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An Algorithm Measuring Donor Cell-Free DNA in Plasma of Cellular and Solid Organ Transplant Recipients That Does Not Require Donor or Recipient Genotyping.

ABSTRACT: Cell-free DNA (cfDNA) has significant potential in the diagnosis and monitoring of clinical conditions. However, accurately and easily distinguishing the relative proportion of DNA molecules in a mixture derived from two different sources (i.e., donor and recipient tissues after transplantation) is challenging. In human cellular transplantation, there is currently no useable method to detect in vivo engraftment, and blood-based non-invasive tests for allograft rejection in solid organ transplantation are either non-specific or absent. Elevated levels of donor cfDNA have been shown to correlate with solid organ rejection, but complex methodology limits implementation of this promising biomarker. We describe a cost-effective method to quantify donor cfDNA in recipient plasma using a panel of high-frequency single nucleotide polymorphisms, next-generation (semiconductor) sequencing, and a novel mixture model algorithm. In vitro, our method accurately and rapidly determined donor:recipient DNA admixture. For in vivo testing, donor cfDNA was serially quantified in an infant with a urea cycle disorder after receiving six daily infusions of donor liver cells. Donor cfDNA isolated from 1 to 2?ml of recipient plasma was detected as late as 24?weeks after infusion suggesting engraftment. The percentage of circulating donor cfDNA was also assessed in pediatric and adult heart transplant recipients undergoing routine endomyocardial biopsy with levels observed to be stable over time and generally measuring <1% in cases without moderate or severe cellular rejection. Unlike existing non-invasive methods used to define the proportion of donor cfDNA in solid organ transplant patients, our assay does not require sex mismatch, donor genotyping, or whole-genome sequencing and potentially has broad application to detect cellular engraftment or allograft injury after transplantation.

SUBMITTER: Gordon PM

PROVIDER: S-EPMC5031701 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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An Algorithm Measuring Donor Cell-Free DNA in Plasma of Cellular and Solid Organ Transplant Recipients That Does Not Require Donor or Recipient Genotyping.

Gordon Paul M K PM Khan Aneal A Sajid Umair U Chang Nicholas N Suresh Varun V Dimnik Leo L Lamont Ryan E RE Parboosingh Jillian S JS Martin Steven R SR Pon Richard T RT Weatherhead Jene J Wegener Shelly S Isaac Debra D Greenway Steven C SC

Frontiers in cardiovascular medicine 20160922

Cell-free DNA (cfDNA) has significant potential in the diagnosis and monitoring of clinical conditions. However, accurately and easily distinguishing the relative proportion of DNA molecules in a mixture derived from two different sources (i.e., donor and recipient tissues after transplantation) is challenging. In human cellular transplantation, there is currently no useable method to detect <i>in vivo</i> engraftment, and blood-based non-invasive tests for allograft rejection in solid organ tra ...[more]

PMID: 27713880

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Project description:BACKGROUND:Immunosuppressed solid organ transplant recipients [SOTRs] have elevated rates of certain rare cancers caused by viruses. Evaluating risk of rare cancers among SOTRs may provide etiological clues for additional cancers linked to poor immunity and viral infections. METHODS:We performed a cohort study of 262,455 SOTRs (1987-2014) from the US SOTR registry linked to 17 population-based cancer registries. First cancers in SOTRs were categorized using an established classification scheme based on site and histology. Standardized incidence ratios (SIRs) compared risk in SOTRs to the general population. We used Poisson regression to calculate incidence rate ratios (IRRs) according to immune-related SOTR characteristics, including time since transplant (i.e., duration of immunosuppression). All statistical tests are two-sided. RESULTS:We examined 694 distinct cancer subtypes, with 33 manifesting statistically significantly elevated SIRs (Bonferroni p?<?7.2 x 10-5). All 33 are rare (incidence <6 per 100,000 person-years) and several have known viral etiology (e.g. Merkel cell carcinoma (SIR = 24.7, 95%CI = 20.8 to 29.1). Additional cancers that were increased include squamous cell carcinomas (SCCs) of the lip (SIR range = 18.3-19.8), eye/adnexa (SIR = 13.8, 95%CI = 7.9 to 22.3), salivary gland (SIR = 9.3, 95%CI = 6.1 to 13.5), and nasal cavity/sinuses (SIR = 4.5, 95%CI = 2.8 to 6.8); sebaceous adenocarcinoma (SIR = 34.3, 95%CI = 26.3 to 44.0); malignant fibrous histiocytoma (15.4); and subtypes of bladder, kidney, lung, and colon cancer (SIR range = 3.2-13.3). Incidence of several cancers increased over time since transplant (ptrend<0.05), including SCCs of the lip, salivary gland, and anogenital sites. CONCLUSIONS:SOTRs experience elevated rates of several rare cancers. Because some of these cancers exhibit aggressive behavior with poor outcomes, it is important to further characterize the role of immunity and the potential involvement of oncogenic viruses to improve prevention and treatment.

Project description:AimsSome risk assessment tools have been developed to categorize mortality risk in heart transplant recipients, but it is unclear whether these tools can be used interchangeable in different transplant regions.Methods and resultsWe performed a retrospective single-centre study in 1049 adult German heart transplant recipients under jurisdiction of Eurotransplant. Univariable and multivariable Cox regression analysis was used to generate a risk scoring system. C-statistics were used to compare our score with a US score and a French score regarding their ability to discriminate between 1 year survivors and non-survivors within our study cohort. Of 38 parameters assessed, seven recipient-specific parameters [age, height, dilated cardiomyopathy (DCM), ischaemic cardiomyopathy (ICM), total bilirubin, extracorporeal membrane oxygenation (ECMO), and biventricular assist device/total artificial heart (BVAD/TAH) implant], one donor-specific parameter (cold ischaemic time), and one recipient-independent and donor-independent other parameter (late transplant era) were statistically significant in predicting 1 year mortality. The initial score was generated by using the regression coefficients from the multivariable analysis as follows: 1.70 * ln age - 4.0 * ln height - 0.9 * diagnosis (= 1 if diagnosis = DCM) - 0.67 * diagnosis (= 1 if diagnosis = ICM) + 0.33 * ln total bilirubin + 1.74 * ln cold ischaemic time + 0.98 * mechanical circulatory support (MCS) implant (= 1 if MCS implant = ECMO) + 0.47 * MCS implant (= 1 of MCS implant = BVAD/TAH) - 0.66 * transplant era (= 1 if transplant era = 2017-2018). The initial score was converted into the Bad Oeynhausen (BO) score as a positive integer variable by means of the following formula: BO score = (initial score + 8) * 3. In patients scoring 2 to <7 points (n = 112), 7 to <11 points (n = 580), 11 to <15 points (n = 339), and 15 to 20 points (n = 18), 1 year survival was 93.1%, 84.2%, 66.9%, and 27.8%, respectively. The c-index of our score was 0.73 [95% confidence interval (CI): 0.69-0.77]. Values were in our cohort for the US and French scores 0.66 (95% CI: 0.62-0.70) and 0.63 (95% CI: 0.59-0.67), respectively.ConclusionsData indicate that our score, but also risk assessment tools from other transplant regions, may be used as a reliable support for risk-adjusted organ allocation and potentially help to improve outcomes in heart transplantation. Further developments will have to include as yet unaccounted risk factors for even more reliable predictions.

Dataset Information

An Algorithm Measuring Donor Cell-Free DNA in Plasma of Cellular and Solid Organ Transplant Recipients That Does Not Require Donor or Recipient Genotyping.

Publications

An Algorithm Measuring Donor Cell-Free DNA in Plasma of Cellular and Solid Organ Transplant Recipients That Does Not Require Donor or Recipient Genotyping.

Similar Datasets

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