Pathological and immunological observations in a case of Lesch-Nyhan-syndrome

A patient with clearly developed features of the full Lesch-Nyhan syndrome and complete lack of activity of hypoxynthine-phosphoribosyl-transferase is described. The clinical picture was characterized by absence of spasticity, good control of autoaggression by behavior therapy, and no signs of renal insufficiency. After death, which was caused by a viral infection, pathological examination and a search for material immunologically crossreacting with hypoxanthine-phosphoribosyltransferase were possible. In spite of increased serum urate levels and raised urinary uric acid excretion there were no signs of urate deposits or damage in the internal organs, including the kidneys. Crossreactive material was found in the liver, kidneys and spleen, a relatively rare finding in the full Lesch-Nyhan-syndrome. The absence of any specific pathological changes in the brain of this patient is in agreement with earlier reports.     

Anti-TNF antibody treatment has no positive effect on survival in a model of pneumococcal sepsis in pigs.

Gram-positive organisms causing sepsis have gained more significance in the past years. Especially patients with acquired immunodeficiency have been shown to be at risk for gram-positive infections. The mortality in Streptococcus pneumoniae bacteremia has been shown to be as high as 20%. Tumor necrosis factor-alpha (TNF-alpha) plays a crucial role in the "sepsis cascade." The previously described positive effect of monoclonal TNF antibody (anti-TNF-mAb) in gram-negative sepsis should be controlled in gram-positive pneumococcal sepsis. In a porcine model, pneumococcal sepsis was induced, and the course and outcome of a group treated with anti-TNF-mAb were compared to those of an untreated control. Streptococcus pneumoniae serotype 6 B was isolated from patients with systemic infection. The isolates were prepared, cryopreserved at -80 degrees C, and recultivated in a standardized fashion as needed. Then 10(9) bacteria were injected intravenously. Pigs of the German Landrace type with a weight of 20-30 kg were anesthetized using standardized midazolam and ketamine intravenous anesthesia. After introduction of central venous, arterial, and urinary catheters, bacteria were injected intravenously via the ear vein. In the therapy group, animals were treated with anti-TNF-mAb (5 mg/kg body weight) intravenously immediately prior to pneumococci injection. Survival and survival times were primary endpoints. Biochemical and vital parameters were also compared. In the anti-TNF-mAb group, 4/11 animals died (35%), compared to 6/11 (55%) in the control group. The mean survival times were 11 and 10 h, respectively (n.s.). TNF levels were significantly different. The TNF peak at 90-240 min was not present in the anti-TNF group (340 pg/ml vs. 19 pg/ml, p = .034). Leukocyte counts differed also significantly. After an initial drop in both groups, we observed a leukocytosis of up to 32.8 +/- 5.0 g/L in the anti-TNF-group, while in the control group leukocyte counts remained below 15.0 g/L (13.3 +/- 3.0 g/L, p = .007). All other parameters did not differ significantly. Thus, anti-TNF-mAb effectively suppresses the TNF peak following gram-positive septicemia. In the presented setting, these effects did not influence overall survival or survival times.     

The role of flow cytometry in improving biocompatibility in transfusion medicine

In transfusion medicine, blood and blood components, donors and patients are increasingly confronted with biomaterials. The need to understand the response of human blood to contact with these artificial surfaces has led to multiple studies on the biocompatibility of biomaterials. Up to this time, these investigations have predominantly been performed using physical, immunological and biochemical methods. Many of these approaches are useful in investigating the multiple factors involved in blood-biomaterial interactions. However, they always reflect the overall behaviour of whole cellular populations in local or systemic reactions. The application of multiparameter flow cytometry, on the other hand, provides insight into antigenic expression and changes at the single-cell level. Therefore, the technique of flow cytometry represents a new and powerful way of analysing and improving the biocompatibility of these materials in blood-contacting applications in this field.     

High levels of 5′-nucleotidase activity in blastic chronic myelogenous leukemia with common all-antigen

The activity of 5′-nucleotidase (5′-N) on the surface of leukemia cells was determined in 44 patients with blast crisis of chronic myelogenous leukemia (CML) and in 52 patients with acute myeloblastic (AML) or acute lymphoblastic (ALL) leukemia. The phenotype of blast cells was classified according to immunological surface markers, including the common ALL-antigen (cALLA). High 5′-N activities were found in the presence of cALLA, whereas low to undetectable levels were characteristic for cALLA-negative leukemias, the difference being highly significant (p 0.0001). While there was a certain overlap of 5′-N levels between cALLA-positive ALL and cALLA-negative AML, no overlap of 5′-N was observed between cALLA-positive lymphoid and cALLA-negative myeloid blast crisis of CML. Thus, 5′-N affords an additional easily-testable biochemical marker that may have its diagnostic and prognostic value especially in the case of blastic chronic myelogenous leukemia.     

Platelet hemostasis capacity in smokers. In vitro function analyses with 3.2% citrated whole blood.

INTRODUCTION: Platelet function may be influenced by cigarette smoking. We therefore examined the effect of smoking on platelet hemostasis capacity (PHC) with an in vitro analyzer (PFA-100). METHODS AND RESULTS: Healthy blood donors (n=54) were included in the study and divided into four groups: nonsmoking males (n=14), nonsmoking females (n=14), smoking males (n=12) and smoking females (n=14). For in vitro analyses, in each participant citrated blood (3.2% buffered) was tested for PHC by two cartridges coated with collagen, and additionally with epinephrine (Col/Epi) or ADP (Col/ADP). Analyses were performed within 4 h after sample taking. PHC was expressed as the time in seconds to occlude the cartridge (closure time, CT). The average CT was significantly prolonged in female smokers compared to the female nonsmoking group for both types of cartridges (Col/Epi: P=.02; Col/ADP: P=.03). No significant differences were detected comparing the CT of smoking and nonsmoking males. After pooling male and female smokers and nonsmokers, no significant differences could be found, neither for the Col/Epi cartridges nor the Col/ADP cartridges. Plaletet aggregation assays performed in parallel showed no significant differences, except a reduced aggregability in male smokers compared to male nonsmokers using epinephrine 8.0 microM/ml as activating agent (P=.01). Furthermore, smoking volunteers presented with a significantly increased fibrinogen level compared to nonsmoking volunteers (P<.01). CONCLUSIONS: The results of our study show that in habitual smokers PHC (PFA-100) and the capability of platelets to react upon agonist stimulation in aggregation assays is not significantly influenced or increased compared to healthy nonsmokers. However, an immediate effect of cigarette smoking cannot be excluded.     

Comparison of flow cytometry vs. a haematology cell analyser-based method to guide the optimal time-point for peripheral blood stem cell apheresis

BACKGROUND AND OBJECTIVES: For timing the onset of apheresis, parameters obtained by flow cytometry and by a haematological cell analyser were compared. MATERIALS AND METHODS: Haematopoietic cell counts (n = 159) were performed by two different methods; CD34 analyses by flow cytometry, immature myeloid information (IMI) and human progenitor cell counts (HPC) by a haematological cell analyser. RESULTS: Comparing the IMI total results with CD34+ analyses (n = 159) revealed a correlation of r = 0.46 (P < 0.05). Similar results were obtained for HPC (r = 0.44; P < 0.05). CONCLUSION: The haematology analyser-based method does not allow the precise determination of absolute haematopoietic stem cell numbers and is thus not able to replace flow cytometry for the monitoring of peripheral blood stem cell counts.