Comparative characteristics of mu chain and alpha chain transcripts expressed by individual tonsil plasma cells.

Plasma cells (PCs) are one of the two major cell types generated during germinal center reactions. To test the hypothesis that PCs express a unique repertoire of immunoglobulin (Ig) genes resulting from intensive antigenic stimulation and selection, the mutational pattern and distribution of V(H) gene segments within 178 transcripts amplified from individual IgM and IgA secreting tonsil PCs were analyzed. The results demonstrated that both mu and alpha transcripts expressed repertoires with limited diversity. Moreover, both mu and alpha transcripts were heavily mutated, with a significantly increased mutational frequency noted for alpha compared to mu transcripts (5.0 x 10(-2) vs 1.8 x 10(-2), P<0.001). In addition, both mu and alpha transcripts showed significantly greater targeting of mutations to RGYW motifs (purine/guanine/pyrimidine/A or T) compared to memory B cells. Finally, clonally expanded cells were detected in alpha but not mu PC compartments. These results indicate that antigen driven stimulation and selection shape the entire expressed PC repertoire, but the impact is greater in alpha expressing PCs.

Clonality of acquired primary pure red cell aplasia: effectiveness of antithymocyte globulin.

Primary pure red cell aplasia (PRCA) was diagnosed in two male patients, 65 and 69 years old respectively. In both, surface markers of peripheral blood nuclear cells revealed the presence of TCR alphabeta+ phenotype. Clonality of T cells was confirmed by the polymerase chain reaction in both patients, in whom, prednisone at a dose of 1 mg/kg/day improved the anemia and lower doses caused its renewal, resulting in the reappearance of the patient's transfusion requirement. On the other hand, the anemia seems to have been treated permanently (second case) with horse antithymocyte globulin (ATG) (20 mg/kg/day 1 to 8 +) since his hemoglobin was about 15 g/dl at the time of writing. In the first patient, the hemoglobin level was 10.5 g/dl one month after the administration of ATG (15 mg/kg/d 1 to 5 +), but unfortunately, the patient died because of a massive gastrointestinal bleeding on the fortieth day following this treatment. We, therefore, suggest that, patients with acquired primary PRCA should be screened to detect the presence of a T-cell clone and recommend that, treatment should start earlier with ATG, if the PRCA is due to a T-cell clonal disorder.

[Arteriovenous fistula of the lung: a rare cause of erythrocytosis]. / Arteriovenöse Fistel der Lunge: Eine seltene Ursache einer Polyglobulie.

Various chronic pulmonary diseases can cause hypoxia mediated erythrocytosis. We report on a 46 year old male patient presenting with erythrocytosis, in whom a pulmonary arteriovenous fistula on the basis of a vascular malformation was identified as a rare cause of hypoxic erythrocytosis. Thus, congenital pulmonary vascular malformations can become clinically manifest in advanced age.

Myeloid antigen expression provides favorable outcome in patients with adult acute lymphoblastic leukemia: a single-center study.

Between July 1992 and July 2001, 81 patients with de novo adult acute lymphoblastic leukemia (ALL) treated according to the German Multicenter Study Group for Adult ALL (GMALL) 01/81 protocol were evaluated in order to analyze the effect of aberrant myeloid antigen expression on prognosis. We observed myeloid antigen aberrant expression in 21 of the adult ALL cases. We did not observe any effect of aberrant myeloid antigen expression on the time to achieve remission, relapse rate, and death rate. After 5 years of follow-up, cumulative disease-free survival of myeloid antigen (My) (+) and My (-) adult ALL patients was 67% and 43%, respectively. These data were not found to be statistically significant (P=0.29), but we did find a statistically significant difference in overall survivals between these two groups (85% vs 50%) (P=0.05). Twenty-nine patients died and the remaining 52 patients were followed for a median of 31 months. We could not find any special effect of the known prognostic factors on prediction of relapse in multivariate analysis. However, myeloid antigen expression was the most significant factor, which affected long-term survival in our patients (P=0.01). These data indicate that myeloid antigen expression is useful for predicting a favorable outcome of adult patients with ALL.