Changes in immunological parameters after conversion from cyclosporine A to azathioprine in renal transplant recipients

Long term CsA therapy did not interfere with the basal levels of natural killer (NK) activity in stable cadaveric renal transplant recipients. However, 3 months after changing immunosuppressive therapy from CsA to AZA, NK activity was significantly decreased (36 +/- 25% vs 19 +/- 15%, P less than 0.01). Following in vitro exposure to IFN-gamma an increase in NK activity from 36 to 44% (P less than 0.05) could be induced during CsA therapy but this was no longer observed after conversion to AZA (19 to 22%, N.S.). A prominent decline in the number of NK cells expressing the surface receptor for the Fc portion of IgG was also found postconversion. The IFN-gamma production capacity after mitogen stimulation of unprimed lymphocytes was more depressed during CsA than during AZA therapy (median 25 vs 80 U/ml 10(6) cells, P less than 0.05), suggesting a reversible inhibition of CsA on lymphokine production. Despite the better IFN-gamma production capacity, both the activity, inducibility and number of NK cells were significantly lower under AZA therapy than under CsA therapy. These findings indicate that CsA exerts its immunosuppressive action without an important interference with NK activity. Monitoring mononuclear cells showed a decrease in absolute numbers of all phenotypically distinct cells studied after conversion. The prominent decrease in CD 8 cells resulted in an increase of CD 4/CD 8 ratio.     

Natural killer cell activity in renal transplant recipients receiving cyclosporine.

Normal subjects (n = 11) had a mean circulating natural killer (NK) cell activity of 188 lytic units per 10(7) peripheral mononuclear blood leukocytes. This activity was significantly enhanced by in vitro incubation with 500 U of alpha-interferon (+207 lytic units). The mean NK activity of renal transplant recipients on azathioprine (n = 17) or on cyclosporine (n = 17) studied at various times after transplantation was significantly decreased, as was the ability of interferon to enhance NK activity. In the cyclosporine group, interferon could not enhance NK titers 1 to 6 weeks after transplantation when the patients were on the highest doses of cyclosporine (mean, 1,002 mg/day) or when they were viremic for cytomegalovirus. After 18 weeks, when the patients received 546 mg/day or when viremia was no longer detected, the ability of interferon to enhance NK activity was more normal. Cyclosporine and cytomegalovirus infection may have a greater effect on the action of interferon on NK activity than on the NK titer per se. This defect may diminish the reserve of NK cells and contribute to post-transplant immunosuppression.     

Comparison of three immunosuppressive regimens in cadaver renal transplantation: long-term cyclosporine, short-term cyclosporine followed by azathioprine and prednisolone, and azathioprine and prednisolone without cyclosporine

We conducted a randomized trial in seven Australian hospitals of the efficacy and safety of three immunosuppressive regimens after first transplantation of a cadaver kidney: long-term cyclosporine, short-term (three months) cyclosporine followed by azathioprine and prednisolone, and azathioprine and prednisolone without cyclosporine. Patients assigned to long-term cyclosporine (n = 138) or short-term cyclosporine followed by azathioprine and prednisolone (n = 141) had similar actuarial 12-month survival (98.4 vs. 96.4 percent) and graft survival (83.9 vs. 82.1 percent). Patients assigned to receive only azathioprine and prednisolone (n = 138), with optional use of antithymocyte globulin, had a significantly poorer survival rate (91.3 percent, P = 0.015) because of deaths from cardiac causes and infection, but their graft survival of 76.0 percent (P = 0.31) did not differ significantly from that of either group receiving cyclosporine. After the switch from cyclosporine to azathioprine and prednisolone, 15 percent of patients had reversible rejection episodes, but the frequency of rejection and graft loss did not differ from that in the long-term cyclosporine group. After the change to azathioprine and prednisolone, serum creatinine levels declined in nearly all patients, so that after three months they were comparable to those in the group receiving azathioprine and prednisolone only, and significantly lower than those in the group receiving long-term cyclosporine therapy (P less than 0.003). We conclude that the two cyclosporine regimens result in comparable patient and graft survival, but that changing to azathioprine and prednisolone at three months improves graft function.     

Different profiles of cytomegalovirus RNA transcripts and anti-cytomegalovirus IgM antibodies in renal transplant recipients.

BACKGROUND: A difference in anti-cytomegalovirus IgM antibody profile has been found between sera from acutely cytomegalovirus (CMV)-infected patients and sera from CMV-infected patients with subclinical infection. OBJECTIVES: The aim of this study is to investigate whether such different IgM antibody responses are correlated with differences in the expression of CMV immediate early and late mRNAs. STUDY DESIGN: We have investigated the anti-CMV IgM response in 46 renal transplant recipients by employing two commercially available IgM kits (AxSYM and IMX) as well as two novel enzyme-linked immunosorbent assays (ELISAs), which were developed using recombinant ppUL32 (pp150) and pUL80a (p38), respectively. The results were compared with four direct CMV diagnostic tests: pp65 antigenemia, viral culture and nucleic acid sequence-based amplification (NASBA), detecting either CMV immediate early 1 (IE1) mRNA (IE1-NASBA), or CMV pp67 (late) mRNA (pp67-NASBA). RESULTS: Analysis of all CMV-infected recipients (n=28) showed that in 16 recipients (group I) more than one direct test became positive after transplantation, while in the other 12 recipients (group II), IE1-NASBA was the only direct test to become positive. In group I, 100, 81, 100 and 50% of the recipients were IgM-positive with AxSYM, IMX, p38 and pp150, respectively. In group II, 100, 83, 17 and 83% of the recipients were IgM-positive with AxSYM, IMX, p38 and pp150, respectively. CONCLUSIONS: Our data indicate that the IgM-response against p38 and pp150 differs significantly (P<0.01) between group I recipients with productive CMV infection, and group II recipients with a non-productive CMV infection which may be of diagnostic and prognostic relevance.     

环孢素治疗丙型肝炎病毒RNA阳性肾移植患者的抗病毒复制效应

背景：丙型肝炎病毒阳性患者接受肾脏移植后,免疫抑制剂的选择及抗丙型肝炎病毒药物的选用是目前关注的重点。 目的：探讨环孢素在丙型肝炎病毒RNA阳性肾移植患者中除抗排斥作用以外的抗病毒复制作用。 方法：纳入11例丙型肝炎病毒RNA阳性肾移植患者,于采用环孢素+咪唑立宾+泼 尼松治疗方案时记为入组,分别对入组前、入组后6,12个月时患者丙型肝炎病毒RNA、血红蛋白、肝肾功能等指标的变化进行检测。 结果与结论：入组前、入组6个月、入组12个月11例患者丙型肝炎病毒RNA中位数(copies/mL)分别为1.22×10⁷,1.11×10⁴,4.19×10⁶;入组6个月时,有8例患者丙型肝炎病毒RNA转阴(丙型肝炎病毒RNA<500 copies/mL),总应答率为73%(8/11);至随访结束,持续病毒学应答率为55%(6/11)。且入组治疗前后患者谷丙转氨酶、血清肌酐、血尿酸水平差异均无显著性意义(P > 0.05),患者血红蛋白水平在入组后升高。随访过程中,仅1例发生排斥反应,甲基强的松龙冲击治疗 3 d后好转。提示对于合并丙型肝炎的肾移植患者,选用环孢素为主的治疗方案,在达到抗排斥治疗作用的同时,可发挥抑制丙型肝炎病毒复制的作用。     

Early metabolic changes in peripheral blood cells of renal transplant recipients treated with cyclosporine A.

We histochemically examined (phosphatase acid-AcP, phosphatase alkaline-ALP, succinate dehydrogenase-SDH, lactate dehydrogenase-LDH) the peripheral blood of renal transplant recipients and controls before (day 0) and after Cyclosporine A (CsA) treatment (days 1, 2, 7 and 30). We wanted to detect the metabolic changes induced in the CsA resistant cells (leucocytes) by CsA and to evaluate the early effects determined by the drug. There was no difference in enzyme activities between the control group and renal patients before CsA treatment (day 0). AcP and ALP activity increased 1 day after CsA administration and became similar to the control by the day 30. LDH activity increased one day after CsA treatment and remained high during the treatment period (30 days), while SDH activity did not change. These enzymatic variations may suggest that the LDH enzyme is involved in the drug degradation as are other phosphatase and oxidoreductase enzymes (i.e. cytochrome P450). Moreover, the high activity of LDH, the enzyme responsible for interconversion of pyruvate in lactic acid, would indicate that anaerobic glycolysis is preferentially used in the pyruvate pathway. However, SDH did not seem to be directly involved in CsA metabolism. Our findings showed that the CsA treatment induced clear variations of the activity of the cellular phosphatase and oxidoreductase enzymes from the first days of drug administration. The variation of the enzymes studied and the appearance time and duration of the metabolic changes, may be markers of the cellular stress due to CsA internalization.     

Neutrophil functions in renal transplant recipients.

Neutrophils obtained from peripheral blood of renal allograft recipients were studied for their ability to kill Gram-positive and Gram-negative bacteria as well as to enhance intracellular metabolism measured by the reduction of NBT salts. In addition, the influence of sera these patients on normal cells was investigated. At the same time, these cells were also tested for candidacidal activity. The data derived from these studies indicate that phagocytic cells from these patients are impaired with respect to their capacity to fight the pathogenic microorganisms as well as their sera do not promote normal killing of microorganisms, while the NBT reaction is not changed significantly. Large doses of steroids and rejection crises do not appear to affect dramatically these functions, while an ATG therapy abolishes neutrophil killing ability.     

Viral infections in renal transplant recipients.

Cytomegalovirus (CMV) infections are common in renal transplant recipients. We studied 23 recipients prospectively to determine whether infections by other herpes-group and non-herpes-group viruses were also present. Sera, obtained at the time of surgery and periodically thereafter, were tested for antibody to CMV, herpes simplex virus (HSV), Epstein-Barr virus (EBV), parainfluenza viruses types 1, 2, and 3, and the viruses of measles and rubella. We found no evidence of an unusual incidence of primary or secondary infection by the non-herpesviruses tested. Rises to CMV, HSV, and EBV antibody titers occurred in 43, 38, and 32% of patients, respectively. All serological rises to herpes-group viruses occurred in patients seropositive at the time of transplantation, with the exception of three patients who experienced primary CMV infections. We conclude that reactivation of all herpes-group viruses tested may occur in transplant recipients. Morbidity was associated only with primarly CMV infection.     

Elective conversion from cyclosporine to azathioprine in recipients with stable renal function 6 months after kidney transplantation

The average cost of cyclosporine over the first 6 months after renal transplantation has been $2450/recipient for recipients with stable renal function. Fifty-nine percent of all patients transplanted in 1984 do not have a third-party payment mechanism for outpatient medicines and many cannot afford cyclosporine. The expense of cyclosporine has, thus, mandated developing a protocol for conversion from cyclosporine to azathioprine. Using a protocol, which included a short overlap of cyclosporine and azathioprine and a temporary, modest increase in prednisone dose, 27 renal allograft recipients with stable renal function have undergone conversion of their immunosuppressive regimen approximately 6 months posttransplant with a minimum follow-up of 4 months from conversion. There has been no graft loss or patient death. Mean serum creatinine has been reduced in recipients with stable function after conversion (1.4 mg/dl 3 months postconversion compared to 1.8 mg/dl preconversion). However, acute breakthrough rejection has occurred in four recipients (15%), and, after reversal of rejection, mean serum creatinine is elevated (3.1 mg/dl) in this group. Only a single patient developed an infection during the conversion period. Thus, a policy of conversion from azathioprine appears to be a reasonable compromise for those patients who cannot afford long-term outpatient treatment with cyclosporine.     

Prostaglandin E2 in renal transplant recipients.

Prostaglandin E2 (PGE2), sodium, potassium and creatinine were determined in the blood and urine of 50 renal transplant recipients treated for at least one year post transplantation with cyclosporine A or azathioprine as immunosuppressive agent. Fourteen healthy subjects were used as a control group. The urinary PGE2 excretion was significantly decreased in the renal transplant recipients on azathioprine therapy while it was unchanged in the patients treated with cyclosporine A. At the same time, a significant decrease in urinary excretion of sodium and potassium was found. On the other hand, a high elevation of blood PGE2 concentration was observed while no significant changes were seen in sodium and potassium in the blood of these renal transplant recipients. It is suggested that an association exists between urinary PGE2 reduction and immunosuppressive treatments in renal transplant recipients and that PGE2 may regulate intrarenal haemodynamics and influence renal tubular electrolyte excretion. Finally, urinary PGE2 can be used as an indicator of successful renal transplantation.     

Effect of herpesvirus infections on T-lymphocyte subpopulations and blastogenic responses in renal transplant recipients receiving cyclosporine

The immunosuppressive effects of three herpesviruses--cytomegalovirus (CMV), Epstein-Barr virus (EBV), and herpes simplex virus (HSV)--were assessed in 29 renal transplant recipients treated with cyclosporine and prednisone. The ratios of Leu 3-positive ("helper-inducer") to Leu 2-positive ("suppressor-cytotoxic") T lymphocytes in peripheral blood were only moderately and transiently decreased during primary CMV infection, with or without concurrent reactivated EBV and HSV infections. This effect was due to an increase in absolute numbers of Leu 2-phenotypic and decrease in Leu 3-phenotypic T cells and was associated with symptomatic viral illness. Reactivated CMV infection alone or together with reactivated EBV and HSV infections resulted in less significant alterations in T-cell subsets than did primary CMV infection. Lymphocyte blastogenesis was not significantly altered during the herpesvirus infections. The data suggest that cyclosporine treatment inhibits the activation of suppressor cells and depression of cellular immune function that have been associated with herpesvirus infections in renal transplant recipients undergoing conventional immunotherapy.     

Switch from cyclosporine A to tacrolimus in renal transplant recipients: impact on Th1, Th2, and monokine responses

We showed previously that pretransplant CD4 helper defects and low in-vitro IL-10 responses predict a low risk of acute kidney graft rejection. To compare the effect of tacrolimus (Tacr) and cyclosporine A (CsA) on the humoral immune response we assessed T helper function, B cell/monocyte responses and in-vitro cytokine responses (TNF-alpha, GM-CSF, IL-1 beta, IL-2, IL-4, IL-6, IL-10) in 20 renal transplant recipients before and 3 months after they were switched from CsA to Tacr because of hyperlipoproteinemia, hirsutism, or gum hyperplasia. T helper function was assessed using a PWM-driven allogeneic coculture system of patient T cells together with control B cells. B cell/monocyte responses were determined using a PWM-stimulated allogeneic coculture system, SAC I-stimulated B-cell cultures and LPS-stimulated monocyte cultures. Immunoglobulin-secreting cell (ISC) responses were assessed in a reverse hemolytic plaque assay, and ELISA were used to determine cytokine secretion. Treatment with Tacr resulted in a decreased expression of costimulatory ligands and adhesion molecules (T cells: CD40L, p < 0.05; CD28 and CD54, p < or = 0.01; B cells: CD25, p = 0.05; CD40, p < 0.001; monocytes: CD40, p < 0.05), which coincided with decreased PHA-stimulated T cell IL-2 responses (398 +/- 153 versus 43 +/- 15 pg/ml, p < 0.05), impaired CD4 helper activity (117% +/- 22% versus 73% +/- 19%, p < 0.05) and increased CD4 suppressor activity (-120% +/- 28% versus -18% +/- 27%, p = 0.02). We observed enhanced CD4 IL-10 responses (p < 0.01) and LPS-stimulated monocyte responses (TNF-alpha, IL-1 beta, and IL-6, p < 0.005; IL-10, p < 0.05), indicating an increased humoral immune responsiveness under treatment with tacrolimus. Our data show that switching of immunosuppressive therapy from CsA to tacrolimus results in suppression of costimulatory ligands, adhesion molecules, Th1 responses and CD4 helper activity. However, enhanced humoral immune responses, Th2 and monokine responses, might have a negative impact on long-term graft function.     

Mononuclear subsets during cytomegalovirus disease in renal transplant recipients treated with cyclosporine and rabbit antithymocyte globulin

The effect of cytomegalovirus (CMV) disease on mononuclear subpopulations of 49 renal transplant recipients treated with cyclosporine and prednisone are reported. Clinical overt CMV infection developed in 8/21 patients treated for rejection with rabbit antithymocyte globulin. They all showed true inversions of the T helper/T suppressor-cytotoxic (Th/Ts-c) ratio. A reduction of T helper cells and increase in T suppressor-cytotoxic cells preceded clinical symptoms of CMV disease by one week. None of the 26 patients without RATG anti-rejection treatment developed CMV disease and in only three of them an inversion of Th/Ts-c ratio was found.     

B19 virus infection in renal transplant recipients.

BACKGROUND: B19 virus infection with persistent anaemia has been reported in organ transplant recipients. Detection of B19 virus DNA in serum is the best direct marker of active infection. OBJECTIVE: The present study evaluated the incidence and clinical role of active B19 virus infection in renal transplant recipients presenting with anaemia. STUDY DESIGN: Forty-eight such recipients were investigated by nested PCR on serum samples. The controls were 21 recipients without anaemia. Active HCMV infection was also investigated as a marker of high immunosuppression. RESULTS AND CONCLUSIONS: In 11/48 (23%) patients B19 virus DNA was demonstrated in serum versus only 1/21 (5%) of the controls. Ten of these 11 patients had already been seropositive at transplantation and active infection occurred in eight of them during the first 3 months after transplantation. The remaining patient experienced a primary infection 9 months after transplantation. Eight (73%) of these 11 patients displayed a concomitant HCMV infection and four (36%) showed increasing serum creatinine levels but none developed glomerulopathy; 3/11 (27%) recovered spontaneously from anaemia whereas 8/11 (73%) needed therapy. In conclusion, the relatively high occurrence (23%) of B19 virus infection in patients presenting with anaemia, suggests that it should be considered in the differential diagnosis of persistent anaemia in renal transplant recipients. Presence of the viral DNA should be assessed early from transplantation and the viral load should be monitored to follow persistent infection and better understand the relation between active infection and occurrence of anaemia, and to assess the efficacy of IVIG therapy and/or immunosuppression reduction in clearing the virus.     

环孢素A和他克莫司对肾移植受者外周血淋巴细胞活性影响的比较

目的：肾移植术后应用Calcineurin抑制剂需常规监测血清药物浓度,然而药物浓度并不能完全反应患者的免疫功能抑制状态,且药物的个体反应性差异较大,本研究旨在通过外周血单核细胞（PBMC）活性检测反应患者对Calcineurin抑制剂的敏感性。方法：采取40例肾移植受者术前抗凝血,Ficoll密度梯度离心法分离PBMC,置于RPMI1640培养基中培养,加入96孔培养板中予刀豆蛋白A刺激,并依次加入不同浓度的环孢素A（CsA）或他克莫司（TAC）,之后加入二苯基四氮唑溴盐（MTT）、二甲亚砜（DMSO）裂解后于波长570nm下测定吸光度。记录受试者肾移植后的急性排斥反应和巨细胞病毒感染等临床事件。结果：①受试者半数PBMC被抑制的药物浓度即为IC50。CsA和TAC的IC50均值分别为162.3ng/ml、0.289ng/ml,TAC对PBMC转化的抑制作用显著强于CsA;②Kendall相关系数分析示CsA的IC50与TAC的IC50之间有显著的相关关系（rk=0.3472,P=0.0082）;③CsA治疗组急性排斥反应发生率显著高于TAC组,而两组患者巨细胞病毒感染发生率差异不明显。结论：TAC抑制人PBMC母细胞转化能力约为CsA的589.1倍,因而TAC治疗的肾移植受者术后急性排斥反应发生率显著较低。将术前淋巴细胞的体外药敏试验与术后治疗性TDM合理结合,是改进个体化免疫抑制方案的举措之一。     

Erythropoiesis and erythropoietin levels in renal transplant recipients

Summary Moderately increased blood levels of endogenous erythropoietin (Epo) usually induce complete restoration of renal anemia after successful kidney transplantation. With good graft function erythropoiesis is maintained by normal Epo serum levels. Persistent anemia can be related to iron deficiency, low excretory graft function, and high dosage of immunosuppressive agents leading to marrow suppression or nephrotoxicity. Acute early rejection is associated with a fall in serum Epo and abrogation of reticulocytosis. About 15% of recipients fail to exhibit the normal feedback regulation and develop a mostly transient post-transplant erythrocytosis. Both an increased sensitivity of erythrocytic progenitors to Epo and inappropriate Epo secretion by the native kidneys may account for this overshooting reaction.Abbreviations Epo erythropoietin - rHuEpo recombinant human erythropoietin - RIA radioimmunoassay - ELISA enzyme-linked immunosorbent assay - RTx renal transplantation - CAPD continuous ambulatory peritoneal dialysis - PTE posttransplant erythrocytosis - Aza azathioprine - CsA cyclosporine A - ALG antilymphoblast globulin     

Pathology of digestive organs in renal transplant recipients

A necropsy study of the pathological findings in the digestive system of 19 renal transplant recipients revealed that gastrointestinal (GI), hepatobiliary, and pancreatic pathologies are common in renal transplant recipients. Fifteen of the 19 patients studied had GI pathology. Hepatobiliary pathology was the most common finding with all but one of the 19 cases exhibiting one or more abnormalities. Pancreatic abnormalities were less frequent with 11 patients demonstrating normal findings.     

Clinical outcomes of tuberculosis in renal transplant recipients

Tuberculosis (TB) is an important cause of morbidity and mortality in renal transplant recipients. Rifampin has a potent sterilizing activity, but it reduces the serum concentrations of the immunosuppressive agents. Moreover, the possible contribution made by mycobacterial infection to the incidence of graft rejection or renal dysfunction remains unclear. In this study, we investigated the recurrence of TB and graft survival duration according to rifampin usage, and we evaluated the factors that could influence the duration time until the recurrence of TB. Seventy-eight TB patients diagnosed after kidney transplantation were studied. Pulmonary TB was diagnosed in 26 of the 78 patients (33.3%), pleural TB in 23 (29.5%), combined pulmonary and pleural TB in 5 (6.4%), miliary TB in 19 (24.4%), and intestinal TB in 2 patients. In the pulmonary (pulmonary TB and pleural TB) TB group, no differences in graft survival and the TB free duration period were observed between the rifampin usage subgroup and the non- rifampin usage subgroup. In the extrapulmonary TB group, no difference was found in mean graft survival time between the rifampin usage subgroup and the non-rifampin usage subgroup, but the rifampin usage subgroup showed that the TB had a tendency to recur later than for the non-rifampin usage subgroup (87 +/- 8 vs. 44 +/- 7 months, respectively, p=0.30). The factor affecting the duration period until the recurrence of TB was the treatment duration (RR=0.761, p=0.030). This study suggests that rifampin does not affect graft survival in renal transplant recipients in whom immunosuppression is carefully monitored. Also, the study results indicate that rifampin may prevent a recurrence of extrapulmonary tuberculosis. Prolonged treatment appears to be appropriate for renal transplant recipients with TB.