K K Venkat

Henry Ford Hospital, Detroit, Michigan, United States

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Publications (47)120.89 Total impact

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    ABSTRACT: Successful kidney transplantation despite positive crossmatch (+CXM) before transplantation is well recognized in combined liver-kidney transplant (CLKT) recipients. This is probably due to immunologic protection of the renal allograft (RA) conferred by the liver allograft. However, occurrences of antibody-mediated rejection and poor long-term RA outcome is also documented with +CXM CLKT recipients, suggesting that such immunologic protection may not be universal. A total of 1,401 CLKT recipients with known status of pre-transplantation CXM were identified from the United Network for Organ Sharing registry from January 1, 1986, to December 31, 2006. Univariate analysis for significant differences in clinical variables and Kaplan-Meier estimate for patient and graft survivals were performed. The results were compared between positive and negative CXM groups. Pre-transplantation +CXM was seen in 17.3% (242/1401) of CLKT recipients studied. The demographic and clinical characteristics were similar between the groups, except for higher panel reactive antibody level and CXM positivity in female recipients. Outcome analysis showed higher RA rejection (19.3% vs 10.8%; P = .026) and increased hospital length of stay (37.3 ± 46.0 vs 28.8 ± 33.2 days; P = .028) in the +CXM group. RA survivals at 1, 3, and 5 years were 8%, 7%, and 6% lower in the +CXM group. The patient and liver allograft survivals were not different between the groups. In CLKT recipients with pre-transplantation +CXM, the immunologic protection of RA conferred by the liver allograft is less robust than previously perceived and may lead to higher rejection rate and poor RA outcome. This can be mitigated with routine pre-transplantation CXM.
    Transplantation Proceedings 11/2013; 45(9):3269-72. · 0.95 Impact Factor
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    ABSTRACT: Advances in kidney transplantation have significantly improved early outcomes but failed to improve long-term graft survival. Despite many causes, the contribution of infection to death-censored graft failure (DCGF) is unknown. The aim of our study is to assess the impact of infections on DCGF using United Network for Organ Sharing data. We analyzed 38,286 DCGFs among 189,110 first kidney transplants performed between January 1, 1990 and December 31, 2006. Information on infection contributing to DCGF was available in 31,326 DCGF recipients. Student's two-sample t test for normally distributed variables, Wilcoxon rank sum test for nonnormally distributed, and Chi-square test for categorical variables were used in univariable comparisons. Multivariable logistic regression analysis was performed to assess the independent contribution of variables to infection-related DCGF. Overall, infection accounted for 7.7% (2397/31,326) of all DCGF. The rate of infection-related DCGF increased from 6.4% in 1990 to 10.1% in 2006 and was significantly higher during 1997 to 2006 when compared with 1990 to 1996 period (9.1% vs. 6.3%, P<0.001). Over these 17 years, the trends in infection-related DCGF and rejection rates showed an inverse relationship with the former exceeding the latter starting in 2005. The risk of infection-related DCGF was higher (14.1%) in recipients older than 65 years and exceeded the rejection rate in those older than 60 years. Urological complications and polyoma infection were the most significant risk factors with odds ratios of 8.77 (confidence interval: 5.15-14.93) and 2.55 (confidence interval: 1.41-4.61), respectively. Infection is increasingly contributing to DCGF in recent years and warrant reevaluation of current immunosuppression protocols, especially in older recipients.
    Transplantation 01/2011; 91(1):94-9. · 3.78 Impact Factor
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    ABSTRACT: Renal transplantation is now considered the treatment of choice for patients with end-stage renal disease. In transplant recipients, infection and rejection are entwined and are unavoidable tribulations unless clinical tolerance becomes a reality. Although rejection rates have significantly decreased with the introduction of newer immunosuppressive agents, infections remain a major cause of morbidity and mortality, and the magnitude of the problem is on the rise. Newer infections are emerging and patterns of known infections are changing. The continuous evolution of donor and recipient characteristics also alters the landscape of infections. In clinical practice, establishing a definite diagnosis of infection in a timely manner remains a challenge in transplant recipients as compared to immunocompetent individuals. Hence a comprehensive knowledge of the principles of management of infections in renal transplant recipients is very essential. In this review, we would like to provide an overview of some of the key principles that we believe are essential in the management of infectious complications in renal transplant recipients with no focus on any individual infection.
    Transplantation reviews (Orlando, Fla.) 04/2010; 24(2):43-51.
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    Ravi Parasuraman, K K Venkat
    American Journal of Kidney Diseases 10/2009; 55(1):192-7. · 5.29 Impact Factor
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    R Thalla, D Kim, K K Venkat, R Parasuraman
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    ABSTRACT: Disseminated cryptococcal infection occurs mainly in the immunocompromised host, particularly in those with impaired cellular immunity. The treatment outcome depends not only on the duration and choice of antifungal therapy, but also on the activity of the organism to persist in different parts of the body despite therapy. We present a case of persistence of cryptococcal infection in the parathyroid gland in a kidney transplant recipient. A 38-year-old male renal transplant recipient diagnosed to have disseminated cryptococcosis was treated with discontinuation of immunosuppression, amphotericin B, and flucytosine for 2 weeks, and fluconazole subsequently. Dialysis was initiated when graft function deteriorated after discontinuation of immunosuppression. The patient showed no clinical signs of active cryptococcal infection on fluconazole therapy. One year after the diagnosis of cryptococcosis, and still on fluconazole, he underwent parathyroidectomy, for severe secondary hyperparathyroidism. Surprisingly, active cryptococcal infection with necrotizing granulomatous inflammation was demonstrated in the parathyroid, despite being on therapy. This patient illustrates that persistence of fungal infection despite prolonged therapy can occur in unusual sites such as the parathyroid and may be a source for future recurrence and dissemination.
    Transplant Infectious Disease 06/2009; 11(4):349-52. · 1.98 Impact Factor
  • Ravi Parasuraman, K K Venkat
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    ABSTRACT: Live kidney donation is considered safe; nevertheless, data supporting such claims are almost exclusively of white origin with very limited long-term outcomes in ethnic minority donors. This prospective observational study consisted of a total of 103 previous kidney donors (54 black and 49 white) with mean follow-up days of 743.5 +/- 603.9 for white and 845.1 +/- 668.5 for black donors. The black donors had a statistically significant greater loss of estimated GFR (eGFR; 39.8 ml/min per 1.73 m2) in comparison with white donors (30.4 ml/min per 1.73 m2; P = 0.001). In multivariate analysis, predonation eGFR of <100 ml/min and age at the time of donation were the significant predictors for postdonation eGFR <60 ml/min among black donors. Because eGFR using the Modification of Diet in Renal Disease 4 formula is not validated in live kidney donors, the significance of eGFR <60 ml/min per 1.73 m2 in previous kidney donors is unclear. Long-term prospective study with a gold standard method such as iothalamate GFR measurement is needed to define the actual decrease in eGFR after kidney donation.
    Clinical Journal of the American Society of Nephrology 10/2008; 3(6):1608-9. · 5.07 Impact Factor
  • Transplantation 01/2008; 86. · 3.78 Impact Factor
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    ABSTRACT: An ideal method for quality of life (QOL) assessment in renal transplant recipients (RTR) has not yet been determined. Present assessments of QOL in RTR are lengthy, cumbersome to administer, and difficult to interpret. We used a previously validated single question QOL scale score (QLS) that directly asks about the patients' overall assessment of their QOL; "Considering all parts of my life-physical, emotional, social, spiritual, and financial--over the past 2 days the quality of my life has been ... ". The QLS ranges from 0 ("very bad") to 10 ("excellent"). Patients were contacted prior to their routine office visit when they were free of acute medical problems. Fifty RTR participated. Psychosocial and medical variables included the Beck Depression Inventory, Illness Effects Questionnaire, Multidimensional Scale of Perceived Social Support, time since transplant, age, creatinine, hemoglobin, and albumin levels. Of the patients, 64% were African-American and 48% were women; 94% of patients had a score>5. Mean QLS was 7.5+/-2.3. Perception of a better QOL correlated with less perception of depression and illness effects and with perception of greater social support and satisfaction with life (all P<.05). Perception of QOL did not correlate with age, time since transplantation, creatinine, hemoglobin or albumin levels. We concluded that QLS is a quick tool to measure subjective QOL in RTR for correlation with psychosocial factors of interest in this group. These studies should be replicated in larger multiethnic populations.
    Transplantation Proceedings 07/2006; 38(5):1283-5. · 0.95 Impact Factor
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    ABSTRACT: The use of mycophenolate mofetil (MMF) in renal transplantation results in a 50% lower incidence of acute rejection compared to azathioprine (AZA). However, the graft survival reports are conflicting: the European trial and US database analysis suggest better survival with MMF, an observation that was not seen in the US and tricontinental studies. We retrospectively reviewed our single-center experience (60% African-Americans) comparing the serum creatinine (SCr) values and 3-year actual graft survival with MMF versus AZA-based immunosuppression. Group I included patients transplanted between January 1990 and December 1992 on cyclosporine (CSA), AZA, and steroids; group II subjects, from January 1996 to December 1998 on CSA, MMF, and steroids. We analyzed SCr and all causes of graft losses at 3, 6, 12, 18, 24, and 36 months posttransplantation. The patient demographics were similar in both groups as was the mean SCr values at different times. The time-group interaction for SCr, the Kruskal-Wallis test for SCr for different categories (<1.5, 1.5 to 2.0, 2.0 to 2.5, and >2.5 mg/dL) and the all-cause graft loss between the two groups were not significantly different. Our results failed to show better long-term actual graft survival despite the 6-year interval between the two groups. These findings agree with the results of the United States and the tricontinental studies. A lower incidence of acute rejection early after transplantation observed with MMF may not always translate into a long-term benefit, possibly due to the influence of nonimmunological factors, such as hypertension, calcineurin inhibitor toxicity, more frequent cytomegalovirus infections, and increased attempts to withdraw steroids using MMF-based protocols.
    Transplantation Proceedings 07/2005; 37(5):2060-2. · 0.95 Impact Factor
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    ABSTRACT: To assess the contribution of the protein content of urine from the native kidneys to post-transplant proteinuria, we prospectively studied 14 live donor transplant recipients with a pre-transplant random urine protein to creatinine ratio (UPr:Cr) >0.5. Seven patients received preemptive transplants, and seven patients were on dialysis pre-transplant (with residual urine output). Resolution of proteinuria was defined as UPr:Cr < 0.2. Immunosuppression consisted of tacrolimus, mycophenolate mofetil and corticosteroids. Anti-hypertensive drugs that might reduce proteinuria were avoided during the study. The serum creatinine was 8.7 +/- 0.7 mg/dL pre-transplant, and the nadir post-transplant serum creatinine was 1.4 +/- 0.1 mg/dL. The pre-transplant UPr:Cr ranged between 0.5 and 9.2 (mean = 2.9 +/- 0.6). The UPr:Cr decreased to <0.2 in all 14 patients at a mean of 4.5 weeks post-transplant (range 1-10 weeks). In conclusion, in live donor renal transplant recipients with immediate graft function, proteinuria of native kidney origin resolves in the early post-transplant period. After the immediate post-transplant period, proteinuria cannot be attributed to the native kidneys, and work up for proteinuria should focus on the allograft.
    American Journal of Transplantation 02/2005; 5(2):351-5. · 6.19 Impact Factor
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    ABSTRACT: To assess the outcome of low-dose-ganciclovir prophylaxis (500 mg twice a day for 3 months) in renal-transplant recipients, a retrospective analysis of 185 patients transplanted between 1998 and 2001 was performed. There were 29 (15.6%) patients who belonged to the highest risk group, donor cytomegalovirus (CMV) positive, recipient negative (D + R-), and 37 (20%) patients in the lowest risk group, D-R-. Induction immunosuppression consisted of polyclonal antibody or OKT3 (n = 62, 33.5%), interleukin-2 receptor antibody (n = 61, 33%), and no induction (n = 62, 33.5%). CMV disease occurred in 13 (7%) patients. Highest incidence was in D + R- group (17.2%), with no cases in D-R- group (P = 0.03). Tissue-invasive CMV occurred in 4 of these 13 patients. In patients developing CMV disease, there was no evidence of ganciclovir resistance and no mortality over a mean follow-up of 42 months. Low-dose ganciclovir was found to be as effective in decreasing the incidence of clinical CMV disease as high-dose ganciclovir (1 gm three times a day for 3-6 months) in previous studies.
    Transplantation 01/2005; 78(11):1689-92. · 3.78 Impact Factor
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    ABSTRACT: Fibromuscular dysplasia is the second commonest anatomical abnormality apart from multiple renal arteries in the potential live donors. Pretransplant evaluation of the donors may include an angiography to evaluate the renal arteries, and failure to recognize renal arterial stenosis, particularly fibromuscular dysplasia, by noninvasive methods may eventually lead to hypertension and ischemic renal failure. We report a case of fibromuscular dysplasia that was undetected by computed tomographic angiography prior to donation. One year after kidney donation, it rapidly progressed to severe symptomatic stenosis with hypertension and acute renal failure. Following renal artery angioplasty, her blood pressure normalized over a period of 2 weeks without any need for antihypertensive medications and the serum creatinine returned to her baseline. The acceptability of renal donors with fibromuscular dysplasia depends on the age, race and the availability of the other suitable donors. Mild fibromuscular dysplasia in a normotensive potential renal donor cannot be considered a benign condition. Such donors need regular follow-up postdonation for timely detection and treatment.
    American Journal of Transplantation 12/2004; 4(11):1910-4. · 6.19 Impact Factor
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    K K Venkat
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    ABSTRACT: This paper reviews current concepts regarding the pathophysiology, diagnostic evaluation, and treatment of microalbuminuria and proteinuria in adults. Microalbuminuria (in diabetics) and proteinuria are early markers for potentially serious renal disease, and are associated with increased risk of atherosclerotic cardiovascular disease. Proteinuria also contributes to renal scarring, and accelerates the progression of chronic kidney disease to end-stage renal failure. Screening of diabetics for microalbuminuria, and the initial workup of proteinuria, should occur in the primary care setting. Reduction of microalbuminuria in diabetics may retard its progression to overt diabetic nephropathy. Therapy of renal diseases should aim for optimal blood pressure control and the maximum possible reduction in urinary protein excretion. Angiotensin-converting enzyme inhibitor (ACE-I) and/or angiotensin-receptor blocker (ARB) therapy is the most effective measure to achieve this. These drugs also provide protection against the cardiovascular problems that are highly prevalent in this patient population.
    Southern Medical Journal 11/2004; 97(10):969-79. · 0.92 Impact Factor
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    ABSTRACT: Immunosuppression for organ transplantation results in increased susceptibility to opportunistic infections including fungal, such as Scedosporium apiospermum. Even though many reported cases of this infection had both local and systemic manifestations, majority of the systemic infections had a fatal outcome. We report a case of a 50-year-old Caucasian male with lymphocutaneous and presumed pulmonary Scedosporium infection 4 years after renal transplantation that was successfully treated with voriconazole and discontinuation of immunosuppression. He received a second transplant 3 years later in the absence of clinical evidence of S. apiospermum infection. Unfortunately, 4 months after transplantation he developed recurrence of the same infection localizing to the soft tissues. Presently this infection is under control with surgical excision and voriconazole therapy. To our knowledge this is the first reported case of recurrent S. apiospermum infection in a renal transplant recipient. We suggest prophylactic antifungal therapy in all re-transplants with this infection.
    American Journal of Transplantation 11/2004; 4(10):1720-4. · 6.19 Impact Factor
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    K K Venkat, Arvind Venkat
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    ABSTRACT: End-stage renal disease is becoming more common in the United States because of the aging of the population and the increased prevalence of predisposing conditions such as diabetes and hypertension. Renal transplantation is the preferred treatment for patients with end-stage renal disease. This article reviews the medical problems that might bring renal transplant recipients to the emergency department, the information emergency physicians should be aware of in evaluating and treating these patients, and the critical importance of close communication between emergency and transplant physicians in treating them.
    Annals of emergency medicine 11/2004; 44(4):330-41. · 4.23 Impact Factor
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    ABSTRACT: Thrombotic microangiopathy (TMA) in renal transplant recipients is commonly associated with calcineurin inhibitors (CNIs), though several factors such as vascular rejection, viral infections and other drugs may play a contributory role. We report a series of 29 patients with TMA, all of whom were on CNIs. Though plasma exchange (PEx) is widely used to treat TMA, therapeutic guidelines are not well defined. All our patients were treated with PEx and discontinuation of CNIs. Thrombotic microangiopathy was diagnosed at a median of 7 days post-transplant. The mean decrease in Hgb and platelets during TMA was 66% and 64%, respectively, and peak serum creatinine during TMA was 7.4 +/- 2.9 mg%. Mean duration of PEx therapy was 8.5 (range 5-23) days. Recovery of platelet count to 150K/mcL and Hgb to 8-10 g/dL were used as endpoints for PEx. Twenty-three/29 (80%) patients recovered graft function after PEx. Twenty/23 (87%) patients who recovered were placed back on CNl. Nineteen/20 (95%) patients tolerated reinstitution of CNl without recurrence of TMA. In post-transplant TMA, PEx was associated with a graft salvage rate of 80%, reversal of hematological changes can be used as the endpoint for PEx therapy and CNl can be reintroduced without risk of recurrence in the majority of patients.
    American Journal of Transplantation 11/2003; 3(10):1289-94. · 6.19 Impact Factor
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    ABSTRACT: For a type I diabetic with end-stage renal disease, the choice between a kidney-alone transplant from a living-donor (KA-LD) and a simultaneous pancreas kidney (SPK) transplant remains a difficult one. The prevailing practice seems to favor KA-LD over SPK, presumably due to the superior long-term renal graft survival in KA-LD and the elimination of the lengthy waiting time on the cadaver transplant list. In this study, two treatment options, KA-LD followed by pancreas-after-kidney (PAK) and SPK transplant, are compared using a cost-utility decision analysis model. The decision tree consisted of a choice between KA-LD + PAK and SPK. The analysis was based on a 5-yr model and the measures of outcome used in the model were cost, utility and cost-utility. The expected 5-yr cost was $277,638 for KA-LD + PAK and $288,466 for SPK. When adjusted for utilities, KA-LD + PAK at a cost of $153,911 was less cost-effective than SPK at a cost of $110,828 per quality-adjusted year. One-way sensitivity analyses were performed by varying patient and graft survival probabilities, utilities and cost. SPK remained the optimal strategy over KA-LD + PAK across all variations. Two-way sensitivity analysis showed that in order for KA-LD + PAK to be at least as cost-effective as SPK, 5-yr pancreas and patient survival rates following PAK would need to surpass 86 and 80%. In conclusion, according to the 5-yr cost-utility model presented in this study, KA-LD followed by PAK is less cost-effective than SPK as a treatment strategy for a type I diabetic with end-stage renal disease. For patients interested in the benefits of a pancreas transplant, it would be reasonable to offer SPK as the optimal treatment, even if a living kidney donor is available.
    Clinical Transplantation 03/1999; 13(1 Pt 1):51-8. · 1.63 Impact Factor
  • Transplantation 01/1999; 67(7). · 3.78 Impact Factor
  • Transplantation Proceedings 01/1999; 31(1-2):744-5. · 0.95 Impact Factor
  • Transplantation 01/1999; 67(7). · 3.78 Impact Factor