Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SPLEEN”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed1999

Planar gamma camera quantitation of 123I, 99mTc or 111In in the liver and spleen of an abdominal phantom.

Three planar, gamma camera methods for quantitating radiopharmaceuticals, such as radiolabeled antibodies, were investigated. Iodine-123 (123I), technetium-99m (99mTc) or indium-111 (111In) in the liver and spleen of an abdominal phantom were assessed in this study. In the first approach, the number of counts detected in a "single image" of the liver or spleen was used to measure radionuclide content using an attenuation correction factor (ACF) calculated from data obtained without radionuclide in the background volume of the phantom. In the other two methods, radionuclide content was derived from either the geometric mean (GM) of counts in conjugate, opposed images ("global conjugate") or in individual, opposed pixels of the conjugate, opposed images ("pixel conjugate") of the liver and spleen. Both of the conjugate image methods were corrected for attenuation with a first order ACF derived from a transmission image. The influence of background radionuclide on the accuracy of quantitation was studied by filling the background volume of the phantom with water containing 7 or 14 percent of the concentration of the radioactive water placed in the liver and spleen. The best estimates of radionuclide content were obtained by quantitation from the GM of counts in conjugate images of the liver and spleen. Radionuclide content of the liver and spleen could be determined from a single image if correction for attenuation was available. In all instances, measurements were less accurate for the spleen and for either organ when 111In was used. These results further validate and extend observations reported by others and provide a basis for radiation dosimetry for these and similar radionuclides and organs in patients.

Abdomen↗
PubMed2006

Pediatric wandering spleen successfully treated by laparoscopic splenopexy.

Wandering spleen is a rare clinical condition associated with a high incidence of splenic torsion and infarction. The preferred treatment is splenopexy to reposition the spleen in the left upper quadrant of the abdomen. We report the case of a 12-year-old girl who presented with intermittent abdominal pain. An abdominal sonography was diagnostic of wandering spleen. The patient was successfully treated by laparoscopic splenopexy. The spleen was repositioned in the left upper quadrant and fixed to the posterior abdominal wall by a mesh patch attached by staples. To reinforce the splenopexy we created an additional support by plicating the phrenocolic ligament and suturing it to the lateral abdominal wall, making a pouch for the inferior pole of the spleen. The postoperative course was rapid and uneventful. A normal spleen position was verified by radionuclide scans at 3 days and 6 months postoperatively. Laparoscopic splenopexy is an excellent option for organ-preserving treatment in wandering spleen.

Child↗
PubMed1993

Comparative study of spleen pathology in drug abusers with thrombocytopenia related to human immunodeficiency virus infection and in patients with idiopathic thrombocytopenic purpura. A morphometric, immunohistochemical, and ultrastructural study.

A morphometric and immunohistochemical study was performed to assess the spleen's alterations in patients with autoimmune thrombocytopenia and in drug abusers with thrombocytopenia (DAT) related to human immunodeficiency virus (HIV) infection. A total of 34 patients were included in the study: 20 DAT patients and 14 with idiopathic thrombocytopenic purpura (ITP). Twenty HIV-negative splenectomy patients without thrombocytopenia were included as controls. Spleen weight in DAT patients (323.25 +/- 149.96 g, mean + standard deviation) was significantly increased compared with the ITP (164.28 +/- 29.79 g, P < 0.0001) and control (175.50 +/- 49.14 g, P < 0.0001) groups. The mean diameter of lymphoid follicles in the spleens of DAT patients (446.83 +/- 99.16 microns, was significantly higher than in those of the control patients (370.87 +/- 55.30 microns, P = 0.019). In control patients' spleens, the number of platelets in Billroth's cords was significantly higher (59.54 +/- 32.72/10(4) microns 2) than in those of the DAT (2.13 +/- 1.42/10(4) microns 2, P < 0.0001) and ITP (P < 0.0001) patients. The number of macrophages and ceroid histiocytes per 10(4) microns 2 of red pulp was significantly increased in both DAT (5.14 +/- 1.90) and ITP (7.48 +/- 4.38) patients compared with the control patients (3.66 +/- 1.10, P < 0.0001) and P = 0.06, respectively), and in ITP patients compared with DAT patients (P = 0.0136). The number of granulopoietic precursors per 10(4) microns 2 of red pulp was higher in the spleens of DAT (1.41 +2- 1.46, P < 0.0001) and ITP (0.92 +/- 0.75, P < 0.0001) patients compared with those of the control group. Transmission electron microscopy studies demonstrated platelet phagocytosis by macrophages of Billroth's cords and presence of myeloid metaplasia in spleens of DAT and ITP patients. Immunohistochemical studies showed a depletion of CD4+ lymphocytes in the T zone of splenic white pulp and an increased number of CD8+ lymphocytes in red pulp of DAT patients' spleens compared with those of ITP and control patients. There were no significant alterations in dendritic reticular cell network in the DAT group compared with the ITP and control groups.

Adolescent↗
PubMed1993

Functional and morphological characterization of 4F7+ spleen accessory dendritic cells.

Recently we have reported on the production of the mAb 4F7. This recognizes a molecule that is upregulated on dermal and epidermal dendritic cells after application of contact allergen. Furthermore, this antibody detects an antigen on spleen and lymph node dendritic cells. In this study, we characterize 4F7+ spleen dendritic cells and show that the mAb recognizes in situ few labeled cells in the white pulp of the spleen and approximately 1% of spleen single cell suspensions as evidenced by cell enrichment, immunoperoxidase staining and FACS analysis. Immunohistological characterization of the cells with mAbs revealed the expression of class II, class I MHC antigens, 33D1, CD11c, ICAM-1, and CD45 molecules. After enrichment and cultivation for approximately 3 days, these cells showed no adherent properties. The capacity of 4F7+ spleen dendritic cells to activate allogeneic T cells in the primary mixed lymphocyte reaction was similar to freshly isolated Ia+ Langerhans cells. With regard to the induction of a proliferative response of CD4+ naive T cells that were incubated with concanavalin A or anti-CD3 mAb, 4F7+ spleen dendritic cells were two to three times more potent than spleen microphages and B cells. Furthermore, 4F7+ cells efficiently stimulated the antigen dependent proliferation of a T helper cell line. The mAb 4F7 will be useful for the purification of dendritic cells and for functional and molecular biological studies.

Animals↗
PubMedDate not supplied

Analysis of spleen specimens for carbon monoxide.

Crucial to the investigation of aircraft fatalities is the analysis of biological specimens for carbon monoxide (CO). In many cases, blood specimens are unavailable or unsuitable for analysis, and the testing of an alternate specimen for CO becomes necessary. Spleen specimens provide a rich source of red blood cells and hence can be a primary substitute for blood. To verify this, 40 paired blood and spleen specimens were analyzed for CO by using a gas chromatographic method. Ten specimens with a spleen CO saturation level (sat.) of less than 10% were associated with corresponding blood specimens with CO sat. less than 10%. Fifteen of the 18 spleen specimens with CO sat. greater than 29% were associated with blood specimens with greater than 48% sat. Results were inconclusive when the spleen CO sat. was between 10 and 29%. We concluded that spleen CO sat. can reflect blood CO sat. in certain situations, particularly when spleen CO sat. is high.

Carbon Monoxide↗
PubMed1989

Alteration of proliferation and subtle changes of protein synthesis in autologous transplanted spleens.

In the case of massive splenic rupture, heterotopic autologous transplantation of splenic tissue into the omentum majus may be used to restore splenic function. Yet little is known about specific functions of the transplants compared to the normal spleen. The goal of this study was to get more information about immunologic functions and protein expression in splenic transplants. As an animal model we used the pig, whose splenic morphology and immunoarchitecture is similar to that of the human spleen. Histologic examination of transplants revealed structures that were comparable to normal spleens (consisting of red and white pulp and including germinal centers). Immunologic tests such as the hemolytic plaque assay and mitogen stimulation revealed that the number of plaque-forming cells was not changed significantly, but the stimulation index for T cells was drastically increased in the autotransplants. Electrophoresis and immunochemical methods showed differences in the protein patterns between both tissues. Several proteins were found to be produced only in the spleen, or were produced in much higher amounts in the spleen than in the splenic transplants. More information about these differences between spleen and splenic transplants is needed before we can recommend a general clinical application of autologous spleen transplantation.

Animals↗
PubMed1984

Variation of the spleen-liver activity ratio due to a change in position.

The ratio of splenic to hepatic activity in the posterior view of a Tc-99m SC liver-spleen scan has been used as an indicator of parenchymal disease. Analysis of liver-spleen scans from a series of patients acquired in both the supine and erect positions revealed that the spleen-liver ratio varied considerably with a change in the patient position. Qualitatively there was a shift of colloid from the liver to the spleen in five of 18 supine views and ten of 18 erect views. Quantitative analysis of 37 cases showed that the median erect spleen-liver ratio was 20% greater than the spleen-liver ratio observed in supine patients. Criteria for an abnormal spleen-liver ratio need to be established in each position.

Colloids↗
PubMed2000

Hepatic lesion differentiated from accessory spleen by a heat-damaged red blood cell scan.

A 34-year-old woman referred for evaluation of an abdominal mass underwent a computed tomographic portagram that showed a large mass in the region of the left hepatic lobe and adjacent to the spleen. A liver-spleen scan with sulfur colloid did not clearly show whether the mass originated in the liver or the spleen. To evaluate the possibility of an accessory spleen, a selective spleen scan using Tc-99m-labeled heat-damaged red blood cells was performed and showed intense uptake in the region of the spleen only. The patient underwent surgical exploration and excision of the lesion, which proved to be focal nodular hyperplasia of the liver. Thus, the heat-damaged red blood cell scan ruled out an accessory spleen as a cause for the mass.

Adult↗
PubMed1986

Changes in proton relaxation times of the rat spleen during adjuvant-induced immunologic reaction.

Possible changes in magnetic resonance (MR) relaxation times resulting from an immune reaction were evaluated in the rat spleen by means of in vitro proton spectroscopy and an established model of immune disease. Heat-killed Mycobacterium butyricum in Freund's adjuvant was injected intradermally into the tail of 28 rats. Ten normal rats served as controls. At different times following the injection of adjuvant (day 7, day 10, day 12, day 14, or day 22), the spleens were removed and weighed, and proton T1 and T2 relaxation times were measured with a 0.25-T spectrometer (10.7 MHz). Water content was also determined. Specimens of each spleen were histologically examined; this included Prussian-blue staining for detection of hemosiderin. In 22 of the 28 adjuvant-injected rats, spleen T1 values increased significantly, from a mean value of 451 msec +/- 23 S.D. (control rats) to a maximum mean value of 571 +/- 15 S.D., which occurred on day 12; this T1 increase paralleled an increase in weight and water content and a histologic appearance of granulomatous inflammation. In these rats, T2 changes were not significant. In the other six adjuvant-injected rats, spleen T2 relaxation time significantly decreased from a mean value of 42 msec +/- 5 S.D. to a mean value of 32 msec +/- 1 S.D. Histologic evaluation indicated that the origin of this T2 decrease was probably the presence of hemosiderin in the spleens of only these six rats. Mean T1 of these spleens decreased slightly, but not significantly.

Adjuvants, Immunologic↗
PubMed1996

Associated head injury should not prevent nonoperative management of spleen or liver injury in children.

The appropriate management of children with liver or spleen injuries and associated head injury after blunt trauma remains controversial. To evaluate the success rates for nonoperative management and the impact this approach has on both abdominal and head injury outcome, children recorded in the National Pediatric Trauma Registry were reviewed. From January 1, 1994 to April 1, 1995, 107 children (aged < 19) were identified with liver, spleen, and associated head injury from blunt trauma. Forty-five (42%) children had combined head and spleen injury, 51 (48%) had head and liver injury, and 11 (10%) had head, liver, and spleen injury. Only 18 (17%) required laparotomy (head and spleen injury, 9 (8%); head and liver injury, 5 (5%); and head, liver, and spleen injury, 4 (4%)). Overall, there were no differences in Glasgow Coma Scale scores for children requiring laparotomy compared with those managed conservatively (13 vs. 14, p > 0.05). For all groups, the mean Injury Severity Score was significantly higher for children requiring laparotomy (19 vs. 31, p < 0.05). However, when comparison of the groups was stratified for type of injury and severity, the transfusion requirements, mortality, and abdominal and neurologic morbidity were all improved in children managed nonoperatively. Contrary to previous guidelines in the literature for selection of patients for nonoperative management of blunt solid organ abdominal injury, the association of altered mental status from head injury with liver and spleen injuries should not impact the decision for observational management.

Abdominal Injuries↗
PubMed2002

Pattern of abdominal free fluid following isolated blunt spleen or liver injury in the pediatric patient.

BACKGROUND: This study correlated isolated, blunt liver or spleen injury with the presence, location, and amount of free fluid in the pediatric blunt trauma patient. METHODS: The hospital trauma registry was reviewed for the period 1/89 to 12/99 for pediatric patients (age < or = 17 years) who sustained blunt, isolated spleen or liver injury and had an abdominal CT scan. Patients with other intraabdominal injuries or inadequate scans were excluded. CT scans were reviewed by two radiologists and the isolated liver or spleen injury confirmed and graded. The presence, location, and amount of free fluid were evaluated in the RUQ, LUQ, and pelvis. Free fluid was quantified as 0 = no fluid, 1 = small amount, 2 = moderate, and 3 = large for each area. RESULTS: There were 134 pediatric patients with an isolated spleen (n = 66) or liver (n = 68) injury. Free fluid was noted in 101 patients (75%), more commonly with spleen (82%) than with liver (69%) injuries. As injury grade increased, so did frequency of patients with free fluid (grade 1 = 50% to grade 5 = 100%) and mean total volume (sum of fluid scores from each region) of free fluid (grade 1 = 0.75 to grade 5 = 6.5). The mean total volume of free fluid was greater for splenic injury (3.1) than for liver injury (1.7). The pelvis was the most common location for free fluid (liver 53%, spleen 71%) and had the greatest mean volume of free fluid (liver 0.9, spleen 1.5) of any single region. CONCLUSION: There is a direct correlation between the severity of the isolated injury and the likelihood and volume of associated free fluid. The pelvis was the most common location to detect free fluid and had the greatest estimated fluid volume.

Adolescent↗
PubMed1979

Morphology and function of isolated hepatocytes transplanted into rat spleen.

Hepatocytes isolated by the collagenase digestive method were transplanted into the spleens of syngeneic rats. Morphology and function of the hepatocytes in the spleen were investigated for 12 to 17 months after transplantation. The transplanted hepatocytes proliferated and reconfigured in the spleen without direct perfusion of portal venous blood and with the presence of an intact host liver. Fourteen to 17 months after transplantation, the hepatocytes which had formed a demarcated nodule occupied approximately 40% of the area of the splenic parenchyma without undifferentiation on microscopic examination. However, the weight of the hepatized spleen did not increase beyond the weight of a normal spleen and the weight of the host liver that had normal morphology also did not differ from a normal liver. Light and electron microscopic studies demonstrated differentiated cord structure and normal architecture for each heptocyte. Furthermore, the hepatized spleen synthesized albumin and glycogen as demonstrated by immunofluorescence and histochemical studies. Ammonia tolerance and indocyanine green clearance tests revealed functioning hepatocytes in the spleen proper. These results indicate that our experimental model lends itself well to investigations in cell growth mechanism and that hepatocellular transplantation has potential clinical application to compensate for impaired hepatic function.

Animals↗
PubMed1985

Association of inclusion of the donor spleen in pancreaticoduodenal transplantation with rejection.

Clinical pancreas transplantation (txp) using a pancreaticoduodenal allograft (pda) and the donor spleen has been applied as treatment for insulin-dependent diabetes mellitus. Inclusion of the spleen in the pda is purported to protect against thrombosis and may be of possible immunological benefit. In pancreatectomized pigs, we compared the results of pda txp with (n = 8) and without (n = 10) the donor spleen. Animals were maintained on cyclosporine (6 mg/kg/day i.v.) and prednisolone (1.5 mg/kg/day i.v. tapered over 7 days to a maintenance dose of 0.5 mg/kg/day i.v.). Pancreatic exocrine enzyme replacement was administered daily. In 10 recipients of the technically successful pda without the spleen, rejection (blood glucose greater than 150 mg/dl) was not seen in the 28 days after txp. Mean daily blood glucose was 95 +/- 8 mg/dl during this period. In contrast, 5 of 8 recipients of the technically successful pda with the donor spleen rejected their grafts an average of 13 days (range 7-16) after txp (P less than 0.01). Mean daily blood glucose was 88 +/- 21 mg/dl prior to the declaration of rejection and increased to 275 +/- 59 mg/dl after rejection (P less than 0.0001). Rejection was histologically confirmed in all cases. None of the recipients of the pda with the donor spleen developed signs of graft-versus-host disease. Glucose tolerance testing carried out 28 days after transplantation in normoglycemic pigs from both experimental groups demonstrated no difference between the groups. In the porcine pda model used in this study, the inclusion of the spleen in the pda was associated with rejection of the transplant.

Animals↗
PubMed1990

Apparent lack of H-Y-specific suppressor cells in female mice given male spleen cells intravenously.

Mice given a pretransplant i.v. infusion of spleen cells from donors incompatible with the recipients with respect to individual minor H antigens exhibit a delayed rejection of skin grafts from these incompatible donors. Attempts were made to detect suppressor T cells, possibly induced by the i.v. infusion of donor cells, among spleen cells from female mice made hyporesponsive to H-Y antigen by an i.v. infusion of male spleen cells. When transferred to nonimmune immunocompetent mice, lymphoid cells from hyporesponsive females delayed the rejection of male skin grafts only slightly. Similar results were obtained when putative suppressor cells were transferred to immunodeficient hosts having had their potential to reject male skin grafts restored with either nonimmune or specifically immune female lymphoid cells. The observed suppression of graft rejection could be accounted for, to a significant extent, by male spleen cells carried over with the transferred female cells to the assay recipients. Though an active host-derived suppressor mechanisms was not found, transferred spleen and lymph-node cells obtained from females given a prior i.v. infusion of male spleen cells were poor at restoring the capacity to reject male skin grafts to immunodeficient female recipients, whereas equal numbers of lymphoid cells from untreated females were much better. Thus, i.v. infusion of male spleen cells appeared to deplete the peripheral lymphoid tissue of the recipients of responsivity to H-Y antigen.

Animals↗
PubMed1993

The role of the spleen in pancreas transplantation.

Early graft thrombosis and rejection of the graft are the two major causes of graft failure in pancreas transplantation. Inclusion of the spleen in the pancreatic graft has been purported as a possible solution to both complications, but severe graft-versus-host disease led to abolishment of this procedure. By irradiating the donor spleen ex vivo during cold storage, we successfully prevented graft-versus-host disease, allowing us to evaluate the advantages of clinical pancreaticosplenic transplantation. This study reports our experience with 12 pancreaticosplenic transplantations. Using Doppler flow measurements, we have been able to examine the hemodynamic advantages. Our results confirm the purported benefit. Vascular resistance indices in the pancreatic graft are significantly lower when the donor spleen is included. This, however, did not lower the incidence of thrombosis (2 out of 12 cases) in our study. Serial radionuclide studies with 99mTc-hexamethyl propylene amine oxime were performed for further evaluation of graft perfusion. With time the spleen uptake diminishes, compatible with atrophy of the organ. This was confirmed histologically. No indication of an immunologic advantage of transplanting the pancreas together with the spleen was found. All patients went through severe rejection crises. A transient reduction in platelet count (55-88%, mean 71%) of preoperative values was observed. This platelet drop is not seen in patients with a pancreas without spleen transplantation. We conclude that in pancreas transplantation, inclusion of the irradiated spleen has no obvious advantages for early graft thrombosis and rejection of the graft.

Adult↗
PubMed2000

Enhanced allograft survival induced by posttransplant donor spleen cell infusion occurs via a mechanism that is distinct from the mechanism of enhancement by donor bone marrow.

BACKGROUND: Our previous studies have shown that the ability of donor bone marrow to augment skin graft survival in antithymocyte serum (ATS)-treated recipients is dependent on the presence of functional CD95-ligand (Fas-ligand) molecules on donor cells. Because donor spleen cells can augment graft survival to a similar degree in the same model, we investigated whether the donor spleen cell effect was also dependent on the presence of CD95-ligand on donor cells and CD95 on recipient cells. METHODS: Mutant mice bearing defects in the expression of CD95 (lpr mutation) and CD95-ligand (gld mutation) were used as recipients and cell donors, respectively. Recipients were injected with rabbit ATS on days -1 and +2, and then were injected with 5x10(7) spleen cells on day +7. Skin graft survival was compared and correlated with the use of mutant mice as recipients and cell donors. RESULTS: The combination of ATS and infusions of wild-type [median survival (MST)=44 days, P=0.0004] and gld (mutant CD95-ligand, MST=37 days, P=0.02) donor spleen cells enhanced C3H graft survival, compared with (C57BL/6 x A)F1 recipients treated with ATS alone (MST=27 days). Furthermore, C57BL/6 lpr (CD95-deficient) strain recipients treated with ATS and donor spleen cells demonstrated enhanced B10.D2(R107) strain skin graft survival (MST=44 days, P=0.003), compared with C57BL/6 lpr recipients treated with ATS alone (MST=31 days). Wild-type C57BL/6 recipients treated in the same manner also exhibited an extension of graft survival (MST=64 days) versus controls treated with ATS alone (MST=31 days). CONCLUSION: The data demonstrate that the ability of donor spleen cells to augment allograft survival is not dependent on the CD95/CD95-ligand pathway; therefore the deletion of allospecific cells by donor spleen cells may be induced via a pathway other than deletion by donor bone marrow cells.

Animals↗
PubMed2001

An essential role for natural killer cells in augmentation of allograft survival mediated by donor spleen cells.

BACKGROUND: Previous studies have shown that skin allograft survival can be augmented by the administration of donor spleen or donor bone marrow in antithymocyte serum (ATS) treated recipients. Because natural killer cells (NK) have been reported to possess immunoregulatory properties, we investigated whether the ability of donor spleen or bone marrow cells to enhance allograft survival was dependent on the presence of donor NK cells. METHODS: Recipient (C57BL/6 x A/J)F1 strain mice (H2 haplotypes Kb/k, Ab/k, E-/k, Db/d) were treated with ATS on days -1 and +2 relative transplantation of a C3H (H-2k) skin allograft. On day +7, each recipient was randomly assigned to one of the following groups that received i.v. donor C3H cell infusions via the tail vein: 1) 5.0x10(7) wild-type donor spleen cells (SPC); 2) 5.0x10(7) spleen cells from C3H/HeJ-Lystbg-2J/+ mice (commonly called beige mice and have selectively impaired NK cell function); 3) 2.5x10(7) wild-type donor bone marrow cells (BMC); 4) 2.5x10(7)beige C3H bone marrow cells; and 5) no donor cell infusion (ATS controls). In another experiment, each recipient was randomly assigned to one of the following groups that received injections of: 1) 4.75x10(7) spleen cells depleted of NK cells; 2) 2.5x10(6) purified splenic NK cells; 3) a coinfusion of 5.0x10(7) beige spleen cells and 2.5x10(6) purified wild-type splenic NK cells. RESULTS: Recipients infused with wild-type SPC exhibited significant augmentation of allograft survival compared with ATS controls. However, graft survival was reduced in recipients that were infused with spleen cells from beige mice compared with recipients infused with wild-type SPC (median survival time (MST): 38 vs. 92 days, P=0.02). In contrast, infusions of beige BMC augmented allograft survival as well as wild-type BMC (MST: 47 vs. 49 days, P=0.76). Furthermore, the ability of wild-type SPC to augment allograft survival was abrogated by the depletion of NK cells (MST=92 vs. 34 days, respectively, P=0.005). The co-infusion of beige SPC and purified splenic NK cells enhanced allograft survival as well as wild-type SPC (MST=56 days, P=0.65). Finally, recipients infused with purified NK cells did not experience increased graft survival compared to recipients that received no infusion (MST=29 vs. 33 days, respectively, P=0.6). CONCLUSIONS: Donor splenic NK cells are necessary, but not sufficient, for the extension of graft survival by infusion of donor splenocytes, suggesting that they may work in concert with another cell-type. In contrast, the extension of graft survival by donor bone marrow does not depend on the presence of donor NK cells.

Animals↗
PubMed2003

Spleen transplantation in miniature swine: surgical technique and results in major histocompatibility complex-matched donor and recipient pairs.

BACKGROUND: Spleen transplantation (Tx) between some strains of rodents can lead to donor-specific tolerance either spontaneously or after a short course of immunosuppression. This study developed a surgical technique for spleen Tx in miniature swine to investigate its immunologic impact in a large animal model. METHODS: The preferred surgical technique of spleen Tx (n=8) involved excision of the donor spleen with its vascular pedicle to the aorta and portal vein. Carrel patches of donor aorta and portal vein were anastomosed to the abdominal aorta and inferior vena cava, respectively, of the (splenectomized) recipient. The results in four major histocompatibility complex-matched pairs that were mismatched for the porcine allelic antigen are reported. Two recipients were untreated, one received a 12-day course of cyclosporine A (CsA) alone, and one received thymic irradiation (700 cGy) and CsA. Hematopoietic cell chimerism was followed by fluorescence-activated cell sorter, and graft survival was assessed by histology. RESULTS: Spleen Tx was technically successful. In two untreated pigs, chimerism was detected in the blood (maximum 5% for 17 and 25 days) and lymph nodes (maximum 6% for 28 and 56 days), but both grafts showed histologic rejection by day 28. In two treated pigs, chimerism was present in the blood for 47 and 57 days, and rejection was prevented, with follow-up for 57 and 217 days, respectively. CONCLUSION: Spleen Tx in major histocompatibility complex-matched pairs treated with CsA+/-thymic irradiation results in prolonged chimerism and is associated with the development of in vivo unresponsiveness to the transplanted spleen.

Animals↗