Prevalence and manifestations of tuberculosis in renal transplant recipients: a single-center experience in Thailand.

This retrospective review presented the prevalence and manifestations of tuberculosis among renal transplant recipients in our center between 1987 and mid 2007. The prevalence of tuberculosis was 5/151 (3.3%) recipients with a median age of 49 years (range = 38-55). The median time of diagnosis after transplantation was 23 months (range = 1-47). All five patients had pulmonary tuberculosis. None developed extrapulmonary infection. Presenting symptoms were fever (60%), productive cough (80%), weight loss (40%), and hemoptysis (20%). One patient had non-parathyroid-related hypercalcemia. Cyclosporine dosage needed to be increased in all patients. Two subjects who experienced side effects of hepatitis and/or jaundice from rifampicin were switched to second-line drugs. Infection with Mycobacterial tuberculosis is a not uncommon problem in renal transplant recipients especially in endemic areas. Tuberculosis must be excluded for immunosuppressed patients with clinical or radiological suspicion.

Pseudallescheria boydii brain abscess in a renal transplant recipient: first case report in Southeast Asia.

Pseudallescheria boydii and its asexual form, Scedosporium apiospermum, are ubiquitous filamentous fungi that rarely cause central nervous system (CNS) infection. Brain abscess caused by P. boydii is a highly lethal infection, usually seen in organ transplant recipients who receive a number of immunosuppressive agents. We have presented a case of a 48-year-old man 6 years after renal transplantation who received methylprednisolone followed by antithymocyte globulin for treatment of acute cellular rejection. Eight weeks later, he developed fever, headache, and left-sided hemiparesis. Further investigation with magnetic resonance imaging of the brain showed multiple ring-enhancing hypodense lesions with marked edema which were compatible with brain abscesses. Following surgical drainage, multiple fungal elements were initially described as Aspergillus species. The patient failed to improve and died from rapidly progressive infection despite treatment with amphotericin B. Later a diagnosis was finally made by the isolation of P. boydii in pus culture. The specific diagnosis is difficult to rapidly make, because P. boydii mimics other fungi morphologically in tissue sections and may produce infections clinically similar to other mycoses. Culture of the organism is required for definitive diagnosis. P. boydii infections are important complications of transplantation. They are difficult to treat due to resistance to amphotericin B. Physicians should consider P. boydii a possible cause of brain abscess in organ transplant recipients, especially with heavy immunosuppressive agents. This is the first case report of CNS infection due to P. boydii in a renal transplant patient in Southeast Asia.

Comparative pharmacokinetics and effect kinetics of orally administered artesunate in healthy volunteers and patients with uncomplicated falciparum malaria.

The single-dose pharmacokinetics of 100 mg of orally administered artesunate (AS) were studied in 6 patient volunteers with uncomplicated falciparum malaria and in 6 healthy volunteers. Plasma concentrations of both the parent drug, AS, and its major metabolite, dihydroartemisinin (DHA), were measured simultaneously by high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). The antimalarial activity of each plasma sample measured by an in vitro bioassay (BA) was used to derive activity concentrations. Artesunate was absorbed rapidly and then almost completely hydrolyzed to DHA in patients, whereas hydrolysis was incomplete in healthy volunteers. The mean +/- standard deviation (SD) maximum concentration (Cmax) of AS was 296+/-110 nmol/L, the time to peak blood level (tmax was 0.71+/-0.66 hr, the half-life (t1/2,z) was 0.41+/-0.34 hr, and the bioavailability over 12 hr (area under the curve [AUC](0-12)) was 253+/-185 nmol hr/L. Measured by HPLC, the Cmax and AUC(0-12) values of DHA in patients with malaria were significantly greater than in volunteers (1,948+/-772 and 1,192+/-315 nmol/L; 4,024+/-1,585 and 1,763+/-607 nmol hr/L, respectively; P < or = 0.05). These differences were even greater when measured by BA. The Cmax for patients with malaria was 2,894+/-2,497 and 795+/-455 nmol/L for volunteers, and AUC(0-12) was 5,970+/-3,625 and 1,307+/-391 nmol hr/L, respectively (P < or = 0.05). In contrast, DHA parameter estimates for t1/2,z and tmax were similar between patients and healthy volunteers, with values of 0.80+/-0.30 versus 0.87+/-0.06 hr and 1.50+/-0.55 versus 1.13+/-0.52 hr, respectively (P > 0.5). Both drug metabolism and tissue protein binding could contribute to the differences between the antimalarial activity of artemisinin drugs in healthy volunteers and malaria infected patients.