Immune recovery after low-dose Campath therapy in a group of pretreated patients affected by B-cell chronic lymphocytic leukemia

Cryptococcosis in liver and kidney transplant recipients receiving anti-thymocyte globulin or alemtuzumab

Rabbit anti-thymocyte globulin (ATG) and alemtuzumab have been used for induction or preconditioning and for the treatment of acute rejection in organ transplant recipients in many centers. Such regimens may lead to a substantial decline in the CD4 lymphocyte count to levels seen in other population groups at high risk of cryptococcosis. In view of this, we examined the impact of such therapy on the cumulative incidence of cryptococcosis among liver and kidney recipients. A total of 834 liver and 727 kidney transplants were performed during the study period. Seven hundred and eighty-one patients did not receive ATG or alemtuzumab; 646 received 1 dose of either drug, and 134 patients received 2 doses of either drug. The cumulative incidence of cryptococcosis was 0.26% (2/781) among those who did not receive ATG or alemtuzumab; 0.3% (2/646) among those who received only 1 dose, and 2.24% (3/134) among those who received 2 doses (P=0.03). There were 5 cases of cryptococcosis in liver recipients and 2 in kidney recipients. There were 3 cases of cryptococcal meningitis, 3 of pneumonia, and 1 of disseminated disease. The 2 kidney recipients had meningitis. Diagnosis occurred at a median of 255 days (range 7-517) after transplantation. The mortality rate was 14.2%. We conclude that the use of 1 dose of ATG or alemtuzumab is not associated with an increased cumulative incidence of cryptococcosis, but that those patients receiving 2 doses are at increased risk.

Bloodstream infections in organ transplant recipients receiving alemtuzumab: no evidence of occurrence of organisms typically associated with profound T cell depletion

BACKGROUND

Alemtuzumab is a humanized monoclonal antibody directed against CD52, a cell surface antigen expressed on B and T lymphocytes, monocytes and NK cells. Its use results in a profound decrease in CD4 positive T lymphocytes. Alemtuzumab is used as induction immunosuppression and therapy for rejection in organ transplant recipients in some centers. We followed a cohort of 449 consecutive transplant recipients who received alemtuzumab to determine the occurrence of bloodstream infections, particularly those previously associated with decrease in CD4 positive T lymphocytes.

PATIENTS AND METHODS

Fifteen percent (69/449) patients had at least one episode of bloodstream infection. However, no patient had bacteremia with Streptococcus pneumoniae, Listeria monocytogenes, non-typhoidal Salmonella or Mycobacterium avium complex. Fungaemia was rare, occurring in 1.5% of patients. The most common organisms isolated from the blood were Staphylococcus aureus (21 episodes), coagulase negative Staphylococcus (14 episodes), Klebsiella pneumoniae (12 episodes), Enterococcus faecium (11 episodes), Pseudomonas aeruginosa (10 episodes), Enterococcus faecalis (9 episodes) and Escherichia coli (7 episodes).

DISCUSSION

We conclude that although alemtuzumab use is associated with profound CD4 positive T lymphocyte depletion, alemtuzumab does not seem to be associated with an increased risk of bloodstream infection with pathogens typically seen in other disorders of CD4 cell depletion, such as acquired immunodeficiency syndrome.