Curtis Mabilangan

Determination of the Biological Form of Human Cytomegalovirus DNA in the Plasma of Solid-Organ Transplant Recipients

Background Whether cytomegalovirus (CMV) DNA exists in plasma as virion-associated or free DNA is uncertain. Methods An assay combining DNase I digestion and CMV quantitative polymerase chain reaction (DNase-CMV-qPCR) was developed to differentiate free naked DNA from virion DNA. One hundred three frozen and 10 fresh CMV DNA-positive plasma samples from solid-organ transplant recipients (SOTRs) were tested. Three sets of paired qPCR (P-qPCR) assays with amplicons of variable length were used to study CMV DNA fragmentation in 20 SOTR plasma samples, viral stocks (Towne, Merlin, AD169) and the first World Health Organization (WHO) international standard (IS) for CMV DNA. Results In all plasma samples, 98.8%-100% of CMV DNA was free DNA; this was the only form in 93 of 103 (90.3%) frozen and all 10 fresh samples tested using DNase-CMV-qPCR. Low levels of virion CMV DNA were found in 10 of 103 (9.7%) samples with higher total DNA load. Cytomegalovirus DNA results were highly reproducible for 3 CMV virus stocks and WHO IS (P > .80), tested by three sets of paired q-PCR. However, for the 20 SOTR plasma samples, the smaller amplicon assay result was 2.6-fold, 3.4-fold, and 6.5-fold higher than the longer amplicion result (P < .001). Conclusions Cytomegalovirus DNA in SOTR plasma is almost exclusively free DNA, highly fragmented, and not virion associated.

Radiation Exposure from Diagnostic Imaging in a Cohort of Pediatric Transplant Recipients

Recipients of solid organ transplants (SOT) have extensive diagnostic imaging (DI). The purpose of this study was to quantify this exposure. Children from northern Alberta with SOTs at Stollery Children’s Hospital, Edmonton, Alberta January 1, 2006, to July 31, 2012, were included. Effective doses of radiation were estimated using published norms for DI performed post-transplant up to October 16, 2014. The 54 eligible children had 6215 DI studies (5628 plain films, 293 computerized tomography (CT) scans, 149 positron emission topography (PET) -CT scans, 47 nuclear medicine scans and 98 cardiac catheterizations). Children less than 5 years of age underwent more DI studies than did older children (median (IQR) 140 (66–210) vs 49 (19–105), p = 0.010). Children with post-transplant lymphoproliferative disorder (N = 8) had more CT scans (median (IQR) 13 (5.5–36) vs 1 (0–5), p<0.001) and PET-CT scans (median (IQR) 3.5 (1.5–8) vs 0 (0–0), p<0.001) than did other children. The estimated cumulative effective dose attributed to DI studies post-transplant was median (range) 78 (4.1–400) millisievert (mSv), and 19 of 54 children (35%; 95% confidence interval 24–49%) had a dose >100 mSv. In conclusion, a significant proportion of pediatric transplant recipients have sufficient radiation exposure post-transplant for DI to be at potential risk for radiation-induced malignancies.

Impact of donor and recipient cytomegalovirus serology on long term survival of heart transplant recipients

Pre‐transplant cytomegalovirus (CMV) serostatus has been associated with lung transplant patient survival. We retrospectively analyzed the relationship between pre‐transplant donor/recipient CMV serostatus and long‐term mortality in a cohort of lung transplant recipients at our center.

Epstein-Barr virus associated smooth muscle tumors in solid organ transplant recipients: Incidence over 31 years at a single institution and review of the literature

Epstein‐Barr virus (EBV) associated smooth muscle tumors (EBV‐SMT) are a rare complication of solid organ transplantation (SOT). Incidence data related to this EBV‐SMT are limited. EBV DNA is universally present in these tumors. How these cells get infected with EBV, whether this is a result of primary EBV infection vs reactivation, and how persistent active EBV infection post‐transplant influences EBV‐SMT pathogenesis remains unknown.

Assignment of cytomegalovirus infection status in infants awaiting solid organ transplant: Viral detection methods as adjuncts to serology

Assignment of CMV infection status in infants awaiting SOT is challenging as passive maternal antibody can lead to false‐positive serology. Since 2000, our protocol has recommended sending throat and urine samples for CMV viral detection, culture, or NAAT, for CMV‐seropositive infants <18 months awaiting SOT. We reviewed pretransplant CMV serology for 152 infants and, for CMV seropositives, examined relationships between CMV IgG OD values, age, and CMV viral detection to explore time to clearance of maternal CMV IgG and evaluate viral detection in assignment of pretransplant CMV infection status. The proportion of CMV‐seropositive infants decreased from 52% in infants 0‐6 months of age to 28% in those 12‐18 months. Among CMV‐seropositive infants, median OD was significantly higher in the 6‐ to 12‐ and 12‐ to 18‐month groups compared to the 0‐ to 6‐month group. Distribution of OD by age group suggested that maternal antibody cleared before 12 months. Of 59 eligible CMV‐seropositive infants, 49 (83%) had CMV viral detection studies and 18 of 49 (36.7%) had detectable CMV: 9 of 30 (30.0%) infants 0‐6 months, 7 of 15 (46.7%) infants 6‐12 months, and 2 of 4 (50.0%) infants 12‐18 months. CMV viral detection studies are useful to confirm positive CMV infection status in CMV‐seropositive infants awaiting SOT. Maternal CMV IgG likely clears before 12 months.

Hepatitis B and C serologic profiles of Canadian organ donors and recipients: retrospective 10-year review at a single center

Hepatitis C virus (HBV) and hepatitis C virus (HCV) are important causes of hepatitis and can be transmitted from organ donor to recipient. This study aimed to determine HBV and HCV serologic profiles of a population of Canadian solid organ transplant (SOT) donors and recipients, including prevalence of recipient HBV immunity.

Epidemiology of Post-Transplant Lymphoproliferative Disorders in Solid Organ Transplant Recipients in a Single Canadian Centre.: Abstract# A545

A545 Epidemiology of Post-Transplant Lymphoproliferative Disorders in Solid Organ Transplant Recipients in a Single Canadian Centre. J. Preiksaitis,1 A. Peters,1 S. Akinwumi,2 C. Mabilangan,1 K. Doucette.1 1Medicine, University of Alberta, Edmonton, AB, Canada; 2Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, Canada. Objective: Many epidemiologic studies of post-transplant lymphoproliferative disorder (PTLD) in solid organ transplant (SOT) populations have limited follow-up, incomplete pre-transplant viral serology and PTLD histology, and study only adults or children. We describe a single center study of the PTLD cases in all adult and pediatric (ped) SOT recipients from January 1, 1984 to June 30, 2013. Methods: Patients (n=4750, 475 age < 18, 4275 age ≥ 18) included 724 heart (15.2%), 551 lung or heart/lung (11.6%), 1298 liver (27.3%), 2099 kidney (44.2%), 66 pancreas or kidney/pancreas (1.4%), and 12 multivisceral or small bowel (.3%). Yearly cumulative incidence (CI) was calculated using the patient-year variant of the incidence defi nition: number of cases/amount of patient-time at risk each year. PTLD risk factors were analyzed using univariate Cox regression analyses, ped and adult patients were analyzed separately. Results: 134 cases of PTLD occurred over a median follow-up (FU) of 5.98 yrs (standard error (SE) 0.09, range 0-29.5 yrs). Ped SOT recipients developed more early lesions and polymorphic PTLD than adults (44 vs. 10%); adults had more monomorphic PTLD (68 vs. 38%). CI of PTLD was 1.31% PY at 1 year, 2.25% PY at 5 years, 3.04% at 10 years, and 3.93% PY at 20 years. Median overall survival (OS) of the entire cohort was 13.8 years (SE .36); PTLD adversely impacted OS in adult (p=.000, HR 1.3 (95% C.Int. 1.1-1.4), but not ped recipients (p=.23). Factors that signifi cantly increased PTLD risk were: younger age at transplant, less time post-transplant, REBV -, and RCMV(adult only). Risk of early (≤ 1 year) and late (> 1 year) PTLD, early/late EBER+ PTLD, and PTLD localized to CNS, GI, allograft and >1 extranodal (EN) site decreased with increased age at transplant. Risk of early PTLD and allograft PTLD in adults was higher from 1984-1991 compared to 2002-13. Being REBVconferred signifi cantly higher risk of early and late PTLD, early and late EBER+ PTLD, and PTLD localized in the CNS , GI tract, allograft, and over 1 EN site in adults. Conclusions: PTLD cases continued to arise 20 yrs post-transplant, and risk was increased by younger age, shorter duration post-transplant, and negative EBV serology. Negative EBV serostatus also increased risk of all PTLD subgroups in adults, including CNS involvement. Abstract# A546 Incidence and Outcomes of De Novo Malignancies After Living Donor Liver Transplantation. T. Hibi, M. Shinoda, Y. Katsuki, K. Inomata, M. Tanaka, O. Itano, M. Kitago, H. Yagi, Y. Abe, Y. Kitagawa. Department of Surgery, Keio University School of Medicine, Tokyo, Japan. A546 Incidence and Outcomes of De Novo Malignancies After Living Donor Liver Transplantation. T. Hibi, M. Shinoda, Y. Katsuki, K. Inomata, M. Tanaka, O. Itano, M. Kitago, H. Yagi, Y. Abe, Y. Kitagawa. Department of Surgery, Keio University School of Medicine, Tokyo, Japan. Background: Little is known about the nature of de novo malignancies after living donor liver transplantation (LDLT). Methods: A single-center, retrospective cohort analysis was conducted for 121 adult patients who underwent LDLT. Our routine surveillance for malignancy included annual upper gastrointestinal endoscopy, fecal occult blood, and chest/abdominal/ pelvic computed tomography. Tumor markers were checked for recipients with a cancer history. Results: A total of 9 (7.4%) de novo malignancies (thyroid, 2; colorectal, 2; laryngeal, 1; and posttransplant lymphoproliferative disorders (PTLD), 4) were detected. For solid tumors, the median duration from transplant to diagnosis was 76 months. One female noticed a neck mass which revealed to be papillary thyroid carcinoma. She is well >5 years after radical resection. The other patient had back pain caused by extensive sacral metastasis from follicular thyroid carcinoma and is now receiving radiation. One male with fecal occult blood positive had superfi cial cancer in the descending colon and underwent endoscopic mucosal resection. Another male had an early cancer in the rectum and underwent laparoscopic anterior resection. A laryngeal cancer was diagnosed in a female who presented with hoarseness. She remains disease free >4 years after defi nitive chemoradiation. For PTLD cases, the median interval from transplant was 117 months. All 4 patients were EBV-PCR negative. The manifestation of disease was paraaortic lymph nodes for 1 and extranodal for 3. Pathological diagnosis was diffuse large B-cell lymphoma in 3 and Hodgkin lymphoma in 1. Complete response was achieved in 2 patients who underwent R-CHOP and both are alive >3 years. PTLD relapsed in 1 female who received rituximab alone because of recurrent hepatitis C: She died 4 months thereafter. Calcineurin inhibitor was reduced in 1 remaining patient who is currently under strict follow-up. Conclusions: Our surveillance program detected solid tumor in only 1 patient and there is a pressing need to establish an effective protocol. Primary sites of solid tumors are distinct from previous publications in deceased donor liver transplantation, suggesting genetic differences among populations. In adult LDLT, the relation between PTLD and EBV infection is unclear: Risk factors and prognostic indicators remain to be elucidated. Abstract# A547 Incidence and Types of Malignancy Post Kidney Transplantation in Saudi Arabia. S. Raza, I. Alahmadi, T. Ali, S. Khan, K. Almeshari, H. Aleid. Department of Kidney and Pancreas Transplantation, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. A547 Incidence and Types of Malignancy Post Kidney Transplantation in Saudi Arabia. S. Raza, I. Alahmadi, T. Ali, S. Khan, K. Almeshari, H. Aleid. Department of Kidney and Pancreas Transplantation, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. Cancer development is a common s=cause of mortality post organ transplantation. Specifi c types of cancer are more common to occur because of Immunosuppresion and been mediated by viral pathogens. incidence and types of cancers are not studied before in our region. we aimed to study the incidence and types of cancer post kidney transplantation in our region. This is a bidirectional single center study of all kidney transplantation performed in a tertiary care center. all patients charts and electronic medical record were reviewed and patients were prospectively surveyed for cancer development. In addition, national cancer registry data were compared using national identifi cation number to insure capturing all patients and to calculate normalized incidence ratio. results; total of 2077 patients underwent kidney transplantation at this center from 1981 to end of 2013. Age range between 1.5 to 71 years, 61% were men and 432 patients were younger than 18 years. Induction with depleting agents was used in 45% of patients and with interleukin blocking agents in 19 % of patients. Viral hepatitis was prevalent in 29 % of patients, 6.5 with hepatitis B and 22.5% with hepatitis C infection. Average followup was 110.4 months and it ranges between 1-370 months post transplantation. 98 (4.7) patients developed cancer post transplantation, of these 16 were younger than 18 years old and 72 ere adults. 42 % of these patients had diseased donor transplantation. Post transplantation lymphoprolierative disorder occurred in 30 patients, 16 of them were EBV mismatched pediatric patients, 53% were nodal disease and 10 were neurological. All PTLD were of B cell except one t Cell derived. Kaposi sarcoma occurred in 17 patients, 2 of them had gastric involvement and rest were skin limited disease. hepatocellular carcinoma developed in 7 patients all of them had viral hepatitis. Skin basal and squemce cell carcinoma developed in 8 patients, no cases of melanoma were seen. Cervical cancer developed in 2 patients only. rest of cancers were solid organ cancers. In conclusion we noted a low incidence of cancer in our region with 4.7% of patients developing cancer. PTLD and Kaposi sarcoma were commonest types of cancer. in comparison to international data, we noticed more hepatocellular carcinoma probably related to prevalence of viral hepatitis in this region and lower skin carcinoma. Abstract# A548 Natural Killer Cell Responses to Autologous and Allogeneic Epstein-Barr Virus (EBV)+ B Cell Lymphomas. O. Hatton,1,2 U. Hadad,1,2 D. Strauss-Albee,1,3 C. Blish,1,3 C. Esquivel,2 S. Krams,1,2 O. Martinez.1,2 1Program in Immunology, Stanford University School of Medicine, Stanford, CA; 2Department of Surgery/Division of Abdominal Transplantation, Stanford University School of Medicine, Stanford, CA; 3Department of Infectious Diseases, Stanford University School of Medicine, Stanford, CA. EBV infection elicits a strong host immune response that is considered to be essential for control of the virus and preventing EBV-associated lymphomas in transplant recipients. The T cell response following EBV infection has been extensively characterized. Like T cells, natural killer (NK) cells are lymphocytes capable of responding to viral infection by secretion of cytokines including IFN-γ and by direct killing of target cells via release of cytotoxic granules. While NK cells have been implicated in the immune response to EBV, direct evidence has been lacking, particularly regarding the NK cell response to EBV+ B cell lymphomas. To assess the ability of NK cells to recognize and respond to EBV-infected B cells, we fi rst generated EBV+ lymphoblastoid cell lines (LCL), a model of EBV+ B cell lymphomas, from a cohort of healthy donors (n=3). Primary human NK cells isolated by negative selection were primed