The Evolving Role of Diagnostic Genomics in Kidney Transplantation.

Monogenic forms of heritable kidney disease account for a significant proportion of chronic kidney disease (CKD) across both pediatric and adult patient populations and up to 11% of patients under 40 years reaching end-stage kidney failure (KF) and awaiting kidney transplant. Diagnostic genomics in the field of nephrology is ever evolving and now plays an important role in assessment and management of kidney transplant recipients and their related donor pairs. Genomic testing can help identify the cause of KF in kidney transplant recipients and assist in prognostication around graft survival and rate of recurrence of primary kidney disease. If a gene variant has been identified in the recipient, at-risk related donors can be assessed for the same and excluded if affected. This paper aims to address the indications for genomic testing in the context for kidney transplantation, the technologies available for testing, the conditions and groups in which testing should be most often considered, and the role for the renal genetics multidisciplinary team in this process.

Long-Term Graft and Patient Outcomes Following Kidney Transplantation in End-Stage Kidney Disease Secondary to Hyperoxaluria.

BACKGROUND: End-stage kidney disease secondary to hyperoxaluria presents a major challenge for transplant physicians given concern regarding disease recurrence. Few contemporary studies have reported long-term outcomes following transplantation in this population. METHODS: This study examined the outcomes of all adult patients with end-stage kidney disease secondary to hyperoxaluria who received a kidney or combined liver-kidney transplant in Australia and New Zealand between 1965 and 2015. Patients with hyperoxaluria were propensity score matched to control patients with reflux nephropathy. The primary outcome was graft survival. Secondary outcomes included graft function, acute rejection, and patient survival. RESULTS: Nineteen transplants performed in 16 patients with hyperoxaluria were matched to 57 transplants in patients with reflux nephropathy. Graft survival was inferior in patients with hyperoxaluria receiving a kidney transplant alone (subhazard ratio [SHR] = 3.83, 95% confidence interval [CI], 1.22-12.08, P = .02) but not in those receiving a combined liver-kidney transplant (SHR = 0.63, 95% CI, 0.08-5.21, P = .67). Graft failure risk was particularly high in patients with hyperoxaluria receiving a kidney transplant alone after more than 1 year of renal replacement therapy (SHR = 8.90, 95% CI, 2.35-33.76, P = .001). Posttransplant estimated glomerular filtration rate was lower in patients with hyperoxaluria (10.97 mL/min/1.73 m2, 95% CI, 0.53-21.42, P = .04). There was no difference between groups in the risk of acute rejection or death with a functioning graft. CONCLUSION: Compared to reflux nephropathy, hyperoxaluria was associated with inferior graft survival in patients receiving a kidney transplant alone. Long-term graft function was lower in patients with hyperoxaluria, but the risks of acute rejection and death were not different.

Prevalence of Skin Cancer and Related Skin Tumors in High-Risk Kidney and Liver Transplant Recipients in Queensland, Australia.

The increased skin cancer incidence in organ transplant recipients is well-known, but the skin cancer burden at any one time is unknown. Our objective was to estimate the period prevalence of untreated skin malignancy and actinic keratoses in high-risk kidney and liver transplant recipients and to assess associated factors. Organ transplant recipients underwent full skin examinations by dermatologically trained physicians. The proportion of examined organ transplant recipients with histopathologically confirmed skin cancer in the 3-month baseline period was estimated. Prevalence ratios with 95% confidence intervals indicated significant associations. Of 495 high-risk organ transplant recipients (average age = 54 years, time immunosuppressed = 8.9 years), 135 (27%) had basal cell carcinoma, squamous cell carcinoma or Bowen's disease (intraepidermal carcinoma) present and confirmed in the baseline period, with respective prevalence proportions of 10%, 11%, and 18% in kidney transplant recipients and 10%, 9%, and 13% in liver transplant recipients. Over 80% had actinic keratosis present, with approximately 30% having 5 or more actinic keratoses. Organ transplant recipients with the highest skin cancer burden were Australian born, were fair skinned (prevalence ratio = 1.61, 95% confidence interval = [1.07, 2.43]), reported past skin cancer (prevalence ratio =3.39, 95% confidence interval = [1.93, 5.95]), and were receiving the most frequent skin checks (prevalence ratio = 1.76, 95% confidence interval = [1.15, 2.70]). In conclusion, high-risk organ transplant recipients carry a substantial measurable skin cancer burden at any given time and require frequent review through easily accessible, specialized services.

Renal fibrosis is the common feature of autosomal dominant tubulointerstitial kidney diseases caused by mutations in mucin 1 or uromodulin.

For decades, ill-defined autosomal dominant renal diseases have been reported, which originate from tubular cells and lead to tubular atrophy and interstitial fibrosis. These diseases are clinically indistinguishable, but caused by mutations in at least four different genes: UMOD, HNF1B, REN, and, as recently described, MUC1. Affected family members show renal fibrosis in the biopsy and gradually declining renal function, with renal failure usually occurring between the third and sixth decade of life. Here we describe 10 families and define eligibility criteria to consider this type of inherited disease, as well as propose a practicable approach for diagnosis. In contrast to what the frequently used term 'Medullary Cystic Kidney Disease' implies, development of (medullary) cysts is neither an early nor a typical feature, as determined by MRI. In addition to Sanger and gene panel sequencing of the four genes, we established SNaPshot minisequencing for the predescribed cytosine duplication within a distinct repeat region of MUC1 causing a frameshift. A mutation was found in 7 of 9 families (3 in UMOD and 4 in MUC1), with one indeterminate (UMOD p.T62P). On the basis of clinical and pathological characteristics we propose the term 'Autosomal Dominant Tubulointerstitial Kidney Disease' as an improved terminology. This should enhance recognition and correct diagnosis of affected individuals, facilitate genetic counseling, and stimulate research into the underlying pathophysiology.

Neutrophil dysplasia characterised by a pseudo-Pelger-Huet anomaly occurring with the use of mycophenolate mofetil and ganciclovir following renal transplantation: a report of five cases.

AIM: The pseudo-Pelger-Huet (PH) anomaly has been associated with a variety of primary haematological disorders, infections and drugs. Recently, the development of dysgranulopoiesis characterised by a pseudo-PH anomaly has been reported in two patients with the use of mycophenolate mofetil (MMF) in the setting of heart and/or lung transplantation. We present a further five cases of MMF-related dysgranulopoiesis characterised by a pseudo-PH anomaly occurring after renal transplantation. METHODS: All patients were receiving standard immunosuppression protocols for renal transplantation, including a combination of MMF, steroids and either cyclosporin or tacrolimus. Oral ganciclovir was also used for cytomegalovirus prophylaxis in each case. RESULTS: Development of dysplastic granulopoiesis occurred a median of 96 days (range 66-196 days) after transplantation. Moderate or severe neutropaenia (<1.0 x 10(9)/l) developed in three cases, and appeared to be directly correlated with the percentage of circulating neutrophils present with dysplastic morphology. Resolution of dysgranulopoiesis occurred in all cases only after dose reduction and/ or cessation of both MMF and ganciclovir. CONCLUSIONS: In our series, the observed dysplastic granulopoiesis appeared related to the combination of MMF and ganciclovir, rather than MMF alone. Further study is required to determine the exact incidence and pathogenesis of this pattern of bone marrow toxicity.