Evaluation of chimerism with DNA polymorphisms in bone marrow transplantation.

Evaluation of chimeric status following allogenic BMT is an important tool for monitoring the replacement of host cells with donor cells and for determining the risk of relapse. Polymorphic DNA sequences can be used as powerful markers in identification of donor/recipient genotype differences, even between close relatives. Polymerase chain reaction (PCR) amplification of three variable number of tandem repeat (VNTR) loci and five single-locus polymorphisms (SLP) was used to identify chimerism in 40 recipient-donor pairs. Mixed chimerism was present in 11 patients, and complete chimerism in 29. This PCR method is a rapid and sensitive assay to detect engraftment and evaluate relapse potential, and thus is very useful in the clinical management of BMT patients.

Essential athrombia: study of a new case.

A constitutional platelet function disorder in a twelve year-old girl characterized by a lifelong bleeding tendency, prolonged bleeding time, normal platelet count, normal clot retraction, normal platelet factor 3 activity and impaired platelet aggregation was reported. Platelet aggregation, studied turbidimetrically, was absent in the presence of usual doses of ADP (1-4 MUM) although a small wave of primary aggregation was obtained by very large ADP concentrations (25-50 muM). The platelets were also unresponsive to epinephrine, thrombin and diluted collagen suspensions. But an almost normal aggregation response occurred with strong collagen suspensions. The platelets responded to Ristocetin. Release of platelet ADP was found to be normal by collagen and thrombin, but impaired by kaolin. Platelet fibrinogen content was normal. The present case, investigated with recent methods, confirms the existence of a type of primary functional platelet disorder characterized solely by an aggregation defect, described in 1955 and 1962 under the name of "essential athrombia."

The frequency of tuberculosis in adult allogeneic stem cell transplant recipients in Turkey.

In general, tuberculosis (Tb) is rarely seen in allogeneic stem cell transplant (alloSCT) recipients, but this observation has been challenged in developing countries such as Turkey, where Tb infection is more prevalent than in Europe and the US. In this retrospective study, we report on the incidence of Tb infections in 351 alloSCT recipients at 4 bone marrow transplantation units in Turkey over the last 10 years. The frequency of Tb in alloSCT recipients after allografting (5 of 351) was far greater than that in the general population (35.4 per 100,000). Of the 351 patients who underwent alloSCT, 77 who received isoniazid (INH) chemoprophylaxis for 6 months did not develop posttransplantation Tb. However, 5 of the remaining 274 patients who received no chemoprophylaxis developed Tb a median of 12 months (range, 10-47 months) after allografting. Antituberculosis therapy resulted in complete recovery in all cases. In 2 additional patients who were found to have active pulmonary Tb at the time of transplantation, alloSCT was delayed until the infections were treated. Infections of mycobacteria other than Mycobacterium tuberculosis were not observed. The number of patients who received and tolerated INH may not be sufficient for firm conclusions, but the data suggest that, in countries where Tb is prevalent, pre- and posttransplantation follow-up for Tb and the use of INH prophylaxis should be considered.