Prospective study of sickle cell trait and venous thromboembolism incidence.

BACKGROUND: Sickle cell trait may increase risk of venous thromboembolism, but this is not fully established. OBJECTIVES: We sought to determine the association of sickle cell trait with deep vein thrombosis and pulmonary embolism. METHODS: Middle-aged African Americans participating in a prospective, population-based cohort investigation, the Atherosclerosis Risk in Communities Study, were followed from 1987 through 2011 for incident hospitalized pulmonary embolism (n = 111) or isolated deep vein thrombosis (n = 138), verified by physician review of medical records. Sickle cell trait (heterozygosity for hemoglobin S, n = 268) was compared with no sickle cell trait (n = 3748). RESULTS: Over a median of 22 years of follow-up, 249 participants had an incident venous thromboembolism. The hazard ratio of venous thromboembolism was 1.50 (95% confidence interval [CI] 0.96-2.36) for participants with vs. without sickle cell trait, after adjustment for age, sex, ancestry, hormone replacement therapy (women), body mass index, diabetes, and estimated glomerular filtration rate. This hazard ratio was 2.05 (95% CI 1.12-3.76) for pulmonary embolism and 1.15 (95% CI 0.58-2.27) for deep vein thrombosis without pulmonary embolism. CONCLUSIONS: Sickle cell trait in African Americans carries a 2-fold increased risk of pulmonary embolism but does not elevate deep vein thrombosis risk. Because neonatal screening for sickle hemoglobin is being conducted in the United States, consideration should be paid to the increased pulmonary embolism risk of individuals with sickle cell trait.

Adenovirus causing fever, upper respiratory infection, and allograft nephritis complicated by persistent asymptomatic viremia.

A 20-year-old woman, with renal transplant complicated by recurrence of focal segmental glomerulosclerosis and post-transplant lymphoproliferative disorder, presented nearly 2 years after transplantation with fever, conjunctivitis, and sinus congestion. She was found to have severe adenovirus (ADV)-induced granulomatous interstitial nephritis, confirmed by immunohistochemical staining for ADV in the renal biopsy, without urinary symptoms, hematuria, or laboratory evidence of a change in allograft function. Fever, upper respiratory tract symptoms, and evidence of adenoviral infection in the allograft resolved with decreased immunosuppression and treatment with cidofovir and intravenous immunoglobulin. Creatinine rose during treatment and remained elevated, possibly related to cidofovir nephrotoxicity. Despite therapy and continued reduction in immunosuppression, asymptomatic low-level viremia persisted for a year. In renal transplant patients with ADV infection, allograft involvement should be highly suspected even without overt urinary symptoms or laboratory evidence of allograft dysfunction. Demonstration of allograft involvement may prompt alternative management that could limit continued allograft infection. No clear recommendations exist for management of asymptomatic ADV viremia in solid organ transplant patients.

Combined effects of AT(1) and ET(A) receptor antagonists, candesartan, and A-127722 in DOCA-salt hypertensive rats.

Several recent studies have provided evidence that many of the hemodynamic and mitogenic actions of angiotensin II (Ang II) are mediated by endothelin-1 (ET-1). We hypothesized that Ang II and ET-1 act synergistically to promote a decline in renal function and the development of renal fibrosis in the deoxycorticosterone acetate (DOCA)-salt model of malignant hypertension and renal dysfunction. Experiments were conducted to determine the effects of ET(A) receptor antagonism (A-127722) and AT(1) receptor antagonism (candesartan cilexetil) on the development of renal fibrosis and the decline of renal function. Surgery was conducted on male, Sprague-Dawley rats to remove the right kidney and implant subcutaneously a time-release pellet containing DOCA. DOCA-treated rats were also given 0.9% NaCl to drink. After recovery from surgery, rats received one of four treatments via the drinking solution: (1) candesartan cilexetil (10 mg/kg/day), (2) A-127722 (10 mg/kg/day), (3) candesartan cilexetil plus A-127722, or (4) untreated controls. Over the course of a 3-week treatment period, systolic arterial pressure in all groups were elevated. However, this increase was significantly attenuated in the group given combined A-127722 and candesartan, but not with candesartan alone. Creatinine clearance, used as a measure of GFR, was significantly higher in rats treated with either or both drugs. At the end of the study, renal medullary tissue was harvested for determination of TGF-beta and fibronectin content (ELISA). TGF-beta levels were not reduced by either ET(A), AT(1), or combined ET(A) and AT(1) receptor blockade. Likewise, fibronectin content was similar among groups. These studies indicate that combined ET(A) and AT(1) receptor blockade may produce some improvement on hemodynamics, but have no effect on progression of renal damage in this non-renin-dependent model of hypertension.