David Lorentzen

The predictive value of donor liver biopsies for the development of primary nonfunction after orthotopic liver transplantation

Methods of accurately assessing the suitability of donor livers prior to transplantation are required if the incidence of primary nonfunction (PNF) is to be reduced. This study evaluated the ability of donor liver biopsies to predict the development of primary nonfunction after transplantation. From June 1987 until May 1990, 170 liver transplants were performed in 147 patients. A total of 124 donor liver biopsies were obtained and divided into three groups. Group 1 biopsies (n = 77) were obtained after revascularization of the liver, group 2 biopsies (n = 19) were obtained prior to donor hepatectomy but examined only after implantation, and group 3 biopsies (n = 28) were obtained as in group 2, but were examined prior to implantation. Three of 89 (3.4%) livers interpreted as having normal histology developed primary nonfunction, while one of 26 (3.8%) biopsies interpreted as having a minimal or moderate amount of fatty infiltration developed primary nonfunction. PNF occurred in 7 of 8 livers with severe fatty infiltration (3), hydropic degeneration (3), and centrilobular necrosis (1). A fourth liver with hydropic degeneration and poor function ultimately failed requiring retransplantation 8 weeks later. Analysis of liver function revealed progressive elevation in aspartate-aminotransferase, alanine-aminotransferase, lactate dehydrogenase, and serum ammonia (NH3) with increasing degrees of fatty infiltration. Donor age and weight was also found to be significantly higher in livers with fatty infiltration. This study suggests that donor liver biopsies demonstrating normal histology or minimal-to-moderate fatty infiltration function adequately, but that donor livers with severe fatty infiltration or hydropic degeneration function poorly and should not be transplanted.

The Significance of Donor-Specific HLA Antibodies in Rejection and Ductopenia Development in ABO Compatible Liver Transplantation

The role of humoral alloreactivity in ABO‐compatible liver transplantation remains unclear. To understand the significance of donor‐specific HLA alloantibodies (DSA) in liver rejection, we applied the currently used strategy for detection of antibody‐mediated rejection of other solid allografts. For this purpose we reviewed the data on 43 recipients of ABO identical/compatible donor livers who had indication liver biopsy stained for complement element C4d and contemporaneous circulating DSA determination. Seventeen (40%) patients had significant circulating DSA in association with diffuse portal C4d deposition (DSA+/diffuse C4d+). These DSA+/diffuse C4d+ subjects had higher frequency of acute cellular rejection (ACR) 15/17 versus 13/26 (88% vs. 50%), p = 0.02, and steroid resistant rejection 7/17 versus 5/26 (41% vs. 19%), p = 0.03. Based on detection of the combination DSA+/diffuse C4d+, 53.6% of cases of ACR had evidence of concurrent humoral alloreactivity. Six of the 10 patients with ductopenic rejection had circulating DSA and diffuse portal C4d, three of whom (2 early and 1 late posttransplantation) developed unrelenting cholestasis, necessitating specific antibody‐depleting therapy to salvage the allografts. Thus, in ABO‐compatible liver transplantation humoral alloreactivity mediated by antibodies against donor HLA molecules appears to be frequently intertwined with cellular mechanisms of rejection, and to play a role in ductopenia development.

The effect of donor age, recipient age, and HLA match on immunologic graft survival in cadaver renal transplant recipients.

We retrospectively analyzed 526 primary cadaver recipients transplanted at a single center to identify pre-transplant variables that predict long-term survival with multivariate analysis. All recipients received atleast three random blood transfusions and were treated under a quadruple-therapy protocol consisting of ALG, azathioprine, prednisone, and cyclosporine. Of 526 consecutive transplants, 86 grafts were lost from acute or chronic rejection. Thirteen grafts were lost for nonimmunologic reasons and 35 recipients died with a functioning graft. A total of 273 patients (52%) experienced at least one episode of acute rejection. Donor age ranged from 3 to 64 years, with 62% of donors less than 30 years of age and 9% of donors over 50 years of age. Donor age was not predictive of long-term graft survival and neither was the difference be-

Pretransplant donor-specific antibodies detected by single-antigen bead flow cytometry are associated with inferior kidney transplant outcomes.

Background. The clinical significance of pretransplant donor-specific antibodies (pre-Tx DSAs) detected by single-antigen bead flow cytometry (SAB-FC) remains unclear. Methods. To investigate the impact that pre-Tx DSAs detected by SAB-FC have on early clinical outcomes, we tested pre-Tx sera from all consecutive deceased-donor kidney transplants performed between January 2005 and July 2006 (n=237). Results. In the study population of which 66% had a high-immunologic risk, mean fluorescence intensity (MFI) more than or equal to 100 for class I and more than or equal to 200 for class II were the lowest DSA thresholds associated with inferior antibody-mediated rejection-free graft survival (75% vs. 90%, P=0.004 and 76% vs. 87%, P=0.017, respectively). The hazard ratio for antibody-mediated rejection increased linearly with higher class II DSA from MFI 100 to 800 (1.7[0.8–3.2], P=0.1 for MFI≥100 vs. 4.7[2.4–8.8], P<0.001 for MFI ≥800). Differences in graft function were only evident in patients with class II MFI more than or equal to 500 (estimated glomerular filtration rate: 47.6 vs. 54.3, P=0.02 and proteinuria: 0.6±0.6 vs. 0.4±0.3, P=0.03). A difference in death-censored graft survival was detected in patients with class II MFI more than or equal to 1000 (75% vs. 91.9%, P=0.055). Conclusion. High-pre-Tx DSAs detected by SAB-FC are associated with incrementally poor graft outcomes in deceased-donor kidney transplant with high-immunologic risk.

Gorillas with Spondyloarthropathies Express an MHC Class I Molecule with Only Limited Sequence Similarity to HLA-B27 that Binds Peptides with Arginine at P2

The human MHC class I gene, HLA-B27, is a strong risk factor for susceptibility to a group of disorders termed spondyloarthropathies (SpAs). HLA-B27-transgenic rodents develop SpAs, implicating HLA-B27 in the etiology of these disorders. Several nonhuman primates, including gorillas, develop signs of SpAs indistinguishable from clinical signs of humans with SpAs. To determine whether SpAs in gorillas have a similar HLA-B27-related etiology, we analyzed the MHC class I molecules expressed in four affected gorillas. Gogo-B01, isolated from three of the animals, has only limited similarity to HLA-B27 at the end of the α1 domain. It differs by several residues in the B pocket, including differences at positions 45 and 67. However, the molecular model of Gogo-B*0101 is consistent with a requirement for positively charged residues at the second amino acid of peptides bound by the MHC class I molecule. Indeed, the peptide binding motif and sequence of individual ligands eluted from Gogo-B*0101 demonstrate that, like HLA-B27, this gorilla MHC class I molecule binds peptides with arginine at the second amino acid position of peptides bound by the MHC class I molecule. Furthermore, live cell binding assays show that Gogo-B*0101 can bind HLA-B27 ligands. Therefore, although most gorillas that develop SpAs express an MHC class I molecule with striking differences to HLA-B27, this molecule binds peptides similar to those bound by HLA-B27.

Luminex-based desensitization protocols: The university of wisconsin initial experience

Background. We have demonstrated that immunodominant donor-specific antibody (DSA) more than 100 mean fluorescence intensity (MFI) at the time of transplant is associated with a significantly higher risk of rejection. We now present short-term outcomes of DSA-based desensitization (DSZ) strategies in patients with a negative complement-dependent cytotoxicity crossmatch. Methods. Between January 1, 2009, and January 1, 2010, live-donor kidney transplant recipients were divided into three protocols based on their immunodominant DSA MFI pretransplant (D1: 100–500, D2: 501–1000, and D3: 1001–3000). Deceased donor kidney transplant recipients were stratified into two protocols (D4: 501–1000 and D5: 1001–3000). The intensity of the conditioning treatment increased with DSA levels and included thymoglobulin induction, plasmapheresis, and intravenous immunoglobulin in the highest risk groups. We compared outcomes between desensitized patients (DSZ) and those undergoing no DSZ (or D0) during the same interval. Results. Forty-eight of 249 (23%) kidney transplants underwent DSZ (n=20, 4, 3, 4, and 17 in D1–D5 protocols, respectively). There was more retransplantation (50% vs. 18%, P<0.001) and live donor transplantation (56% vs. 30%, P<0.001) in the DSZ group. In this group, mean peak panel reactive antibody and MFI at transplant were 51%±7% and 960±136, respectively. The incidence of antibody-mediated rejection (25% vs. 12.5%, P=0.008) and acute cellular rejection (23% vs. 14%, P=0.02) was greater in the DSZ group. However, mixed rejection (8%), graft loss (0 vs. 6), patient death (0 vs. 3), cytomegalovirus infection (15% vs. 12%), and 1-year serum creatinine (1.4±0.5 and 1.4±0.4 mg/dL) were similar between DSZ and no-DSZ groups. Conclusion. Long-term follow-up is needed to determine the role of Luminex-based strategies in current preconditioning regimens.

Acute Cellular and Antibody‐Mediated Rejection of the Pancreas Allograft: Incidence, Risk Factors and Outcomes

Antibody‐mediated rejection (AMR) after pancreas transplantation is a recently identified entity. We describe the incidence of, risk factors for, and outcomes after AMR, and the correlation of C4d immunostaining and donor‐specific antibody (DSA) in the diagnosis of AMR. We retrospectively analyzed 162 pancreas transplants in 159 patients who underwent 94 pancreas allograft biopsies between 2006 and 2009. Univariate and multivariate analyses were performed to evaluate risk factors for pancreas graft AMR. One‐year rejection rates and survival after rejection were calculated by Kaplan–Meier methods. AMR occurred in 10% of patients by 1‐year posttransplant. Multivariate risk factors identified for AMR include nonprimary simultaneous pancreas–kidney (SPK) transplant, primary solitary pancreas (PAN) transplant and race mismatch. After pancreas rejection, patient survival was 100% but 20% (8 of 41) of pancreas grafts failed within 1 year. Graft survival after acute cellular rejection (ACR), AMR and mixed rejection was similar. Of biopsies that stained >5% C4d, 80% were associated with increased Class I DSA. In summary, AMR occurs at a measurable rate after pancreas transplantation, and the diagnosis should be actively sought using C4d staining and DSA levels in patients with graft dysfunction, especially after nonprimary SPK and primary PAN transplantation.

Outcomes of simultaneous liver/kidney transplants are equivalent to kidney transplant alone: a preliminary report.

Background. With adoption of Model for End-Stage Liver Disease, the number of simultaneous liver-kidney transplants (SLK) has greatly increased. A recent registry study questioned the equity of allocating kidney transplants (KTx) simultaneously with liver transplantation due to poor outcomes (Locke et al., Transplantation 2008; 85: 935). Methods. To investigate outcome of KTx in SLK, all SLK (n=36) performed at our center from January 2000 to December 2007 were reviewed and KTx outcomes compared with those of kidney transplant alone (KTA) performed during that period (n=1283). We also reviewed whether pretransplant panel reactive antibody and donor-specific antibody affected KTx outcome in SLK. Results. One- and 3-year KTx and patient survival were not different between KTA and SLK regardless of sensitization level. There were 348 (27%) KTx failures in KTA vs. 6 (17%) in SLK (NS). Overall freedom from acute cellular rejection (ACR) and antibody-mediated rejection (AMR) in SLK was 93 and 96% at 3 years, compared with 72 and 78% in KTA (P=0.0105 and P=0.0744, respectively). Sensitized KTx recipients had more ACR and AMR (32 and 38%) at 3 years compared with nonsensitized recipients (28 and 20%) (P=0.23 and 0.0001, respectively). No differences in ACR and AMR were observed when SLK was divided and level of sensitization compared (P=0.17 and 0.65, respectively). Conclusion. SLK is a life-saving procedure with excellent patient and graft survival. AMR incidence in the KTx appears reduced in SLK compared with KTA regardless of level of preoperative panel reactive antibody. A high level of donor-specific antibody should not preclude simultaneous transplantation when clinically indicated.

A Comparative Study of Major Histocompatibility Complex and Red Blood Cell Antigen Phenotypes as Risk Factors for Recurrent Urinary Tract Infections in Women

Recurrent urinary tract infections (RUTI) are a significant health problem for many women, and host characteristics that increase susceptibility are not completely defined. This study evaluated data from 99 patients to examine further the question of a possible association between major histocompatibility complex (MHC) or red blood cell (RBC) antigen phenotype and predisposition to RUTIs. MHC class I and II, ABO, and Lewis RBC phenotypes were determined serologically. The MHC class II phenotypes of 55 subjects were also determined by DNA polymerase chain reaction techniques. There were no significant differences in the proportions of HLA-A or -B antigen types between patients and controls, nor in the frequencies of serologically or DNA-defined HLA-DR or -DQ phenotypes. Patient ABO and Lewis RBC phenotypes were not statistically different than those for controls. Thus, the overall risk for women to develop RUTIs does not appear to be associated with any single HLA, ABO, or Lewis phenotype.

Risk factors for sensitization by blood transfusions. Comparison of the UW/Madison and UC/San Francisco donor-specific transfusion experience.

We have tested the predictive model for risk of sensitization by donor-specific transfusions developed at the University of California, San Francisco for its applicability to the DST experience at UW/Madison. Patient sample sizes between the two groups were similar (n = 249 for UW/Madison, n = 261 for UCSF) and the two groups of patients had similar compositions in terms of mean age, ABO type, baseline panel-reactive antibody, and pregnancy rate. The two groups differed in that the UW/Madison group had a higher percentage of males, diabetic patients, previously transplanted patients, and 0 haplotype-matched (2 HLA-mismatched related and unrelated) recipients. In addition, all the UW/Madison patients received azathioprine (AZA) whereas only half the UCSF group was given AZA. Despite these differences, application of the UCSF model for prediction of sensitization by DST gave remarkably similar results in our patient population, with pregnancy, prior transplant, baseline PRA, and HLA antigen sharing giving similar odds ratios and P values. However, when female sex was included in the model along with the other variables, the significance of pregnancy risk disappeared. We have developed an alternative multivariate model using stepwise logistic regression that identifies baseline PRA greater than 40%, female sex, and prior transplant as significant risk factors for sensitization, while number of HLA (A, B, DR) antigens shared and increasing recipient age significantly decreased risk of sensitization by DST.