[Clinical efficacy of lower dose rituximab for chronic refractory immune thrombocytopenic purpura].

OBJECTIVE: To investigate the efficacy and safety as well as the effects of lower dose of rituximab on B-lymphocytes, serum immunoglobulin, and platelet glycoprotein-specific antibodies in patients with chronic refractory immune thrombocytopenic purpura (ITP). METHODS: Twenty chronic refractory ITP patients, median age 47 (20 to 60) years old, received intravenous rituximab at the dose of 100mg once weekly for 4 consecutive weeks. Laboratory studies included complete blood cell count, regular monitoring of liver and kidney functions, blood coagulation and serum concentrations of IgG, IgM and IgA. CD3(+), CD4(+), CD8(+), CD19(+), CD20(+) cell numbers were assayed by flow cytometry prior to and following rituximab. Platelet glycoprotein antibodies were detected by ELISA. The detection of indicators were compared by paired T test, with P < 0.05 as statistically significant. RESULTS: There was significant difference of the average platelet count between prior- \[(13 ± 5) × 10(9)/L\] and post-treatment \[(124 ± 106) × 10(9)/L\] with lower dose rituximab (P < 0.01). Reaching PLT peak period was of (24 ± 7) d with median time of 18 d. The responses were of 11(55%) CR, 4 (20%) R and 5 (25%) NR, respectively, with median response duration of 8 months (5 - 23 months). There were no significant changes of peripheral blood white blood cell count, hemoglobin, serum immunoglobulin, as well as CD3(+), CD4(+), CD8(+) lymphocyte counts during prior- and post-treatment. CD19(+)/CD20(+) cells were almost depleted in all patients \[(125.65 ± 14.12) × 10(6)/L vs (50.53 ± 29.11) × 10(6)/L, P < 0.01)\]. Expectedly, three cases of positive detection of platelet antibodies were negative after 4 weeks of lower dose of rituximab; one patient experienced infusion-related reaction. CONCLUSION: Treatment with lower dose rituximab may be an effective and safe approach in patient with chronic refractory ITP. However, the optimal therapeutic schedule, long-term efficacy and adverse events need further investigation.

The role of Kupffer cells in rat liver regeneration revealed by cell-specific microarray analysis.

Liver regeneration after partial hepatectomy is a process with various types of cells involved. The role of Kupffer cells (KCs) in liver regeneration is still controversial. In this study we isolated KCs from regenerating liver and conducted cell-specific microarray analysis. The results demonstrated that the controversial role of KCs in liver regeneration could be explained with the expression patterns of TGF-α, IL-6, TNF, and possibly IL-18 during liver regeneration. IL-18 may play an important role in negative regulation of liver regeneration. The functional profiles of gene expression in KCs also indicated that KC signaling might play a negative role in cell proliferation: signaling genes were down regulated before cell division. Immune response genes in KCs were also down regulated during liver regeneration, demonstrating similar expression profiles to that of hepatocytes. The expression patterns of key genes in these functional categories were consistent with the temporal functional profiles.

The number of the genes in a functional category matters during rat liver regeneration after partial hepatectomy.

Rat liver regeneration after partial hepatectomy (PH) is a good model to study the regulation of cell proliferation. We isolated hepatocytes from regenerating liver at different time points after PH and used microarray Rat Genome 230 2.0 chip to analyze the functional profiles of all up- or down-regulated genes manually and with automatic gene ontological tools. We found that the transcript expressions of PH and sham operation group were apparently different. For PH group, in the priming phase (2-12 h), signaling, transcription, response to stimulus genes predominated in up-regulated genes; in the proliferation phase (24-72 h), cell proliferation genes predominated; in the termination phase (120-168 h), differentiation and translation genes predominated; while metabolism genes predominated in the down-regulated genes at all time points (2-168 h). These functional profiles are consistent with the cellular and molecular phenomenon observed during liver regeneration, and can be closely connected with the biological process. Moreover, the results indicated that not only the quantity of specific genes but also the number of the genes in the specific functional category was regulated during liver regeneration, which means the number of similar genes in a specific functional category matters as well as the regulation of the genes. The changes of the number of the regulated cell proliferation genes and metabolism genes during liver regeneration were similar to the expression patterns of some cell division genes and metabolism genes.

Analysis of time-course gene expression profiles of sinusoidal endothelial cells during liver regeneration in rats.

Liver regeneration (LR) after partial hepatectomy (PH) requires the coordinate contribution of different cell types. Liver sinusoidal endothelial cells (LSECs), representing the largest population of nonparenchymal cells, are proven to be crucial in LR. However, the details about their implications in regeneration are not still clear. In this study, percoll density centrifugation and immunomagentic bead methods were used to isolate LSECs with high purity and yield; global transcriptional profiles of LSECs during the regeneration were investigated by microarray. 1,629 genes were identified to be LR-related. Among them, there were 833 known genes whose expression patterns were clustered into eight classes. Gene function enrichment analysis showed that genes involved in the major LSEC functions, i.e., coagulation, phagocytosis, and transport, were highly enriched in cluster characterized by rapid induction and gradual return, suggesting the quick reestablishment of LSEC function after PH. Genes in immunity/inflammation and defense response were enriched in clusters exhibiting transient downregulation and quick recovery, possibly being associated with suppression of immunity/inflammation pathway in LSECs at early phase. Genes in glycogen synthesis and glycolysis were enriched in the clusters marked by "significant increase and gradual return" and "slight increase and then downregulation", implying an enhanced carbohydrate metabolism at early phase; detoxification-related genes were markedly distributed in the cluster with feature of rapid increase and then reduction, which was helpful in eliminating waste substance. Taken together, the measurement of gene expression profiling of LSECs and expression pattern analysis of functionally categorized genes gave insight into the mechanism of action of this cell on LR.

Expression patterns and action analysis of genes associated with physiological responses during rat liver regeneration: cellular immune response.

AIM: To study the cellular immune response during rat liver regeneration (LR) at a transcriptional level. METHODS: Genes associated with the cellular immune response were obtained by collecting the data from databases and retrieving articles. Gene expression changes during LR were detected by rat genome 230 2.0 array. RESULTS: A total of 127 genes were found to be associated with LR. The number of initially and totally expressing genes in the initial phase of LR [0.5-4 h after partial hepatectomy (PH)], transition from G(0)-G(1) (4-6 h after PH), cell proliferation (6-66 h after PH), cell differentiation and structure-function reconstruction (66-168 h after PH) was 54, 11, 34, 3 and 54, 49, 70, 49 respectively, illustrating that the associated genes were mainly triggered at the initiation of LR, and worked at different phases. According to their expression similarity, these genes were classified into 41 up-regulated, 21 predominantly up-regulated, 41 down-regulated, 14 predominantly down-regulated, 10 similarly up-regulated and down-regulated genes, respectively. The total up- and down-regulated expression times were 419 and 274, respectively, demonstrating that the expression of most genes was increased while the expression of a small number of genes was decreased. Their time relevance was classified into 14 groups, showing that the cellular physiological and biochemical activities were staggered during LR. According to the gene expression patterns, they were classified into 21 types, showing the activities were diverse and complicated during LR. CONCLUSION: Antigen processing and presentation are enhanced mainly in the forepart, prophase and anaphase of LR. T-cell activation and antigen elimination are enhanced mainly in the forepart and prophase of LR. A total of 127 genes associated with LR play an important role in cellular immunity.