Therapy with plasmapheresis and intravenous immunoglobulin for acute humoral rejection in kidney transplantation

BACKGROUND: Acute humoral rejection (AHR) is characterized by acute graft dysfunction associated with de novo production of donor-specific alloantibodies (DSA) and C4d deposition in peritubular capillaries of the renal allograft. It has been reported the combination of plasmapheresis (PP) and intravenous gamma globulin (IVIG) as effective rescue therapy for established AHR. METHODS: Between 1999 and 2004, seven kidney allografts recipients suffered from AHR diagnosed by severe rejection and C4d staining in peritubular capillaries. All patients had a negative cross-match before renal transplantation. RESULTS: All patients were treated with daily sessions of PP and in four cases IVIG was added after the last PP session. Tacrolimus and mycophenolate mofetil were employed as maintenance immunosuppressive regimen. In one case, rituximab was added to PP and IVIG owing to refractory humoral rejection. At 1 year, patient survival was 100%, allograft survival was 70%, and the mean serum creatinine was 201 micromol/L. CONCLUSIONS: AHR is a severe form of rejection associated with a poor prognosis, but its early diagnosis and treatment with PP and IVIG allows reversal of AHR reaching a 70% graft survival at 1 year.     

Reversal of steroid- and anti-lymphocyte antibody-resistant rejection using intravenous immunoglobulin (IVIG) in renal transplant recipients

BACKGROUND: Despite the recent advances in immunosuppression, steroid-resistant rejection remains a difficult problem in renal transplant recipients. METHODS: We reviewed our experience with i.v. immunoglobulin (IVIG) in the treatment of steroid- and antilymphocyte antibody-resistant rejection in renal transplant patients. Between September 1996 and March 1999, 17 patients were treated with IVIG to reverse steroid- or antilymphocyte antibody-resistant rejection. A total of 2 g/kg of IVIG was administered to patients during each treatment course. RESULTS: With a mean follow-up of 21.5+/-9.5 months from the time of IVIG administration, patient and graft survival rates were 94% (16/17) and 71% (12/17), respectively. The baseline mean serum creatinine level prior to rejection was 2.2+/-0.7 mg/dl and peaked at 3.3+/-1.1 mg/dl at the time of the diagnosis of refractory rejection. IVIG therapy was associated with a fall in the mean creatinine to 2.8+/-1.1 mg/dl. The most recent serum creatinine in patients with functioning grafts was 2.8+/-1.6 mg/dl. In 82% of allograft biopsies after IVIG, reversal or reduction in the severity of rejection was demonstrated. In addition, IVIG therapy rescued three of four patients with antilymphocyte antibody-resistant rejection. CONCLUSIONS: IVIG rescue therapy for steroid- or antilymphocyte antibody-resistant rejection is associated with resolution or improvement of rejection severity, stable renal function, and reasonable graft survival.     

Impact of rituximab therapy for treatment of acute humoral rejection

Abstract: Introduction: Antibody mediated rejection (AMR) is associated with a greater incidence of allograft loss because traditional approaches ‐ pulse steroid or anti‐lymphocyte antibodies are usually ineffective. This retrospective analysis documented the benefit of rituximab administration in addition to plasmapheresis (PP). Methods: We retrospectively reviewed the data from 54 kidney transplant patients treated for AMR between 2001 and 2006, including 26 patients who received PP plus rituximab (Group A), versus 28 subjects who underwent PP without rituximab (Group B). Only patients whose serum IgG levels were below normal values received intravenous gamma globulin (IVIG). In addition to clinical and demographic variables we evaluated graft/patient survivals at two years post‐diagnosis, Banff classification of rejections, serum creatinine and calculated GFR values at baseline, rejection, resolution as well as three, six, 12 and 24 months thereafter. Results: The demographic features of the cohorts showed no significant differences. The two‐year graft survival for patients treated with rituximab plus PP was 90%, significantly better than 60% in the PP cohort (p = 0.005). Upon multivariate analysis administration of rituximab was the most significant factor (≥ 0.009); whereas, IVIG also produced a useful effect (p = 0.05). Neither the mean (≥ 0.42) nor the slope (p = 0.25) of GFR values showed a significant difference among salvaged kidneys over 24 months after completion of AMR treatment. The rates and types of infectious complications at three and six months did not show significant differences or impact on graft survival. Conclusion: Addition of rituximab improved the outcomes of PP treatment of antibody mediated rejection episodes.     

Development of posttransplant antidonor HLA antibodies is associated with acute humoral rejection and early graft dysfunction

BACKGROUND: The goal of this study was to determine whether the production of posttransplant antibodies directed against donor HLA mismatches (donor specific antibody; DSA) is associated with renal allograft rejection and early graft dysfunction. METHODS: Forty-nine adult renal allograft recipients with increased risk of rejection were enrolled during the period of October 2001 through May 2003 and were prospectively monitored for the development of anti-HLA antibodies. RESULTS: Of 49 patients, eight (16.3 %) patients were diagnosed with acute humoral rejection (AHR) and 11/49 (22.4%) patients were diagnosed with acute cellular rejection (ACR). A strong association between pretransplant HLA sensitization and AHR was found (P=0.005). Of the eight patients diagnosed with AHR, the majority developed DSA before or concomitant with episodes of rejection (P<0.001). Only 3 of 41 patients (7.3%) without AHR developed DSA. The pathogenic role of alloantibodies was further substantiated by analyzing their association with graft function as measured by serum creatinine levels. The average serum creatinine after the third month posttransplantation in DSA producers was 2.24+/-1.01 mg/dL, while in non-DSA patients the average serum creatinine was 1.41+/-0.37 mg/dL (P<0.01). CONCLUSION: This study reveals a strong association between the production of DSA, AHR, and early graft dysfunction. Our findings indicate that prospective monitoring for anti-HLA antibodies following transplantation is a useful test for the diagnosis and classification of AHR for identifying patients at risk of early graft dysfunction.     

Plasmapheresis and intravenous immune globulin provides effective rescue therapy for refractory humoral rejection and allows kidneys to be successfully transplanted into cross-match-positive recipients

BACKGROUND: Hyperacute rejection (HAR) and acute humoral rejection (AHR) remain recalcitrant conditions without effective treatments, and usually result in graft loss. Plasmapheresis (PP) has been shown to remove HLA- specific antibody (Ab) in many different clinical settings. Intravenous gamma globulin (IVIG) has been used to suppress alloantibody and modulate immune responses. Our hypothesis was that a combination of PP and IVIG could effectively and durably remove donor-specific, anti-HLA antibody (Ab), rescuing patients with established AHR and preemptively desensitizing recipients who had positive crossmatches with a potential live donor. METHODS: The study patients consisted of seven live donor kidney transplant recipients who experienced AHR and had donor-specific Ab (DSA) for one or more mismatched donor HLA antigens. The patients segregated into two groups: three patients were treated for established AHR (rescue group) and four cross-match-positive patients received therapy before transplantation (preemptive group). RESULTS: Using PP/IVIG we have successfully reversed established AHR in three patients. Four patients who were cross-match-positive (3 by flow cytometry and 1 by cytotoxic assay) and had DSA before treatment underwent successful renal transplantation utilizing their live donor. The overall mean creatinine for both treatment groups is 1.4+/-0.8 with a mean follow up of 58+/-40 weeks (range 17-116 weeks). CONCLUSIONS: In this study, we present seven patients for whom the combined therapies of PP/IVIG were successful in reversing AHR mediated by Ab specific for donor HLA antigens. Furthermore, this protocol shows promise for eliminating DSA preemptively among patients with low-titer positive antihuman globulin-enhanced, complement-dependent cytotoxicity (AHG-CDC) cross-matches, allowing the successful transplantation of these patients using a live donor without any cases of HAR.     

C4d-positive acute humoral renal allograft rejection: effective treatment by immunoadsorption.

There is increasing evidence for an important pathogenetic role of alloantibodies in acute renal allograft rejection. Acute humoral rejection (AHR) has been reported to be associated with a poor transplant survival. Although treatment modalities for cellular rejection are fairly well established, the optimal treatment for AHR remains undefined. Ten of 352 kidney allograft recipients transplanted at the authors' institution between November 1998 and September 2000 were diagnosed as having AHR, supported by severe graft dysfunction, C4d deposits in peritubular capillaries (PTC), and accumulation of granulocytes in PTC. AHR was diagnosed 18.9 +/- 17.5 d posttransplantation. All patients were subjected to immunoadsorption (IA) with protein A (median number of treatment sessions, 9; range, 3 to 17). Seven recipients with additional signs of cellular rejection (according to the Banff classification) received also antithymocyte globulin. In nine of ten patients, AHR was associated with an increase in panel reactive antibody reactivity. A pathogenetic role of alloantibodies was further supported by a positive posttransplant cytotoxic crossmatch in all tested recipients (n = 4). In nine of ten recipients, renal function recovered after initiation of anti-humoral therapy. One patient lost his graft shortly after initiation of specific therapy. Another recipient with partial reversal of AHR returned to dialysis 8 mo after transplantation. Mean serum creatinine in functioning grafts was 2.2 +/- 1.2 mg/dl after the last IA session (n = 9) and 1.5 +/- 0.5 mg/dl after a follow-up of 14.2 +/- 7.1 mo (n = 8). In conclusion, this study suggests that AHR, characterized by severe graft dysfunction, C4d staining, and peritubular granulocytes, can be effectively treated by timely IA. In the majority of patients, IA treatment can restore excellent graft function over a prolonged time period.     

Successful therapy with rituximab of refractory acute humoral renal transplant rejection: a case report

Acute humoral rejection (AHR) is generally less responsive to conventional anti-rejection treatment with consequent allograft losses. Therapeutic options include antilymphocyte antibody (ATG), intravenous immunglobulin (IVIG), plasmapheresis, or immunoadsorption with protein A together with intensification of immunsuppression with a tacrolimus/mycophenolate mofetil combination. This report describes a transplant recipient who responded to rituximab therapy as treatment for steroid-, ATG-, IVIG-, and plasmapheresis-resistant AHR.     

Successful rescue therapy with plasmapheresis and intravenous immunoglobulin for acute humoral renal transplant rejection

Plasmapheresis (PP) and intravenous immunoglobulin (IVIg) remove donor-specific antibodies, a cause of acute humoral rejection (AHR). We describe the use of PP and IVIg as rescue therapy for AHR. The records of 143 renal transplants performed between October 1, 2000 and April 1, 2002 were reviewed. Patients who underwent PP and IVIg therapy for AHR were identified. The data reviewed included age, sex, source of transplant, number of human leukocyte antigen mismatches, transplant number, number of PP and IVIg treatments, dose of IVIg, time of AHR, serum creatinine (SCr) level at AHR, SCr level after PP and IVIg at 3 months, days to achieve 30% decline in SCr, and graft survival. Immunosuppression included basiliximab induction, tacrolimus, and prednisone (+/- sirolimus or mycophenolate mofetil [CellCept, Roche Pharmaceutical, Nutley, NJ]). PP was followed by IVIg infusion. Nine patients were treated for AHR with PP and IVIg. All nine patients demonstrated biopsy-proven AHR. One graft was lost. Mean 3-month and 1-year SCr levels were 1.9 and 1.8, respectively, in the remaining eight patients. AHR in renal transplantation can be effectively treated with PP and IVIg.     

Treatment of C4d-positive acute humoral rejection with plasmapheresis and rabbit polyclonal antithymocyte globulin

BACKGROUND: Alloantibody-mediated acute rejection is a major cause of renal allograft loss despite aggressive therapy. Patients with humoral rejection can be identified with high sensitivity and specificity by the presence of peritubular capillary C4d staining on renal biopsy and donor-specific anti-human leukocyte antigen antibodies. Standard therapy for acute humoral rejection (AHR) has been removal of donor-specific antibodies by plasmapheresis (PPH) in conjunction with intravenous immunoglobulin therapy. We describe a series of seven patients with C4d positive AHR who received combined therapy with PPH and polyclonal rabbit antithymocyte globulin (rATG). METHODS: PPH (1.4 volume exchange) was initiated on diagnosis of AHR on an alternate day basis for a mean number of 6.8 treatments, in conjunction with rATG (0.75 mg/kg/day 5-10 days) until the serum creatinine returned to 120% of nadir. RESULTS: The nadir posttreatment creatinine was significantly lower than pretreatment creatinine (1.0+/-1.2 vs. 2+/-1.4, P <0.007) with only one episode of graft loss. On follow-up there was no difference in renal allograft survival between the AHR group and the 60 patients without AHR who underwent transplantation during the same period. We describe the ability of rATG to induce apoptosis in vitro peripheral blood and activated B cells. CONCLUSION: Combination therapy using PPH and rATG is an effective means of reversing AHR in renal allografts.     

Reducing De Novo Donor-Specific Antibody Levels during Acute Rejection Diminishes Renal Allograft Loss

The effect of de novo DSA detected at the time of acute cellular rejection (ACR) and the response of DSA levels to rejection therapy on renal allograft survival were analyzed. Kidney transplant patients with acute rejection underwent DSA testing at rejection diagnosis with DSA levels quantified using Luminex single-antigen beads. Fifty-two patients experienced acute rejection with 16 (31%) testing positive for de novo DSA. Median follow-up was 27.0 ± 17.4 months postacute rejection. Univariate analysis of factors influencing allograft survival demonstrated significance for African American race, DGF, cytotoxic PRA >20% (current) and/or >50% (peak), de novo DSA, C4d and repeat transplantation. Multivariate analysis showed only de novo DSA (6.6-fold increased allograft loss risk, p = 0.017) to be significant. Four-year allograft survival was higher with ACR (without DSA) (100%) than mixed acute rejection (ACR with DSA/C4d) (65%) or antibody-mediated rejection (35%) (p < 0.001). Patients with >50% reduction in DSA within 14 days experienced higher allograft survival (p = 0.039). De novo DSAs detected at rejection are associated with reduced allograft survival, but prompt DSA reduction was associated with improved allograft survival. DSA should be considered a potential new end point for rejection therapy.     

A Comparison of Plasmapheresis Versus High-Dose IVIG Desensitization in Renal Allograft Recipients with High Levels of Donor Specific Alloantibody

Several protocols allow for the successful transplantation of sensitized renal allograft recipients, yet no one best method has emerged. The aim of the current study was to compare the efficacy of high-dose IVIG with two different plasmapheresis (PP)-based regimens in kidney transplant recipients with high levels of donor specific alloantibody (DSA) defined as a positive T-cell cytotoxicity crossmatch. With the primary goal of achieving a negative crossmatch, we employed three protocols sequentially between April 2000 and May 2005: (i) PP, low-dose IVIG, anti-CD20 antibody (n = 32); (ii) high-dose IVIG (n = 13); and (iii) PP, low-dose IVIG, anti-CD20 antibody and pre-transplant Thymoglobulin combined with post-transplant DSA monitoring (n = 16). IVIG decreased DSA activity in all treated patient, yet only 38% (5/13) achieved a negative crossmatch. In contrast, a negative crossmatch was achieved in 84% in PP group and 88% in the PP/monitoring group (p < 0.01 vs. IVIG). Even with a negative crossmatch, the rejection rates were 80% (IVIG), 37% (PP) and 29% (PP/monitoring), respectively, (p < 0.05 IVIG vs. PP). We conclude that multiple PP treatments leads to more reproducible desensitization and lower humoral rejection rates than a single high-dose of IVIG, but that no regimen was completely effective in preventing humoral rejection.     

Acute humoral rejection in renal allograft recipients: I. Incidence, serology and clinical characteristics

BACKGROUND: Acute rejection (AR) associated with de novo production of donor-specific antibodies (DSA) is a clinicopathological entity that carries a poor prognosis (acute humoral rejection, AHR). The aim of this study was to determine the incidence and clinical characteristics of AHR in renal allograft recipients, and to further analyze the antibodies involved. METHODS: During a 4-year period, 232 renal transplants (Tx) were performed at our institution. Assays for DSA included T and B cell cytotoxic and/or flow cytometric cross-matches and cytotoxic antibody screens (PRA). C4d complement staining was performed on frozen biopsy tissue. RESULTS: A total of 81 patients (35%) suffered at least one episode of AR within the first 3 months: 51 had steroid-insensitive AR whereas the remaining 30 had steroid-sensitive AR. No DSA were found in patients with steroid-sensitive AR. In contrast, circulating DSA were found in 19/51 patients (37%) with steroid-insensitive AR, and widespread C4d deposits in peritubular capillaries were present in 18 of these 19 (95%). In at least three cases, antibodies were against donor HLA class II antigens. DSA were not found in the remaining 32 patients but C4d staining was positive in 2 of 32. The DSA/C4d positive (n=18) and DSA/C4d negative (n=30) groups differed in pre-Tx PRA levels, percentage of re-Tx patients, refractoriness to antilymphocyte therapy, and outcome. Plasmapheresis and tacrolimus-mycophenolate mofetil rescue reversed rejection in 9 of 10 recipients with refractory AHR. CONCLUSION: More than one-third of the patients with steroid-insensitive AR had evidence of AHR, often resistant to antilymphocyte therapy. Most cases (95%) with DSA at the time of rejection had widespread C4d deposits in peritubular capillaries, suggesting a pathogenic role of the circulating alloantibody. Combined DSA testing and C4d staining provides a useful approach for the early diagnosis of AHR, a condition that often necessitates a more intensive therapeutic rescue regimen.     

双滤过法血浆分离治疗移植肾术后排斥反应及术前高度致敏

目的探讨肾移植术后排斥反应和术前高度致敏的治疗方法。方法采用双滤过法血浆分离术（ＤＦＰＰ）治疗３６例术后排斥反应和９例术前高度致敏患者。结果２４例急性排斥中２２例逆转,１０例加速性排斥（ＡＣＲ）全部逆转,１例慢性排斥肾功能稳定,１例超急性排斥（ＨＡＲ）摘除移植肾;排斥反应采用ＤＦＰＰ治疗者其一年移植肾生存率为８４．０％。去致敏抗体者８例已接受肾移植,其中１例术后发生ＨＡＲ。结论认为ＤＦＰＰ是治疗排斥反应和预防高敏患者术后发生致敏抗体介导的ＨＡＲ和ＡＣＲ的有效方法,显著提高了排斥反应的逆转率和移植肾生存率     

Experience with OKT3 in vascularized pancreas transplantation

With refinements in technical aspects of whole organ pancreas transplantation, allograft rejection is currently the major cause of graft failure. The monoclonal antibody OKT3 has emerged as a highly effective antirejection therapy in renal and hepatic allograft recipients, but its efficacy in pancreas transplantation remains to be determined. During a 12-month period, 28 vascularized whole organ pancreas transplants were performed with pancreatico-cystostomy. Sixteen episodes of allograft rejection were treated with monoclonal antibody OKT3. Indications for OKT3 use included steroid- or antilymphocyte globulin (ALG)-resistant allograft rejection in isolated pancreas (n = 8) or simultaneous kidney-pancreas (n = 8) transplants. A total of 34 rejection episodes occurred in the 16 patients (mean, 2.1; range, one to five). The diagnosis of rejection was based on clinical criteria, a reduction in urinary amylase clearance, radionuclide scanning, hyperglycemia, or associated renal allograft dysfunction in combined engraftments. Postoperative immunosuppression consisted of cyclosporine, prednisone, azathioprine, and prophylactic ALG. OKT3 was administered for a full 14-day course concomitant with low-dose steroids, azathioprine, and cyclosporine. The mean age of the patient population was 32.1 years (range 24 to 39) with a mean duration of insulin-dependent diabetes mellitus (IDDM) of 20.9 years. Monoclonal antibody therapy was instituted in two clinical settings: early rejection (within 3 months of transplant, n = 10); and late rejection (after 3 months, n = 6). OKT3 successfully reversed allograft rejection in ten (62.5%) cases, including six early (60%) and four late (66.7%) episodes. In isolated pancreas transplants, OKT3 therapy reversed pancreas allograft rejection in only two patients (25%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Simultaneous kidney-pancreas transplantation without antilymphocyte induction

BACKGROUND: The introduction of potent new immunosuppressive agents may allow simultaneous kidney-pancreas transplantation to be performed without antilymphocyte induction. METHODS: We analyzed 30 simultaneous kidney-pancreas transplantations receiving tacrolimus, mycophenolate mofetil, and steroids without without antilymphocyte induction. Eighteen patients underwent pancreas transplantation with portal-enteric (P-E) drainage and the remaining 12 had systemic bladder (S-B) drainage. Target 12 hr trough tacrolimus levels for the first 3 months after simultaneous kidney-pancreas transplantation were 15-20 ng/ml. The oral mycophenolate mofetil dose was 2-3 g/day begun immediately posttransplant in two to four divided doses. Steroids were tapered according to protocol. RESULTS: All patients experienced immediate function of both kidney and pancreas grafts. One-year actuarial patient, kidney, and pancreas graft survival rates are 93, 93, and 90%, respectively. Nine patients (30%) had a total of 13 rejection episodes (12 biopsy proven) including 4 within 2 weeks, 6 between 2 weeks and 3 months, and 3 beyond 3 months after simultaneous kidney-pancreas transplantation. Three rejection episodes were treated with steroids alone and 10 were treated with antilymphocyte therapy (5 OKT3 and 5 ATGAM). A total of seven patients (23%) received antilymphocyte therapy. Three patients (10%) had more than one rejection episode. Two pancreas grafts (7%) and one kidney graft (3%) were lost from rejection. Four patients (13%) developed cytomegalovirus infection, but none had tissue-invasive cytomegalovirus. At present, 22 surviving patients (81%) remain on triple immunosuppression with tacrolimus, mycophenolate mofetil, and prednisone with excellent dual graft function. CONCLUSION: Tacrolimus, mycophenolate mofetil, and prednisone immunosuppression without without antilymphocyte induction is safe and effective after simultaneous kidney-pancreas transplantation.     

Improved survival of primary cadaveric renal allografts in blacks with quadruple immunosuppression.

Black recipients of cadaveric kidneys have been shown to have a lower rate of allograft survival than whites. Data were reviewed from 642 primary cadaveric transplants: results in 276 patients (163 white and 113 black) (group 1) who had received triple therapy (azathioprine-CsA-prednisone, 1985-87) were compared with those in 366 patients (180 white and 186 black) (group 2) receiving quadruple immunosuppression (MALG-azathioprine-CsA-prednisone, 1987-90). Blacks in group 2 had better patient (97% vs. 91%, P = 0.03) and graft (77% vs. 55%, P = 0.0002) survival at 1 year than in group 1. There was no difference in these parameters among whites in either group. Racial differences in graft survival noted in group 1 disappeared in group 2. While HLA BDR matching improved in group 2 patients (P = 0.0001), whites received better matched kidneys than blacks in both groups (P = 0.001). HLA matching was associated with improved graft survival only in white recipients of 4 BDR-matched kidneys. In group 1, more blacks than whites had at least one episode of acute rejection (76% vs. 57%, P = 0.001); blacks also lost more grafts to acute and chronic rejection. In group 2, there were no racial differences in the number of rejection episodes or immunologic graft losses. Of 14 potential variables examined by parametric analysis, only quadruple therapy significantly reduced risk of graft loss in blacks. Quadruple immunosuppression improved primary cadaveric renal allograft survival in black recipients, abrogating previously noted racial differences.     

Successful rescue and maintenance of long-term remission of anti-HLA antibody-mediated acute allograft rejection by rituximab-containing therapy: case report

Abstract:  A 38-yr-old man with chronic renal failure received a second kidney transplantation from a cadaveric donor. Complement-dependent cytotoxicity cross-match (CDC) was negative against T cells, but positive with the B-cell warm test. Human leukocyte antigen (HLA)-typing showed a one haplo-identical match. The blood type was compatible. He was treated with tacrolimus, mycophenolate mofetil (MMF), methylpredonisolone (MP), and basiliximab as immunosuppressive therapy. A clinical episode graft biopsy and Flow-PRA on post-operative day (POD) 19 showed anti-HLA antibody-mediated acute rejection (AHR). The patient was treated with plasmapheresis (PP). Renal biopsy performed on POD 65 because of re-rise of serum creatinine level showed worsening of renal injury. The patient was treated with rituximab (100 mg/body) with PP and MP pulse therapy, followed by tacrolimus and MMF. Graft function thereafter improved. A renal allograft biopsy specimen on POD 300 and Flow-PRA showed the remission of AHR within one-yr after transplantation.     

Sirolimus rescue therapy for refractory rejection in renal transplantation.

BACKGROUND: Acute renal allograft rejection episodes refractory to antilymphocyte preparations almost inevitably progress to transplantation loss. To reverse ongoing rejection processes, we administered sirolimus (RAPA) after failure of conventional immunosuppressive regimens including full courses of antilymphocyte sera. METHODS: All 36 renal transplantation recipients reported herein displayed either Grade IIB or Grade III biopsy-proven (Banff 1993 criteria) ongoing rejection episodes despite prior treatment with pulse and/or oral recycling of steroids and at least one 14- to 21-day course of murine (OKT3) or equine (ATGAM) antilymphocyte treatment. We compared the actual 12-month outcomes of two demographically similar cohorts of patients treated for refractory rejection with RAPA (Group I; n=24) or mycophenolate mofetil (MMF; Group II; n=12) added to a baseline regimen of cyclosporine (CsA)/prednisone (Pred). RESULTS: Rescue therapy reversed the renal dysfunction in 96% of patients in the RAPA group versus 67% in the MMF group (P=0.03) despite the fact that a greater fraction of patients in the RAPA (17 of 24) than the MMF group (6 of 12) had experienced two or more episodes of acute rejection before study entry and the fact that the recurrent bouts of acute rejection occurred within the first 6 months posttransplant in 94% of patients in the RAPA group compared with 50% (P=0.005) in the MMF group. Among the patients who were reversed successfully, the rates of rebound acute rejection were similar (4% vs. 8%). The mean serum creatinine values were slightly, although not significantly, lower among RAPA than MMF patients at 1, 3, 6, and 12 months: namely, 2.6 vs. 2.8, 2.8 vs. 3.2, 3.0 vs. 3.3, and 2.8 vs. 3.2 mg/dL, respectively. The 1-year patient and graft survival rates were similar: namely, 88% vs. 92% and 83% vs. 67% for the RAPA versus MMF groups. CONCLUSION: RAPA is a potent immunosuppressive agent for the treatment of refractory renal allograft rejection.     

Acute humoral rejection in kidney transplantation: II. Morphology, immunopathology, and pathologic classification

The incidence of acute humoral rejection (AHR) in renal allograft biopsies has been difficult to determine because widely accepted diagnostic criteria have not been established. C4d deposition in peritubular capillaries (PTC) of renal allografts has been proposed as a useful marker for AHR. This study was designed to test the relative value of C4d staining, histology, and serology in the diagnosis of AHR. Of 232 consecutive kidney transplants performed at a single institution from July 1995 to July 1999, all patients (n = 67) who developed acute rejection within the first 3 mo and had a renal biopsy with available frozen tissue at acute rejection onset, as well as posttransplant sera within 30 d of the biopsy, were included in this study. Hematoxylin and eosin and periodic acid-Schiff stained sections were scored for glomerular, vascular, and tubulointerstitial pathology. C4d staining of cryostat sections was done by a sensitive three-layer immunofluorescence method. Donor-specific antibodies (DSA) were detected in posttransplant recipient sera using antihuman-globulin-enhanced T cell and B cell cytotoxicity assays and/or flow cytometry. Widespread C4d staining in PTC was present in 30% (20 of 67) of all acute rejection biopsies. The initial histologic diagnoses of the C4d(+) acute rejection cases were as follows: AHR only, 30%; acute cellular rejection (ACR) and AHR, 45%; ACR (CCTT types 1 or 2) alone, 15%; and acute tubular injury (ATI), 10%. The distinguishing morphologic features in C4d(+) versus C4d(-) acute rejection cases included the following: neutrophils in PTC, 65% versus 9%; neutrophilic glomerulitis, 55% versus 4%; neutrophilic tubulitis, 55% versus 9%; severe ATI, 75% versus 9%; and fibrinoid necrosis in glomeruli, 20% versus 0%, or arteries, 25% versus 0%; all P < 0.01. Mononuclear cell tubulitis was more common in the C4d(-) group (70% versus 100%; P < 0.01). No significant difference between C4d(+) and C4d(-) acute rejection was noted for endarteritis, 25% versus 32%; interstitial inflammation (mean % cortex), 27.2 +/- 27% versus 38 +/- 21%; interstitial hemorrhage, 25% versus 15%; or infarcts, 5% versus 2%. DSA were present in 90% (18 of 20) of the C4d(+) cases compared with 2% (1 of 47) in the C4d(-) acute rejection cases (P < 0.001). The pathology of the C4d(+) but DSA(-) cases was not distinguishable from the C4d(+), DSA(+) cases. The C4d(+) DSA(-) cases may be due to non-HLA antibodies or subthreshold levels of DSA. The sensitivity of C4d staining is 95% in the diagnosis of AHR compared with the donor-specific antibody test (90%). Overall, eight grafts were lost to acute rejection in the first year, of which 75% (6 of 8) had AHR. The 1-yr graft failure rate was 27% (4 of 15) for those AHR cases with only capillary neutrophils versus 40% (2 of 5) for those who also had fibrinoid necrosis of arteries. In comparison, the 1-yr graft failure rates were 3% and 7%, respectively, in ACR 1 (Banff/CCTT type 1) and ACR 2 (Banff/CCTT type 2) C4d(-) groups. A substantial fraction (30%) of biopsy-confirmed acute rejection episodes have a component of AHR as judged by C4d staining; most (90%), but not all, have detectable DSA. AHR may be overlooked in the presence of ACR or ATI by histology or negative serology, arguing for routine C4d staining of renal allograft biopsies. Because AHR has a distinct therapy and prognosis, we propose that it should be classified separately from ACR, with further sub-classification into AHR 1 (neutrophilic capillary involvement) and AHR 2 (arterial fibrinoid necrosis).     

Clinical course and pathologic findings of successful second ABO-incompatible renal transplantation in a patient with donor-specific anti-HLA antibody

Abstract:  Donor-specific anti-HLA antibody and anti-blood group antibody could cause antibody-mediated rejection (AMR). Here, we report a successful second ABO-incompatible (ABO-I) renal transplantation in a patient with donor-specific anti-HLA antibody and its pathologic findings. A 50-yr-old woman underwent second ABO-I (A1 to O) renal transplantation. She had received the first renal graft from her mother following splenectomy in July 2003; however, graft function was lost 50 d after transplantation because of AMR. The patient received the second renal graft in November 2005, from her husband whose blood type was also A1. The recipient had donor-specific anti-HLA antibody because flow panel reactive antibody and flow cytometry crossmatch were strongly positive prior to the plasmapheresis (PP) therapy. Pre-transplant intensive immunosuppression, PP, and low dose (100 mg/m²) anti-CD20 antibody (rituximab) administration were performed as desensitization therapy. The recipient clinically developed acute rejection, and allograft biopsy specimen at day 6 post-transplant revealed AMR type II according to the Banff 2003 classification. However, the graft function was rescued by PP/low dose (100 mg/kg) intravenous immunoglobulin (IVIG) therapy, and the biopsy specimen at day 43 post-transplant showed border-line change without AMR. Rituximab and PP/low-dose IVIG therapy might improve the clinical course and pathologic findings in this AMR-related high-risk transplantation.