Inhibition of agonist-induced platelet aggregation by magnesium sulfate warrants its use as an alternative in vitro anticoagulant in pseudothrombocytopenia.

MgSO4 is effective in preventing spontaneous in vitro platelet agglutination in anticoagulant-induced pseudothrombocytopenia (PTCP). In order to learn more about its potential as an in vitro anticoagulant, platelets from MgSO4-anticoagulated blood were stimulated by several differentially-acting agonists (ADP, ARA, TRAP, epinephrine, collagen and ristocetin). Platelet aggregation in blood samples from 11 and 17 volunteers was measured by light-transmission aggregometry (LTA) according to Born and impedance aggregometry (MultiplateTM), respectively. Agonist-induced platelet aggregation was markedly lower in MgSO4-anticoagulated samples when compared with citrate-anticoagulated samples (decrease of 95.75% (ristocetin), 69.02% (collagen) and 75.73% (epinephrine)) or hirudin-anticoagulated samples (decrease of 85.99% (ADP), 80.98% (ARA), 77.24% (ristocetin), 54.37% (collagen) and 50.14% (TRAP)). The anti-aggregatory effect of MgSO4 is dose-dependent and readily detectable at a concentration of 7.5 mmol/l. Analysis of the agonist signaling pathways suggest that MgSO4 interferes with the final step of platelet aggregation, namely the intracellular mobilization of Ca2+.

A therapy with miglustat, 2-hydroxypropyl-ß-cyclodextrin and allopregnanolone restores splenic cholesterol homeostasis in Niemann-pick disease type C1.

BACKGROUND: Niemann-Pick disease type C1 (NPC1) is an autosomal-recessive lipid-storage disorder with an estimated minimal incidence of 1/120,000 live births. Besides other neuronal and visceral symptoms, NPC1 patients develop spleen dysfunction, isolated spleno- or hepatosplenomegaly and infections. The mechanisms of splenomegaly and alterations of lipid metabolism-related genes in NPC1 disease are still poorly understood. METHODS: Here, we used an NPC1 mouse model to study a splenoprotective effect of a treatment with miglustat, 2-hydroxypropyl-ß-cyclodextrin and allopregnanolone and showed that this treatment has a positive effect on spleen morphology and lipid metabolism. RESULTS: Disease progress can be halted and blocked at the molecular level. Mutant Npc1 (Npc1-/-) mice showed increased spleen weight and increased lipid accumulation that could be avoided by our treatment. Also, FACS analyses showed that the increased number of splenic myeloid cells in Npc1-/- mice was normalized by the treatment. Treated Npc1-/- mice showed decreased numbers of cytotoxic T cells and increased numbers of T helper cells. CONCLUSIONS: In summary, the treatment promotes normal spleen morphology, stabilization of lipid homeostasis and blocking of inflammation, but alters the composition of T cell subtypes.

Performance of the XN-2000 WPC channel-flagging to differentiate reactive and neoplastic leukocytosis.

BACKGROUND: The distinction between reactive and neoplastic leukocytes, especially atypical lymphocytes suspected to be reactive or neoplastic, is a particular challenge in automated hematological cell differentiation. The aim of the study was to evaluate the performance of the XN analyzer supplemented with the WPC channel for differentiating between reactive and neoplastic leukocytosis. METHODS: Blood samples of 253 patients with viral infections, lymphoma or leukemia were analyzed by the Sysmex XN-2000 analyzer equipped with the WPC channel. The results were compared to routine leukocyte differentiation using the routine Sysmex XE-2100 analyzer and automated digital microscopy (DM96). The combined information from standard morphology, immune phenotyping and clinical diagnosis served as a reference. RESULTS: The XN WPC channel demonstrated an excellent performance for differentiating neoplastic (AUC=0.933) and reactive leukocytosis (AUC=0.900) as compared to morphological smear examination (AUC=0.949 and AUC=0.968, respectively) or to the differentiation results of our routine hematology analyzer (AUC=0.630 and AUC=0.635, respectively). CONCLUSIONS: Our data show that the combined WDF/WPC of the Sysmex XN-Series analyzer is advantageous in the automated differentiation of neoplastic and reactive leukocytosis, thus supporting the correct diagnostic decision in the daily laboratory routine.

Expression of tissue factor in pancreatic adenocarcinoma is associated with activation of coagulation.

AIM: To study expression of tissue factor (TF) in pancreatic cancer and its role in the development of thromboembolism. METHODS: TF expression was studied in eight human pancreatic carcinoma cell lines by Northern blot and indirect immunofluorescence. Expression of alternatively spliced TF (asTF) was assessed by RT-PCR. In addition, TF expression was determined by immunofluorescence in pancreatic tissues of 19 patients with pancreatic adenocarcinoma (PCa), 9 patients with chronic pancreatitis (CP) and 20 normal controls. Plasma samples (30 PCa-patients, 13 CP-patients and 20 controls) were investigated for soluble TF levels and coagulation activation markers [thrombin-antithrombin III complex (TAT), prothrombin fragment 1 + 2 (F1 + 2)]. RESULTS: All pancreatic carcinoma cell lines expressed TF (8/8) and most of them expressed asTF (6/8). TF expression at the protein level did not correlate with the differentiation of the carcinoma cell line. All but two pancreatic cancer tissue samples stained positive for TF (17/19). In all samples of CP weak staining was restricted to pancreatic duct cells, whereas only a few subendothelial cells were positive in 9/20 of normal controls. TF and TAT levels in PCa patients were significantly elevated compared to controls whereas elevated F1 + 2 levels did not reach statistical significance compared to controls. In CP patients TAT and F1 + 2 levels proved to be significantly elevated compared to controls, although TAT elevation was less pronounced than in PCa patients. CONCLUSION: We conclude that in addition to the upregulated expression of TF on the cell membrane, soluble TF might contribute to activation of the coagulation system in pancreatic cancer.