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Biomedical subjects

O N Fernando

Publications and source records attributed to O N Fernando.

At least 19 recordsLinked to original sources

Prolonged action of a chimeric interleukin-2 receptor (CD25) monoclonal antibody used in cadaveric renal transplantation.

A high affinity chimeric CD25 mAb (chRFT5: SDZ CHI 621) blocking interleukin-2 binding to the interleukin-2 receptor alpha-chain was evaluated in a phase I/II study in human renal cadaveric transplantation. The chRFT5 was well tolerated with no immediate adverse effects during 6 spaced infusions (from before transplantation to day 24) in 24 patients escalating from 2.5- to 25-mg dosages. The chRFT5 had a long terminal half-life with a mean of 13.1 days. There was good correlation between the detection of chRFT5 in the serum by radioimmunoassay, the coating and suppression of CD25 on T cells, and antibody activity in patient serum samples. The chRFT5 activity persisted in vivo for up to 120 days. No antibody response to the chRFT5 was detected in any of the patients, even though two patients who required treatment with antithymocyte globulin or OKT3 developed xenogeneic antiglobulin responses while chRFT5 was still present in vivo. There was a 33% incidence of rejection and the first rejection episode always occurred during chRFT5 therapy. Patients who did not reject during therapy did not reject during the first year following transplantation. Equal numbers of patients received dual and triple immunosuppressive therapy together with chRFT5. Posttransplant lymphoproliferative disorder developed in 2 patients, both on triple therapy, at 9 months after transplantation. The disorder did not develop in any patient receiving dual therapy, and no further cases have been observed to a minimum of 2 years' follow-up. No other viral, fungal, or bacterial infectious complications were prevalent in patients treated with chRFT5.

Adult

Renal transplantation in young boys with posterior urethral valves: preliminary report.

Seven boys (mean age 38 months) with posterior urethral valves underwent renal transplantation between June 1988 and August 1991. Urodynamic studies were performed before transplantation in 6/7 patients. In 4 the investigation indicated bladders of capacity and compliance which were deemed suitable for transplantation. Two patients had poorly compliant bladders; one of these underwent bladder augmentation before engraftment and the other proceeded to transplantation without bladder surgery. Six patients have functioning renal allografts with a mean follow-up of 1.3 years and a mean plasma creatinine of 51.6 mumol/l. Mean glomerular filtration rate (ml/min/1.73 m2 SA) 6 months after transplantation was 76.8 and at 1 year it was 84.5. In one patient early rejection was followed by transplant nephrectomy. Careful pre-operative evaluation is mandatory for a successful outcome of renal transplantation in young boys with posterior urethral valves.

Body Height

Cadaveric renal transplantation in children under 5 years of age.

From March 1987 to August 1990 23 cadaveric renal transplants were performed in 19 children under the age of 5 years at the time of transplantation. The mean age of the recipients was 3.3 years (range 1.3-4.7) and the mean weight 13.0 kg (range 9.3-19.2). The mean donor age was 7.8 years (range 1.5-25). All children received triple immunosuppression with prednisolone, cyclosporin A and azathioprine, and 4 who had 2 grafts during this period also received antithymocyte globulin at the time of the second transplant. Patient survival is 100%. Actuarial first cadaveric graft survival was 57% at 1 year and remains unchanged at 3 years. There were 10 graft losses, 4 were associated with renal venous thrombosis without apparent rejection. Two were lost due to acute vascular rejection with associated renal venous thrombosis, and the remaining 4 losses followed cellular or chronic vascular rejection. The mean glomerular filtration rate +/- SD was 51.4 +/- 23.6 ml/min per 1.73 m2 (n = 11) at 1 year and 43.5 +/- 25.3 at 2 years (n = 6). The mean height standard deviation score improved from -2.2 +/- 1.1 at the time of transplantation to -1.3 +/- 1.0 1 year post transplant (n = 11). The immunosuppression was well tolerated with a low incidence of side effects. Cadaveric renal transplantation remains a difficult but rewarding undertaking in children under 5 years of age.

Age Factors

Double-blind, placebo-controlled trial of human lymphoblastoid interferon prophylaxis of cytomegalovirus infection in renal transplant recipients.

We have conducted a double-blind, placebo-controlled trial of human lymphoblastoid interferon prophylaxis of cytomegalovirus (CMV) infection in 74 renal transplant recipients. Interferon (3 x 10(6) units was given thrice weekly for the first 6 weeks, then twice weekly for a further 8 weeks. During the period of interferon therapy, the incidence of CMV excretion was lower in the interferon group (28% versus 50%, P = 0.065), mainly due to a significant reduction of CMV reactivation (9% versus 56%, P = 0.02). However, for the whole study period (including the follow-up period after interferon therapy), there was no difference in the incidence of CMV excretion (44% versus 53%). The onset of CMV excretion was delayed (8.2 +/- 0.8 to 20.9 +/- 5.5 weeks, P = 0.04). The duration of CMV excretion was also reduced (11.1 +/- 3.1 to 29.4 +/- 5.7 weeks, P = 0.008). The number of positive CMV isolates from urine and saliva was significantly less in the interferon group. There was no difference in the site of CMV excretion. Of the patients in the treatment group who excreted CMV, 43% developed disease as compared to 63% in the control group (difference not significant). There was also no significant difference in the severity of the CMV infection between the two groups. Benefit appears to be restricted to seropositive recipients of seronegative kidneys. The interferon regime used in this study was well tolerated, with mild fever being the only reported side-effect. No patient had to stop therapy because of toxicity. The incidence of rejection and graft loss was not different between the two groups.

Adult

Conversion of stable renal allografts at one year from cyclosporin A to azathioprine: a randomized controlled study.

Seventy-seven stable, nondiabetic, cadaveric renal transplants were randomized at 1 year to convert from cyclosporin A to azathioprine or to continue on cyclosporin A. Prednisolone was increased twofold during the period of conversion, and there was a 3-week overlap period during which azathioprine and cyclosporin A were given. No grafts were lost due to rejection related to conversion, but 9 of the 33 patients who were randomized to convert experienced rejection episodes and 6 were returned to cyclosporin A. Conversion to azathioprine resulted in a drop in creatinine and improvement in blood pressure control. In the group randomized to stay on cyclosporin A, 6 patients had to be subsequently converted to azathioprine because of cyclosporin A toxicity in spite of well-controlled plasma levels. The creatinine levels after successful conversion remained stable whereas those of the patients continuing on cyclosporin A showed a progressive decline. We conclude that conversion from cyclosporin A to azathioprine can be achieved safely. Progressive deterioration in graft function with continuing cyclosporin A therapy does occur and should be taken as an indication for conversion.

Adult

Cyclosporin-induced renal magnesium leak in renal transplant patients.

Renal transplant patients (n = 116) attending an outpatients clinic were screened for hypomagnesaemia. No azathioprine-treated patients (n = 46) but 24% (17 of 70) of the cyclosporin treated patients were hypomagnesaemic. The hypomagnesaemia in all cases was associated with a renal magnesium leak. This leak did not correlate with plasma bicarbonate, urate, calcium, cyclosporin or creatinine concentrations, nor did it correlate with the use of loop diuretics or duration of the transplant. A renal magnesium leak is common in renal transplant patients treated with cyclosporin and it is independent of other markers of nephrotoxicity.

Adult

Low-dose vs high-dose intravenous methylprednisolone therapy for acute renal allograft rejection in patients receiving cyclosporin therapy.

Three mg/kg bodyweight per day of intravenous methylprednisolone for 3 consecutive days is as effective as 15 mg/kg bodyweight per day of methylprednisolone in reversing acute renal allograft rejection (80% vs 68%; 95% confidence intervals of the difference are -8% to 32%). This dose was not associated with an increased incidence of further rejection episodes. It may not be necessary to continue with the common practice of administering high-dose intravenous methylprednisolone for acute renal graft rejection.

Clinical Trials as Topic

Dietary fish oil supplements preserve renal function in renal transplant recipients with chronic vascular rejection.

The effect of dietary fish oil supplements on renal failure and lipid abnormalities was studied in 14 adult renal transplant recipients with chronic vascular rejection. The rate of decline of renal function (assessed by studying the slope of reciprocal plasma creatinine plots) slowed significantly during a 6-month period on fish oil supplements compared with the preceding 6-month control period (slope 1/cr during supplementation -3.6 X 10(-5) mumols/l per month compared with -13.5 X 10(-5) before, the difference in slope being -9.8 X 10(-5), 95% confidence interval (CI) -16.2 X 10(-5), -3.5 X 10(-5), P less than 0.05). Total plasma triglyceride concentrations decreased during supplementation (mean change -1.15 mmol/l, 95% CI -1.84, -0.47, P less than 0.003), but there was no change in total plasma cholesterol concentration or urinary protein excretion. Platelet function was studied in nine patients. Platelet aggregation induced by adrenaline and collagen was reduced by fish oils (median change in per cent aggregation), adrenaline 2 mumols/l, -36% (95% CI -68%, -8%, P less than 0.05), collagen 1 mg/1, -13% (95% CI -44%, -2%, P less than 0.05). Platelet thromboxane A2 release in response to these agents was also significantly reduced. These results demonstrate that fish oils preserve residual function in renal graft failure due to chronic vascular rejection.

Adult

Symptomatic cytomegalovirus infection in seropositive kidney recipients: reinfection with donor virus rather than reactivation of recipient virus.

74 patients receiving cadaver kidney grafts were investigated prospectively for cytomegalovirus (CMV) infection. Among seropositive recipients CMV infection, especially symptomatic and disseminated infection, occurred significantly more frequently when kidneys came from seropositive than from seronegative donors. Since seropositive recipients can become infected with donor virus, the excess is probably accounted for by reinfection. This conclusion was supported by restriction enzyme typing of virus isolates from recipient pairs receiving kidneys from the same donor; proven reinfection with donor strain virus was significantly commoner than proven reactivation of recipient virus. Furthermore, symptoms occurred only in the proven reinfection group. Although the proportion of reinfections that caused symptoms was less than that seen in primary infections, prior natural infection with CMV clearly does not prevent symptomatic reinfection in seropositive recipients, a point which has profound implications for future vaccination strategies in renal allograft recipients and choice of donors.

Cadaver

Controlled trial of azathioprine and cyclosporin to prevent anti-HLA antibodies due to third-party transfusion.

The beneficial effect of elective transfusion on renal allograft survival must be weighed against the risks of sensitisation. We report a randomised controlled trial in which patients in end-stage renal failure who were non-parous and not previously transplanted or transfused, were entered in a transfusion protocol during which one group received no drugs (controls), one received azathioprine, and one received cyclosporin. Each group was given three identical transfusions of leucocyte-enriched fresh blood at 2-3 week intervals. The transfused blood was of known HLA type and donor/recipient pairs were completely mismatched. Sensitisation rates were assessed by T and B cell cross-matches between donor and recipients and by the screening of all sera against lymphocytes from 40 random donors. Fifty-one patients have completed the protocol, 20 in the control group, 12 in the azathioprine group, and 19 in the cyclosporin group. The sensitisation rate in the control group was 30%, occasionally of high titre, and persistent. In the azathioprine group, 25% developed anti-HLA antibodies and reactivity was of high titre and was broadly specific. Sensitisation in the cyclosporin group was 10%, was narrowly specific, reacting with only 10% of a panel, and was transient. There was no difference in graft survival between the groups. We conclude that cyclosporin therapy concurrent with third-party transfusion reduces the incidence, titre, and duration of sensitisation.

Antibody Formation