 14 B-lineage-ALLs, and 13 chronic myelogenous leukemias (CMLs)], human leukemic cell lines (K562, KG1, HL60, Raji, NALM6, TALL-104, CEM-S, and CEM-T) and normal bone marrow cells was measured in 51Cr-release assay (CRA). The patient-derived leukemias could be subdivided into three groups based on their sensitivity to NK-92 cells: insensitive (< or =19% lysis), sensitive (20-49% lysis), and highly sensitive (> or =50% lysis) at an E:T ratio of 9:1. Of 46 patient-derived samples, 24 (52.2%) were sensitive or highly sensitive to NK-92-mediated in vitro cytotoxicity (6 of 12 AMLs, 7 of 7 T-ALLs, 5 of 14 B-lineage-ALLs, and 6 of 13 CMLs). NK-92 cells were highly cytotoxic against all of the eight leukemic cell lines tested in a standard 4-h CRA. Normal human bone marrow hematopoietic cells derived from 18 normal donors were insensitive to NK-92-mediated cytolysis. In comparison with human lymphokine-activated killer cells, normal NK cells, and T cells, NK-92 cells displayed more powerful antileukemia activity against a patient-derived T-ALL as well as K562 and HL60 cells, both in in vitro CRA and in a xenografted human leukemia SCID mouse model. The NK-92 cells did not induce the development of leukemia in SCID mice after i.v., i.p., or s.c. inoculation. In adoptive transfer experiments, SCID mice receiving i.p. inoculations of human leukemias derived from a T-ALL (TA27) and an AML (MA26) that were highly sensitive to the cytolysis of NK-92 cells in vitro, as well as a pre-B-ALL (BA31) that was insensitive to the in vitro cytolysis of NK-92 cells, were treated by administration of NK-92 cells with or without rhIL2 (2 x 10(7) NK-92 cells i.p.; one dose or five doses). Survival times of SCID mice bearing the sensitive TA27 and MA26 leukemias were significantly prolonged by adoptive cell therapy with NK-92 cells. Some of the animals who received five doses of NK-92 cells with or without rhIL2 administration were still alive without any signs of leukemia development 6 months after leukemia inoculation. In contrast, survival of mice bearing the insensitive BA31 leukemia were not affected by this treatment. This in vitro and in vivo antileukemia effect of NK-92 cells suggests that cytotoxic NK cells of this type may have potential as effectors of leukemia control.

Differential growth patterns in SCID mice of patient-derived chronic myelogenous leukemias

The development of an in vivo model for the study of CML would be of significant importance in studying its biological behavior and developing novel therapeutic strategies. We examined the ability of human leukemic cells derived from patients in either chronic (CP), accelerated (AP) or blast phase (BP) CML to grow and disseminate in CB17-SCID mice by subcutaneous (s.c.) inoculation without conditioning treatment or administration of cytokines. Additionally, samples derived from patients with CP-CML were injected s.c. into CB17-SCID mice treated with anti-Asialo GM1 (an anti-NK cell antibody) and NOD-SCID mice (absent NK cell activity) to study the potential role of NK cell-mediated anti-leukemic activity in preventing the propagation of CP-CML cells. We observed a significant differential growth pattern of CML cells in the mice such that BP-CML grew rapidly as s.c. tumors and disseminated, while AP-CML or CP-CML cells grew temporarily as small nodules that spontaneously regressed and did not disseminate. This differential growth pattern suggests possible important biological differences. Furthermore, no significant difference in s.c. growth or dissemination of CP-CML samples derived from newly diagnosed patients in untreated CB17-SCID mice and CB-17 SCID mice treated with Anti-Asialo GM1 and NOD-SCID mice occurred, suggesting that factors other than NK cell anti-leukemic activity may be important.

Isolation of mycobacteria from lymph node lesions in deer

A total of 14,842 farmed deer were slaughtered and examined postmortem in Irish abattoirs between January 1993 and September 1996. Lymph node lesions were detected in 119 deer and these were examined histopathologically and cultured. A total of 115 of the lesions were characterised as tuberculous and, on culture, Mycobacterium avium was isolated from 49 of them, M bovis from 41, unclassified mycobacteria from five, and 20 of the tuberculous lesions did not yield any isolate. Tubercles which yielded M avium on culture contained on average more acid-fast bacilli, more epithelioid macrophages and fewer Langhans giant cells than tubercles from which M bovis was isolated. Twelve lesions from feral deer culled from a national park were also examined and M bovis was isolated from nine.

The effects of mexiletine, desipramine and fluoxetine in rat models involving central sensitization

Drugs that are clinically effective (mexiletine and desipramine) or ineffective (fluoxetine) in the treatment of human neuropathic pain were evaluated for efficacy in rat models involving central sensitization (i.e., formalin model and the L5/L6 spinal nerve ligation model of neuropathic pain) using tests that differ in stimulus modality: noxious chemical stimulus (formalin model) as well as noxious (pin prick) and innocuous mechanical stimuli (application of von Frey filaments). Mexiletine (10-100 mg/kg, s.c.) significantly (P < 0.05) attenuated hyperalgesia in formalin-treated (60 mg/kg and 100 mg/kg) and neuropathic rats (100 mg/kg) as well as tactile allodynia in neuropathic rats (100 mg/kg). Desipramine (1-100 mg/kg, s.c.), on the other hand, reduced hyperalgesia significantly (P < 0.05) in formalin-treated (3, 10, 30 and 100 mg/kg) and neuropathic rats (10 mg/kg and 100 mg/kg), but did not reduce tactile allodynia in the neuropathic rats. Fluoxetine (3-30 mg/kg, s.c.) did not inhibit either hyperalgesia or allodynia in any of the tests employed. Fluoxetine, which is relatively ineffective in reducing neuropathic pain in humans, was also ineffective in reducing hyperalgesia and allodynia associated with central sensitization in rats. Thus, drugs which are effective in reducing human neuropathic pain consistently attenuated hyperalgesia in formalin-treated or neuropathic rats. Desipramine also distinguished mechanical hyperalgesia from tactile allodynia in rats rendered neuropathic by spinal nerve ligation. These data are consistent with the hypothesis that the neuronal mechanisms underlying these two manifestations of neuropathic pain are different.

Growth pattern and clinical correlation of subcutaneously inoculated human primary acute leukemias in severe combined immunodeficiency mice

We examined the ability of patient-derived human leukemic blasts to generate leukemic growth and dissemination in severe combined immunodeficiency (SCID) mice by subcutaneous inoculation without conditioning treatment or administration of growth-promoting cytokines. Additionally, we correlated the growth pattern with the clinical outcome of patients from whom the leukemic cells were derived. The leukemias displayed three distinct growth patterns, ie, either aggressive, indolent, or no tumor growth. Leukemic cells from 6 of 13 patients with acute myeloid leukemia (AML), 4 of 7 T-cell acute lymphoblastic leukemia (T-ALL), and 11 of 16 patients with B-lineage ALL grew as subcutaneous tumors, with a significant number subsequently disseminating into distant organs in SCID mice. Patients whose leukemic blasts displayed an aggressive growth and dissemination pattern in SCID mice had a relatively poor clinical outcome, whereas patients with AML and T- or B-lineage ALL whose leukemic blasts grew indolently or whose cells failed to induce growth had a more favorable clinical course. Our study has shown that the subcutaneous inoculation of patient-derived human leukemic cells in SCID mice can engraft and grow as subcutaneous tumors with subsequent dissemination to distant organs in a manner analogous to their pattern of growth in humans. Additionally, these data suggest a clinical correlation to the growth and dissemination of some leukemic subtypes that may represent not only an additional prognosticator for patient outcome, but also a vehicle for the study of the biologic behavior of human leukemias and the development of novel therapeutic strategies.

Effects of the 5-HT uptake inhibitors, femoxetine and paroxetine, and a 5-HT1A/B agonist, eltoprazine, on the behavioural satiety sequence

In rats allowed access to a 35% sucrose solution, following a 4-h period of food and water deprivation, an initial period of sucrose consumption was followed by a short period of grooming and exploratory behaviour, later superseded by resting. This "behavioural satiety sequence" was advanced in time by the 5-HT uptake inhibitors femoxetine and paroxetine and by the 5-HT1A/B agonist eltoprazine at anorectic and subanorectic doses. These effects, which are similar to those previously observed with another 5-HT uptake inhibitor, fluoxetine, are compatible with an increase in postprandial satiety.

Effects of chronically administered fluoxetine and fenfluramine on food intake, body weight and the behavioural satiety sequence

Rats were administered fenfluramine (FF: 3 mg/kg) or fluoxetine (FX: 6 mg/kg) daily for 3 weeks. On acute administration, FF suppressed consumption of 35% sucrose (in a 40 min test) and overnight chow intake. Repeated administration saw the rapid development of extensive tolerance to these effects. FF had no effects on body weight, and no withdrawal effects were apparent. FX reduced chow intake and body weight throughout the treatment period, but there was evidence of some tolerance to the suppression of chow intake and sucrose drinking. Following FX withdrawal, normal body weight was restored in 4 days; food intake was normal during this period. A delayed rebound hyperphagia commenced on day 5 of withdrawal, and persisted for at least 6 days. The behavioural satiety sequence (drinking--activity--grooming--resting) was disrupted by acute FF; on chronic treatment, FF advanced the onset of postprandial resting, but also increased drinking time. FX advanced the behavioural satiety sequence on acute administration, but not after chronic treatment. We consider the implications of these results for the use of resting behaviour as an indicator of postprandial satiety.

A comparison of the effects of d- and l-fenfluramine and d-amphetamine on energy and macronutrient intake in human subjects

The anorectic activity of the d and l isomers of d-fenfluramine (d-FF) (l-FF) were compared with d-amphetamine (d-amp) when given separately and together in 12 healthy male volunteers. The study was double blind and placebo controlled. Food intake was measured using an automated food dispenser. Anorectic activity was examined using a) total energy intake b) nutrient selection c) selection of foods categorised by nonsweet/sweet taste. Total energy intake was significantly reduced by d-FF (17%) d-amp (26%) d-FF + d-amp (36%) and l-FF + d-amp (31%). d-Amp and both combinations significantly reduced energy intake from all macronutrients in the total food. d-FF reduced carbohydrate but not fat or protein intake derived from all foods. When nonsweet and sweet tasting foods were examined separately, l-FF also significantly reduced energy (by 19%), fat and carbohydrate intake from nonsweet food. Neither d-FF nor l-FF reduced protein from nonsweet food. No anorectic drug given alone reduced sweet food intake, only d-amp given with d-FF had this effect. In contrast to nonsweet food, d-FF did not reduce carbohydrate from sweet foods. The results are in agreement with previous work that d-FF spares protein consumption but suggest that d-FF does not selectively reduce carbohydrate intake per se.

Differential effects of d-fenfluramine, l-fenfluramine and d-amphetamine on the microstructure of human eating behaviour

An observational technique, demonstrated to provide reliable data under a variety of conditions, was used to evaluate the effects of d-fenfluramine, l-fenfluramine, d-amphetamine, and fenfluramine-amphetamine combinations on eating behaviour in human subjects. Following an overnight fast, subjects ate lunch from a dispenser allowing free access to a choice of ten sweet and savoury foods, of varying macronutrient composition. D-fenfluramine (30mg) and d-amphetamine (15mg) reduced food intake; l-fenfluramine (30mg) was essentially inactive. The net effects of d-fenfluramine and d-amphetamine on food intake were additive, but the behavioural mechanisms of action were different for the two drugs. D-amphetamine decreased the duration of the meal, as well as the time spent chewing or manipulating food and the number of bites, but had no effect on eating rate; by contrast, d-fenfluramine decreased the rate of eating, but had no effect on meal duration.

The effect of the 5-HT re-uptake inhibitor fluoxetine on food intake and body weight in healthy male subjects

Eleven healthy male subjects of normal body weight received either 60 mg of the 5-HT re-uptake inhibitor fluoxetine (FXT) or matching placebo daily for two weeks, with a minimum one month wash-out period between treatments. Subjects attended on days 1, 8 and 15 from 08.50 h to 15.15 h in each treatment period when food and fluid intake, body weight, pulse and blood pressure, pupil diameter and plasma levels of FXT and NorFXT were measured and visual analogue scales (VAS) for subjective ratings of hunger, satiety, thirst, mood, arousal, nausea and gastric discomfort were completed. The trial was of a double-blind randomised crossover design, each subject acting as his own control. FXT reduced food intake by 15.7 per cent on day 1; by 12.6 per cent on day 8 but not on day 15. Hunger ratings were lowered by FXT on days 8 and 15 but not on day 1. Subjects were less thirsty when taking FXT but there was no concomitant reduction in fluid intake. FXT produced some mydriasis and slowed heart rate. In two weeks treatment with FXT there was a statistically significant weight loss of 1.07 kg compared to a mean weight gain of 0.15 kg on placebo. The incidence of reported side effects was low, drowsiness and stomach discomfort were reported by some subjects on days 8 and 15.

Behavioural analysis of the anorectic effects of fluoxetine and fenfluramine

Two sets of experiments were carried out to compare the effects of fenfluramine and fluoxetine on consummatory and operant behaviour. In food-deprived rats allowed access to a 35% sucrose solution, an initial period of sucrose consumption was followed by a short period of grooming and exploratory behaviour, later superceded by resting. This "behavioural satiety sequence" was advanced by fluoxetine, but disrupted by dl-fenfluramine, which suppressed post-prandial resting, even at sub-anorectic doses. Fluoxetine also elicited resting behaviour following water drinking. However, this did not appear to be a non-specific sedative effect, since fluoxetine increased post-prandial grooming. In rats performing on random interval schedules of food reinforcement, fluoxetine caused proportionally greater decreases in responding on a reinforcement-lean schedule (RI-300s), as compared to a reinforcement-rich schedule (RI-7.5s); this effect is similar to that of a reduction in level of food deprivation. By contrast, fenfluramine reduced responding equally on both schedules. In both paradigms, the effects of fluoxetine were compatible with an increase in postprandial satiety, but the effects of fenfluramine were not.