Summary:Pneumonia due to Pneumocystis carinii is an infrequent complication following autologous stem cell transplantation (ASCT) which is associated with a high mortality. Although administration of trimethoprim/sulfamethoxazole (TMP/SMX) is an effective prophylactic strategy for Pneumocystis carinii pneumonia (PCP), treatment-associated toxicity frequently results in discontinuation of therapy. We have conducted a prospective randomized trial comparing atovaquone, a new anti-Pneumocystis agent, with TMP/SMX for PCP prophylaxis following autologous peripheral blood stem cell (PBSC) transplantation. Thirty-nine patients were studied. Twenty patients received atovaquone suspension and 19 patients received TMP/SMX. The median ages were 44 (range 20-68) and 47 (range 32-63) years, respectively. A similar number of patients with solid tumors (14 vs 15) and hematologic malignancies (five vs five) were treated in each group. Either TMP/SMX (160/800 mg) or atovaquone (1500 mg) was administered daily from transplant day −5 until day −1, discontinued from day 0 to engraftment, then resumed 3 days per week until day +100 post-transplant. The median time to engraftment (ANC Ͼ0.5 × 10 9 /l) was similar in both groups. Eighty percent of the patients randomized to atovaquone prophylaxis completed the study. Four atovaquone-treated patients were removed from study; two patients (10%) did not receive a transplant and two patients (10%) were removed due to a protocol violation. None of the 16 patients treated with atovaquone experienced treatment-associated adverse effects. Of the 19 patients randomized to receive TMP/SMX, 55% completed the study. Nine TMP/SMX-treated patients were removed from the study; one patient (5%) did not receive a transplant and eight patients (40%) were removed due to drug intolerance (P Ͻ 0.003). The rate of intolerance to TMP/SMX led to the early discontinuation of this randomized trial. Intolerance of TMP/SMX included elevated transaminase levels

These results suggest that there is no absolute barrier to pig hematopoietic cell engraftment in primates, and that this may be facilitated if the return of anti-Gal IgG can be prevented.

Summary:The original definition of hepatic veno-occlusive disease (VOD), which is still widely accepted, includes onset of the clinical syndrome before day +20 following highdose chemotherapy (HDC) and stem cell transplantation (SCT). We retrospectively identified four patients following HDC and SCT presenting with late onset VOD occurring at day +24, day +27, day +34 and day +42 post SCT. All patients had moderate VOD, with successful resolution of the VOD before day +100 with optimal supportive therapy. Common risk factors for VOD shared by all four patients included an older age (median age: 60 years), and use of a busulphan-containing regimen. Mean and maximum bilirubin levels for all patients during the VOD syndrome were 2.02, 1.76, 5.09, 2.87 mg/dl and 2.5, 2.2, 8.9 and 4.1 mg/dl, respectively, which correlated well with duration of VOD. All patients encountered platelet transfusion-dependent thrombocytopenia during VOD. Ursodeoxycholic acid was used as VOD prophylaxis beginning at a mean of 33 days prior to onset of VOD. As the cellular target of hepatic VOD is as yet unidentified, it is uncertain whether ursodiol or other common characteristics of patients with late onset VOD influence the pathogenesis and natural history of this disease. We believe that the uncommon clinical entity of late onset VOD, a potentially fatal regimen-related toxicity, should not be ignored as a diagnosis of liver disease after 3 or more weeks following HDC and SCT. Keywords: late onset VOD; high-dose chemotherapy; peripheral blood stem cell transplantation; ursodeoxycholic acid; VOD risk factors Hepatic veno-occlusive disease (VOD) is the leading cause of regimen-related morbidity and mortality in the first 2 months following high-dose chemotherapy (HDC) and bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT) 1 with an incidence ranging from 0% to 70%. 2 VOD was originally defined as a clinical syndrome occurring by day +20 following SCT with at least two of the following features: jaundice, tender hepatomegaly and ascites or unexplained weight gain. 3 In the absence of histological confirmation, the combination of all three clinical features has been reported to have a specificity of 92% and sensitivity of 56%. 2,4 It is now clear that VOD can develop in patients beyond day +20, thus necessitating that a time limit be omitted from the diagnostic criteria for VOD. 1,2,5 The entity of late onset VOD is not well described. Beyond the third and fourth weeks post SCT, the main differential diagnoses of liver injury include infective causes, acute GVHD, drug-related insults and recurrent disease. 6 Given that severe VOD is associated with a mortality approaching 100% by day +100 with no truly effective therapeutic options, 1,3,5,7 early detection and institution of appropriate supportive measures are vital. VOD must not be ignored as a diagnostic consideration beyond 3 to 4 weeks post SCT in patients with clinical or biochemical liver dysfunction and/or weight gain. Here, we review the clinical ...