A scheme for defining cause of death and its application in the T cell depletion trial.

The primary cause of death (COD) provides important information in many studies of hematopoietic stem cell transplantation (HSCT). A panel of experts critically assessed the CODs submitted by 15 transplantation centers for 281 patients who died in a randomized multicenter trial of unrelated HSCT. The panel reviewed the CODs reported by the transplantation centers, which used the Center for International Blood and Marrow Transplant Research and National Marrow Donor Program COD reporting form. The panel determined that the existing criteria for primary and contributing CODs lacked sufficient stringency for uniform interpretation. A hierarchy was developed and applied to the T cell depletion project. Using its scheme, the panel reclassified 157 CODs (56%) reported by the transplantation centers. The changes resulted in increased recognition of graft-versus-host disease as the primary COD and a concomitant decrease in attribution of the primary COD to infection. This algorithm promotes consistent assignment of primary and contributing CODs for patients with leukemia or lymphoma who expire after myeloablative allogeneic HSCT.     

Reservoir of Candida albicans infection in a vascular bypass graft demonstrates a stable karyotype over six months.

We retrospectively analyzed five Candida albicans isolates from two infection episodes in a single patient 6 months apart. Using contour-clamped homogeneous field electrophoresis (CHEF), random amplified polymorphic DNA (RAPD) fingerprinting, and restriction fragment length polymorphism (RFLP) complex probe 27A as means of molecular typing, we demonstrate an unvarying genotype amongst the infection-causing C. albicans strains. Several months later, the patient yielded C. glabrata in a yeast survey of oral and rectal sites. The preponderance of C. glabrata and lack of C. albicans isolated from normal flora sites suggests that this patient harbored the prior C. albicans bloodstream isolate on a Gore-Tex graft for 6 months prior to the second episode of fungemia.     

CD10 and BCL6 expression in the diagnosis of angioimmunoblastic T-cell lymphoma: utility of detecting CD10+ T cells by flow cytometry

Angioimmunoblastic T-cell lymphoma (AITCL) is a histologically distinct and relatively common subtype of T-cell lymphoma. Although the putative normal cell counterpart is a mature CD4+ T cell, the precise cell of origin remains elusive. We evaluated cases with a diagnosis of AITCL to determine the specificity and utility of CD10 coexpression, particularly by flow cytometry (FCM), in facilitating this diagnosis. Coexpression of BCL6 was also assessed. Eight AITCL cases were evaluated histologically, immunohistochemically, and by 4-color FCM. Four cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), were also analyzed. The lymphoma cells in all 8 AITCL cases were CD4+, CD45RO+ T cells, with classic extrafollicular meshworks of CD21/CD23/CD35+ follicular dendritic cells. Furthermore, all cases of AITCL cases contained interfollicular CD10+ cells by immunohistochemistry, and increased coexpression of CD10 on T cells was also detected in 6 of 8 cases by FCM. CD10 coexpression was not observed in all 4 PTCL-NOS cases. Although not specific for AITCL, increased numbers of BCL6+ cells were seen in AITCL as compared with PTCL-NOS. Double immunohistochemistry performed on an AITCL case with high numbers of BCL6+ cells highlighted coexpression of BCL6 and CD4 on the same cells. The finding suggests that AITCL may be a neoplasm of (possibly intrafollicular) CD10+, BCL6+, and CD4+ memory T cells. Although our series is small, our results suggest that CD10 coexpression may be a useful discriminant, particularly if the differential diagnosis is PTCL-NOS, and demonstrate that this can be determined by FCM.     

Challenges in the control of gonorrhea in South America and the Caribbean: monitoring the development of resistance to antibiotics

OBJECTIVE:: The objective of this study was to ascertain the antimicrobial susceptibility of Neisseria gonorrhoeae isolates from 6 South American and 13 Caribbean countries participating in the Gonococcal Antimicrobial Surveillance Program (GASP) from 1990 to 1999. STUDY:: A GASP network of laboratories was launched in the Americas and the Caribbean during the 1990s. Standardized methods and interpretative criteria were established for the isolation of N. gonorrhoeae, strain identification, and determination, and quality control of antimicrobial susceptibility. RESULTS:: Two countries (Argentina and Uruguay) maintained continuous surveillance during the study period. Some countries gathered data periodically and several others were unable to initiate antimicrobial surveillance as a result of lack of resources. The percentage of penicillin-resistant N. gonorrhoeae isolated in the region over the decade varied considerably (1.0-11.9% carried chromosomal resistance and 17.9-38.8% produced beta-lactamase) with an overall trend to declining numbers of penicillin-resistant isolates. For tetracycline, 7.4% to 36.3% carried chromosomal resistance, whereas 12.0% to 27.4% carried plasmid-mediated resistance. There were no reports of ciprofloxacin-resistant isolates, although N. gonorrhoeae with decreased susceptibility to ciprofloxacin and azithromycin as well as spectinomycin-resistant isolates were identified in some countries.