Chimerism studies in HLA-identical nonmyeloablative hematopoietic stem cell transplantation point to the donor CD8(+) T-cell count on day + 14 as a predictor of acute graft-versus-host disease.

Chimerism analysis of hematopoietic cells has emerged as an essential tool in nonmyeloablative hematopoietic stem cell transplantation. We have investigated the development of donor chimerism in granulocytes and CD4(+) and CD8(+) T cells in blood and bone marrow of 24 patients with hematologic malignancies who received HLA-identical sibling peripheral blood stem cell grafts after conditioning with fludarabine and 2 Gy of total body irradiation. The T-cell chimerism of blood and bone marrow was tightly correlated. Complete donor chimerism was reached earlier in the granulocytes than in the T cells. Mixed T-cell chimerism was common at the time of onset of acute graft-versus-host disease (aGVHD), and both CD4(+) and CD8(+) donor T-cell chimerism increased with the occurrence of aGVHD grades II to IV (P =.0002 and P =.019, respectively). The rate of disappearance of recipient CD8(+) T cells was faster in patients with aGVHD grades II to IV than in patients without clinically significant aGVHD (P =.016). This observation indicates a role of graft-versus-lymphohematopoietic tissue reactions in creating complete donor T-cell chimerism. A donor CD8(+) T-cell count above the median on day +14 increased the risk of subsequent development of aGVHD grades II to IV (P =.003).     

Detection of large deletions in the LDL receptor gene with quantitative PCR methods

Background  

Familial Hypercholesterolemia (FH) is a common genetic disease and at the molecular level most often due to mutations in the LDL receptor gene. In genetically heterogeneous populations, major structural rearrangements account for about 5% of patients with LDL receptor gene mutations.     

Hemostatic coronary risk factors in a healthy population of Maracaibo,Venezuela

The purpose of the present work was to determine the plasma concentrations of fibrinogen and Von Willebrand Factor (VWF) as well as platelet aggregation, in an apparently healthy population of 306 men and 41 women, 33 to 65 years of age, workers of the national oil industry (PDVSA, Maracaibo), as a base investigation in a 5-year prospective national collaborative study. The participants were previously subjected to a thorough clinical examination with cardiovascular evaluation and laboratory tests. Clottable fibrinogen and VWF concentrations were determined in platelet poor plasma, the last one by immunoclectrophoresis, and a multimeric analysis of VWF was performed on those plasmas with concentrations higher than 150 U/dL by SDS agarose electrophoresis, followed by cellulose membrane transference. Platelet aggregation was studied in platelet rich plasma with no addition of stimulants and after collagen and ristocetin were added. Forty per cent of men and 65.8% of women, showed fibrinogen concentrations above 300 mg/dL (p < 0.01) and 12.2% of men and 15.4% of women had VWF values higher than 150 U/dL, with normal multimeric distribution. Fourteen individuals presented spontancous platelet aggregation and increased aggregation in 12 and 13 of them, after induction with collagen and ristocetin respectively. Comparing these findings with those of previous collaborative studies from other countries, the present results could mean that an important proportion of the population here studied, could be at risk for a future coronary event; however, as these are the base findings in Maracaibo, the significance of our results will be better evaluated at the end of the five year study.     

A controlled trial of treatment of acquired immunodeficiency in severe measles with thymic humoral factor.

A randomized controlled trial of treatment with thymic humoral factor (THF) in 20 children with severe complicated acute measles infection, resulted in objective benefit as evidenced by improvement in the ESR and a fall in C-reactive protein, fewer complications and a reduced incidence of secondary herpes infection. An increased ratio of helper to suppressor T cells (OKT4/OKT8 ratio) and a greater lymphocyte transformation response to phytohaemagglutin was seen in those children receiving THF. We conclude that THF treatment helps to prevent the development of complications particularly secondary viral infections possibly by enhancing cell-mediated immune responses.     

A hybrid form of myeloid/NK-cell acute leukemia and myeloid/NK-cell precursor acute leukemia

Natural killer (NK)-cell leukemia/lymphoma is a rare entity that has been defined only in recent years. In the Revised European-American Lymphoma and World Health Organization classifications, only the mature NK-cell malignancies are included. However, at least 3 types of precursor NK-cell neoplasms have been reported in the literature. These include myeloid/NK-cell acute leukemia, myeloid/NK-cell precursor acute leukemia, and blastic NK-cell lymphoma/leukemia. These leukemias are characterized by the presence of blasts, which express CD56, in the peripheral blood, bone marrow, lymph nodes, and/or extranodal tissues. We report a case that is morphologically consistent with myeloid/NK-cell acute leukemia but immunologically is myeloid/NK-cell precursor acute leukemia. This case is unique in its cutaneous presentation without involvement of the peripheral blood. Extensive flow cytometric studies were performed on the skin biopsy and bone marrow aspirate specimens, which included many markers that had not been tested before in these entities. The clinical implications of these findings are discussed.     

Evaluation of a rapid western immunoblotting procedure for the diagnosis of bovine spongiform encephalopathy (BSE) in the UK.

Bovine brain tissue samples from 625 UK cattle, clinically suspected as bovine spongiform encephalopathy (BSE) cases, were used in a blind analysis to assess a rapid Western immunoblotting technique (Prionics Check; Prionics AG, Zurich), which detects bovine disease-specific protease-resistant prion protein (PrP(Sc)). By means of statutory histopathological examination, 599 of the 625 cattle were confirmed as BSE cases by the demonstration of spongiform encephalopathy, the remaining 26 being classified as negative. Duplicate samples from the same animals were also examined by electron microscopy for the presence of abnormal brain fibrils (scrapie-associated fibrils; SAFs). The Prionics technique showed a high sensitivity, particularly when compared with the fibril detection test; the detection rates were 99.3% and 92.0% respectively, with histopathology being used as the "gold standard". The false negative results by the Prionics test were possibly related to the sampling procedure. Analysis of 50 BSE-positive samples revealed similar glycoprofiles, the majority of PrP(Sc)isoforms being di-glycosylated protein. The Prionics test also detected PrP(Sc)in the four brain samples from the 26 histopathologically negative animals, apparently reducing the specificity of the test to 84.6%; however, confirmatory positive results in these samples were obtained by demonstrating SAF or by immunohistochemical examination, or both. It was concluded that the Prionics test detected PrP(Sc)in a small percentage (0.64%) of clinically suspected BSE cases showing no spongiform change. Since January 2000, the Prionics Western blot test has been introduced as one of the statutory tests for the diagnosis of clinically suspected BSE and scrapie cases in the UK. Copyright Harcourt Publishers Ltd.     

HLA associations in insulin-dependent diabetes: search for heterogeneity in different groups of patients from a homogeneous population

A total of 317 unrelated Danish patients with insulin-dependent diabetes mellitus (IDDM) have been HLA-DR typed and the antigen and phenotype frequencies compared with those in 1177 unrelated Danish controls. The strong positive associations with DR3 and 4 and the strong negative one with DR2 were confirmed, and the remaining antigens showed a hierarchy from weakly positive to strongly negative associations: DRw9, w8, 1, 5, w6, 7. The study population included various special groups of patients selected in order to study heterogeneity: very early (less than 5 years) and very late (greater than 40 years) onset IDDM, pregnancy-induced IDDM, IDDM nephropathy, and long-term (greater than 40 years) survivors without complications. When comparing these groups, the following minor differences were seen: the DR3,4 phenotype is significantly (p = .02) more frequent in IDDM with onset before age 20 (35%) than in other cases (24%), and in familial IDDM (48%) than in other cases (28%); the frequency of the DR4 antigen was significantly (p = .008) more frequent in long-term survivors (86%) than in other patients (69%), while it was significantly (p = .02) less frequent in IDDM nephropathy (63%) than in long-term survivors. However, apart from the age-at-onset heterogeneity, which was suspected a priori, these differences may be due to chance, and the main conclusion of this study is that the HLA-DR associations in IDDM are indeed extraordinarily homogeneous irrespective of the clinical characteristics at onset and course of the disease.     

HLA-DP and bonemarrow transplantation: DP-incompatibility and severe acute graft versus host disease

Thirteen recipients of HLA-haploidentical, DR compatible bone marrow (BM) and the corresponding BM donors were HLA-DP typed using primed lymphocyte typing (PLT). Severe acute GVHD (greater than or equal to grade 2) developed within 3 months after BM-transplantation in all of eight recipients of DP incompatible BM, but in none of five recipients of DP-compatible BM. This difference was highly significant (p less than 0.001, Fisher's exact test). Moreover, severe acute GVHD was significantly increased in recipients of haploidentical, DR compatible, but DP incompatible BM as compared to severe acute GVHD in 88 recipients of HLA-identical BM (p less than 0.0001). In contrast, there was no difference in acute GVHD between recipients of haploidentical, DR and DP compatible BM and recipients of HLA-identical BM. The data presented here provide strong evidence for the first time that HLA-DP antigens play a role as transplantation antigens.     

Emergency screening for ethylene glycol in serum

We have exploited the "interference" of ethylene glycol in the Du Pont aca triglyceride method to develop a convenient and rapid screening method for detecting ethylene glycol in serum. Pretreatment of patient's serum with lipase, glycerol kinase, and other cofactors usually added for triglyceride analysis removes triglycerides and glycerol, but not ethylene glycol, from the sample. The aca triglyceride method may then be used to estimate the ethylene glycol concentration in serum.