Posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) and r... more Posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) and range from lymphoid hyperplasias to lymphomas. The authors report 11 transplant recipients with recurrent EBV-associated lesions. Four patients presented with EBV-positive mononucleosis-like lymphadenitis. One had recurrence of a similar lesion and the other three developed polymorphic PTLDs. Matched clonal studies in oae patient showed clonal lymphoid and EB viral populations in the recurrent lesion, but not in the initial lesion. Six patients presented with polymorphic PTLDs. Five later developed histologically dissimilar tumors that resembled non-Hodgkin's lymphoma (two B-cell and one T-cell origin), Hodgkin's disease (one patient), or smooth muscle tumor (one patient). Matched clonal studies were available from one patient and showed that the primary and recurrent lesions were clonally distinct. The sixth patient had recurrence of histologically and clonally identical polymorphic PTLD. One patient presented with monomorphic PTLD and developed recurrence of a clonally identical tumor after a 6-month remission. This study shows that a few patients with EBV-associated lesions have clinical recurrence, which may be either a relapse of the original process or a new EBV-associated lesion. In some patients, the new lesion appeared to represent a more fully developed malignancy than did the antecedent lesion.
The human antibody response to polyomavirus capsid proteins is not well characterized. Recombinan... more The human antibody response to polyomavirus capsid proteins is not well characterized. Recombinant BK virus (BKV), JC virus (JCV) and simian virus 40 (SV40) virus-like particles (VLP) were produced in a baculovirus system, and mouse monoclonal antibodies (mAbs) to these proteins were generated using standard methods. Nine of 12 BKV mAbs showed neutralizing activity. The non-neutralizing antibodies also bound BKV pseudocapsids in an ELISA binding assay. Most antibodies recognized conformational species-specific epitopes, but several exceptions were found: (i) BKV mAb BK-F11 cross-reacted with a linear buried epitope common to both JCV and SV40 pseudocapsids, (ii) two of six JCV antibodies (JC-6.7 and JC-7.9) and two of 13 SV40 antibodies (VP1-H2 and VP1-I2) recognized linear buried epitopes common to all three viruses and (iii) SV40 antibody VP1-E5 recognized a linear surface epitope on JCV pseudocapsids.
Heart-lung transplant recipients are predisposed to acute rejection episodes, bronchiolitis oblit... more Heart-lung transplant recipients are predisposed to acute rejection episodes, bronchiolitis obliterans, and opportunistic infections. In 9.4% of recipients at the University of Pittsburgh, a posttransplant lymphoproliferative disorder (PTLD) developed, and in 60% of cases, it ...
A multiplex polymerase chain reaction (PCR)-liquid hybridization assay detecting a minimum 10 fg ... more A multiplex polymerase chain reaction (PCR)-liquid hybridization assay detecting a minimum 10 fg of cytomegaloviral (CMV) DNA has been developed. This assay successfully detected viral nucleic acids in 25/26 (96.2%) routinely embedded allograft liver biopsies with CMV hepatitis. No CMV DNA was detected in 15 native and 12 donor liver tissues sampled at the time of liver transplantation. These results indicate that archived formalin-fixed, paraffin-embedded liver tissues obtained from patients with significant liver disease can be successfully analyzed for CMV by PCR, retrospectively. Failure to detect CMV in native and donor livers implies that any latent virus present within these tissues is very focally distributed, or is below the threshold of detection applicable to PCR.
The systemic distribution of Epstein-Barr virus (EBV) genomes was studied in paraffin-embedded ti... more The systemic distribution of Epstein-Barr virus (EBV) genomes was studied in paraffin-embedded tissues from 12 fatal cases of Post-transplantation lymphoproliferative disease (PTLD), using an in situ hybridization technique employing an alpha-35S-dCTP-radiolabeled BamHI-W fragment of EBV DNA. The presence of EBV was documented in various PTLD-involved organs. The hybridization signal for the virus localized predominantly in the abnormal lymphoid cells, but signals also were detected in hepatocytes and/or adrenal cortical cells in five cases. The distribution of autoradiographic label within the lymphoid cells was focal and its intensity varied from field to field suggesting a nonuniformity of the viral genomic load in the infected tissues. Recruitment of EBV genome-bearing cells was not observed into inflammatory mononuclear infiltrates found in organs without histopathologic evidence of PTLD.
Journal of the American Society of Nephrology : JASN, Jan 7, 2014
Isolated endarteritis of kidney transplants is increasingly recognized. Notably, microarray studi... more Isolated endarteritis of kidney transplants is increasingly recognized. Notably, microarray studies revealed absence of immunologic signatures of rejection in most isolated endarteritis biopsy samples. We investigated if isolated endarteritis responds to rejection treatment and affects kidney transplant survival. We retrospectively enrolled recipients of kidney transplant who underwent biopsies between 1999 and 2011 at seven American and Canadian centers. Exclusion criteria were recipients were blood group-incompatible or crossmatch-positive or had C4d-positive biopsy samples. After biopsy confirmation, patients were divided into three groups: isolated endarteritis (n=103), positive controls (type I acute T cell-mediated rejection with endarteritis; n=101), and negative controls (no diagnostic rejection; n=103). Primary end points were improved kidney function after rejection treatment and transplant failure. Mean decrease in serum creatinine from biopsy to 1 month after rejection t...
Advances in experimental medicine and biology, 2006
This article traces the discovery of polyomaviruses and outlines investigations, which shed light... more This article traces the discovery of polyomaviruses and outlines investigations, which shed light on potential modes of transmission of this increasingly important group of human pathogens. The pathobiology of the virus is summarized with particular reference to interactions with host cell receptors, cell entry, cytoplasmic trafficking, and targeting of the viral genome to the nucleus. This is followed by a discussion of sites of viral latency and factors leading to viral reactivation. Finally, we present biochemical mechanisms that could potentially explain several key elements of tissue pathology characteristic of BKV mediated damage to human kidney.
Posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) and r... more Posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) and range from lymphoid hyperplasias to lymphomas. The authors report 11 transplant recipients with recurrent EBV-associated lesions. Four patients presented with EBV-positive mononucleosis-like lymphadenitis. One had recurrence of a similar lesion and the other three developed polymorphic PTLDs. Matched clonal studies in one patient showed clonal lymphoid and EB viral populations in the recurrent lesion, but not in the initial lesion. Six patients presented with polymorphic PTLDs. Five later developed histologically dissimilar tumors that resembled non-Hodgkin's lymphoma (two B-cell and one T-cell origin), Hodgkin's disease (one patient), or smooth muscle tumor (one patient). Matched clonal studies were available from one patient and showed that the primary and recurrent lesions were clonally distinct. The sixth patient had recurrence of histologically and clonally identical polymorphic PTLD. One patient presented with monomorphic PTLD and developed recurrence of a clonally identical tumor after a 6-month remission. This study shows that a few patients with EBV-associated lesions have clinical recurrence, which may be either a relapse of the original process or a new EBV-associated lesion. In some patients, the new lesion appeared to represent a more fully developed malignancy that did the antecedent lesion.
The characteristics and outcome in 10 patients who underwent retransplantation after losing their... more The characteristics and outcome in 10 patients who underwent retransplantation after losing their renal grafts to BK virus-associated nephropathy (BKAN) are described. The patients underwent retransplantation at a mean of 13.3 months after failure of the first graft. Nephroureterectomy of the first graft was performed in seven patients. Maintenance immunosuppression regimens after the first and second grafts were similar, consisting of a combination of a calcineurin inhibitor, mycophenolate mofetil, and prednisone. BKAN recurred in one patient 8 months after retransplantation, but stabilization of graft function was achieved with a decrease in immunosuppression and treatment with low-dose cidofovir. After a mean follow-up of 34.6 months, all patients were found to have good graft function with a mean creatinine of 1.5 mg/dL. From this collective experience from five transplant centers (although the follow-up after retransplantation was not extensive), it can be concluded that patients with graft loss caused by BKAN can safely undergo retransplantation. The risk of recurrence does not seem to be increased in comparison with the first graft.
Posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) and r... more Posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) and range from lymphoid hyperplasias to lymphomas. The authors report 11 transplant recipients with recurrent EBV-associated lesions. Four patients presented with EBV-positive mononucleosis-like lymphadenitis. One had recurrence of a similar lesion and the other three developed polymorphic PTLDs. Matched clonal studies in oae patient showed clonal lymphoid and EB viral populations in the recurrent lesion, but not in the initial lesion. Six patients presented with polymorphic PTLDs. Five later developed histologically dissimilar tumors that resembled non-Hodgkin's lymphoma (two B-cell and one T-cell origin), Hodgkin's disease (one patient), or smooth muscle tumor (one patient). Matched clonal studies were available from one patient and showed that the primary and recurrent lesions were clonally distinct. The sixth patient had recurrence of histologically and clonally identical polymorphic PTLD. One patient presented with monomorphic PTLD and developed recurrence of a clonally identical tumor after a 6-month remission. This study shows that a few patients with EBV-associated lesions have clinical recurrence, which may be either a relapse of the original process or a new EBV-associated lesion. In some patients, the new lesion appeared to represent a more fully developed malignancy than did the antecedent lesion.
The human antibody response to polyomavirus capsid proteins is not well characterized. Recombinan... more The human antibody response to polyomavirus capsid proteins is not well characterized. Recombinant BK virus (BKV), JC virus (JCV) and simian virus 40 (SV40) virus-like particles (VLP) were produced in a baculovirus system, and mouse monoclonal antibodies (mAbs) to these proteins were generated using standard methods. Nine of 12 BKV mAbs showed neutralizing activity. The non-neutralizing antibodies also bound BKV pseudocapsids in an ELISA binding assay. Most antibodies recognized conformational species-specific epitopes, but several exceptions were found: (i) BKV mAb BK-F11 cross-reacted with a linear buried epitope common to both JCV and SV40 pseudocapsids, (ii) two of six JCV antibodies (JC-6.7 and JC-7.9) and two of 13 SV40 antibodies (VP1-H2 and VP1-I2) recognized linear buried epitopes common to all three viruses and (iii) SV40 antibody VP1-E5 recognized a linear surface epitope on JCV pseudocapsids.
Heart-lung transplant recipients are predisposed to acute rejection episodes, bronchiolitis oblit... more Heart-lung transplant recipients are predisposed to acute rejection episodes, bronchiolitis obliterans, and opportunistic infections. In 9.4% of recipients at the University of Pittsburgh, a posttransplant lymphoproliferative disorder (PTLD) developed, and in 60% of cases, it ...
A multiplex polymerase chain reaction (PCR)-liquid hybridization assay detecting a minimum 10 fg ... more A multiplex polymerase chain reaction (PCR)-liquid hybridization assay detecting a minimum 10 fg of cytomegaloviral (CMV) DNA has been developed. This assay successfully detected viral nucleic acids in 25/26 (96.2%) routinely embedded allograft liver biopsies with CMV hepatitis. No CMV DNA was detected in 15 native and 12 donor liver tissues sampled at the time of liver transplantation. These results indicate that archived formalin-fixed, paraffin-embedded liver tissues obtained from patients with significant liver disease can be successfully analyzed for CMV by PCR, retrospectively. Failure to detect CMV in native and donor livers implies that any latent virus present within these tissues is very focally distributed, or is below the threshold of detection applicable to PCR.
The systemic distribution of Epstein-Barr virus (EBV) genomes was studied in paraffin-embedded ti... more The systemic distribution of Epstein-Barr virus (EBV) genomes was studied in paraffin-embedded tissues from 12 fatal cases of Post-transplantation lymphoproliferative disease (PTLD), using an in situ hybridization technique employing an alpha-35S-dCTP-radiolabeled BamHI-W fragment of EBV DNA. The presence of EBV was documented in various PTLD-involved organs. The hybridization signal for the virus localized predominantly in the abnormal lymphoid cells, but signals also were detected in hepatocytes and/or adrenal cortical cells in five cases. The distribution of autoradiographic label within the lymphoid cells was focal and its intensity varied from field to field suggesting a nonuniformity of the viral genomic load in the infected tissues. Recruitment of EBV genome-bearing cells was not observed into inflammatory mononuclear infiltrates found in organs without histopathologic evidence of PTLD.
Journal of the American Society of Nephrology : JASN, Jan 7, 2014
Isolated endarteritis of kidney transplants is increasingly recognized. Notably, microarray studi... more Isolated endarteritis of kidney transplants is increasingly recognized. Notably, microarray studies revealed absence of immunologic signatures of rejection in most isolated endarteritis biopsy samples. We investigated if isolated endarteritis responds to rejection treatment and affects kidney transplant survival. We retrospectively enrolled recipients of kidney transplant who underwent biopsies between 1999 and 2011 at seven American and Canadian centers. Exclusion criteria were recipients were blood group-incompatible or crossmatch-positive or had C4d-positive biopsy samples. After biopsy confirmation, patients were divided into three groups: isolated endarteritis (n=103), positive controls (type I acute T cell-mediated rejection with endarteritis; n=101), and negative controls (no diagnostic rejection; n=103). Primary end points were improved kidney function after rejection treatment and transplant failure. Mean decrease in serum creatinine from biopsy to 1 month after rejection t...
Advances in experimental medicine and biology, 2006
This article traces the discovery of polyomaviruses and outlines investigations, which shed light... more This article traces the discovery of polyomaviruses and outlines investigations, which shed light on potential modes of transmission of this increasingly important group of human pathogens. The pathobiology of the virus is summarized with particular reference to interactions with host cell receptors, cell entry, cytoplasmic trafficking, and targeting of the viral genome to the nucleus. This is followed by a discussion of sites of viral latency and factors leading to viral reactivation. Finally, we present biochemical mechanisms that could potentially explain several key elements of tissue pathology characteristic of BKV mediated damage to human kidney.
Posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) and r... more Posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) and range from lymphoid hyperplasias to lymphomas. The authors report 11 transplant recipients with recurrent EBV-associated lesions. Four patients presented with EBV-positive mononucleosis-like lymphadenitis. One had recurrence of a similar lesion and the other three developed polymorphic PTLDs. Matched clonal studies in one patient showed clonal lymphoid and EB viral populations in the recurrent lesion, but not in the initial lesion. Six patients presented with polymorphic PTLDs. Five later developed histologically dissimilar tumors that resembled non-Hodgkin's lymphoma (two B-cell and one T-cell origin), Hodgkin's disease (one patient), or smooth muscle tumor (one patient). Matched clonal studies were available from one patient and showed that the primary and recurrent lesions were clonally distinct. The sixth patient had recurrence of histologically and clonally identical polymorphic PTLD. One patient presented with monomorphic PTLD and developed recurrence of a clonally identical tumor after a 6-month remission. This study shows that a few patients with EBV-associated lesions have clinical recurrence, which may be either a relapse of the original process or a new EBV-associated lesion. In some patients, the new lesion appeared to represent a more fully developed malignancy that did the antecedent lesion.
The characteristics and outcome in 10 patients who underwent retransplantation after losing their... more The characteristics and outcome in 10 patients who underwent retransplantation after losing their renal grafts to BK virus-associated nephropathy (BKAN) are described. The patients underwent retransplantation at a mean of 13.3 months after failure of the first graft. Nephroureterectomy of the first graft was performed in seven patients. Maintenance immunosuppression regimens after the first and second grafts were similar, consisting of a combination of a calcineurin inhibitor, mycophenolate mofetil, and prednisone. BKAN recurred in one patient 8 months after retransplantation, but stabilization of graft function was achieved with a decrease in immunosuppression and treatment with low-dose cidofovir. After a mean follow-up of 34.6 months, all patients were found to have good graft function with a mean creatinine of 1.5 mg/dL. From this collective experience from five transplant centers (although the follow-up after retransplantation was not extensive), it can be concluded that patients with graft loss caused by BKAN can safely undergo retransplantation. The risk of recurrence does not seem to be increased in comparison with the first graft.
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