[Biomorphology of the Bacterial Invasion in Chronic pharyngotonsillitis ]

BACKGROUND

The study investigates whether relapses of chronicpharyngotonsillitis result from new infections caused by theoro-pharyngeal microbial flora or are reactivations of persistent bacterial infections of the tonsils.

METHODS

90 patients, who were surgically treated for chronicpharyngotonsillitis (age 13 months to 38 years, at least 5 episodes of disease and antibiotic treatment in the past) were included. The surgery was performed in the antibiotic- and symptom-free period (at least 6 weeks after the last exacerbation). Sections of tonsillar tissue were investigated for invasive bacteria using fluorescence in situ hybridization (FISH) with group and species-specific 15/23S RNA based probes.

RESULTS

Abundant foci of invasive bacteria were found in 86% of the resected tonsils, despite previous treatment with antibiotica and absent symptoms of ongoing infection. The diffuse infiltration of the tonsils was most predominant in the youger children. Local invasive processes such as abscesses, fissures filled with pus and superficial infiltration of the tonsillar epithelium were more typical for adults. All of the foci were polymicrobial and contained up to 10 different species or groups of bacteria. The local concentrations of invasive bacteria were up to 1012 bacteria/ml.

CONCLUSIONS

The chronic pharyngotonsillitis is the result of persistent invasive bacterial infections. The polymicrobial nature of the infectious foci enables them to resist the antibiotic treatment and to exacerbate afterwards. The surgical treatment is unavoidable as long as antibiotic treatment fails to clear the infection.

Phospholamban: a promising therapeutic target in heart failure?

Dilated cardiomyopathy and end-stage heart failure result in characteristic functional, biochemical and molecular alterations. Multiple defects in cardiac excitation-contraction coupling have been suggested to underlie disturbed myocardial function and progressive remodeling. Ca2+ uptake and release by the sarcoplasmic reticulum (SR) have been shown to be altered in various animal models and human conditions. This review will focus on SR Ca2+ ATPase and its regulatory protein, phospholamban, as potential therapeutic targets. We summarize structural and genetic approaches, which have helped to elucidate the physiological role of phospholamban as a principal regulator of cardiac contractility and beta-adrenergic stimulation in the heart. These findings are extended to the clinical arena, indicating a phospholamban/SR Ca2+ ATPase mismatch in human heart failure. Evidence is then provided, using genetically engineered mouse models, that SR dysfunction may play a key role in the onset and progression of heart failure. Phospholamban deficiency may prevent such left ventricular dysfunction and its progression to heart failure in some of the animal models with dilated cardiomyopathy. Based on these findings, we discuss the question of whether and how interfering with the phospholamban/SR Ca2+ ATPase interaction may be a promising therapeutic approach for heart failure.

Superinhibition of sarcoplasmic reticulum function by phospholamban induces cardiac contractile failure

To determine whether selective impairment of cardiac sarcoplasmic reticulum (SR) Ca(2+) transport may drive the progressive functional deterioration leading to heart failure, transgenic mice, overexpressing a phospholamban Val(49) --> Gly mutant (2-fold), which is a superinhibitor of SR Ca(2+)-ATPase affinity for Ca(2+), were generated, and their cardiac phenotype was examined longitudinally. At 3 months of age, the increased EC(50) level of SR Ca(2+) uptake for Ca(2+) (0.67 +/- 0.09 microm) resulted in significantly higher depression of cardiomyocyte rates of shortening (57%), relengthening (31%), and prolongation of the Ca(2+) signal decay time (165%) than overexpression (2-fold) of wild type phospholamban (68%, 64%, and 125%, respectively), compared with controls (100%). Echocardiography also revealed significantly depressed function and impaired beta-adrenergic responses in mutant hearts. The depressed contractile parameters were associated with left ventricular remodeling, recapitulation of fetal gene expression, and hypertrophy, which progressed to dilated cardiomyopathy with interstitial tissue fibrosis and death by 6 months in males. Females also had ventricular hypertrophy at 3 months but exhibited normal systolic function up to 12 months of age. These results suggest a causal relationship between defective SR Ca(2+) cycling and cardiac remodeling leading to heart failure, with a gender-dependent influence on the time course of these alterations.

Rescue of contractile parameters and myocyte hypertrophy in calsequestrin overexpressing myocardium by phospholamban ablation

Cardiac-specific overexpression of murine cardiac calsequestrin results in depressed cardiac contractile parameters, low Ca(2+)-induced Ca(2+) release from sarcoplasmic reticulum (SR) and cardiac hypertrophy in transgenic mice. To test the hypothesis that inhibition of phospholamban activity may rescue some of these phenotypic alterations, the calsequestrin overexpressing mice were cross-bred with phospholamban-knockout mice. Phospholamban ablation in calsequestrin overexpressing mice led to reversal of the depressed cardiac contractile parameters in Langendorff-perfused hearts or in vivo. This was associated with increases of SR Ca(2+) storage, assessed by caffeine-induced Na(+)-Ca(2+) exchanger currents. The inactivation time of the L-type Ca(2+) current (I(Ca)), which has an inverse correlation with Ca(2+)-induced SR Ca(2+) release, and the relation between the peak current density and half-inactivation time were also normalized, indicating a restoration in the ability of I(Ca) to trigger SR Ca(2+) release. The prolonged action potentials in calsequestrin overexpressing cardiomyocytes also reversed to normal upon phospholamban ablation. Furthermore, ablation of phospholamban restored the expression levels of atrial natriuretic factor and alpha-skeletal actin mRNA as well as ventricular myocyte size. These results indicate that attenuation of phospholamban function may prevent or overcome functional and remodeling defects in hypertrophied hearts.

Interactions between phospholamban and beta-adrenergic drive may lead to cardiomyopathy and early mortality

BACKGROUND

Relieving the inhibition of sarcoplasmic reticular function by phospholamban is a major target of beta-adrenergic stimulation. Chronic beta-adrenergic receptor activity has been suggested to be detrimental, on the basis of transgenic overexpression of the receptor or its signaling effectors. However, it is not known whether physiological levels of sympathetic tone, in the absence of preexisting heart failure, are similarly detrimental.

METHODS AND RESULTS

Transgenic mice overexpressing phospholamban at 4-fold normal levels were generated, and at 3 months, they exhibited mildly depressed ventricular contractility without heart failure. As expected, transgenic cardiomyocyte mechanics and calcium kinetics were depressed, but isoproterenol reversed the inhibitory effects of phospholamban on these parameters. In vivo cardiac function was substantially depressed by propranolol administration, suggesting enhanced sympathetic tone. Indeed, plasma norepinephrine levels and the phosphorylation status of phospholamban were elevated, reflecting increased adrenergic drive in transgenic hearts. On aging, the chronic enhancement of adrenergic tone was associated with a desensitization of adenylyl cyclase (which intensified the inhibitory effects of phospholamban), the development of overt heart failure, and a premature mortality.

CONCLUSIONS

The unique interaction between phospholamban and increased adrenergic drive, elucidated herein, provides the first evidence that compensatory increases in catecholamine stimulation can, even in the absence of preexisting heart failure, be a primary causative factor in the development of cardiomyopathy and early mortality.

Conversion of psoriasis patients from the conventional formulation of cyclosporin A to a new microemulsion formulation: a randomized, open, multicentre assessment of safety and tolerability

OBJECTIVE

To assess the safety, tolerability and efficacy of a new cyclosporin A (CyA) microemulsion formulation, Sandimmun Neoral (Neoral), in patients with severe psoriasis that was stable on CyA administered as Sandimmun (SIM).

METHODS

In this 24-week, open, randomized, prospective, multicentre trial, 28 patients continued on the same dosage of SIM, while 30 converted to Neoral at 2.5 mg/kg/day or a dosage equivalent to their pre-conversion SIM dosage. During the study, dosages could be adjusted to maintain efficacy, because of adverse events or after disease stabilization. The maximum permitted dosage for either formulation was 5.0 mg/kg/day. Primary efficacy criteria were change in Psoriasis Area and Severity Index (PASI) from baseline and time to relapse.

RESULTS

The dosage was increased to maintain efficacy in 22 patients (Neoral 13; SIM 9) and 20 dose reductions for safety were required (Neoral 14, SIM 6). In both groups, PASI scores remained stable throughout and relapses were primarily a result of dosage reduction after disease stabilization. No significant difference was found between groups in the proportion of patients remaining relapse-free. Adverse events were recorded in 20 patients receiving Neoral and 14 receiving SIM. Most drug-related events were of mild or moderate severity and reflected the known CyA side-effect profile. Dose titration guidelines ensured that mean blood pressure and serum creatinine concentrations remained stable in both groups.

CONCLUSIONS

If the guidelines for CyA use are followed and the Neoral dosage does not exceed 5 mg/kg/day, conversion of stable patients with severe psoriasis from SIM to Neoral should present no clinically relevant safety or tolerability problems and efficacy of treatment is maintained.

Cardiac-specific overexpression of calsequestrin results in left ventricular hypertrophy, depressed force-frequency relation and pulsus alternans in vivo

Cardiac-specific overexpression of calsequestrin has been shown to result in significant decreases in contractile parameters and intracellular Ca(2+)transients in vitro. Therefore, the purpose of the present study was to determine the effects of calsequestrin overexpression on basal cardiac function and the force-frequency relation in vivo. Calsequestrin overexpression mice (CSQ-OE, n=20) and their isogenic controls (WT) were studied with an integrative approach using transthoracic echocardiography, stress-shortening relations, and invasive hemodynamics in intact closed-chest mice. M-mode echocardiography indicated that calsequestrin overexpression resulted in concentric hypertrophy (+52%) and an increase in LV ejection phase indices. However, mean end-systolic stress-shortening coordinates revealed that at matched end-systolic wall-stress, fractional shortening was depressed in CSQ-OE mice. This was confirmed by depressed indices of LV isovolumic contraction and relaxation in CSQ-OE v. WT mice. Furthermore, overexpression of calsequestrin resulted in a downward and leftward shift of the biphasic force-frequency relation; thus, the critical heart (HR(crit)) was significantly lower in calsequestrin-overexpression mice (264+/-15 bpm) than in wild-type controls (365+/-21 bpm). Surprisingly, calsequestrin overexpression was associated with the induction of pulsus alternans in every animal (at an average heart rate of 428+/-26 bpm), whereas none of the wild-type controls displayed this phenomenon. We conclude that: (i) although increased levels of calsequestrin result in decreased myocardial contractility and a depressed force-frequency relation, LV wall stress is reduced and chamber function is normal, and (ii) an increase in SR Ca(2+)storage capacity induces pulsus alternans in the intact anesthetized mouse.

The transgenic expression of highly inhibitory monomeric forms of phospholamban in mouse heart impairs cardiac contractility

Transgenic mice were generated with cardiac-specific overexpression of the monomeric, dominant-acting, superinhibitory L37A and I40A mutant forms of phospholamban (PLN), and their phenotypes were compared with wild-type (wt) mice or 2-fold overexpressors of wt PLN (wtOE). The level of PLN monomer in cardiac microsomes was increased 11-13-fold, and the apparent affinity of the sarco(endo)plasmic reticulum Ca(2+)-ATPase for Ca(2+) was decreased from pCa 6.22 in wt or 6.12 in wtOE to 5.81 in L37A and 5.72 in I40A. Basal physiological parameters, measured in isolated myocytes, indicated a significant reduction in the rates of shortening (+dL/dt) and relengthening (-dL/dt). Hemodynamic measurements indicated that peak systolic pressure was unaffected but that pressure changes (+dP/dt and -dP/dt) were lowered significantly in both mutant lines, and relaxation time (tau) was also lengthened significantly. Echocardiography for both mutants showed depressed systolic function and an increase in left ventricular mass of over 1.4-fold. Significant decreases in left ventricular shortening fraction and velocity of circumferential shortening and increases in ejection time were corrected by isoproterenol. The use of antibodies specific against Ser(16)- and Thr(17)-PLN peptides showed that phosphorylation of both pentameric and monomeric PLN were increased between 1.2- and 2.4-fold in both the L37A and I40A lines but not in the wtOE line. These observations show that overexpression of superinhibitory mutant forms of PLN causes depression of contractile parameters with induction of cardiac hypertrophy, as assessed with echocardiography.

Maximal inhibition of SERCA2 Ca(2+) affinity by phospholamban in transgenic hearts overexpressing a non-phosphorylatable form of phospholamban

Phospholamban is a phosphoprotein in the cardiac sarcoplasmic reticulum (SR) which regulates the apparent Ca(2+) affinity of the SR Ca(2+)-ATPase (SERCA2). To determine the levels of phospholamban which are associated with maximal inhibition of SERCA2, several lines of transgenic mice were generated which expressed increasing levels of a non-phosphorylatable form of phospholamban (S16A,T17A) specifically in the heart. This mutant form of phospholamban was chosen to prevent phosphorylation as a compensatory mechanism in vivo. Quantitative immunoblotting revealed increased phospholamban protein levels of 1.8-, 2.6-, 3.7-, and 4.7-fold in transgenic hearts compared with wild types. There were no changes in the expression levels of SERCA2, calsequestrin, calreticulin, and ryanodine receptor. Assessment of SR Ca(2+) uptake in hearts of transgenic mice indicated increases in the inhibition of the affinity of SERCA2 for Ca(2+) with increased phospholamban expression. Maximal inhibition was obtained at phospholamban expression levels of 2.6-fold or higher. Transgenic hearts with functional saturation in phospholamban:SERCA2 (>/=2.6:1) exhibited increases in beta-myosin heavy chain expression, associated with cardiac hypertrophy. These findings demonstrate that overexpression of a non-phosphorylatable form of phospholamban in transgenic mouse hearts resulted in saturation of the functional phospholamban:SERCA2 ratio at 2.6:1 and suggest that approximately 40% of the SR Ca(2+) pumps are functionally regulated by phospholamban in vivo.

Cardiac-specific overexpression of a superinhibitory pentameric phospholamban mutant enhances inhibition of cardiac function in vivo

Phospholamban is a regulator of the Ca(2+) affinity of the cardiac sarcoplasmic reticulum Ca(2+) ATPase (SERCA2a) and of cardiac contractility. In vitro expression studies have shown that several mutant phospholamban monomers are superinhibitory, suggesting that monomeric phospholamban is the active species. However, a phospholamban Asn(27) --> Ala (N27A) mutant, which maintained a normal pentamer to monomer ratio, was shown to act as a superinhibitor of SERCA2a Ca(2+) affinity. To determine whether the pentameric N27A mutant is superinhibitory in vivo, transgenic mice with cardiac-specific overexpression of mutant phospholamban were generated. Quantitative immunoblotting revealed a 61 +/- 6% increase in total phospholamban in mutant hearts, with 90% of the overexpressed protein being pentameric. The EC(50) value for Ca(2+) dependence of Ca(2+) uptake was 0.69 +/- 0.07 microM in mutant hearts, compared with 0.29 +/- 0.02 microM in wild-type hearts or 0. 43 +/- 0.03 microM in hearts overexpressing wild-type PLB by 2-fold. Myocytes from phospholamban N27A mutant hearts also exhibited more depressed contractile parameters than wild-type phospholamban overexpressing cells. The shortening fraction was 52%, rates of shortening and relengthening were 46% and 38% respectively, and time for 80% decay of the Ca(2+) signal was 146%, compared with wild-types (100%). Langendorff-perfused mutant hearts also demonstrated depressed contractile parameters. Furthermore, in vivo echocardiography showed a depression in the ratio of early to late diastolic transmitral velocity and a 79% prolongation of the isovolumic relaxation time. Isoproterenol stimulation did not fully relieve the depressed contractile parameters at the cellular, organ, and intact animal levels. Thus, pentameric phospholamban N27A mutant can act as a superinhibitor of the affinity of SERCA2a for Ca(2+) and of cardiac contractility in vivo.

Microemulsion formulation of cyclosporin (Sandimmun Neoral) vs Sandimmun: comparative safety, tolerability and efficacy in severe active rheumatoid arthritis. On behalf of the OLR 302 Study Group

OBJECTIVE

To compare the safety, tolerability and efficacy of the new oral microemulsion formulation of cyclosporin A (CyA; Sandimmun Neoral) and the original CyA formulation (Sandimmun), in patients with severe active rheumatoid arthritis (RA), over a 12-month period.

METHODS

In this double-blind, multicentre study, patients were randomized to treatment with Neoral or Sandimmun, starting with 2.5 mg/kg/day, with dose adjustments after 4 weeks. Primary efficacy criteria included patients' assessment of disease activity. Pharmacokinetic and safety assessments were performed at regular intervals.

RESULTS

Compared with Sandimmun, Neoral showed a consistent trend towards greater clinical efficacy from week 12 onwards, including a significant difference in patients' assessment of disease activity at the study end-points. A significantly lower increase in dose from baseline was observed with Neoral at week 24. Pharmacokinetic assessments at week 24 showed increased absorption and decreased variability with Neoral. No differences in safety were found between treatment groups.

CONCLUSION

These observations indicate that Neoral is as safe and at least as effective as Sandimmun and have important implications for patient management given the increasing role for CyA in the treatment of severe, active RA.

Conversion of patients with rheumatoid arthritis from the conventional to a microemulsion formulation of cyclosporine: a double blind comparison to screen for differences in safety, efficacy, and pharmacokinetics

OBJECTIVE

To assess whether patients with rheumatoid arthritis (RA) may be converted, on a milligram-to-milligram basis, from conventional cyclosporin A (CyA, Sandimmun) to the microemulsion formulation (Neoral) with maintenance of longterm safety, and to compare cyclosporin A (CyA) pharmacokinetics between formulations.

METHODS

In this double blind, multicenter, parallel group study, 51 patients receiving stable conventional CyA maintenance treatment were randomized to continue conventional CyA (n = 27) or to convert to CyA microemulsion (n = 24) and were monitored for 52 weeks. Trough blood CyA levels were measured before and at intervals after conversion. CyA steady-state area under the curve was assessed one week before and 2 and 6 weeks after randomization in 15 patients in each treatment arm. CyA trough levels and pharmacokinetic results remained unknown to investigators throughout the study. CyA doses were titrated as necessary on the basis of clinical evaluation and disease activity assessments.

RESULTS

Initial mean daily doses were 3.5 mg/kg/day (conventional CyA) and 3.3 mg/kg/day (CyA microemulsion) and did not change significantly during the study. The mean bioavailability of CyA from the microemulsion formulation was 23% higher than from conventional CyA. Replicate assessments indicated a more reproducible pharmacokinetic profile with CyA microemulsion. The overall incidence and nature of adverse events and changes in vital signs and laboratory variables were similar in both groups. No clinically relevant differences in efficacy were found between treatments. No loss of efficacy and no tolerability problems occurred after conversion from conventional to microemulsion CyA.

CONCLUSION

Existing CyA dosing guidelines, formulated for conventional CyA, are suitable for longterm CyA microemulsion therapy of patients with RA. These results indicate the pharmacokinetic advantages of the microemulsion formulation.

Screening for basiliximab exposure-response relationships in renal allotransplantation

The immunosuppressant basiliximab--a chimeric monoclonal antibody specific to the interleukin-2 receptor on activated T-lymphocytes--significantly reduces the incidence of acute cellular rejection following renal transplantation. Screening for exposure-response relationships was performed within a randomized, blinded, placebo-controlled efficacy trial in which patients received 40 mg basiliximab (20 mg on days 0 and 4) by intravenous infusion in addition to cyclosporine and corticosteroids. In a subset of patients, serum samples were collected pre-transplant and once in weeks 2, 3 and 4 for determination of basiliximab concentrations. A population pharmacostatistical model was used to derive individual empirical Bayes estimates of each patient's pharmacokinetic parameters. Biopsy-confirmed acute rejection episodes were recorded to month 6 post-transplant. Forty basiliximab-treated patients were evaluated, 30 men and 10 women, aged 48 +/- 12 yr (range, 24-73) and weighing 72.4 +/- 12.9 kg (range, 52.5-107.5). The basiliximab distribution volume was 7.5 +/- 1.7 L, the half-life 7.5 +/- 2.5 d and the clearance 33 +/- 12 mL/h. There was no clinically relevant influence of weight, age, or gender on basiliximab disposition. Receptor-saturating serum basiliximab concentrations (> 0.2 microgram/mL) were maintained for 41 +/- 23 d. Twenty-five patients remained rejection-free over the 6-month observation period, while a total of 26 biopsy-confirmed acute rejection episodes occurred in the remaining 14 patients. Of these episodes, 12 occurred during receptor blockade. No apparent relationship to basiliximab concentration on the day of onset was observed range, 0.1-9.0 microgram/mL) nor did the time of suppression offset represent a period of increased risk for rejection episodes. Fourteen rejection episodes occurred after basiliximab had cleared from the serum. The durations of receptor suppression preceding these events did not differ compared with those in patients who remained rejection-free: 32 +/- 11 versus 45 +/- 26 d, respectively (p = 0.1269). Given the durations of receptor saturation achieved with the chosen basiliximab regimen, this screen for exposure-response relationships did not identify the duration of receptor saturation in peripheral blood as a predictive factor for acute rejection episodes. Further exploration for exposure-effect relationships in a larger population is warranted.

Disposition and immunodynamics of basiliximab in liver allograft recipients

A randomized, open-label prospective study was conducted with recipients of primary cadaveric liver allografts to characterize the disposition and immunodynamics of basiliximab, an interleukin-2 receptor, alpha-chain chimeric monoclonal antibody for immunoprophylaxis of acute rejection. Patients received a total intravenous dose of 40 mg basiliximab in addition to baseline dual immunosuppression consisting of cyclosporine (INN, ciclosporin) and steroids. The central distribution volume was 5.6 +/- 1.7 L with a steady-state volume of 7.5 +/- 2.5 L. It was cleared slowly with a total body clearance of 75 +/- 24 ml/hr and an elimination half-life of 4.1 +/- 2.1 days. Basiliximab was measurable in drained ascites fluid, and clearance by this route was an average of 20% of total clearance. Total body clearance correlated positively with volume of postoperative blood loss (r = 0.5253, p = 0.0101), suggesting that bleeding may represent an additional route of drug removal. A threshold relation was observed between serum concentration of basiliximab and CD25 expression on T lymphocytes whereby complete saturation of interleukin-2 receptor alpha-chain was maintained as long as serum concentrations exceeded 0.1 microgram/ml. The duration of receptor saturation was 23 +/- 7 days after transplantation (range, 13 to 41 days).

Safety and tolerability of conversion from stable Sandimmun maintenance treatment to Sandimmun Neoral in patients with rheumatoid arthritis

OBJECTIVE

To assess the safety and tolerability of converting patients with rheumatoid arthritis (RA) taking a stable dose of cyclosporin A (CyA) maintenance treatment (Sandimmun, SIM) to a new microemulsion capsule formulation, Sandimmun Neoral (Neoral), at an initial dose of 2.5 mg/kg/day.

METHODS

In this single arm, open multicenter study, 28 patients were recruited to enter a 6 week pre-conversion period; of these, 22 patients completed 12 weeks' treatment with Neoral.

RESULTS

During the 12 week post-conversion period, 11 patients experienced adverse events considered to be drug related; most were mild to moderate in severity and reflected the known safety profile for CyA. Only slight differences in efficacy variables were observed after conversion. The mean Neoral dose at Week 12 (2.84 mg/kg/day) was lower than the mean SIM pre-conversion dose (3.38 mg/kg/day). The study showed that, in patients with RA undergoing stable SIM maintenance treatment, conversion to an initial Neoral dose of 2.5 mg/kg/day did not give rise to any clinically relevant safety and tolerability concerns, and efficacy of the treatment was maintained compared with SIM.

CONCLUSION

This conversion strategy constitutes a clinically acceptable alternative to a 1:1 dose conversion.

Disposition of basiliximab, an interleukin-2 receptor monoclonal antibody, in recipients of mismatched cadaver renal allografts

BACKGROUND

Basiliximab is an interleukin-2 receptor (IL-2R; CD25) chimeric monoclonal antibody for immunoprophylaxis against acute rejection in renal transplantation. Its pharmacokinetics were characterized in a multicenter open-label, prospective dose-escalation study to identify a single-dose regimen providing IL-2R-saturating serum concentrations in the critical first posttransplant month.

METHODS

Thirty-two recipients of primary, mismatched cadaver kidneys were enrolled: 20 men and 12 women, who were 47+/-11 years old and weighed 65+/-12 kg. The immunosuppression regimen consisted of steroids and azathioprine from day 0 and cyclosporine from day 10. Basiliximab was infused over 30 min as a single dose preoperatively.

RESULTS

Thirty patients were evaluable for basiliximab pharmacokinetics: 24 received 40 mg and 6 received 60 mg. Basiliximab was well tolerated without evidence of cytokine-release syndrome, hypersensitivity reactions, or anti-idiotype antibody response. Peak concentration and area under the concentration curve increased proportionally with dose. Postinfusion concentrations declined in a biphasic manner with a terminal half-life of 6.5+/-2.1 days. Weak, widely dispersed correlations were noted between body weight versus distribution volume (r=0.29) and versus clearance (r=0.45), suggesting no clinical relevance for weight-adjusted dosing. There were no apparent gender-related differences in basiliximab disposition. Previous phase II data indicated that serum concentrations in excess of 0.2 microg/ml are sufficient to saturate IL-2R epitopes on circulating T lymphocytes. Concentrations were above this threshold for 26+/-8 days (range 16 to 46) at the 40-mg dose level and for 32+/-11 days (range 22 to 51) at the 60-mg dose level.

CONCLUSIONS

Total basiliximab doses of 40-60 mg were well tolerated, nonimmunogenic, and estimated to provide immunoprophylaxis to cover the first posttransplant month.

Randomised trial of basiliximab versus placebo for control of acute cellular rejection in renal allograft recipients. CHIB 201 International Study Group

BACKGROUND

Currently available immunosuppressive regimens for cadaver-kidney recipients are far from ideal because acute-rejection episodes occur in about 30% to 50% of these patients. In the phase III study described here we assessed the ability of basiliximab, a chimeric interleukin (IL)-2 receptor monoclonal antibody, to prevent acute-rejection episodes in renal allograft recipients.

METHODS

380 adult recipients of a primary cadaveric kidney transplant were randomly allocated, in this double-blind trial, to receive a 20 mg infusion of basiliximab on day 0 (day of surgery) and on day 4, to provide IL-2-receptor suppression for 4-6 weeks (n=193), or to receive placebo (n=187). Both groups received baseline dual immunosuppressive therapy with cyclosporin and steroids throughout the study. The primary outcome measure was incidence of acute-rejection episodes during the 6 months after transplantation. Safety and tolerability were monitored over the 12 months of the study.

FINDINGS

376 patients were eligible for intention-to-treat analysis (basiliximab, n=190; placebo, n=186). No significant differences in patient characteristics were apparent. The incidence of biopsy-confirmed acute rejection 6 months after transplantation was 51 (29.8%) of 171 in the basiliximab group compared with 73 (44.0%) of 166 in the placebo group (32% reduction; 14.2% difference [95% Kaplan-Meier CIs 3% to 24%], p=0.012). The incidence of steroid-resistant first rejection episodes that required antibody therapy was significantly lower in the basiliximab group (10% vs 23.1%, 13.1% difference [5.4% to 20.8%], p<0.001). At weeks 2 and 4 post-transplantation, the mean daily dose of steroids was significantly higher in the placebo group (p<0.001 with one-way analysis of variance). The incidence of graft loss at 12 months post-transplantation was 23 (12.1%) of 190 in the basiliximab group and 25 (13.4%) of 186 in the placebo group (1.3% difference [-5% to 9%], p=0.591). The incidence of infection and other adverse events was similar in the two treatment groups. The acute tolerability of basiliximab was excellent, with no evidence of cytokine-release syndrome. 14 deaths (basiliximab n=9; placebo n=5; -2.0% difference [-6% to 2%], p=0.293) occurred during the 12-month study and a further three deaths (basiliximab n=1; placebo n=2) occurred within the 380-day cut-off period. One post-transplantation lymphoproliferative disorder was recorded in each group.

INTERPRETATION

Prophylaxis with 40 mg basiliximab reduces the incidence of acute rejection episodes significantly, with no clinically relevant safety or tolerability concerns.

Solitary skeletal lesions as primary manifestations of non-Hodgkin's lymphoma. Report of two cases and review of the literature

Two patients with solitary skeletal lesions of the lower extremity were eventually diagnosed as having high-grade malignant B-cell non-Hodgkin's lymphoma. In both cases staging revealed no other nodal or extranodal involvement. One patient had been symptomatic for more than 2 years, presenting originally as a case of chronic synovitis. The second patient presented with slight exertional pain in his left knee of relatively recent history. In his case the initial plain X-ray showed little evidence of bony destruction, while magnetic resonance imaging revealed an extensive lesion in the left tibial plateau. Orthopedic surgeons should be aware of the differential diagnosis of primary lymphoma of bone. Early use of magnetic resonance imaging, in addition to plain X-ray and scintigraphic imaging, can be helpful in leading to an early biopsy and consequently early treatment. Magnetic resonance imaging should be regarded as the method of choice for follow-up examinations of lymphoma lesions.