Number Of Peripheral Blood Lymphocytes Research Articles

Engraftment of human T, B and NK cells in CB.17 SCID/beige mice by transfer of human spleen cells

Models of severe combined immuno-deficient (SCID) mice reconstituted with a competent human immune system represent a valuable tool for the study of human immune responses in vivo. Reconstitution with human cells can be achieved using large numbers of peripheral blood lymphocytes, but levels of engraftment are poor and graft versus host disease (GVHD) frequently occurs. SCID/beige mice are at the same time deficient for adaptive and innate immunity and the objective of this study was to develop a safe and efficient way to achieve human lymphocyte engraftment in these mice using human spleen cells. After institutional authorisations and informed consent of relatives, a piece of spleen was obtained from cadaveric organ donors and the splenocytes were isolated and cryopreserved for later use. Single intraperitoneal injections of 5–100 × 10 6 splenocytes were performed into SCID/beige mice. Reconstitution of a human immune system was monitored weekly by the presence of human cells and IgG in peripheral blood. The mice were sacrificed 4 weeks after the injection and the engraftment in lymphoid organs was studied. A reproducible reconstitution was obtained with intraperitoneal injection of 30–40 × 10 6 spleen cells. Human T, B and NK cells as well as human IgG were present in peripheral blood. In lymphoid tissues, the same lymphocytic subpopulations were detected and in addition some antigen presenting cells. The reconstitution was functional because graft rejection was observed after transplantation of human allogeneic tissues. When less than 30 × 10 6 cells were injected, the reconstitution was variable. When more than 40 × 10 6 cells were injected, GVHD occurred with increasing frequency. In conclusion, we show that intraperitoneal injection of 30–40 × 10 6 human splenocytes into SCID/beige mice induces a quick and functional engraftment of human T, B and NK cells with no risk of GVHD. This model may be used to study human transplantation immunobiology in vivo.

The Effect of a Novel Immunosuppressant, FTY720, in Mice Without Secondary Lymphoid Organs

FTY720 is a novel immunosuppressive agent that is thought to reduce the number of peripheral blood lymphocytes (PBL) by directing them toward secondary lymphoid organs such as the lymph nodes and Peyer's patches. We studied the effects of FTY720 on aly/aly mice that do not have either lymph nodes or Peyer's patches, as well as on splenectomized aly/aly mice. FTY720 was orally administered by gavage (1 mg/kg) to aly/aly mice as well as to aly/+ mice with and without a splenectomy on 14 consecutive days. The number of lymphocytes was then counted using True Cell beads and flow cytometry. The number of B220-, CD3-, and CD4-positive cells was also determined. In addition, skin grafts from C3H donor mice were performed on these mice. FTY720 was effective in significantly reducing the total lymphocyte count as well as the B220-, CD3-, and CD4-positive subtypes in the peripheral blood of aly/+ mice as well as in aly/aly mice with and without a splenectomy. While we did observe allograft skin graft rejection in both the aly/+ mice as well as the aly/aly mice recipients and splenectomized aly/aly mice, the graft survival was prolonged in all groups. The skin allografts treated by FTY720 thus demonstrated fewer lymphocytic cells and less infiltration of CD4-positive cells. The administration of FTY720 to mice without lymph nodes, Peyer's patches, or spleens still results in peripheral lymphopenia. In all groups, FTY720 was found to prevent the infiltration of CD4-positive cells in skin allografts while also prolonging skin allograft survival. The fate of these lymphocytes, however, is unclear.

Sex and low-level sampling stress modify the impacts of sewage effluent on the rainbow trout ( Oncorhynchus mykiss) immune system

The objective of the present study was to investigate the influence of chronic exposure to municipal sewage treatment effluent at environmentally relevant concentrations on immune parameters in rainbow trout ( Oncorhynchus mykiss), including the assessment of potential differences in reactivity between sexually mature male and female fish. Trout were exposed to 1.5 and 15% (v/v) secondary treated municipal sewage effluent for 32 weeks. Fish were injected intra-peritoneally either with inactivated Aeromonas salmonicida to simulate an infection or with PBS as control for this immune challenge 6 weeks prior to sampling. Exposure to effluent resulted in a decrease in A. salmonicida-specific serum antibody level and blood lymphocyte numbers in mature females, but not in male fish. Injection of A. salmonicida resulted in enhanced serum lysozyme activity in mature male trout, which were not exposed to effluent. This stimulating effect of A. salmonicida could not be found in effluent-exposed trout, again potentially revealing a suppressive effect of the effluent. An influence of sampling fish on two consecutive days was observed in many immune parameters, most likely reflecting handling stress. Leucocyte and lymphocyte numbers in peripheral blood were consistently lower in male and female fish on the second sampling day. Phagocytosis in head kidney macrophages from male trout was also influenced by sampling day, whereby a stimulation of this reaction occurred on the second day of sampling. Liver mixed function oxygenase activity was found to be enhanced in mature male trout exposed to 15% effluent. In conclusion, the study showed, that exposure to sewage treatment plant effluent, in surface water relevant concentrations, can lead to potentially adverse effects on selected immune reactions in rainbow trout. However, this study also demonstrated that both handling stress and the sex of mature fish have distinct influences on the immune response detected in male and female fish and are likely to influence measured immune parameters to the extent that subtle effluent induced changes may be difficult to detect.

Preoperative administration of FTY720 prolonged renal allograft survival

Background FTY729 is an immunomodulator obtained by chemical modification of Myriocin(ISI-1) which exists in the culture filtrate of an ascomycete, Isaria sinclairii. It has been reported that postoperative administration of FTY720 prolonged survival of various kinds of transplanted organs. In the present study, we evaluated the effect of 2-day preoperative administration of FTY 720 on graft survival. Materials and methods We used a rat renal transplantation model in which Wistar King Aptekman Hokkaido (WKAH, RT1 K) served as the organ donor and Lewis (LEW, RT l) as the recipient. FTY720 was given to the recipients consecutively 2 days (day-2, day-1) before transplantation at the doses of 1, 3 or 5 mg/kg/day. Renal allograft survivals, hematological parameters of recipient blood and phenotypic analysis of recipient splenic cells and graft infiltrate were evaluated. Results Consecutive 2-day preoperative oral administration of FTY 720 at the doses of 1, 3 or 5 mg/kg/day significantly prolonged WKAH allograft survivals compared with those of the untreated recipients. The number of peripheral blood lymphocytes was markedly decreased in the recipients treated with FTY720 at the doses of 3 mg/kg/day or 5 mg/kg/day on the 5th postoperative day. Preoperative FTY 720 administration significantly decreased the number of CD4 positive cells and the percentage of interleukin 2 receptor (IL-2 R) positive cells infiltrating both spleen and allograft at the dose of 3 mg/kg/day or 5 mg/kg/day. Conclusion FTY 720 could act as a safe and potent immunomodulator by decreasing the number of peripheral lymphocytes, especially CD4 positive cells and IL-2R positive cells when it is given to the recipient preoperatively.

The Distribution Pattern of Lymphocyte Subsets according to the Level of Serum Albumin in Preoperative Patients with Gastric Cancer

Purpose: Considering that nutritional state correlates to immunity, we performed this study to evaluate the correlation by assessing the numerical changes of the levels of serum albumin and lymphocyte subsets. Materials and Methods: The study was performed on patients who were diagnosed as having gastric cancer and who underwent curative surgery from August 1998 to August 2004 in the Gyeongsang National University Hospital and whose peripheral blood lymphocyte subsets were tested prior to surgery. The study population was a total of 150 cases. Results: The change in the lymphocyte subsets in relation to the change in the level of serum albumin in all patients with gastric cancer was determined, and was compared to disease stages. When patients were classified by using the level of serum albumin with 3.2 mg/dl as the cut-off point (low group: serum albumin 3.2 mg/dl), the number of peripheral blood lymphocytes, CD3+ cells, CD4+ cells, CD8+ cells, and CD16+ 56 cells were, significantly lower in the group with the level of serum albumin below 3.2 mg/dl (low group) than it was in the group with a serum albumin level above 3.2 mg/dl (normal group) (P

Internal biliary drainage improves decreased number of gut mucosal T lymphocytes and MAdCAM-1 expression in jaundiced rats

BackgroundAlthough the effect of preoperative biliary drainage in patients with obstructive jaundice is controversial, bacterial or endotoxin translocation is one of the main postoperative problem in jaundiced patients. Failure in gut barrier functions causes bacterial translocation; homing and distribution of T lymphocytes in the intestinal lamina propria are important for gut mucosal immune defense. This study was performed to examine whether bile regulates the numbers of T lymphocyte subsets or the expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in experimental jaundice in rats with and without external and internal biliary drainage. MethodsFour groups of Wistar rats were used: those that received a sham operation (SHAM), common bile duct ligation (CBDL), CBDL followed by external drainage (ED), and CBDL followed by internal drainage (ID). Numbers of CD4+ and CD8+ T lymphocytes and MAdCAM-1–positive cells in the lamina propria were counted immunohistochemically in the specimens of jejunum and ileum of each group. Bacterial translocation was examined by culturing from the mesenteric lymph node complex isolated from rats in each group. ResultsA significant decrease in numbers of CD4+ and CD8+ T lymphocytes and MAdCAM-1–positive cells in the lamina propria was seen in obstructive jaundice, although numbers of peripheral blood lymphocytes increased in comparison with the sham-operated control. The numbers of CD4+ and CD8+ T lymphocytes and MAdCAM-1 expression in the lamina propria did not recover to a normal level after external drainage, but did so after internal drainage. Frequencies of bacterial translocation were high in the CBDL and ED group. In contrast, bacterial translocation was not present in any animals in the SHAM group and was at a low percentage in the ID group. ConclusionsChanges in the number of T lymphocytes and MAdCAM-1 expression are associated with the presence of bile in the gastrointestinal tract and are inversely correlated with the frequency of bacterial translocation induced by CBD ligation. MAdCAM-1 expression maintained by the presence of bile may regulate T-lymphocyte homing to the lamina propria in obstructive jaundice.

Evidence for immune defects in breast and lung cancer patients.

Immunosuppression is often identified in cancer patients. The aim of this study was to evaluate several immune parameters for patients with breast and lung cancer. Immunophenotyping analysis showed that the cancer patients investigated had significantly lower absolute numbers of peripheral blood lymphocytes than controls. The immunosuppression was more evident for the breast cancer subgroup. The most severe immune defect noticed was the marked impairment of IFN-gamma secretion. A shift toward the Th2 phenotype as revealed by assessment of intracellular level of IFN-gamma and IL-4 was also noticed. The secretion of proinflammatory cytokines IL-1beta and TNF-alpha in whole blood cultures was not impaired. Although the proportion of activated cells was slightly lower than in the control group, our results showed that both peripheral T lymphocytes and NK cells of cancer patients could be induced to express early activation marker CD69 after ex vivo mitogen stimulation. In conclusion, our study revealed several immune defects in cancer patients. This suggests that an appropriate immunotherapeutical approach might be used to restore compromised immune functions with beneficial effects on both antitumor and general immunity.

FTY720 treatment prolongs skin graft survival in a completely incompatible strain combination

FTY720 has shown potent immunomodulatory activity in a variety of animal organ transplant models. However, the in vivo immunosuppressive mechanism of FTY720 is still not fully understood. It has been suggested that the marked decrease in the number of peripheral blood lymphocytes during FTY720 administration could be responsible for its immunosuppressive effects. Our aims were: (1) to study the effects of FTY720 treatment on skin graft survival using a fully mismatched strain combination and (2) to evaluate lymphocyte numbers in different sites at 5 days after skin transplant. C57BL/6 mice and BALB/c mice were the donors and recipients respectively. BALB/c mice received FTY720 (1 mg/kg/d) orally for 4 consecutive days. Drug administration started 1 day before skin transplants. A small segment of tail skin was affixed on the right dorsal side of the mouse via sutures. The administration of FTY720 (4 mg/kg) prolonged skin graft survival from 12.6 ± 2.2 days (no treatment) to 16.6 ± 4.2 days. The histologic findings of rejection were similar for all groups. Five days after transplant, lymphocyte numbers were significantly increased in lymph nodes compared with nontransplanted or isogenic graft mice. FTY720 decreased lymphocyte numbers only in the spleen. In conclusion, FTY720 prolonged skin graft survival in a fully mismatched strain combination when administered for 4 days (day −1 to day +2) at a dose of 1 mg/kg/d. The decreased number of lymphocytes in the spleen suggests that the spleen may be a target of FTY720 activity, during the early posttransplant period.

Modulation of inflammation and response to dexamethasone by Annexin 1 in antigen-induced arthritis.

Annexin 1 (Anx-1) is a putative mediator of the antiinflammatory actions of glucocorticoids (GCs). This study investigated the role of Anx-1 in experimental arthritis and in GC-mediated inhibition of inflammation, using antigen-induced arthritis (AIA) in Anx-1 knockout (Anx-1(-/-)) mice. Arthritis was induced by intraarticular injection of methylated BSA (mBSA) in mice preimmunized with mBSA. Disease was assessed after 7 days by histologic examination of the knee joints. Serum levels of anti-mBSA IgG were determined by enzyme-linked immunosorbent assay. Cytokine messenger RNA (mRNA) expression was detected by real-time polymerase chain reaction. A significant exacerbation of arthritis was observed in the Anx-1(-/-) mice compared with wild-type (WT) mice. This was associated with increased mRNA expression of synovial interleukin-1 beta, tumor necrosis factor alpha, interleukin-6, and macrophage migration inhibitory factor. Dexamethasone significantly reduced the histologic severity of synovitis and bone damage in the WT mice, but exerted no inhibitory effects in the Anx-1(-/-) mice, and also significantly reduced the serum levels of anti-mBSA IgG and the numbers of peripheral blood neutrophils and lymphocytes in WT mice, but had no such effect in Anx-1(-/-) mice. Anx-1 exerts endogenous antiinflammatory effects on AIA via the regulation of cytokine gene expression, and also mediates the antiinflammatory actions of dexamethasone in AIA.

Immune and airway effects of house dust mite aeroallergen exposures during postnatal development of the infant rhesus monkey

The effect of chronic environmental aeroallergen exposure on the immune system and airways has not been experimentally defined in very young children. The purpose of this study was to determine the immunophenotype of peripheral blood and airway leucocytes in the newborn rhesus macaque monkey, following recurrent aerosol exposure to house dust mite (HDM) (Dermatophagoides farinae). A regimen of HDM aerosolization was initiated for 2 h per day, three times per week, starting when rhesus macaque monkeys were 1 week of age. All monkeys were inoculated with diptheria, tetanus, and acellular pertussis vaccine at 5 weeks of age to simulate human infant vaccination schedules. Following 8 weeks of HDM aeroallergen exposure, infant monkeys exhibited a significant reduction in the total peripheral blood lymphocyte numbers and a decreased frequency of peripheral blood CD4+ T lymphocytes with a CD45RA-'memory' immunophenotype. Lavage CD4+ T lymphocytes from HDM-exposed monkeys showed elevated expression of CD25, as well as an increase in CD45RA-/CD62L-/CD11ahigh immunophenotype. Eosinophils were more abundant within airways of HDM-exposed monkeys, accumulating maximally within the trachea. These data demonstrate the development of immunological responses following chronic inhalation of a common environmental allergen during postnatal maturation in the non-human primate.

Ability of CD8(+) T cell anti-feline immunodeficiency virus activity correlated with peripheral CD4(+) T cell counts and plasma viremia.

In the host defense mechanism against feline immunodeficiency virus (FIV) infection, CD8(+) T cells specifically attack virus-infected cells and suppress the replication of the virus in a non-cytolytic manner by secreting soluble factors. In this study, we measured CD8(+) T cell anti-FIV activity in 30 FIV-infected cats. We investigated its relationship with the number of peripheral blood lymphocytes, particularly the CD4(+) T cell and CD8(+) T cell counts, and the relationship between anti-FIV activity and the number of T cells of CD8alpha(+)beta(lo) and CD8alpha(+)beta(-) phenotypes. A clearly significant correlation was observed between anti-FIV activity and the number of CD4(+) T cells. A weaker anti-FIV activity was associated with a greater decrease in the number of CD4(+) T cells. However, there was no significant correlation between anti-FIV activity and the number of B or CD8(+) T cells. Compared with SPF cats, FIV-infected cats had significantly higher CD8alpha(+)beta(lo) T cell and CD8alpha(+)beta(-) T cell counts, but, no significant correlation was observed between these cell counts and anti-FIV activity. This anti-FIV activity significantly correlated with plasma viremia, which was detected in cats with a weak anti-FIV activity. These results suggest that the anti-FIV activity of CD8(+) T cells plays an important role in plasma viremia and the maintenance of CD4(+) T cells in the body. It is unlikely that CD8alpha(+)beta(lo) or CD8alpha(+)beta(-) T cells appearing after FIV infection represent a phenotype of CD8(+) cells with anti-FIV activity.

The expression patterns of CD44 and CD45RB on peripheral blood T lymphocytes in the rejection of allogeneic murine skin transplantation

Until now, the rejection was diagnosed through a biopsy, but this method of diagnosis reflected the advanced tissue damage of the transplanted organ and contained the innate problem of being invasive. In relation, our research attempted to evaluate the viability of analyzing the surface antigens of the peripheral blood activated T lymphocytes after murine skin transplantation as a non-invasive and early diagnostic tool for diagnosis of rejection. After mouse skin was transplanted, the expression patterns of activated T lymphocyte markers, CD44 and CD45RB were analyzed along with T lymphocyte markers, CD3, CD4 and CD8 using flow cytometry. The skins from the tails of allogeneic BALB/c(H2d) mice and syngeneic C57BL/6J mice were transplanted to C57BL/6J(H2b) mice as test and control groups, respectively. Peripheral blood, which was sampled from the tail every other day from day 3 to day 15 was stained with anti-CD44 (or CD45RB), anti-CD4 (or CD8) and anti-CD3 monoclonal antibodies simultaneously, and analyzed by 3-color FACS. Rejection occurred only in the test group from day 8 to day 13 (median: day 10). Although the proportions of CD3 + lymphocytes, CD4 + lymphocytes and CD8 + lymphocytes showed no difference, the total number of peripheral blood lymphocytes and the number of CD3 + lymphocytes and CD8 + lymphocytes decreased more sharply in the control after day 7. The proportion and the number of CD44 +CD3 +-lymphocytes, CD44 +CD4 +-lymphocytes and CD44 +CD4 +CD3 +-lymphocytes began to increase after day 7, to peak on day 11, and then to decrease, showing a significant difference. The proportion and number of CD44 +CD8 +-lymphocytes and CD44 +CD8 +CD3 +-lymphocytes showed similar trends. No significant difference was observed in any subsets of the CD45RB antigen. The analysis of the expression patterns of surface antigen CD44 on peripheral blood T lymphocytes using flow cytometry is sensitive, safe, easily repeatable and controllable, and, therefore, can be considered a promising tool for the diagnosis of rejection. However, the clear change in CD44 occurred between day 9 and day 13, when rejection was observed grossly. Therefore, it is regarded more useful as a screening test or follow-up indicator rather than as an early diagnostic tool.

Assessment of thymic activity in human immunodeficiency virus-negative and -positive adolescents by real-time PCR quantitation of T-cell receptor rearrangement excision circles.

Circular DNA molecules known as T-cell receptor rearrangement excision circles (TREC) arise during T-cell development and are present in cells that have recently emigrated from the thymus. In cross-sectional studies, the number of peripheral blood lymphocytes bearing TREC decreases with age, consistent with an anatomically demonstrated loss of thymic epithelial tissue. TREC numbers increase following hematopoietic stem cell transplantation and during therapy for human immunodeficiency virus (HIV) infection. Quantitation of TREC has therefore been proposed as a parameter of thymic activity. In this study, we used real-time PCR to quantify TREC in peripheral blood samples obtained longitudinally from HIV-seronegative adolescents. TREC values in peripheral blood T cells were very stable throughout adolescence, once thought to be a time of rapid involution of the thymus. In addition, in a cross-sectional analysis, we examined TREC values in a cohort of HIV-positive adolescents and found evidence of ongoing thymopoiesis in perinatally infected individuals, despite lifelong infection. These data demonstrate the utility of TREC assessment in adolescents and that HIV infection does not uniformly result in accelerated thymic involution in childhood.

Intratumoural and peripheral blood lymphocyte subsets in patients with metastatic renal cell carcinoma undergoing interleukin-2 based immunotherapy: association to objective response and survival.

The aim of the present study was to analyse lymphocyte subsets in consecutive peripheral blood samples and consecutive tumour tissue core needle biopsies performed before and during interleukin-2 based immunotherapy, and to correlate the findings with objective response and survival. Twenty-six patients with metastatic renal cell carcinoma were treated with low dose s.c. interleukin-2, interferon-α and histamine. A total of 250 blood samples and 62 core needle biopsies from 23 and 19 of these patients, respectively, were analysed. After 2 weeks of treatment, a significant positive correlation between absolute number of peripheral blood lymphocytes (P=0.028), CD3 (P=0.017), CD57 (P=0.041) and objective response was demonstrated. There was no correlation between any peripheral blood leukocyte subsets and survival. Cytotoxicity of peripheral blood mononuclear cells was not correlated to objective response or survival. Within the tumour tissue at baseline, a significant positive correlation between CD4 (P=0.027), CD8 (P=0.028), CD57 (P=0.007) and objective response was demonstrated. After one month of immunotherapy, a significant positive correlation between intratumoral CD3 (P=0.026), CD8 (P=0.015), CD57 (P=0.009) and objective response was demonstrated. A significant positive correlation between intratumoral baseline CD4 (P=0.047), baseline CD57 (P=0.035), CD3 at one month (P=0.049) and survival was demonstrated. These data provide novel in vivo evidence of the possible contribution of lymphocyte subsets in the tumour reduction in responding patients during interleukin-2 based immunotherapy. Confirmation of the results requires further studies including a larger number of patients.British Journal of Cancer (2002) 87, 194–201. doi:10.1038/sj.bjc.6600437 www.bjcancer.com© 2002 Cancer Research UK

Peripheral blood lymphocytes and selected serum interleukins in workers operating X-ray equipment

The objective of these studies was to determine the effect of low X-ray doses on peripheral blood lymphocytes in the workers operating X-ray equipment. In 30 workers and 18 persons who constituted the control group the absolute number of peripheral blood lymphocytes, the number of T CD4+ and T CD8+ lymphocytes, the ratio CD4+/CD8+ and the concentration of serum interleukins (IL-2, IL-4, IL-6) were tested. Subgroups with respect to sex and employment period were selected. A significant increase in IL-2 concentration in workers as compared to controls was observed and significantly decreased IL-4 level in operating X-ray equipment was revealed. The lowest levels of IL-4 were noted in the women subgroup. A high positive, statistically significant correlations between the number of lymphocytes and the concentration of IL-2 and the level of IL-4 were observed. Moreover, our studies revealed that lymphocyte number and interleukin concentrations in serum of X-ray operators do not depend on the assumed ranges of the length of employment period.

Decreased total numbers of peripheral blood lymphocytes with elevated percentages of CD4+CD45RO+ and CD4+CD25+ of T-helper cells in non-segmental vitiligo.

Vitiligo is a disorder involving progressive skin depigmentation caused by host mediated destruction of melanocytes. Its pathogenesis is known to correlate with elevated levels of activated skin-infiltrating T lymphocytes and is presumed to be autoimmune in nature. In the present study, we characterize the immunophenotype of peripheral blood T cells from vitiligo patients, with the objective of developing an investigative and diagnostic tool for the disease, using analysis of peripheral blood. Subjects for this investigation included 32 patients diagnosed with non-segmental vitiligo and 28 age-and gender-matched, normal, healthy control participants. Whole venous blood taken from each subject was analyzed using 2-color flow cytometry for immunologically-relevant lymphocyte subsets. When compared with healthy control subjects, peripheral blood from individuals with vitiligo was found to have lower total numbers of lymphocytes (p<0.039). Vitiligo patients also had elevated percentages of memory (CD4+CD45RO+) T cells; (p<0.05), but NK-T cells (CD3+CD16+CD56+) and naive T cells (CD4+CD45RA+) were present at lower total numbers and percentages than in healthy controls (p<0.01 and 0.05 respectively). Blood from severely afflicted subjects exhibited elevated CD3+HLADR+ and CD4+CD45RO+ as well as lower percentages of NK-T cells (p<0.05) when compared with mild cases. In conclusion, disease-associated, peripheral blood lymphocyte immunophenotypic profiles of vitiligo patients are consistent with the hypothesis of T cell activation as a major feature of the disorder. These include elevated memory and reduced naive T cell percentages and increased expression of the activation-associated surface antigen CD25. These changes presumably reflect increased antigen-mediated activation. Moreover, because a corollary effect is increased activation-induced cell death (AICD), lower overall lymphocyte counts observed in vitiligo-afflicted subjects is also expected.

Effects of sevoflurane general anesthesia: immunological studies in mice

Based on the immunomodulatory effects of anesthesia and surgery, a study was undertaken to assess the effect of sevoflurane anesthesia on the immune system in a murine model without surgery. Adult male mice were anesthetized with 3% sevoflurane (1.2 minimal alveolar concentration, MAC) in oxygen for 40 min, whereas nontreated animals served as controls. After sevoflurane anesthesia, peripheral blood leukocyte counts, the splenic composition and in vitro macrophage phagocytic activity and lymphoproliferative response were assessed. The in vivo specific immune response to sheep red blood cells (SRBC), a conventional T-dependent antigen was determined. In addition, liver, spleen, thymus and kidney histopathology and also hepatic and renal functions after anesthesia were studied. Sevoflurane diminished the number of peripheral blood lymphocytes and splenic B-cell counts, enhancing CD4 + lymphocytes in spleen. The in vitro functionality of macrophages and the mitogen-induced lymphoproliferative response were preserved, while the in vivo immune response to SRBC was enhanced in treated animals. Microscopic studies revealed conserved architecture of the spleen, thymus, lymph node, liver and kidney, and there were no differences in serum parameters of hepatic and renal functions between treated and control groups. Our results suggest that 3 days after the anesthetic exposure, animals treated with sevoflurane modulated their peripheral blood leukocyte counts, splenic lymphoid composition and the characteristics of the specific response to SRBC, while there was no evidence of hepatic or renal toxicity.

Increased Expression of Fas (APO-1, CD95) on CD4+ and CD8+ T Lymphocytes during Total Body Irradiation

Fas/APO-1 (CD95) is a cell surface molecule that can transduce apoptotic signals into cells. We examined the expression of Fas antigen on CD4+ and CD8+ T cells of patients who received total body irradiation (TBI) as a preparative regimen for allogeneic bone marrow transplantation. Numbers of peripheral blood lymphocytes were significantly reduced after TBI. Cytofluorometric analysis revealed a significantly higher expression of Fas on CD4+ and CD8+ T cells after TBI. Serum soluble Fas concentrations were significantly elevated after TBI. Changes in the Fas system were therefore accompanied by TBI-induced lymphocytopenia, suggesting that Fas plays a role in irradiation-induced apoptosis in vivo.

EFFECT OF SHORT-COURSE, HIGH-DOSE STEROID THERAPY IN A CHILD WITH MYELODYSPLASTIC SYNDROME

High-dose methylprednisolone (HDMP) has been shown to induce differentiation of myeloid leukemic cells with a remarkable antileukemic effect in children with various subtypes of acute myeloblastic leukemia (AML). Here the beneficial effect of short-course HDMP therapy in a child with myelodysplastic syndrome (MDS) is reported. Oral methylprednisolone sodium succinate (Prednol-L) was administered at a single daily dose of 30 mg/kg for 5 days to a 4-year-old girl with refractory anemia with excess of blasts and hypocellular bone marrow before the initiation of chemotherapy. In addition to dramatic clinical improvement, the patient's white blood cell count increased from 2.3 2 10 9 /L to 5.0 2 10 9 /L, and peripheral blood blast cells disappeared 4 days after HDMP treatment. Repeated bone marrow aspirate 1 week after the initiation of HDMP disclosed increased cellularity with no blasts. Furthermore, short-course HDMP treatment stimulated the increase in the number of peripheral blood lymphocytes and CD3 + , CD4 + , CD8 + , CD19 + , CD34 + , and NK cells. Results obtained with HDMP from the previous studies and the present case suggest that high-dose methylprednisoloneis a promising agent in the treatment of MDS and it is recommended as an initial treatment especially for MDS children with hypocellular bone marrow at presentation.

Effect of a Novel Immunosuppressant, FTY720, on Allograft Survival after Renal Transplant in Rats

FTY720 was developed by chemical modification of ISP-1 which was purified from culture filtrates of an ascomycete, Isaria sinclairii. We evaluated the effect of FTY720 on allograft survival using a rat renal transplantation model in which Wistar King Aptekman Hokkaido rats (WKAH, RT1^K) served as the organ donor and Lewis rats (LEW, RT1^l) as the recipient. WKAH renal allografts were acutely rejected by the untreated LEW recipients at a mean graft survival ± SD of 7.2 ± 0.4 days (n = 5). Consecutive oral administration of FTY720 following transplantation significantly prolonged allograft survival in a dose-dependent manner over the range of 0.05–3 mg/kg/day. The mean allograft survival of the recipients treated with FTY720 at a doses of 0.05, 0.1, 0.5, 1, and 3 mg/kg/day was 12.2 ± 3.3 (n = 5, p < 0.05, vs. untreated host), 11.2 ± 2.4 (n = 5, p < 0.05, vs. untreated host), 13.6 ± 0.9 (n = 5, p < 0.01, vs. untreated host), 14.6 ± 1.7 (n = 5, p < 0.01, vs. untreated host) and 20.2 ± 0.8 days (n = 5, p < 0.01, vs. untreated host). In the recipients treated with FTY720 (3 mg/kg/day), the number of peripheral blood lymphocytes significantly decreased. From the results of the flow cytometric study, FTY720 significantly diminished the percentage of interleukin-2 receptor (IL-2R)-positive cells in the allografts (6.34 ± 0.81% in the untreated recipients vs. 3.10 ± 0.86% in the recipients treated with FTY720, p < 0.05). As to the CD4/CD8 ratio of splenic cells and graft infiltrate, there was no significant difference between the untreated hosts and the recipients treated with FTY720. In conclusion, FTY720 significantly extended rat renal allograft survival and the immunosuppressive effects of FTY720 may be due to a reduction in not only the number of peripheral lymphocytes but also the percentage of IL-2R-positive cells in the allografts.