PET-CT as an effective imaging modality in the staging and follow-up of post-transplant lymphoproliferative disorder following solid organ transplantation.

INTRODUCTION: To establish the role of positron-emission tomography (PET)-computed tomography (CT) in post-transplant lymphoproliferative disorder (PTLD) patients, compared to conventional imaging (ultrasonography/CT/magnetic resonance imaging) in relation to its accuracy, sensitivity and specificity. METHODS: 30 patients (26 males and 4 females), with a median age of 49.5 (range 18-74) years, were retrospectively evaluated. In 29 cases, the diagnosis was confirmed by histopathology. Malignant lymphoma was detected in 20 cases, polymorphic lymphoproliferative disorder in six cases, multiple myeloma in two cases and Hodgkin's disease in one case. A total of 49 PET-CTs (13 studies for staging at diagnosis and 36 studies at follow-up as assessment post-therapy) were compared to conventional imaging. Imaging results in accordance with disease status were assessed at a median follow-up of 17.8 (range 1.5-42.2) months post-PET-CT. RESULTS: In 41 of 49 examinations performed for staging and on follow-up, PET-CT and conventional imaging findings were concordant. Compared to conventional imaging, PET-CT showed comparable sensitivity (75 percent vs. 83 percent), similar specificity (100 percent in both modalities) and comparable accuracy (77 percent vs. 85 percent) during staging at diagnosis. PET-CT was found to be superior to conventional imaging modalities at follow-up, with greater sensitivity (100 percent vs. 81 percent), specificity (80 percent vs. 100 percent) and accuracy (97 percent vs. 83 percent). CONCLUSION: PET-CT is an accurate diagnostic tool for staging and for the follow-up of PTLD patients. It represents a good alternative imaging method to avoid contrast-related nephrotoxicity in patients who often develop impaired renal function secondary to chronic immunosuppressive therapy. However, further studies are recommended before considering PET-CT as a routine diagnostic tool in PTLD.

Significance of Epstein-Barr virus (EBV) load and interleukin-10 in post-transplant lymphoproliferative disorders.

The complex relationship between EBV, IL-10 and lymphomagenesis has been widely investigated and several studies have highlighted the diagnostic value of EBV DNA copies and serum IL-10, that may be considered as tumor markers. Notwithstanding the great number of data published in the last few years on the behavior of EBV DNA copies in the peripheral blood of transplanted patients, a threshold value significant for impending or overt post-transplant lymphoproliferative disorder (PTLD) has not yet been defined. Too many factors, both technical and clinicopathological, may affect the results of clinical studies, making their comparison difficult. On the contrary, although the role of IL-10 in PTLDs has been well documented, a sufficient number of studies exploring sensitivity and specificity of serum IL-10 measurement is lacking. The aim of this review is to summarise data on EBV load quantification and serum IL-10 detection in transplanted patients, providing clinicians with wide and useful information in order to improve bedside management of transplanted patients with regard to PTLDs occurrence and treatment.

Incidence of sepsis in central venous catheter-bearing patients with hematologic malignancies: preliminary results.

BACKGROUND: Indwelling central venous catheters (CVCs) are essential devices in the management of patients with hematological disorders treated with chemotherapy. However, their nature predisposes patients to unwanted complications. METHODS: CVC-related complications were retrospectively analyzed in 227 hematologic patients who were consecutively admitted to our hematology department between May 2002 and April 2004. Patients' diagnoses comprised acute myeloid leukemia (36.8%), acute lymphoid leukemia (7.3%), lymphoproliferative disorders (28.3%), multiple myeloma (19.5%), myeloproliferative syndromes (5%) and others (3.1%). The CVCs used were polyurethane three lumen 7-Fr (111 patients) for chemotherapy and 12-Fr (114 patients) for chemotherapy and peripheral blood stem cell apheresis, plus two tunneled catheters. RESULTS: The pathological events were: bacteriaemias (n=46); occlusions (n=10); exit tunnel infections (n=8); thrombosis (n=6); lung emboli (n=2). Among febrile patients the bacteriemia frequency was 20%, of which 13.6% were CVC-related (with a higher incidence in leukemia patients (p=0.027). Among the isolates, gram-positive bacteria were found in 29 cases (23 CVC-related cases), and gram-negative bacteria in 16 cases (8 CVC-related cases). Only one patient had Candida albicans sepsis. At univariate and multivariate analysis significant risk factors for infection (p<0.0001) were only the number of days/catheters and neutropenia duration. CONCLUSIONS: In our hematologic patients, the CVC complications were mainly septic, with only 10.1% of CVC-related bacteriemias, despite prolonged catheterization duration. Acute leukemia patients were at major risk for sepsis, probably due to a more severe neutropenia and prolonged catheterization duration.