Incidence and management of leukopenia/neutropenia in 233 kidney transplant patients following single dose alemtuzumab induction.

BACKGROUND: The purpose of this study was to determine the incidence and management strategies for post-transplant leukopenia/neutropenia in kidney recipients receiving alemtuzumab induction during the first year following transplantation. METHODS: We prospectively identified 233 adult patients who underwent kidney transplantation with alemtuzumab induction at a single institution. The incidence and severity of leukopenia (white blood cell count [WBC] ≤2500/mm(3)) and neutropenia (absolute neutrophil count [ANC] ≤500/mm(3)) were evaluated at 1, 3, 6, and 12 months post-transplantation. We determined any association with cytomegalovirus (CMV) infection, graft rejection, and infections requiring hospitalization. We also reviewed interventions performed, including medication adjustments, treatment with granulocyte stimulating factor, and hospitalization. RESULTS: The combined incidence of either leukopenia or neutropenia was 47.5% (n = 114/233) with an average WBC nadir of 1700 ± 50/mm(3) at 131.0 ± 8.5 days and an average ANC nadir of 1500 ± 100/mm(3) at 130.4 ± 9.6 days. No significant difference in graft rejection, CMV infection, or infections requiring hospitalization was found in the leukopenia/neutropenia group vs the normal WBC group (P = .3). The most common intervention performed for leukopenia/neutropenia group was prophylactic medication adjustment. Six patients (5.2%) required a change in >1 medication. The majority of these patients also required granulocyte stimulating factor (61.5%; 32/52), with an average of 2.5 doses given. A total of 25 patients (21.9%) required hospitalization due to leukopenia/neutropenia with an average length of stay of 6 days. CONCLUSIONS: Kidney transplant patients receiving alemtuzumab induction required significant interventions due to leukopenia/neutropenia in the first year post-transplantation. These results suggest the need for additional studies aimed at defining the optimum management strategies of leukopenia/neutropenia in this population.

Application of combined liver-intestinal transplantation as a staged procedure.

Liver-intestinal transplantation is a complex surgical procedure that historically has required prolonged operative periods. This report is the first series where liver-intestinal transplantation was performed as a staged procedure. Specifically, allograft reperfusion was followed by resuscitation and stabilization in an intensive care unit before completion of the transplant procedure. Triage of recipients to the intensive care unit following allograft reperfusion was determined at the time of operation and was based upon the clinical condition of the recipient including hemodynamic stability, evidence of coagulopathy, and assessment of early liver function. Medical stabilization was followed by completion of the transplant procedure and definitive abdominal closure within 72 hours. The application of combined liver-intestinal transplantation as a staged procedure demonstrated no effect upon early graft function, incidence of complications, or ability to perform a definitive abdominal closure.

Continuous negative abdominal pressure device to treat pseudotumor cerebri.

OBJECTIVE: To study the effects of an externally applied negative abdominal pressure device designed to lower the effects of intra-abdominal pressure (IAP) on headaches and pulsatile tinnitus in severely obese women with pseudotumor cerebri (PTC). DESIGN: Short-term clinical intervention trial in the Clinical Research Center. Days 1 and 3 were 'control' days; on days 2 and 4-6 patients were in the device from 8:00 am to noon and from 1:00 to 5:00 pm, and on nights 7-11 they were in the device from 10:00 pm to 8:00 am. The last four patients were treated in a device with a counter-traction mechanism. SUBJECTS: Seven centrally obese women with PTC. MEASUREMENTS: Headache and pulsatile tinnitus severity were graded by the patient using visual analog scale (1-10) and averaged for the time that the device was in use or not in use. IAP was estimated from urinary bladder pressure (UBP) before and during device use. The internal jugular vein (IJV) elliptical cross-sectional area was measured with B-mode ultrasonography; the timed average velocity was measured by Doppler. RESULTS: There was a decrease in both headache (6.8+/-0.8 to 4.2+/-0.8, P<0.05) and pulsatile tinnitus (4.2+/-0.5 to 1.8+/-0.5, P<0.02) within 5 min, and in headache (to 2.2+/-0.8, P<0.01) and tinnitus (to 1.7+/-0.5, P<0.01) within 1 h of device activation. UBP decreased (P<0.001) from 19.1+/-3 to 12.5+/-2.8 cmH2O. Headache remained improved throughout time that the device was used. During the second week, five of seven patients slept in the device without difficulty and four awoke without headache. There was a progressive decrease (P<0.01) in headache during the day after sleeping in the device at night as compared with days 1 and 3 when it was not used (6.5+/-0.5, day 1; 4.1+/-0.7, day 3; 3.1+/-0.8, day 8; 2.3+/-0.8, day 10). Headaches returned late in the afternoon in two patients; the device was reactivated and headache again improved. Five patients underwent IJV sonography; the IJV area decreased (129+/-53 to 100+/-44 mm2, P=0.06) without a change in IJV flow (1004+/-802 to 1000+/-589 ml/min) with the device. When activated, the device was pulled into the patient, creating discomfort that was alleviated with the counter-traction mechanism in the last four patients. One patient developed a 5 cm area of blisters that resolved when the device was worn over a hospital gown. CONCLUSIONS: Decreasing IAP relieved headaches and pulsatile tinnitus in PTC. When patients slept in the device, they awoke without headache or tinnitus, which remained markedly improved throughout most of the following day. This study supports the hypothesis that PTC in obese women is secondary to an increased IAP.

Effects of increased renal parenchymal pressure on renal function.

OBJECTIVE: Acute renal failure is seen with the acute abdominal compartment syndrome (AACS). The cause of acute renal failure in AACS is thought to be multifactorial, including increased renal venous pressure, renal parenchymal pressure (RPP), and decreased cardiac output. Previous studies have established the role of renal venous pressure as an important mediator of this renal derangement. In this study, we evaluate the role of renal parenchymal compression on renal function. METHODS: Two groups of swine (20-26 kg) were studied after left nephrectomy and placement of a renal artery flow probe and ureteral cannula. Two hours were allowed for equilibration, and an inulin infusion was begun to calculate inulin clearance as a measurement of glomerular filtration. In group 1 animals (n = 6), RPP was elevated by 30 mm Hg for 2 hours with renal parenchymal compression. RPP then returned to baseline for 1 hour. In group 2 (n = 6), the RPP was not elevated. The cardiac index, preload, and mean arterial pressure remained stable. Blood samples for plasma renin activity and plasma aldosterone were taken at baseline and at hourly intervals. RESULTS: Elevation of RPP in the experimental group showed no significant decrease in renal blood flow index or glomerular filtration when compared with control animals. There were no significant elevations of plasma aldosterone or plasma renin activity in the experimental animals when compared with control. CONCLUSION: Elevated renal compression alone did not create the pathophysiologic derangements seen in AACS. However, prior data from this laboratory found that renal vein compression alone caused a decreased renal blood flow and glomerular filtration and an increased plasma renin activity, plasma aldosterone, and urinary protein leak. These changes are partially or completely reversed by decreasing renal venous pressure as occurs with abdominal decompression for AACS. These data strengthen the proposal that renal vein compression, and not renal parenchymal compression, is the primary mediator of the renal derangements seen in AACS.

Effect of increased renal venous pressure on renal function.

OBJECTIVE: Acute renal failure is seen with the acute abdominal compartment syndrome (AACS). Although the cause of acute renal failure in AACS may be multifactorial, renal vein compression alone has not been investigated. This study evaluated the effects of elevated renal vein pressure (RVP) on renal function. METHODS: Two groups of swine (18-22 kg) were studied after left nephrectomy and placement of a renal artery flow probe to measure renal artery blood flow, renal vein catheter, and ureteral cannula. Two hours were allowed for equilibration and an inulin infusion was begun to calculate inulin clearance for measurement of glomerular filtration rate. Group 1 animals (n = 4) had RVP elevated by 30 mm Hg for 2 hours with renal vein constriction. RVP was then returned to baseline for 1 hour. In group 2 (n = 4), the RVP was not elevated. The cardiac index (2.9 +/- 0.5 L/min/m2) and mean arterial pressure (101 +/- 9 mm Hg) remained stable. Plasma renin activity and serum aldosterone were measured every 60 minutes. RESULTS: Elevation of RVP (0-30 mm Hg above baseline) in the experimental group showed a significant decrease in renal artery blood flow index (2.7 to 1.5 mL/min per g) and glomerular filtration rate (26 to 8 mL/min) compared with control. In addition, there was significant elevation of plasma serum aldosterone (14 to 25 microng/dL) and plasma renin activity (2.6 to 9.5 microng/mL per h) as well as urinary protein leak in the experimental animals compared with control. These changes were partially or completely reversible as RVP returned toward baseline. CONCLUSION: Elevated RVP alone leads to decreased renal artery blood flow and glomerular filtration rate and increased plasma renin activity, serum aldosterone, and urinary protein leak. These changes are consistent with the renal pathophysiology seen in AACS, morbid obesity, and preeclampsia. The changes are partially or completely reversed by decreasing renal venous pressure as occurs with abdominal decompression for AACS.

Physiologic effects of externally applied continuous negative abdominal pressure for intra-abdominal hypertension.

BACKGROUND: To determine the ability of an externally applied continuous negative abdominal pressure device (CNAP) to reverse the effects of elevated intra-abdominal pressure on the central nervous and cardiovascular systems. METHODS: Anesthetized, ventilated swine had catheters placed for measurement of intra-abdominal (IAP), intracranial (ICP), central venous, pulmonary artery, pulmonary artery occlusion, mean arterial, peak inspiratory, inferior vena cava, and femoral vein pressures. After the animals stabilized, baseline measurements were obtained. IAP was increased by incrementally instilling an isosmotic polyethylene glycol solution into the peritoneal cavity until it was 25 mm Hg above baseline. IAP was maintained at 25 mm Hg above baseline for 2 hours. CNAP was then applied for 2 hours. All parameters were remeasured 30 minutes after each increase in IAP, at 2 hours after attaining maximum IAP, and lastly at 2 hours after abdominal decompression. Cardiac index was maintained near baseline by volume expansion. RESULTS: Elevation of IAP to 25 mm Hg above baseline for 2 hours caused increases (p<0.05) in central venous pressure (10.3+/-0.9 to 15.2+/-1.7), inferior vena cava pressure (13.0+/-1.0 to 29.5+/-1.5), femoral vein pressure (13.5+/-0.5 to 33.3+/-1.3), ICP (10.6+/-1.5 to 21.0+/-1.5), and peak inspiratory pressure (18.3+/-0.3 to 34.2+/-1.0). The mean arterial pressure (106.3+/-3.5 to 125.8+/-3.4), pulmonary artery pressure (24.3+/-2.3 to 31.3+/-1.7), and pulmonary artery occlusion pressure rose (12.3+/-0.9 to 17.5+/-3.5), but not significantly. Cardiac index (3.3+/-0.5 to 3.4+/-0.4) remained essentially unchanged. CNAP significantly (p<0.05) decreased IAP (30.7+/-1.3 to 18.2+/-1.3), central venous pressure (15.2+/-1.7 to 12.4+/-2.1), inferior vena cava (29.5+/-1.5 to 19.2+/-1.3), and ICP (21.0+/-1.5 to 16.2+/-1.3). Pulmonary artery occlusion pressure (17.5+/-3.5 to 15.0+/-3.1) and peak inspiratory pressure (34.2+/-1.0 to 29.7+/-1.1) decreased, but not significantly. CONCLUSION: Acutely elevated IAP causes a significant increase in ICP and impaired cardiovascular and pulmonary function. Abdominal decompression remains the standard of care for abdominal compartment syndrome. However, in patients in whom an increased IAP does not require surgical decompression, the results of this study suggest that externally applied CNAP may be of value.

Treatment of intracranial hypertension using nonsurgical abdominal decompression.

BACKGROUND: Elevated intra-abdominal pressure (IAP) increases intracranial pressure (ICP) and reduces cerebral perfusion pressure (CPP). We evaluated a nonsurgical means of reducing IAP to reverse this process. METHODS: Swine with a baseline ICP of 25 mm Hg produced by an intracranial balloon catheter were studied. In group 1 (n = 5), IAP was increased by 25 mm Hg. Continuous negative abdominal pressure (CNAP) was then applied. Group 2 (n = 4) had neither IAP elevation nor CNAP. Group 3 (n = 4) had CNAP without IAP elevation. RESULTS: Elevation of IAP by 25 mm Hg above baseline led to deleterious changes in ICP (25.8+/-0.8 to 39.0+/-2.8; p < 0.05) and CPP (85.2+/-2.0 to 64.8+/-2.6; p < 0.05). CNAP led to a reduction in IAP (30.2+/-1.2 to 20.4+/-1.3; p < 0.05) and improvements in cerebral perfusion (ICP, 33+/-2.7; CPP, 74.4+/-1.2; both p < 0.05). Group 2 had stable ICP (25.8+/-0.25 to 28.7+/-1.7; p > 0.05) and CPP (80.8+/-1.4 to 80.5+/-1.8; p > 0.05). In group 3, CNAP decreased cardiac index (2.9+/-0.2 to 1.1+/-0.4; p < 0.05), mean arterial pressure (105.2+/-4.0 to 38.2+/-12.0; p < 0.05), and CPP (74.2+/-4.7 to 14.5+/-12.2; p < 0.05). CONCLUSION: Elevations in IAP led to increased ICP and decreased CPP. CNAP ameliorated these intracranial disturbances. With normal IAP, CNAP impaired cerebral perfusion.

Multisystem organ failure secondary to increased intraabdominal pressure.

Acutely increased intraabdominal pressure can lead to multisystem organ dysfunction. Organ dysfunction consists of acute pulmonary failure secondary to compressive atelectasis and associated with high peak inspiratory pressures and impaired gas exchange, acute renal failure with marked oliguria without hypernaturia, intestinal and hepatic ischemia possibly leading to bacterial translocation or necrosis with peritonitis, increased intracranial pressures which may cause brain dysfunction or aggravate head injury edema, venous thrombosis and thromboembolism, and abdominal wall ischemia or necrosis. The diagnosis is made clinically in a patient with high peak inspiratory pressures, oliguria and an apparently tight abdomen, although urinary bladder pressure > or = 20 cm H2O pressure is suggestive. However, chronically increased intraabdominal pressure as is seen in the morbidly obese, pregnancy and cirrhosis may be misleading. As to treatment, once the diagnosis is made, the patient's abdomen should be opened and the tension relieved. The intestinal contents need to be protected and evaporative water loss minimized by either closing the skin and not the fascia or, if this is not possible, using an impermeable protective dressing. If the abdomen is difficult to close at the primary operation, it is best to prevent the development of an acute abdominal compartment syndrome by closing only the skin or leaving it open and using an impermeable dressing. In conclusion, the acute abdominal compartment syndrome has become increasingly recognized as a cause for multisystem organ failure. Recognition of the problem or prevention is mandatory for optimal patient survival.

Intragraft cytokine expression in tolerant rat renal allografts with rapamycin and cyclosporin immunosuppression.

The Th-1/Th-2 paradigm proposes clonal expansion of Th-2 lymphocytes as the basis of tolerance towards allografts. Intragraft cytokine expression was evaluated in a highly stringent model of renal transplantation. ACI and Lewis rats were used as donors and recipients, respectively, for heterotopic renal transplantation. Group A (n = 8) received a single dose of rapamycin and cyclosporin 12 h prior to engraftment, followed by 7 d of cyclosporin post-operatively. Isografts (Group B, n = 5) and control allografts (Group C, n = 4) received no immunosuppression. Sacrifice was performed after 120 d. Intragraft expression of IL-10, IL-4, and IFN-gamma was determined using qualitative reverse transcriptase-polymerase chain reaction (RT-PCR). All groups had functionally normal grafts at sacrifice, with 50% histological tolerance among Group A animals. No isografts showed evidence of cellular infiltrate, and all control allografts showed severe rejection. IL-10 was only detected in the tolerant animals (p < 0.001). Similarly, IL-4 was detected predominantly in the tolerant allografts (p < 0.05). IFN-gamma was only isolated in rejected allografts, whether treated or untreated (p < 0.001). We conclude that the expansion of Th-2 cells is associated with tolerance, while the expansion of Th-1 cell is associated with acute cellular rejection.

Intragraft cytokine expression and tolerance induction in rat renal allografts.

BACKGROUND: Intragraft cytokine expression was evaluated in a model of renal transplantation. ACI and Lewis rats were used as donors and recipients, respectively, for heterotopic renal transplantation. METHODS: Treated allograft rats (n=10) received a preoperative dose of rapamycin and cyclosporine, followed by 7 days of cyclosporine postoperatively. Isograft rats (n=5) and control allograft rats (n=4) received no immunosuppression. Sacrifice was performed after 120 days. Expression of interleukin (IL)-4, IL-10, and interferon-gamma (IFN-gamma) transcripts was determined with semiquantitative reverse transcriptase-polymerase chain reaction. RESULTS: All treated allograft rats had normal function with 50% histologic rejection. All isografts had normal function. IL-4 and IL-10 were in greater density in allografts with normal histology, whereas IFN-gamma was only seen in allografts with cellular rejection. No IL-10 was seen in isografts, but IL-4 was detected in 3/5 isografts. CONCLUSIONS: We conclude that the lymphocyte population's elaboration of IL-4 and IL-10 is associated with tolerance, whereas the production of IFN-gamma and absence of IL-4 is associated with histology suggestive of acute cellular rejection.

Abdominal compartment syndrome.

The ACS is a clinical entity that develops from progressive, acute increases in IAP and affects multiple organ systems in a graded fashion because of differential susceptibilities. The gut is the organ most sensitive to IAH, and it develops evidence of end-organ damage before the development of the classic renal, pulmonary, and cardiovascular signs. Intracranial derangements with ACS are now well described. Treatment involves expedient decompression of the abdomen, without which the syndrome of end-organ damage and reduced oxygen delivery may lead to the development of multiple organ failure and, ultimately, death. Multiple trauma, massive hemorrhage, or protracted operation with massive volume resuscitation are the situations in which the ACS is most frequently encountered. Knowledge of the ACS, however, is also essential for the management of critically ill pediatric patients (especially those with AWD) and in understanding the limitations of laparoscopy. The role of IAH in the pathogenesis of NEC, central obesity co-morbidities, and pre-eclampsia/eclampsia remains to be fully studied.

Flow cytometric analysis of chimerism in the rat tolerant to a renal allograft.

BACKGROUND: Chimerism, produced by the two-way migration of cells between graft and host, is a proposed mechanism by which tolerance occurs. The appearance of donor/recipient chimeras in tolerant ACI to Lewis rat heterotopic renal transplants was assessed in peripheral blood leukocytes using flow cytometry after staining with monoclonal antibodies. MATERIALS AND METHODS: ACI and Lewis rats were used as donor and recipient, respectively, after Rapamycin and Cyclosporin immunosuppression with or without donor blood or bone marrow transfusion. ACI and Lewis animals were also used for isograft and single-kidney controls. Animals were sacrificed at various time points after initial operation. Flow cytometry was performed on isolated peripheral blood leukocytes at sacrifice. Histologic and functional data were also obtained. The monoclonal antibody panel included RT1(a) (ACI, MHC I) combined with CD2, CD4, CD8, CD16, and CD25 or RT1(a,c) (bone marrow chimeras). RESULTS: RT1(a)+, CD8+ cells were transiently present in the peripheral blood leukocytes of Lewis recipients with the exception of allogeneic bone marrow recipients. No significant number of RT1(a)+, CD16+ ("dendritic" cell-line) chimeras was seen. Veto cells (RT1(a,c)+) were transiently present in the bone marrow recipients, but they did not lead to improved outcome. Furthermore, no correlation was made between histologic tolerance and any of these donor-derived cells. CONCLUSION: Donor/recipient chimerism, and the veto cell phenomenon are not operational tolerance mechanisms in this stringent model of ACI to Lewis rat renal transplantation.

The immunologic role of IFN-gamma in ACI to Lewis kidney transplantation.

BACKGROUND: One of the proposed mechanisms of tolerance induction is the Th-1/Th-2 paradigm. The Th-1 cell is proinflammatory, secreting IFN-gamma and IL-2. Conversely, the Th-2 cell is anti-inflammatory, secreting IL-4 and IL-10. In our earlier studies a shift toward Th-2 dominance was required for tolerance induction in this model. MATERIALS AND METHODS: ACI and Lewis rats were used as donors and recipients, respectively. Twelve hours prior to engraftment, rapamycin 1.5 mg/kg po and cyclosporin 10 mg/kg sc were given, followed by 5 mg/kg sc postop (days 1-7). Lewis rats were used as isografts. Functional allograft tolerance was induced consistently in 100% of the recipients with 50% of the allografts exhibiting normal histology beyond 120 days. Qualitative RT-PCR was performed on the grafts to determine IFN-gamma expression with beta-actin housekeeping gene as control. RESULTS: IFN-gamma was expressed in all untreated allografts (5/5) and all treated, yet rejecting, allografts (4/4). None of the isografts (0/5) or histologically tolerant allografts (0/4) expressed IFN-gamma. This distribution was statistically significant (P < 0.001, Fischer's exact test). CONCLUSION: Our findings support a shift from Th-2 to Th-1 predominance as the corollary mechanism responsible for preventing histologic tolerance.