Raymond L. Heilman

Urinary Tract Stones in Pregnancy

The presence of stones during an otherwise uneventful pregnancy is a dramatic and potentially serious issue for the mother, the fetus, and the treating physicians alike. The incidence and predisposing factors are generally the same as in nonpregnant, sexually active, childbearing women. Unique metabolic effects in pregnancy such as hyperuricuria and hypercalciuria, changes in inhibitors of lithiasis formation, stasis, relative dehydration, and the presence of infection all have an impact on stone formation. The anatomic changes and physiologic hydronephrosis of pregnancy make the diagnosis and treatment more challenging. Presenting signs and symptoms include colic, flank pain, hematuria, urinary tract infection, irritative voiding, fever, premature onset or cessation of labor, and pre-eclampsia. The initial evaluation and treatment are again similar to those used for the nonpregnant population. The most appropriate first-line test is renal ultrasonography, which may, by itself, allow the diagnosis to be made and provide enough information for treatment. Radiographic studies, including an appropriately performed excretory urogram, give specific information as to size and location of the stones, location of the kidneys, and differential renal function and can be used safely, but the ionizing radiation risks should be considered. All forms of treatment with the exception of extracorporeal shock wave lithotripsy and some medical procedures are appropriate in the pregnant patient. Close coordination by the urologist, the obstetrician, the pediatrician, the anesthesiologist, and the radiologist is required for the appropriate care of these patients.

Impact of Subclinical Inflammation on the Development of Interstitial Fibrosis and Tubular Atrophy in Kidney Transplant Recipients

Our aim was to study the impact of subclinical inflammation on the development of interstitial fibrosis and tubular atrophy (IF/TA) on a 1‐year protocol biopsy in patients on rapid steroid withdrawal (RSW). A total of 256 patients were classified based on protocol biopsy findings at months 1 or 4. Group 1 is 172 patients with no inflammation, group 2 is 50 patients with subclinical inflammation (SCI), group 3 is 19 patients with subclinical acute rejection (SAR) and group 4 is 15 patients with clinical acute rejection (CAR). On the 1‐year biopsy, more patients in group 2 (SCI) (34%, p = 0.004) and group 3 (SAR) (53%, p = 0.0002), had an IF/TA score > 2 compared to group 1 (control) (15%). IF/TA was not increased in group 4 (CAR) (20%). The percent with IF/TA score > 2 and interstitial inflammation (Banff i score > 0) was higher in group 2 (16%, p = 0.004) and group 3 (37%, p < 0.0001) compared to group 1 (3%). In a multivariate analysis, patients in groups 2 or 3 had a higher risk of IF/TA score > 2 on the 1‐year biopsy (OR 6.62, 95% CI 2.68–16.3). We conclude that SCI and SAR increase the risk of developing IF/TA in patient on RSW.

Biomarkers for Early and Late Stage Chronic Allograft Nephropathy by Proteogenomic Profiling of Peripheral Blood

Background Despite significant improvements in life expectancy of kidney transplant patients due to advances in surgery and immunosuppression, Chronic Allograft Nephropathy (CAN) remains a daunting problem. A complex network of cellular mechanisms in both graft and peripheral immune compartments complicates the non-invasive diagnosis of CAN, which still requires biopsy histology. This is compounded by non-immunological factors contributing to graft injury. There is a pressing need to identify and validate minimally invasive biomarkers for CAN to serve as early predictors of graft loss and as metrics for managing long-term immunosuppression. Methods We used DNA microarrays, tandem mass spectroscopy proteomics and bioinformatics to identify genomic and proteomic markers of mild and moderate/severe CAN in peripheral blood of two distinct cohorts (n = 77 total) of kidney transplant patients with biopsy-documented histology. Findings Gene expression profiles reveal over 2400 genes for mild CAN, and over 700 for moderate/severe CAN. A consensus analysis reveals 393 (mild) and 63 (moderate/severe) final candidates as CAN markers with predictive accuracy of 80% (mild) and 92% (moderate/severe). Proteomic profiles show over 500 candidates each, for both stages of CAN including 302 proteins unique to mild and 509 unique to moderate/severe CAN. Conclusions This study identifies several unique signatures of transcript and protein biomarkers with high predictive accuracies for mild and moderate/severe CAN, the most common cause of late allograft failure. These biomarkers are the necessary first step to a proteogenomic classification of CAN based on peripheral blood profiling and will be the targets of a prospective clinical validation study.

Relationship between Inpatient Hyperglycemia and Insulin Treatment after Kidney Transplantation and Future New Onset Diabetes Mellitus

BACKGROUND AND OBJECTIVES Approximately two-thirds of kidney transplant recipients with no previous history of diabetes experience inpatient hyperglycemia immediately after kidney transplant surgery; whether inpatient hyperglycemia predicts future new onset diabetes after transplant (NODAT) is not established. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A retrospective study was conducted to determine the risk conferred by inpatient hyperglycemia on development of NODAT within 1 year posttransplant. All adult nondiabetic kidney transplant recipients between June 1999 and January 2008 were included. Posttransplant inpatient hyperglycemia was defined as any bedside capillary blood glucose > or = 200 mg/dl or insulin therapy during hospitalization. NODAT was defined as HbA1C > or = 6.5%, fasting venous serum glucose > or = 126 mg/dl, or prescribed diet or medical therapy for diabetes mellitus. RESULTS The study cohort included 377 patients. NODAT developed in 1 (4%) of the 28 patients without inpatient hyperglycemia, 4 (18%) of the 22 patients with inpatient hyperglycemia but not treated with insulin, and in 98 (30%) of the 327 of the patients who were diagnosed with inpatient hyperglycemia and were treated with insulin. In adjusted analyses, requirement of insulin therapy during hospitalization posttransplant was associated with a 4-fold increase in NODAT (relative risk 4.01; confidence interval, 1.49 to 10.7; P = 0.006). CONCLUSION Development of inpatient hyperglycemia after kidney transplantation in nondiabetic patients significantly increased the risk of NODAT. Additionally, we observed a significantly increased risk of cardiovascular events in patients who developed NODAT.

Molecular classifiers for acute kidney transplant rejection in peripheral blood by whole genome gene expression profiling.

There are no minimally invasive diagnostic metrics for acute kidney transplant rejection (AR), especially in the setting of the common confounding diagnosis, acute dysfunction with no rejection (ADNR). Thus, though kidney transplant biopsies remain the gold standard, they are invasive, have substantial risks, sampling error issues and significant costs and are not suitable for serial monitoring. Global gene expression profiles of 148 peripheral blood samples from transplant patients with excellent function and normal histology (TX; n = 46), AR (n = 63) and ADNR (n = 39), from two independent cohorts were analyzed with DNA microarrays. We applied a new normalization tool, frozen robust multi‐array analysis, particularly suitable for clinical diagnostics, multiple prediction tools to discover, refine and validate robust molecular classifiers and we tested a novel one‐by‐one analysis strategy to model the real clinical application of this test. Multiple three‐way classifier tools identified 200 highest value probesets with sensitivity, specificity, positive predictive value, negative predictive value and area under the curve for the validation cohort ranging from 82% to 100%, 76% to 95%, 76% to 95%, 79% to 100%, 84% to 100% and 0.817 to 0.968, respectively. We conclude that peripheral blood gene expression profiling can be used as a minimally invasive tool to accurately reveal TX, AR and ADNR in the setting of acute kidney transplant dysfunction.

Hyperglycemia during the Immediate Period after Kidney Transplantation

BACKGROUND AND OBJECTIVES Hyperglycemia and new-onset diabetes occurs frequently after kidney transplantation. The stress of surgery and exposure to immunosuppression medications have metabolic effects and can cause or worsen preexisting hyperglycemia. To our knowledge, hyperglycemia in the immediate posttransplantation period has not been studied. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted a retrospective, observational study to characterize the prevalence and assess the pharmacologic management of hyperglycemia in kidney transplant recipients who underwent transplantation at our center between June 1999 and December 2006. Data were abstracted from electronic and pharmacy databases. RESULTS The study cohort included 424 patients (mean age 51 yr; 58% men; 25% with pretransplantation diabetes). All patients with and 87% without pretransplantation diabetes had evidence of hyperglycemia (bedside glucose >or=200 mg/dl or physician-instituted insulin therapy), whereas the prevalence of hypoglycemia was low (4.5%). Hyperglycemia was sustained throughout hospitalization. All patients with and 66% without pretransplantation diabetes required insulin at hospital discharge. Patients with pretransplantation diabetes were treated primarily with short-acting insulin during the first 24 h after transplantation but were transitioned to long-acting insulin as the hospital stay progressed. CONCLUSIONS Investigators have historically attempted to identify hyperglycemia after hospital discharge. Our data indicate that a substantial number of patients without pretransplantation diabetes develop hyperglycemia and require insulin during the hospital phase of their care immediately after kidney transplantation. Prospective studies are needed to delineate factors that contribute to development of new-onset diabetes after transplantation among patients with transient hyperglycemia.

Pretransplant risk score for new-onset diabetes after kidney transplantation

OBJECTIVE New-onset diabetes after kidney transplantation (NODAT) has adverse clinical and economic implications. A risk score for NODAT could help identify research subjects for intervention studies. RESEARCH DESIGN AND METHODS We conducted a single-center retrospective cohort study using pretransplant clinical and laboratory measurements to construct a risk score for NODAT. NODAT was defined by hemoglobin A1c (HbA1c) ≥6.5%, fasting serum glucose ≥126 mg/dL, or prescribed therapy for diabetes within 1 year posttransplant. Three multivariate logistic regression models were constructed: 1) standard model, with both continuous and discrete variables; 2) dichotomous model, with continuous variables dichotomized at clinically relevant cut points; and 3) summary score defined as the sum of the points accrued using the terms from the dichotomous model. RESULTS A total of 316 subjects had seven pretransplant variables with P < 0.10 in univariate logistic regression analyses (age, planned corticosteroid therapy posttransplant, prescription for gout medicine, BMI, fasting glucose and triglycerides, and family history of type 2 diabetes) that were selected for multivariate models. Areas under receiver operating curves for all three models were similar (0.72, 0.71, and 0.70). A simple risk score calculated as the sum of points from the seven variables performed as well as the other two models in identifying risk of NODAT. CONCLUSIONS A risk score computed from seven simple pretransplant variables can identify risk of NODAT.

De novo donor-specific human leukocyte antigen antibodies early after kidney transplantation

Background Our aim was to determine the incidence of de novo donor-specific human leukocyte antigen (HLA) antibody (dnDSA) during the first year after kidney transplantation and the impact of early dnDSA on acute rejection and protocol biopsy findings. Methods We selected all patients who received a kidney transplant at our center between July 2010 and March 2012. Single antigen bead assay was performed at 1, 4 and 12 months after transplantation. Only DSAs with a mean fluorescence intensity (MFI) of greater 999 were included. Results We included 245 kidney transplant recipients who did not have a DSA before transplantation. At 12 months, 8.2% of the patients developed dnDSA; 2.4% of them were to HLA class I and 6.5% to HLA class II. Of the 32 patients with a dnDSA at 1 or 4 months, only 8 (25%) persisted at 12 months. The risk of antibody-mediated rejection (AMR) was higher in the dnDSA group. For the dnDSA group with MFI of 3,000 or greater (compared with the group with MFI<3,000), the hazard ratio for AMR was 10.6 (95% confidence interval, 2.27–49.5). The cumulative incidence of AMR or mixed rejection at 1 year was 30% in the group with dnDSA MFI level of 3,000 or greater but only 4% for the group with dnDSA with MFI less than 3,000. On 1-year protocol biopsies, the dnDSA group showed more interstitial inflammation, tubulitis, and glomerulitis. Conclusion We conclude that dnDSA occurring during the first posttransplantation year may be transient, and the risk of AMR is higher in patients with a dnDSA MFI level that is greater than 3,000.

Gene Expression in Biopsies of Acute Rejection and Interstitial Fibrosis/Tubular Atrophy Reveals Highly Shared Mechanisms That Correlate With Worse Long-Term Outcomes

Interstitial fibrosis and tubular atrophy (IFTA) is found in approximately 25% of 1‐year biopsies posttransplant. It is known that IFTA correlates with decreased graft survival when histological evidence of inflammation is present. Identifying the mechanistic etiology of IFTA is important to understanding why long‐term graft survival has not changed as expected despite improved immunosuppression and dramatically reduced rates of clinical acute rejection (AR) (Services UDoHaH. http://www.ustransplant.org/annual_reports/current/509a_ki.htm). Gene expression profiles of 234 graft biopsy samples were obtained with matching clinical and outcome data. Eighty‐one IFTA biopsies were divided into subphenotypes by degree of histological inflammation: IFTA with AR, IFTA with inflammation, and IFTA without inflammation. Samples with AR (n = 54) and normally functioning transplants (TX; n = 99) were used in comparisons. A novel analysis using gene coexpression networks revealed that all IFTA phenotypes were strongly enriched for dysregulated gene pathways and these were shared with the biopsy profiles of AR, including IFTA samples without histological evidence of inflammation. Thus, by molecular profiling we demonstrate that most IFTA samples have ongoing immune‐mediated injury or chronic rejection that is more sensitively detected by gene expression profiling. These molecular biopsy profiles correlated with future graft loss in IFTA samples without inflammation.

The prevention of recrudescent coccidioidomycosis after solid organ transplantation.

Background. Coccidioidomycosis is an endemic fungal infection of the southwestern United States that causes considerable morbidity and mortality in transplant recipients, often as the result of reactivated infection. Methods. A retrospective review of the medical records of 47 patients with prior coccidioidomycosis who underwent solid organ transplantation (18 liver, 24 kidney, 3 pancreas, and 2 combined organ) at our tertiary care academic medical center. Results. Of 47 transplant recipients with a history of coccidioidomycosis, 44 had quiescent infection at transplantation. Of the three with active coccidioidomycosis at transplantation, two were taking azole prophylaxis and had no further coccidioidal infection after transplantation. One of the three had positive serologic findings identified only on the day of transplantation, and prophylaxis was initiated a few hours after surgery along with immunosuppression; nevertheless, the treatment course was complicated by disseminated coccidioidomycosis. Seven patients did not initiate or self-discontinued prophylaxis; one patient who discontinued prophylaxis experienced recurrent pulmonary infection. Conclusions. For patients undergoing transplantation in an area endemic for coccidioidomycosis, we recommend routine evaluation for evidence of prior infection and initiation of azole prophylaxis. For our patients with quiescent infection, azoles suppressed any recrudescent coccidioidomycosis after transplantation. The selection of patients who would benefit from prophylaxis and the optimal dose and duration of such prophylaxis should be studied further.