Tacrolimus trough levels after month 3 as a predictor of acute rejection following kidney transplantation: a lesson learned from DeKAF Genomics

Most calcineurin inhibitor (CNI)‐based protocols reduce blood trough goals approximately 2–3 months post‐transplant in clinically stable kidney transplant recipients. The CNI target trough level to prevent rejection, after reduction, is unknown. Using a multivariate Cox proportional hazards model, we determined the association of time‐varying tacrolimus (TAC) trough levels with acute rejection (AR) occurring in the first 6 months post‐transplant, but specifically we assessed this association after 3 months. A total of 1930 patients received TAC‐based immunosuppression prior to AR in a prospective study. Of the 151 (7.8%) who developed AR, 47 developed AR after 3 months post‐transplant. In an adjusted time‐varying multivariate model, each 1 ng/ml decrease in TAC trough levels was associated with a 7.2% increased risk of AR [hazards ratio (HR) = 1.07, 95% confidence interval (CI) (1.01, 1.14) P = 0.03] in the first 6 months. There was an additional 23% increased risk of AR with each 1 ng/ml decrease in the TAC trough levels in months 3–6 [HR = 1.23, 95% CI (1.06, 1.43) P = 0.008]. In conclusion, lower TAC trough levels were significantly associated with increased risk of AR in the first 6 months post‐transplant with additional risk of AR between months 3 and 6 post‐transplant. The timing and practice of TAC dose reduction should be personalized based on the individual's risk factors.     

Viral myocarditis and coagulopathy: increased tissue factor expression and plasma thrombogenicity

We investigated the effects of viral infection on Tissue Factor (TF) expression and activity in mice within the myocardium to understand increased thrombosis during myocarditis. Mice were infected with coxsackie virus B3 (CVB3) and the hearts were collected at day 4, 8 and 28 post infection (p.i.). Myocardial TF expression and cellular activity as well as plasma activity were analyzed from CVB3 infected mice by Western blot, chromogenic Factor Xa generation assay, in situ staining for active TF and immunohistochemistry. In addition to TF expression, hemodynamic parameters were measured during the time course of infection. Furthermore, we analyzed myocardial tissues from patients with suspected inflammatory cardiomyopathy. TF protein expression was maximally 5-fold elevated 8 days p.i. in mice and remained increased on day 28 p.i. (P < 0.001 vs. non-infected controls). Alterations in TF expression were associated with fibrin deposits within the myocardium. The TF pathway inhibitor protein expression in the myocardium was not altered during myocarditis. Active cellular TF co-localized with CD3 positive cells and VCAM-1 positive endothelial cells in the myocardium. The TF expression was positively correlated with the amount of infiltrating CD3 and Mac3 positive cells (Spearman-Rho ρ = 0.749 P < 0.0001 for CD3⁺ and ρ = 0.775 P < 0.0001 for Mac3⁺; N = 35). Increased myocardial TF expression was associated with a 2-fold elevated plasma activity (P < 0.05 vs. non-infected controls). In the human hearts, the TF expression correlated postively with an endothelial cell activation marker (ρ = 0.523 P < 0.0001 for CD62E; N = 54). Viral myocarditis is a hypercoagulative state which is associated with increased myocardial TF expression and activity. Upregulation of TF contributes to a systemic activation of the coagulation cascade.     

Same-day <Superscript>90</Superscript>Y radioembolization: implementing a new treatment paradigm

Purpose

To assess the feasibility of conducting pretreatment mesenteric angiography, coil embolization, ^99mTc macroaggregated albumin (^99mTc-MAA) scintigraphy, and ⁹⁰Y radioembolization treatment in a single, same-day, combined outpatient encounter.

Methods

This was a retrospective study of 78 patients treated during the period 2008 – 2015 who were managed in a single outpatient encounter under the guidance of the Interventional Radiology Department and The Nuclear Medicine Department. Pretreatment planning was performed by reviewing baseline imaging and estimated perfused liver volume bearing the tumor. The region of interest was estimated using 3-D software; this value was used for dosimetry planning. Maximum lung shunting fractions of 10 % for hepatocellular carcinoma and 5 % for liver metastases were assumed. Subsequently, hepatic angiography and ^99mTc-MAA scintigraphy were performed followed by ⁹⁰Y treatment in one outpatient encounter. Total in-room procedure time was recorded.

Results

All patients underwent same-day angiography, ^99mTc-MAA scintigraphy and ⁹⁰Y radioembolization. Of the 78 patients, 16 received multiple segmental treatments to both lobes, 44 received treatment to the right lobe, and 18 received treatment to the left lobe. The median dose was 106 Gy. The median number of ⁹⁰Y vials needed was two (range one to six). The median in-room time was 160 min (75 – 250 min). The residential status of the patients was as follows, 18 % (14/78) were local residents, 55 % (43/78) traveled from outside the city limits, 18 % (14/78) were from out-of-state, and 9 % (7/78) were resident abroad. Of the 78 patients, 61 (77 %) had hepatocellular carcinoma, and 17 (22 %) had liver metastases. The median lung dose was 3.5 Gy.

Conclusion

This study demonstrated the feasibility of same-day ⁹⁰Y evaluation and treatment while maintaining the principles of safe and effective ⁹⁰Y infusion including tumoricidal dosimetry (lobar, segmentectomy), minimization of nontarget flow, and minimization of lung dose. This paradigm translates into expeditious cancer care and significant cost savings.

     

Toll-like receptor-4 deficiency attenuates doxorubicin-induced cardiomyopathy in mice

BACKGROUND: Cardiac inflammation and generation of oxidative stress are known to contribute to doxorubicin (Dox)-induced cardiomyopathy. Toll-like receptors (TLRs) are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signalling, we investigated whether or not TLR4 is involved in Dox-induced cardiotoxicity. METHODS AND RESULTS: Five days after a single injection of Dox (20 mg/kg; i.p.), left ventricular pressure-volume loops were measured in wild-type and TLR4-deficient mice (TLR4-/-) Dox-treated and control mice. Analyses of possible pathophysiological mechanisms were performed in left ventricular tissue and isolated myocytes, respectively. Dox injection resulted in an impairment of left ventricular function and neurohumoral activation, indexed by increased ET-1 expression. This was further associated with an increase in cardiac oxidative stress, inflammation and apoptosis, as indicated by an up-regulation of cardiac lipid peroxidation, TNF-alpha expression and enhanced content of TUNEL-positive cells. In contrast, TLR4-/- Dox mice showed improved left ventricular function with reduced oxidative and inflammatory stress response including reduced cardiac apoptosis. These results were found to be associated with an increase of GATA-4 expression. CONCLUSIONS: TLR4 deficiency improves left ventricular function and attenuates pathophysiological key mechanisms in Dox-induced cardiomyopathy.