Effects of recombinant interleukin-2 and revaccination for hepatitis B in previously vaccinated, non-responder, chronic uraemic patients. Collaborative Group of Girona

BACKGROUND: Growing evidence suggests that it is possible to seroconvert chronic renal failure patients who are absolute non- responders to hepatitis B vaccine by means of either additional booster vaccine doses or associated IL-2 administration or both. We have studied the possibilities of hepatitis B seroconversion by revaccination and its dependence on vaccine dose, and the effects of a concurrent low-dose rHuIL-2 regime. METHODS: Forty known absolute non- responders with chronic renal failure were entered into a complete revaccination protocol. Patients were randomly assigned to two dosage groups of either 20 or 40 micrograms hepatitis B vaccine administered at 0, 1, 2 and 6 months. Further randomly selected patients from each dosage group were given 500,000 U of rHuIL-2 in the same deltoid area 4 h after vaccine administration. RESULTS: Sixty-seven per cent of patients revaccinated with 40 micrograms attained antibody protecting levels compared to only 20% of those receiving doses of 20 micrograms (P < 0.025). When compared with initial values, the ThCD4/CD25 cell count was significantly reduced immediately after HuR-IL2 administration (P < 0.003) and significantly increased 1 month after the last dose was given (P < 0.0003). A definite rHuIL-2 effect on HBV antibody synthesis could not be demonstrated, nor was erythropoietin found to enhance seroconversion. CONCLUSIONS: From these results we suggest that more intense and frequent antigenic stimulation as obtained by revaccination using four doses of 40 micrograms may effectively reduce the pool of hepatitis B vaccine nonresponders in chronic renal failure patients.      

Keratinocytes induce local tolerance to skin graft by activating interleukin-10-secreting T cells in the context of costimulation molecule B7-H1

BACKGROUND: Intermingled skin grafting using autologous skin islets inlaid in allogeneic skin sheets was found to delay graft rejection, contributing to a significant reduction in mortality for patients with severe burns. In this study we examine the down-regulatory mechanisms underlying the effect of the autologous skin islets. METHODS: Mixed culture of lymphocytes with epidermal cells of autologous and allogeneic origin were performed with a comparing of cell activity from cytokine-knockout mice. And the Th1/Th2-related cytokine profiles were examined. RESULTS: Autologous keratinocytes act as potent inducers of suppression in the mixed culture by making a shift of the cytokine profile from Th1 to Th2. The observed suppression is predominantly mediated by interleukin (IL)-10, because the effect could be reversed by application of a neutralizing antibody to IL-10. The results of reconstitution experiments in BALB/c mice, with or without IL-10 gene-knockout, are consistent with this finding. These demonstrated that T cells were main effective components for the IL-10-related suppression. Furthermore, a newly identified member of the human B7 family (B7-H1) is found to play an important role in activating human IL-10-secreting lymphocytes. When transfected with the CD80 gene, autologous keratinocytes lost the ability to down-regulate the mixed cell culture, which effect could be reversed by introduction of the anti-CD80 antibody. CONCLUSIONS: Our study provides new evidence that autologous keratinocytes present in intermingled skin grafts are inducers for local immune tolerance by expression of B1-H1 in their activation of the IL-10-secreting T cells.     

Immunization with an adjuvant hepatitis B vaccine in liver transplant recipients: antibody decline and booster vaccination with conventional vaccine.

Patients after orthotopic liver transplantation (OLT) due to hepatitis B virus (HBV)-related disease are at risk of endogenous hepatitis B reinfection and may receive life long prophylaxis with hepatitis B hyperimmunoglobulin (HBIG). In a previous study 16 of 20 OLT patients were immunized successfully with an adjuvant hepatitis B vaccine. To maintain protective antibody levels under immunosuppressive therapy, 11 of these patients were revaccinated with a double dosed conventional hepatitis B vaccine. Median interval between last vaccination and booster was 24 months (range 22-31 months). Antibody titres against hepatitis B surface antigen (anti-HBs) were monitored at the day of booster vaccination (day 0), at day 7 and day 28. At day 0, all vaccinees but one had anti-HBs titres greater than 500 IU/L (median 1,925 IU/L, range 196-7,612 IU/L). Maximum antibody titres after previous vaccination declined by a median of 82% (range 47-96%). After booster vaccination the anti-HBs titre increased significantly by a median factor of 2.42 (P<0.05). In conclusion, the majority of liver transplant recipients who previously had responded to adjuvant hepatitis B vaccine exhibited sufficient immunocompetence to produce a substantial antibody response after booster immunization with a conventional vaccine.     

Impaired immune responses and antigen-specific memory CD4+ T cells in hemodialysis patients

Serologic responses to T cell-dependent vaccinations are severely attenuated in patients with ESRD, but the reasons for this is unknown. In this study, a detailed analysis of antigen-specific T cell responses was performed. Patients on hemodialysis and age- and gender-matched healthy control subjects were vaccinated with hepatitis B surface antigen (HBsAg), antigen-specific CD4(+) T cells were monitored at regular intervals with intracellular cytokine staining and proliferation assays. IL-2-and IFN-gamma-producing CD4(+) T cells were identified as either central or effector memory CD4(+) T cells using antibodies directed against CD45RO and the chemokine receptor CCR7. Control subjects mounted a memory T cell response comprising both central and effector memory CD4(+) T cells, with the central memory response occurring 1 wk before the effector memory response. IL-2(+) HBsAg-specific memory CD4(+) T cells were primarily detected within the effector population. Patients with ESRD showed a delayed response of IL-2-and IFN-gamma-producing central memory CD4(+) T cells, but their maximal responses were similar to those of control subjects. In contrast, patients with ESRD produced only 6.3% of the IL-2(+) HBsAg-specific effector memory CD4(+) T cells produced by control subjects (0.5 +/- 0.2 x 10(4)/L versus 8 +/- 3.5 x 10(4)/L; P < 0.001), and this impaired response correlated with antigen-specific T cell proliferation and anti-HBsAg IgG titers. In conclusion, the production of antigen-specific effector memory CD4(+) T cells after vaccination, which is critical to achieve an adequate humoral response, is severely impaired in patients with ESRD.     

Melanoma skews dendritic cells to facilitate a T helper 2 profile

BACKGROUND: Patients with progressing melanoma have a circulating cytokine profile reflecting a T helper cell type 2 (Th2) imbalance, while patients responding to therapy favor a Th1 profile. The aim of this study was to determine the role of circulating dendritic cells (DCs) in mediating this imbalance. METHODS: Isolated human peripheral blood mononuclear cells (PBMCs) were exposed to cell-free melanoma-conditioned medium (MCM) or control fibroblast-conditioned medium before stimulation. In separate experiments, isolated circulating DCs were exposed to MCM before addition of T cells. DC maturation and function were determined. Mixed leukocyte response T-cell proliferation was quantified and supernatants were assayed for Th1 (interleukin [IL]-2 and interferon gamma) and Th2 (IL-4, IL-5, and IL-10) cytokines. RESULTS: PBMCs exposed to MCM produced significantly more Th2-type cytokines (IL-4, IL-5, and IL-10) over time than those exposed to control medium. DCs exposed to MCM before addition of T cells, produced a similar pattern of a sustained longer term Th2 response after an initial burst of IL-2. Exposure to MCM did not significantly affect DC maturation or IL-12 production. T-cell proliferation did not change significantly in the mixed leukocyte response, however, the percentage of viable CD4+ T cells in the MCM-treated group was significantly less than control (37 vs 50%, P < .05). CONCLUSIONS: Exposure of PBMCs to melanoma produces a Th2-type cytokine profile, which may be, in part, facilitated by DCs.     

干预协同刺激信号诱导不明原因早期复发性流产患者外周血Th1/Th2转换的体外研究

目的观察体外干预细胞毒性T细胞相关抗原4(CTLA-4)对不明原因早期复发性流产(URSA)患者外周血辅助性T细胞(Th)1/Th2转换的影响。方法用人绒毛膜癌细胞株JEG-3制备的滋养细胞抗原刺激30例URSA患者外周血单核细胞,分为实验组A:加重组蛋白CTLA-4Ig(10和1 mg/L)组,实验组B:加CTLA-4抗体(10和1 mg/L)组;对照组:加IgG(10和1 mg/L)组。采用酶联免疫吸附试验(ELISIA)测上清液中白细胞介素(IL)-2、干扰素γ(IFN-γ)和IL-4水平。结果与相应浓度的对照组相比,CTLA-4Ig组IL-4水平显著升高(P<0.05),IL-2显著降低(P<0.05),IFN-γ两组间无显著性差异(P>0.05);而CTLA-4抗体组IL-4水平均显著低于对照组(P<0.01),而IFN-γ、IL-2水平均明显高于对照组(P<0.05)。CTLA-4Ig 10 mg/L组与CTLA-4Ig 1mg/L组比较,IL-4显著升高(P<0.05),IL-2显著降低(P<0.05),IFN-γ两组间无显著性差异(P>0.05)。与同浓度的对照组及CTLA-4抗体1 mg/L组相比,CTLA-4抗体10 mg/L组IL-4较低,而IFN-γ和IL-2稍高,但两组间亦无显著性差异(P>0.05)。结论CTLA-4Ig使URSA患者Th1/Th2型细胞因子向Th2型细胞因子偏移,有利于URSA的治疗;而CTLA-4抗体可以上调Th1型细胞因子,下调Th2型细胞因子,不利于妊娠。     

Response to a Vaccination Schedule With 4 Doses of 40 μg Against Hepatitis B Virus in Cirrhotic Patients Evaluated for Liver Transplantation

We conducted a retrospective study to evaluate the response to recombinant hepatitis B vaccine after 4 intramuscular doses (40 μg) administered at 0, 1, 2, and 6 months in 157 cirrhotic patients who were liver transplant candidates. Seventeen nonresponders were revaccinated with the same schedule. We studied the association between the following variables and the vaccine response: age, gender, etiology of cirrhosis, diabetes, severity of liver disease (Child-Pugh class and Model for End-Stage Liver Disease [MELD] score), and the number of administered doses. The response rates were: 1 dose, 40% (2/5); 2 doses, 0% (0/7); 3 doses, 32.7% (16/49); and 4 doses, 31.3% (30/96) of patients. The median hepatitis B surface antibody (anti-HBs) titer was 45 mU/mL (range, 11-620 mU/mL). The response rate to revaccination was 41.2% (median anti-HBs titer, 88 mU/mL; range, 18-190 mU/mL). Diabetics showed a lower response rate than nondiabetic patients (17.2% vs 35.3%; P = .046). No association was observed between the response rate to vaccine and the other variables. In conclusion, the response rate to hepatitis B vaccine reached a little more than 30% in cirrhotic patients who received 3 or 4 doses. No higher response rate was observed among patients who received 4 doses. Diabetes was associated with a lower response rate. Anti-HBs seroconversion rates were not associated with the other variables. Revaccination may significantly increase the response rate to hepatitis B vaccine in cirrhotic patients, and may be considered in nonresponders after the third dose. Early vaccination against HBV should be considered in such patients.     

Immunologic Human Renal Allograft Injury Associates with an Altered IL-10/TNF-α Expression Ratio in Regulatory B Cells

Human B cells with immunoregulatory properties in vitro (Bregs) have been defined by the expression of IL-10 and are enriched in various B-cell subsets. However, proinflammatory cytokine expression in B-cell subsets is largely unexplored. We examined the cytokine profiles of human PBMCs and found that subsets of CD24^hiCD38^hi transitional B cells (TrBs), CD24^hiCD27⁺ memory B cells, and naïve B cells express IL-10 and the proinflammatory cytokine TNF-α simultaneously. TrBs had the highest IL-10/TNF-α ratio and suppressed proinflammatory helper T cell 1 (Th1) cytokine expression by autologous T cells in vitro more potently than memory B cells did, despite similar IL-10 expression. Whereas neutralization of IL-10 significantly inhibited TrB-mediated suppression of autologous Th1 cytokine expression, blocking TNF-α increased the suppressive capacity of both memory and naïve B-cell subsets. Thus, the ratio of IL-10/TNF-α expression, a measure of cytokine polarization, may be a better indicator of regulatory function than IL-10 expression alone. Indeed, compared with TrB cells from patients with stable kidney graft function, TrBs from patients with graft rejection displayed similar IL-10 expression levels but increased TNF-α expression (i.e., reduced IL-10/TNF-α ratio), did not inhibit in vitro expression of Th1 cytokines by T cells, and abnormally suppressed expression of Th2 cytokines. In patients with graft dysfunction, a low IL-10/TNF-α ratio in TrBs associated with poor graft outcomes after 3 years of follow-up. In summary, these results indicate that B cell–mediated immune regulation is best characterized by the cytokine polarization profile, a finding that was confirmed in renal transplant patients.     

In vitro cytokine responses in liver transplant recipients treated with cyclosporine A and tacrolimus

The inhibitory effect of Cyclosporine A (CsA) and Tacrolimus (Tacr) on interleukin 2 (IL-2) are well known, and the importance of Th1-type (IL-2, interferon gamma), and Th2-type (IL-4, IL-6, and IL-10) cytokine secretion in preventing allograft rejection is a controversial issue. The immunological mechanisms involved in long-term liver transplant recipients under CsA and Tacr were not studied precisely.
This study was designed to evaluate the effects of CsA and Tacr on the immune response of 62 long-term survivors following liver transplantation.
T-cell and B-cell subpopulations, the T helper (Th) cell activity, T-cell cytokine production, Staphylococcus aureus Cowan strain I (SAC-I)-stimulated B-cell responses and PWM-stimulated B-cell responses were examined.
CsA and Tacr decreased whole T-cell populations as well as CD4+T-cell IL-2 responses (p < 0.005, Tacr and p = 0.02, CsA), impaired CD4+ cell Th activity (p < 0.01, Tacr and p = 0.02, CsA) and reduced SAC-I-stimulated B-cell responses (immunoglobulin-secreting cells [ISC]: p = 0.001, Tacr and p < 0.05, CsA). A significantly impaired T-cell IL-10 secretion (p = 0.0001) and decreased Th function of whole T cells was found in Tacr-treated patients only, whereas unstimulated Th1 responses and SAC-I-stimulated B-cell IL-6 responses were reduced in CsA-treated patients.
Our data show that Tacr suppresses T-, CD4+-, and B-cell responses more effectively than CsA which may be relevant in the maintenance of long-term stable liver graft function.     

Cytokine profile of liver- and blood-derived nonspecific T cells after liver transplantation: T helper cells type 1/0 lymphokines dominate in recurrent hepatitis C virus infection and rejection

Orthotopic liver transplantation (OLT) is a successfultreatment in patients with hepatitis C virus (HCV)-associated end-stage liver disease worldwide. T lymphocytes and their cytokines are believed to have a pivotal role in the defense against HCV and in allograft rejection. An immunosuppressive drug regimen may cause a cytokine imbalance toward a T helper (TH) cell type 2 profile that is associated with the persistence of infection and acceptance of the graft. The aim of this study is to assess whether cytokine imbalances toward a TH 1- or TH2-type response may have a role in recurrent HCV infection and rejection after OLT Twenty-one intrahepatic Tcell lines of 15 patients with recurrent HCV infection after OLT (group A) and 15 lines of 11 patients with rejection (group B) were studied. Both patient groups had received liver allografts because of HCV-associated end-stage liver disease. Patients with HCV-induced liver disease who did not undergo OLT served as controls: 17 patients with chronic hepatitis C (CH-C) and 8 patients with cirrhosis. At the time of liver biopsy, 14 blood-derived Tcell lines of 12 patients with recurrent HCV infection, 7 of 10 patients with rejection, and 18 of 18 control patients were also investigated. Regardless of the underlying disease (recurrent HCV infection, rejection, HCVinduced hepatitis, and cirrhosis), all liver tissue-derived Tcell lines produced interferon-'Y; some additionally produced interleukin-4 (IL-4), but none produced IL-10, indicating that the TH0/1 cytokine profile dominates. Tcell lines showing a TH1 cytokine profile derived from intrahepatic T cells could be established significantly more often in recurrent HCV infection and rejection than in controls with CH-C (Fisher's exact test, P < .05). The cytokine profile of intrahepatic T cells did not differ from that obtained in peripheral blood. TH0/1 cytokine profile dominates the intrahepatic and blood-derived immune response in recurrent HCV infection and rejection after OLT regardless of the mode of immunosuppressvn. The lymphokine profile of immunocompromised patients with recurrent HCV infection or rejection does not differ principally from that of patients with HCV-induced hepatitis and cirrhosis, but seems to show a TH1 profile significantly more often.     

Naturally occurring prostate cancer antigen-specific T cell responses of a Th1 phenotype can be detected in patients with prostate cancer

BACKGROUND: Cytotoxic T cells (CTL) are considered one of the primary effector cell populations in antitumor immunity. Recent studies, however, have demonstrated the critical importance of helper T cells (Th), specifically interferon gamma (IFN gamma)-secreting Th1 cells, either by supporting an appropriate CTL environment or by recruiting other effector cells. We evaluated whether patients with prostate cancer have naturally occurring Th-cell responses specific for two prostate cancer-associated antigens, prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP), and whether Th1-type responses to these antigens could be detected. METHODS: Peripheral blood mononuclear cells (PBMC) were collected from 80 patients with prostate cancer and 20 male controls without prostate disease. Th-cell responses were evaluated by measuring antigen-specific proliferation. IFN gamma and IL-5 secretion in response to antigen stimulation was determined by enzyme-linked immunosorbent assay. RESULTS: T cell proliferative responses specific for PSA and PAP could be detected in patients with prostate cancer. Six percent (5/80) of patients had T cell responses specific for PSA and 11% (9/80) for PAP. T cell responses specific for PSA were more prevalent in patients with metastatic disease (P = 0.02), whereas responses specific for PAP could be detected in patients irrespective of disease stage. IFN gamma-producing Th cells, specific for both PSA and PAP, could be identified in patients with prostate cancer. CONCLUSIONS: Patients with prostate cancer can have detectable Th-cell responses specific for the prostate cancer-associated proteins PSA and PAP. The presence of antigen-specific Th1 immune responses in prostate cancer patients suggests that an immune environment capable of supporting antigen-specific CTL may exist in vivo. Prostate 47:222-229, 2001.     

Downregulation of T helper type 1 immune response and altered pro-inflammatory and anti-inflammatory T cell cytokine balance following conventional but not laparoscopic surgery

BACKGROUND: The clinical advantages of laparoscopic procedures result from a minimized surgical trauma. The present study was performed to investigate immunosupression following laparoscopic operations as compared with open surgery. Our analysis focused on the T cell secretion of cytokines that regulate the critical balance of either T helper type-1 (Th1)- and Th2-mediated immune responses on pro- and antiinflammatory activities. METHODS: In a prospective study, immunological data of 26 patients submitted to laparoscopic cholecystectomy (LCE) and 17 patients undergoing conventional cholecystectomy (CCE) for symptomatic cholecystolithiasis were compared. Patients with acute cholecystitis and patients developing postoperative complications or receiving immunosuppressive medication were excluded. Production of interferon (IFN)-gamma, interleukin (IL)-2, IL-4, tumor necrosis factor (TNF)-alpha, and IL-10 by isolated T cells stimulated by cross-linking of CD3 and CD28 was evaluated preoperatively as well as on postoperative days 1 and 6 or 7. Cytokines were measured by immunoenzymometric assay. RESULTS: IFN-gamma, TNF-alpha, and IL-2 production by T cells decreased significantly by 48.3%, 36.6%, and 36.8%, respectively, on postoperative day 1 after CCE, but not after LCE. These results indicate severe suppression of Th1-type and proinflammatory cytokines after the open operation. In contrast, IL-4 and IL-10 did not show significant changes in either group suggesting that Th2 cell response and anti-inflammatory activity remained normal. CONCLUSIONS: The present study shows that open, but not laparoscopic cholecystectomy is associated with a marked suppression of T lymphocytes functions as indicated by deregulation of both the Th1/Th2 and the pro-/anti-inflammatory cytokine balance. The results therefore suggest that downregulation of Th1 cell-mediated immune response and pro-inflammatory activity of T cells is a hallmark of open, but not laparoscopic surgery.     

Immunogenicity and safety of an experimental adjuvanted hepatitis B candidate vaccine in liver transplant patients.

Patients with chronic liver disease are at higher risk of hepatitis B (HB) virus infection before and after liver transplantation, and they commonly have a suboptimal immune response to HB vaccines. In this randomized trial, we compared the immunogenicity of primary vaccination with 2 doses of an experimental adjuvanted HB vaccine (adjuvant system 04 containing aluminium and monophosphoryl lipid A [HB-AS04]) to that of 3 double doses of a licensed HB vaccine in 93 liver transplant candidates. Depending on the waiting list for liver transplantation, a booster dose of HB-AS04 or double booster dose of the licensed HB vaccine was given before or after surgery, at 6 to 12 months after initiation of the vaccination course. The percentage of subjects with seroprotective anti-HB surface antibody concentrations 1 month after booster was twice as high in the HB-AS04 group (60.0%), vs. patients in the comparator group (32.0%) (P = 0.035). In subjects who did not undergo liver transplantation before administration of the booster, better immunogenicity results were obtained: 80% of subjects were seroprotected after HB-AS04 vaccination vs. 60% with the comparator (P = 0.2302). Despite a slightly higher reactogenicity, the safety profile of the HB-AS04 vaccine was clinically acceptable. In conclusion, an improved antibody response was observed in liver transplant candidates with 3 doses of HB-AS04, as compared to 4 double doses of a comparator. Liver transplant candidates could benefit from the use of this experimental adjuvanted HB vaccine to further increase their protection against HB infection.     

Immune responses and prediction of major infection in patients undergoing transhiatal or transthoracic esophagectomy for cancer

OBJECTIVE: To investigate alterations in immune responses after transhiatal versus transthoracic esophageal resection and to evaluate the role of preoperative immune functions in predicting postoperative infectious complications. SUMMARY BACKGROUND DATA: Impaired immune defense is associated with a decreased resistance to infection. Patients undergoing esophageal resection via a transhiatal or transthoracic approach are prone to develop infectious complications. There are no randomized data on immune responses after two major surgical interventions. METHODS: The study group consisted of 20 patients who were randomly allocated to a limited transhiatal or extended transthoracic esophagectomy for cancer. Blood samples were taken before the operation and at regular intervals thereafter from day 1 to day 10. Monocyte and T-helper type 1 (Th1) and type 2 (Th2) lymphocyte functions were assessed in stimulated whole blood cultures. RESULTS: Both surgical groups had severely depressed in vitro production of interleukin (IL)-12, IL-10, interferon-gamma, IL-2, IL-4, and IL-13 on postoperative day 1. Depression of Th2-type cytokine production was more profound after transthoracic than after transhiatal esophagectomy (IL-4, P=.005; IL-13,P=.007). Postoperative reduction in Th1-type cytokine production was similar between the two groups (interferon-gamma, P=.40; IL-2, P=.06). Irrespective of the surgical approach, patients who developed major infectious complications after surgery presented with a diminished T-cell cytokine production before the operation compared to those who had a relatively uneventful recovery (IL-4, P=.045; interferon-gamma, P=.064). In regression analysis, the occurrence of postoperative major infection was best predicted by increased duration of anesthesia ( P<.0001) and low preoperative interferon-gamma production ( P=.006). CONCLUSIONS: Both transhiatal and transthoracic esophagectomy induced severely depressed monocyte and T-lymphocyte cytokine production. The extent of the surgical procedure had a differential immunosuppressive impact on Th2-type but not on Th1-type cell activity, indicating that the two Th pathways were downregulated through distinct mechanisms. Preoperative interferon-gamma determination would be useful to anticipate the occurrence of postoperative major infectious complications.     

Characteristic cytokine products of Th1 and Th2 cells in hemodialysis patients.

Dysfunction of the host defense against infection in hemodialysis (HD) patients has major clinical and socioeconomic implications. T helper type 1 (Th1) and type 2 (Th2) cytokines are implicated in regulating the immune responses and, therefore, may be involved in impaired status. The present study was designed to examine Th1 and Th2 cytokine profiles in 22 stable HD patients (aged 63 +/- 11 years) and 22 healthy controls (aged 60 +/- 6 years). The T cell activity was significantly retarded in HD patients as compared with normal persons. The proportions of T cytotoxic/suppressor cells and natural killer cells were significantly higher in HD patients than in controls. In contrast, the proportions of T helper/inducer and B cells were significantly lower in HD patients than in controls. The production of interleukin (IL) 2, which is involved in cell-mediated immune responses, and the production of IL-4 and IL-10, which affect humoral immunity, were significantly lower in patients than in controls. The production of IL-12 by macrophages and of interferon gamma by Th1 cells was significantly higher in HD patients than in controls. The concentration of plasma sIL-2R was significantly higher in patients than in controls. These results suggest that both cellular immunity induced by Th1 and humoral immunity induced by Th2 decrease in HD patients, but that improved IL-12 secretion by macrophages activated natural killer cells to produce interferon gamma, which in turn induced macrophage activity.     

Granulocyte-macrophage colony-stimulating factor as an adjuvant to hepatitis B vaccination in maintenance hemodialysis patients

Patients on maintenance hemodialysis (HD) have poor seroconversion rate after hepatitis B vaccination. The present study was designed to test the efficacy of granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjuvant to hepatitis B vaccination for improving seroconversion rate in maintenance HD patients. Twelve chronic HD patients were randomly assigned to receive either hepatitis B vaccination alone or hepatitis B vaccination 24 h after 1 dose of GM-CSF for primary immunization. A group of 16 chronic HD patients who had not seroconverted after a standard two-dose hepatitis B vaccination were randomly assigned either to a booster dose of hepatitis B vaccine alone or a booster dose given 24 h after one dose of GM-CSF. In the primary immunization group only 2 of 6 patients (33%) who had received vaccination alone, versus 5 of 6 patients (83%) who had received hepatitis B vaccine after one dose of GM-CSF, developed seroprotective antibody titers. Moreover, seroprotective antibody titers (IU/ml) were significantly higher in the latter group (275 +/- 286.5 vs. 14 +/- 22, p < 0.05). In patients who had not seroconverted with prior hepatitis B vaccination, GM-CSF adjuvant therapy significantly increased the seroconversion rate versus booster dose alone (87.5 vs. 25%, respectively, p < 0.02), with significantly higher seroprotective antibody titers (84 +/- 80 vs. 19 +/- 33 IU/ml, respectively, p < 0. 05). These findings suggest that administration of one dose of GM-CSF, as adjuvant therapy, prior to primary or booster dose hepatitis B vaccination may significantly increase seroconversion rate and seroprotective antibody titers in chronic HD patients.     

T-cell activation follows Th1 rather than Th2 pattern in haemodialysis patients.

BACKGROUND: Patients on chronic intermittent haemodialysis (HD) show an impaired cellular and humoral immune response that clinically appears with frequent infectious complications and low vaccination responses. This immune defect strongly correlates with reduced in vitro proliferative responses of T cells. The defect is localized in antigen presenting cells, which show a decreased co-stimulatory activity. Furthermore, the impaired immune response correlates with an increased production of pro-inflammatory cytokines. In response to primary activation, CD4 positive T helper (Th) cells mainly differentiate into either Th1 or Th2 cells. Th1 cells support cell mediated immunity whereas Th2 cells enhance humoral immune responses. Since both types of responses mutually inhibit each other, the impaired humoral immune response seen in HD patients could either be due to a reduced number of Th2 cells or to a predominant Th1 response. METHODS: We analysed the Th cell profile in HD patients using flow cytometry. Monocytic cytokine expression was analysed using both flow cytometry and enzyme linked immunoadsorbant assays. RESULTS: Our data demonstrate that the cytokine differentiation profile in circulating T cells from HD patients is dysregulated and characterized by an increase in Th1 cells, but a normal amount of Th2 cells. Moreover, the skewed helper cell responses correlate with a higher percentage of monocytes capable of secreting the Th1 promoting cytokine interleukin 12 (IL-12). CONCLUSIONS: Our findings contribute to a better understanding of the pathogenesis of impaired cellular immune functions in dialysis patients and, in particular, the decreased antibody production after vaccination. They provide a link between overproduction of pro-inflammatory cytokines (IL-12) and imbalanced T-cell activation.     

Increased CD4+ CD25+ T regulatory cell activity in trauma patients depresses protective Th1 immunity

OBJECTIVES: We recently reported increased CD4 CD25 T regulatory (Treg) activity after burn injury in mice. This study sought to determine if Tregs mediate the reduction in TH1-type immunity after serious injury in man and if Treg function is altered by injury. METHODS: Peripheral blood was withdrawn from 19 consenting adult patients (35.1 +/- 16.3 years of age) with Injury Severity Scores (ISS) 36.6 +/- 13.9 on days 1 and 7 after trauma and from 5 healthy individuals. CD4 T cells were purified and sorted into Treg (CD25(high)) and Treg-depleted populations. After activation of cells with anti-CD3/CD28 antibody, production of the TH1-type cytokine IFNgamma, TH2-type cytokines (IL-4 and IL-5), and the inhibitory cytokine IL-10 was measured using cytometric bead arrays. Treg activity was measured by in vitro suppression of autologous CD4 T cell proliferation. RESULTS: All patients survived, 9 (47%) developed infection postinjury. IFNgamma production by patient CD4 T cells was decreased on day 1 and day 7, when compared with healthy controls. However, when Tregs were depleted from the CD4 T cells, the IFNgamma production increased to control levels. Tregs were the chief source of IL-4 and IL-5 as well as IL-10. Treg suppression of T cell proliferation increased significantly from day 1 to day 7 after injury. CONCLUSIONS: We demonstrate for the first time that human Tregs are increased in potency after severe injury. Most significantly, Tregs are important mediators of the suppression of T cell activation and the reduction in TH1 cytokine production found after injury.