Plan-do-study-act cycles as an instrument for improvement of compliance with infection control measures in care of patients after cardiothoracic surgery.

The aim of this study was to determine whether compliance with infection control measures for the care of patients during and after cardiothoracic surgery could be improved by using 'plan-do-study-act' (PDSA) improvement cycles in a 715-bed university hospital. The endpoints of these cycles were indices of correct procedure based on infection control standards. The intervention consisted of instruction and training of nursing and medical staff on the use of PDSA cycles, feedback of the baseline measurements, and the use of posters in the proximity of the operating room (OR). At follow-up, overall compliance only improved in the room used by the perfusionists and the OR. After the follow-up period, monitoring revealed a drop in compliance in the OR, but improved compliance during vascular catheter care of patients with prolonged stay in the intensive care unit (ICU), and during wound care of patients on the nursing ward. The last series of monitoring showed that compliance with general infection control measures in the OR had improved again, and that compliance had remained satisfactory on the ward and in the ICU, with the exception of patients recently transferred to the ICU from the OR. The results show that by using PDSA cycles, compliance with infection control measures can improve significantly. However, repeated monitoring is necessary to ensure continued compliance.

Cell survival in canine aortic heart valves stored in nutrient medium.

For transplantation of viable aortic valves a period of preservation will generally be needed. To maintain cell viability during this preservation period valves can be stored in nutrient medium after sterilisation in an antibiotic solution. To obtain quantitative data about the survival of aortic valve fibroblasts after preservation, we determined the number of viable fibroblasts in canine aortic valves after several weeks of preservation. The results shows that after storage of 1 week in nutrient medium cell survival is about 80%, after 2 weeks cell survival has declined substantially, while after 3 weeks survival is already unacceptably low. Storage for periods over 4 weeks results in almost completely non-viable aortic valves. These results show that only valves preserved for 1 to 2 weeks in nutrient medium can be considered as viable aortic valves.

Differential avidity and cyclosporine sensitivity of committed donor-specific graft-infiltrating cytotoxic T cells and their precursors. Relevance for clinical cardiac graft rejection.

We have used limiting dilution analysis to study the qualitative and quantitative differences between graft-infiltrating cytotoxic T cell populations propagated from endomyocardial biopsies of heart transplant patients who experienced one or more acute rejection episodes and patients who never showed signs of rejection. Limiting dilution cultures were stimulated with autologous or donor cells both in the absence or in presence of cyclosporine and of CD8 in the cytotoxic phase. Almost all antigen-primed, committed cytotoxic T cells (cCTL) present in the graft of patients with rejections were CsA resistant. In contrast, in most patients of the nonrejector group, a substantial part of the cCTL could be inhibited by CsA. The CTL precursors (pCTL) in both groups were predominantly CsA sensitive. Addition of CD8 mAb during the cytotoxicity phase of the limiting dilution analysis was used to differentiate between CTL populations with high avidity for donor antigens and populations with low avidity. The predominant subpopulation in the graft of rejectors was a CsA-resistant cCTL with high avidity, while in the graft of most nonrejectors, cCTL with low avidity dominated. In most rejectors, CD8 mAb had only a minor influence on the pCTL frequency estimates, and thus on T cells with high avidity. CsA-sensitive pCTL with high avidity might represent an intermediate stage between the naive pCTL and mature, functional, CsA-insensitive cCTL with high avidity for donor antigens.

Human heart endothelial-cell-restricted allorecognition.

We studied the reactivity of cardiac graft-infiltrating cells, cultured from endomyocardial biopsy specimens, toward heart endothelial cells (Hec). In two cases, Hec derived from the specific donor heart or Hec compatible with the donor were lysed, but not the syngeneic B cell line. A vessel-derived endothelial cell line was not lysed. Panel studies suggest that the epitopes recognized are, in one case, a Hec-specific peptide presented in the context of HLA-Bw41 and, in the other case, a Hec-specific peptide presented by a subtype of HLA-B44. In conclusion, we showed that cardiac graft-infiltrating cells cultured from endomyocardial biopsy specimens can exhibit cytotoxic reactivity specifically directed against HLA-peptide complexes on Hec.

C1.7 monoclonal antibody designates high-avidity CD4+ cytotoxic T lymphocytes involved in clinical heart rejection.

BACKGROUND: It is assumed that not all donor-specific cytotoxic T lymphocytes (CTLs), but only those with a high avidity for donor antigens, can function as terminal effector cells in transplant rejection. METHODS: In the present study, we searched for markers that would exclusively designate these high-avidity CTL. RESULTS: FACS analysis of donor-specific CTL clones obtained from heart transplant patients revealed that high- and low-avidity CTL varied in their expression of p38, a surface molecule involved in signal transduction, which is stained by the antibody C1.7. High- and low-avidity CD8+ CTL and high-avidity CD4+ CTL expressed p38, whereas low-avidity CD4+ CTL did not. Noncytotoxic and naive CD4+ lymphocytes also lacked p38 surface expression. CONCLUSION: Therefore, we conclude that p38 is a marker for CD4+ lymphocytes with the potency to damage the transplanted heart. Accordingly, p38 might be used to analyze the contribution of CD4+ CTL in immune responses, such as transplant rejection.

Donor-specific cytokine production by graft-infiltrating lymphocytes induces and maintains graft vascular disease in human cardiac allografts.

BACKGROUND: The development of graft vascular disease (GVD) in the allograft is a major impediment for long-term survival of heart transplant recipients. GVD may be mediated by cellular processes, in response to the transplanted heart, and regulated by cytokines. METHODS: We studied donor-specific cytokine production patterns in graft-infiltrating lymphocyte cultures propagated from endomyocardial biopsies. The biopsies were derived from patients with and without signs of GVD, as diagnosed by angiography at 1 year after heart transplantation. RESULTS: In the first year after transplantation, significantly more T-helper (Th) 1 cytokines (interleukin [IL]-2: P=0.04; interferon-gamma: P=0.01), but not Th2 (IL-4 and IL-6) cytokines, were produced by cultures of patients with GVD compared with patients without GVD. Thereafter, the Th1 cytokine levels in patients with GVD normalized to the levels of patients without GVD. Detectable levels of IL-6 were produced significantly more often (P=0.009) by cultures obtained more than 1 year after transplantation from patients with GVD. CONCLUSIONS: The results suggest that high levels of Th1 cytokines produced by graft-infiltrating lymphocytes early after transplantation may be responsible for activation of vascular endothelium, leading to the migration and proliferation of smooth muscle cells that is characteristic of GVD. IL-6, produced later after transplantation, continues this process by promoting smooth muscle cell proliferation.

A randomized trial comparing safety and efficacy of OKT3 and a monoclonal anti-interleukin-2 receptor antibody (BT563) in the prevention of acute rejection after heart transplantation.

In a prospective randomized trial, BT563, a murine IgG, anti-interleukin-2 receptor antibody, was compared with OKT3 for use as an early rejection prophylaxis after heart transplantation. Patients received either BT563 (n=31) or OKT3 (n=29) during the first 7 days after transplantation; cyclosporine was started on day 3. Median follow-up was 34 months. A cytokine release syndrome occurred in the majority of patients of the OKT3-treated group but in none of the BT563 recipients. The mean duration of electrical stimulation of the heart in the BT563 group was longer than in the OKT3 group (5.1 vs. 2.1 days). In both groups, one patient required insertion of a permanent pacemaker. Freedom from acute rejection at 3 months was not significantly different between the two groups (BT563: 5/29, 17%; OKT3: 6/29, 21%). In the BT563 group, however, rejection tended to occur earlier after transplantation. There was no difference in the overall incidence of rejection. The incidence of infectious complications was evenly distributed in both groups. Malignancies occurred in two patients, both in the OKT3 group. In conclusion, the use of this anti-interleukin-2 receptor monoclonal antibody in heart transplant recipients is safe and devoid of the side effects that accompany the use of OKT3. OKT3 and BT563 result in a similar freedom from rejection at 3 and 12 months after heart transplantation.

Blockade of the interleukin (IL)-2/IL-2 receptor pathway with a monoclonal anti-IL-2 receptor antibody (BT563) does not prevent the development of acute heart allograft rejection in humans.

BACKGROUND: Anti-interleukin (IL)-2 receptor (IL-2R) antibodies have been used as rejection prophylaxis after organ transplantation. Despite this induction treatment, acute rejections may occur. We wondered whether these rejections developed via the IL-2/IL-2R pathway. METHODS: In a prospective trial using BT563, a murine IgG1 anti-IL-2R antibody, for rejection prophylaxis after heart transplantation, 20 patients were treated in combination with cyclosporine from the day of transplantation (group A). As a control group, 31 patients were also treated with BT563, but in these patients, cyclosporine treatment was initiated on day 3 (group B). RESULTS: Three patients from group A and two patients from group B died in the first postoperative month (of causes not related to acute rejection) and were left out of the analysis of rejection incidence. Freedom from acute rejection at 1 week after transplantation in group A (14/17; 82%) was lower than in group B (16/29; 55%), although the difference did not reach statistical significance. There was no difference in either the number of acute rejection episodes at 12 weeks or the required rejection treatments between groups A and B. Infectious complications were evenly distributed in both groups. Immunohistochemistry showed that during acute rejection, in the presence of circulating BT563, IL-2R-bearing cells were present in only one of five rejection biopsies (20%), whereas these cells were often present (6/8, or 75%) in rejections occurring in the absence of BT563. The presence of BT563 was associated with a similar difference in the mRNA expression of IL-2 (2/5 vs. 6/8). CONCLUSIONS: Apparently, despite adequate blockade of the IL-2/IL-2R pathway, patients may develop acute rejection, reflecting the redundancy of the cytokine network. The ever-present IL-15 may well be a candidate for overtaking the role of IL-2.

Cytomegalovirus seronegative heart transplant recipients. Prophylactic use of anti-CMV immunoglobulin.

Thirty-two CMV seronegative heart transplant patients received prophylactic anti-CMV immunoglobulin during the first three posttransplant months. One of the 16 recipients of a heart from a seronegative donor acquired CMV infection and developed CMV disease. In eight of the 16 recipients of a heart from a seropositive donor, CMV infection was observed. Viremia was diagnosed in seven of them, but only two of these patients developed CMV disease. The incidence of CMV infection and of CMV disease in the globulin-treated CMV seronegative recipients of a heart from a seropositive donor was comparable to the incidence of CMV infection and of CMV disease in 31 nonglobulin-treated CMV seropositive recipients. This was significantly lower (percentage difference 69 percent, 95 percent CI 42-97 percent, p less than 0.001) than expected on the basis of the data from the literature and indicates that passive immunization with anti-CMV immunoglobulins induces the same protection against CMV disease as natural acquired anti-CMV resistance. This protective effect was temporary, as one patient developed symptomatic CMV infection four months after transplantation at a time when the anti-CMV immunoglobulin levels had decreased to pretransplantation values.

Intraoperative two-dimensional echocardiography in complicated infective endocarditis of the aortic valve.

Six patients with complicated native and prosthetic aortic valve endocarditis were operated on. The data from cineangiocardiography and from precordial and intraoperative two-dimensional echocardiography were compared with the surgical findings. Surgical inspection revealed a mycotic aneurysm in six patients. In addition, a fistulous connection to the right atrium, an abscess in the interventricular septum, and mitral valve endocarditis were found in one of the patients. The pathologic conditions disclosed during the operation were correctly visualized with two-dimensional epicardial echocardiography, done before cardiopulmonary bypass. Cineangiography provided this information in one patient, and precordial two-dimensional echocardiographic analysis was correct in two patients. Thus, intraoperative two-dimensional echocardiography provides detailed information in complicated native and prosthetic aortic valve endocarditis that is of importance in the surgical management.

Aprotinin administration in the pericardial cavity does not prevent platelet activation.

OBJECTIVES: Aprotinin is frequently administered systemically to patients undergoing cardiopulmonary bypass to inhibit activation of platelets and plasma protein systems and thus reduce postoperative blood loss. Two reports on local aprotinin administration, that is, into the pericardial cavity, also indicated improvement in postoperative blood loss, but the underlying mechanism was not investigated. We previously reported the disappearance of glycoprotein Ib from the platelet surface and the appearance of platelet-derived microparticles in the pericardial cavity of patients undergoing cardiopulmonary bypass as signs of platelet activation. Here, we investigated whether such local aprotinin administration reduced platelet activation. METHODS: In a double-blind study, 6 patients received aprotinin (500,000 KIU) into the pericardial cavity during the operation and 7 patients received a placebo. Platelet surface glycoprotein Ib expression, concentration of microparticles, and concentration of complexes of platelets with leukocytes, erythrocytes, or each other, were measured by flow cytometry. RESULTS: We confirmed the reduced glycoprotein Ib expression and the increased concentration of microparticles in the pericardial cavity, as previously reported, and found no increased concentration of platelet complexes. However, no differences between aprotinin and placebo treatments were observed in these platelet activation parameters in the pericardial cavity or the systemic circulation. CONCLUSION: We conclude that administration of aprotinin into the pericardial cavity during cardiopulmonary bypass and at concentrations similar to the systemic application does not reduce platelet activation in that compartment or the systemic circulation.

Effect of cryopreservation and HLA-DR matching on the cellular immunogenicity of human cardiac valve allografts.

The cellular immunogenicity of fresh and cryopreserved human cardiac valve leaflets was measured in a lymphocyte proliferation assay. One fresh leaflet and a cryopreserved leaflet derived from the same valve were cut into 2 mm diameter pieces and incubated with responder peripheral blood mononuclear cells, matched or mismatched for HLA-DR. The tritiated thymidine incorporation into the lymphocytes measured after 7 days, was expressed as stimulation index. Fresh, HLA-mismatched valve pieces induced high stimulation index in all cases (median 9, range 4 to 117). The cryopreservation procedure resulted in a significantly lower stimulation index (p = 0.002, Wilcoxon), with a median stimulation index of 2 (range 0 to 9). In the instances where HLA-DR matched combinations were studied, cryopreservation was also associated with lower stimulation index. HLA matching itself was able to reduce the stimulation index both with cryopreserved and fresh valve pieces as stimulator, resulting in a median stimulation index of 4 (range 2 to 117) for the HLA-DR-mismatched and 1 (range 0 to 5) for the matched lymphocytes (p = 0.006, Wilcoxon). In conclusion, human cardiac valves are able to stimulate immune competent cells in vitro, even after cryopreservation. The cellular allogeneic response in vitro could be an explanation for valve allograft degeneration observed in the clinic. Matching for HLA-DR may reduce these effects.

The intragraft cytokine mRNA pattern reflects the efficacy of steroid antirejection therapy.

BACKGROUND: We studied the effect of antirejection therapy on intragraft cytokine mRNA expression. METHODS: Therapy consisted of three doses of 1 gm of intravenous methylprednisolone. We determined its effect on intragraft mRNA expression of immunoregulatory (interleukin-2, interleukin-4) and inflammatory cytokines (interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha), and the high-affinity interleukin-2 receptor (p55 chain) in endomyocardial biopsy specimens from cardiac allograft recipients. RESULTS: By reverse-transcriptase polymerase chain reaction methods, we detected mRNA transcription for interleukin-2 in 56% of the pretreatment endomyocardial biopsy specimens (n = 16), for interleukin-4 in 31%, and for interleukin-6 in 56% of the specimens, and interleukin-2 receptor, interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha were constitutively expressed. Individual cytokine mRNA profiles were not helpful in differentiating between rejections that proved to be methylprednisolone resistant (n = 9) or methylprednisolone sensitive (n = 7). After successful antirejection therapy, the overall intragraft mRNA expression was downregulated. None of the posttreatment endomyocardial biopsy specimens taken from six patients with methylprednisolone-sensitive rejections expressed the interleukin-2 gene, in contrast to 88% of the endomyocardial biopsy specimens obtained from eight patients with methylprednisolone-resistant rejections (p = 0.005). Moreover, intragraft interleukin-4 and interleukin-6 mRNA transcripts were hardly detectable (both 17%) in methylprednisolone-reversible rejections, but in ongoing rejections interleukin-4 mRNA expression was found in 62% (p = 0.14), and interleukin-6 was found in 88% of the endomyocardial biopsy specimens (p = 0.03). Semiquantitative analysis showed that the intragraft interleukin-2 receptor, interleukin-1 beta, and tumor necrosis factor-alpha mRNA levels were lower in posttreatment endomyocardial biopsy specimens from methylprednisolone-reversible rejections than in endomyocardial biopsy specimens from methylprednisolone-irreversible rejections (p = 0.03). CONCLUSIONS: Our data suggest that the efficacy of antirejection therapy with methylprednisolone is reflected in intragraft cytokine mRNA profiles.

Coronary artery disease after heart transplantation: timing of coronary arteriography.

The increasing numbers of long-term survivors after heart transplantation make yearly coronary arteriography, used by most centers to study the development of transplant coronary artery disease, less practical. Therefore the prevalence and clinical relevance of coronary artery disease in 119 one-year survivors of heart transplantation were studied. Visual analysis revealed two main patterns of vascular changes: abnormalities of the epicardial vessels and their major branches and abnormalities of the tertiary branches. The prevalence of all abnormalities in the coronary vascular tree increased from 34% after 1 year to 79% after 5 years. The prevalence of anatomically significant lesions (more than 50% stenosis in the epicardial branches or abrupt ending/proximal occlusion of tertiary branches) was only 11% after 5 years. During follow-up of 25 to 87 (median, 43) months, no significant coronary artery disease developed in the 101 patients who showed normal epicardial vessels or abnormal tertiary branches only at their first year angiography, and none of the patients died of ischemic heart disease. Of the 18 patients with abnormal epicardial vessels, three patients died of ischemic heart disease; one of these patients was treated with atherectomy and is alive at the moment of this report, and two patients showed progression of discrete lesions without evidence of ischemia until now. Based on these findings, a schedule for timing of arteriography was developed depending on the first-year coronary findings.

Intragraft monitoring of rejection after prophylactic treatment with monoclonal anti-interleukin-2 receptor antibody (BT563) in heart transplant recipients.

BACKGROUND: Anti-interleukin-2 receptor monoclonal antibodies have been used successfully in the prevention of rejection in cardiac allografts in several animal models. METHODS: In an open randomized study murine monoclonal CD3 antibody and BT563, a murine anti-interleukin-2 receptor monoclonal antibody, were given as rejection prophylaxis during the first week after heart transplantation. Cyclosporine therapy was initiated at the third postoperative day. RESULTS: In half the BT563-treated patients an early rejection was histologically shown at week 1, whereas heart transplant recipients treated with murine monoclonal CD3 antibody had a rejection incidence at week 1 of only 9%. During BT563 treatment CD25-positive cells (i.e., cells bearing the interleukin-2 receptor) were not detectable in peripheral blood. However, immunohistologic studies of endomyocardial biopsy specimens taken 1 week after transplantation showed the presence of CD25-positive cells within these specimens in 8 of 10 (80%) of patients with rejection. In patients without rejection CD25-positive cells were present in the biopsy specimens of only two of nine patients (22%). Reverse-transcriptase polymerase chain reaction studies on biopsy material showed the presence of messenger RNA for the interleukin-2 receptor in all and for interleukin-2 in three of five (60%) of biopsy specimens of rejecting grafts. CONCLUSIONS: Although CD25-positive cells were not detectable in peripheral blood during BT563 treatment, these cells were at the same time found to be present within 80% of the endomyocardial biopsy specimens from the rejecting grafts. By initiating cyclosporine treatment at day 0, the synergistic effect of combining cyclosporine and anti-interleukin-2 receptor monoclonal antibodies may result in a lower rejection incidence.

The nature of acute rejection is associated with development of graft vascular disease after clinical heart transplantation.

BACKGROUND: To determine mechanisms that trigger graft vascular disease (GVD) after heart transplantation, we studied parameters that reflect both early and late intragraft allogeneic reactions. METHOD: With reverse transcriptase-polymerase chain reaction analysis, mRNA expression of interleukin-2 (IL-2), interleukin-4, interleukin-6, interleukin-10, interferon-gamma, platelet-derived growth factor-alpha, and transforming growth factor-beta was measured in endomyocardial biopsy (EMB) specimens obtained from 34 recipients during the first acute rejection episode (n = 29) or at a comparable time after transplantation for patients without rejection (n = 5) and at time of assessment of GVD by coronary angiography at 1 year (n = 34). RESULTS: At the time of assessment of GVD, mRNA expression of IL-2, interleukin-4, and interleukin-6 were barely detectable, whereas messenger coding for interferon-gamma, interleukin-10, transforming growth factor-beta, and platelet-derived growth factor-alpha genes were constitutively expressed. Moreover, intragraft mRNA patterns of cytokines and growth factors between patients with GVD (n = 17) or without GVD (n = 17) were comparable. In contrast, during the first acute rejection episode a completely different pattern was found. Development of GVD was associated with IL-2 mRNA expression and not with the other cytokines analyzed. IL-2 mRNA was present in 77% of rejection EMB specimens obtained from patients with GVD versus 33% of the EMB specimens obtained from patients without GVD (p = 0.03) and not detectable in EMB specimens obtained from patients with no rejection. Also nonimmunologic risk factors such as longer ischemia time (median 193 vs 141 minutes; p = 0.002) and higher donor age (median 32 vs 23 years; p = 0.02) were associated with GVD. But no relation was found between these nonimmunologic risk factors and IL-2-positive acute rejections. CONCLUSIONS: Nonspecific risk factors and IL-2-positive rejections may independently trigger GVD after clinical heart transplantation.

Cytotoxicity of graft-derived lymphocytes: specific for donor heart endothelial cells?

BACKGROUND: Previously, we showed that lymphocytes cultured from cardiac allografts can lyse lymphoid cell lines from donor origin. Because endothelial cell form the first allogeneic barrier to be encountered in vivo, the reactivity of graft-infiltrating cells against donor heart-derived endothelial cells (DoHEC) may be more relevant for understanding the clinical course after heart transplantation. METHODS: Endomyocardial biopsies (EMB) were taken at different times after transplantation, both during acute rejection and during quiescence. Lymphocytes cultured from these EMB were assayed for cell-mediated cytotoxicity in a 4-hour chromium 51 release test by use of target panels of different cell types derived from donor or third party. Cell specificity was investigated by addition of a tenfold excess of unlabelled target cells to 51Cr-labeled DoHEC. RESULTS: These experiments show that DoHEC can be lysed by lymphocytes derived from EMB. Antigens that were recognized on DoHEC were often donor human leukocyte antigen class I antigens. Some cultures in addition recognized alloantigens present only on DoHEC and not on donor-derived B cells as suggested by lack of or partial inhibition of DoHEC lysis by addition of excess competitor B cells. Endothelial cell-specific reactivity was unequivocally identified after limiting dilution of EMB-derived cultures. CONCLUSION: We conclude that not only DoHEC-reactive but also DoHEC-specific cells are present among the cardiac graft infiltrating cells.

The avidity, not the mere presence, of primed cytotoxic T-lymphocytes for donor human leukocyte class II antigens determines their clinical relevance after heart transplantation.

BACKGROUND: To analyze the relevance of CD4-positive cytotoxic T-lymphocytes (CTL) in clinical heart rejection, we studied the frequency and avidity of donor human leukocyte antigen class II-specific CTL present within the graft during a rejection episode and during a period without rejection. METHODS: For this analysis endomyocardial biopsies of heart transplant recipients were cultured to obtain graft-infiltrating lymphocytes (GIL). GIL cultures exhibiting donor class II-directed cytotoxicity were considered for this study. With limiting dilution analysis, the frequency of donor class II-specific CTL that had been primed by donor antigens in vivo (designated cCTL) was determined in GIL cultures established from endomyocardial biopsies taken during a rejection episode (n = 10) or during a period without rejection (n = 11). Addition of anti-CD4 to the limiting dilution analysis revealed the fraction of donor class II-specific cCTL having a high avidity for donor antigen. RESULTS: During a rejection episode, 196 (median) donor class II-specific cCTL/106 GIL were present. In a period without rejection, the frequency of donor class II-specific cCTL was not significantly different (median = 330/10(6); p = 0.1). Addition of anti-CD4, however, revealed that donor class II-specific cCTL with a high avidity for donor antigen are predominant during a rejection episode (median = 100%) but are in minority during a period without rejection (median = 35%; p < 0.0001). CONCLUSIONS: These results suggest that graft-infiltrating CD4+ CTL can mediate heart rejection provided they have a high avidity for donor antigen.

Pulsed-wave transmitral Doppler do not diagnose moderate acute rejection after heart transplantation.

The value of pulsed-wave transmitral Doppler for the diagnosis of moderate acute rejection was examined in a total of 347 Doppler recordings obtained in 32 consecutive cardiac allograft recipients. Serial Doppler examinations (median, 11 per patient; range, 1 to 23) were performed simultaneously with endomyocardial biopsies from the first week after heart transplantation to a follow-up of 186 days (median; range, 10 to 395 days after transplantation). Pulsed-wave transmitral Doppler did not allow noninvasive diagnosis of moderate acute rejection in individual patients. Peak filling rate normalized for mitral stroke volume, early diastolic velocity, and mean diastolic velocity were significantly increased, whereas diastolic filling period was decreased during moderate acute rejection compared to other biopsy classes. The wide overlap of measurements in individual recipients with or without rejection may be due, however, to a variety of hemodynamic factors after transplantation affecting diastolic function, which are superimposed on the restrictive left ventricular filling pattern caused by persistent mild acute rejection and left ventricular hypertrophy. These hemodynamic factors include pulmonary hypertension, perioperative ischemia, reperfusion injury, and changes in both blood pressure and loading conditions caused by hypertension and its treatment. Differences between studies with regard to the detection of moderate acute rejection by transmitral Doppler may be caused by chance, because most studies were relatively small. Differences in methods, patient selection, duration of follow-up, prevalence of hypertension and left ventricular hypertrophy, and differences in antihypertensive drug regimens may also play a role. Furthermore differences in the incidence of mild acute rejection, its treatment, and the type of maintenance immunosuppressive regimen used may have influenced the outcome of these studies considerably.

Prophylactic therapy with OKT3 does not affect donor specific reactivity of peripheral blood lymphocytes from heart transplant recipients.

To avoid the nephrotoxic effect of high-dose cyclosporin A (CsA) immediately posttransplant, heart transplant recipients received as prophylactic therapy intravenous OKT3 for seven days instead of intravenous CsA. Patients receiving OKT3 were compared with patients receiving CsA with respect to specific proliferation and cytotoxicity of their peripheral blood mononuclear cells (PMNC) against donor antigens, at different times within three months post-transplant. No effect of the initial immunosuppressive therapy was observed on these parameters. Acute rejection did not induce a consistent effect on the relative proliferation. PMNC from patients who experienced one or more rejection episodes showed a decrease in donor specific relative proliferative response in time after transplantation, while nonrejectors did not or only slightly, independent of the initial immunosuppressive protocol. Within the group of patients not receiving OKT3, this effect of rejection reached significance. In conclusion, no effect of prophylactic OKT3 therapy compared with prophylactic CsA therapy was observed on donor reactivity of PMNC in vitro during the subsequent three to four months post-transplant.