Impact of letermovir prophylaxis in CMV reactivation and disease after allogenic hematopoietic cell transplantation: a real-world, observational study

Letermovir for CMV prevention in CMV-seropositive adults undergoing allo-HCT was implemented at our program in 2021. This study investigates the results from the use of letermovir. The study includes all the 140 CMV-seropositive patients who underwent an allo-HCT during the years 2020, 2021, and 2022 at our institution. Thirty-eight (27.4%) of these patients received letermovir, administered from day + 7 to day + 100 and restarted if patients were on treatment with steroids. The day + 180 and 1-year cumulative incidences of CMV reactivation were 5.3% and 12.1% for patients who received letermovir and 52.9% and 53.9% for those who did not (P < 0.001) (HR 0.19, P < 0.001). Four (10.5%) of these thirty-eight patients had a CMV reactivation, but only 2 (5.3%) cases occurred during the administration of letermovir. During the first year after allo-HCT, 13 (9.2%) patients had CMV disease; the day + 180 and 1-year cumulative incidences were 2.6% and 6.0% for patients who received letermovir and 9.9% and 12.3% for those who did not (P = 0.254) (HR 1.01, P = 0.458). Two (4.2%) of the patients included in the letermovir group had CMV disease, but both of them after letermovir discontinuation. Letermovir induced a protective effect on CMV reactivation risk, but its use was not associated with a significant reduction of CMV disease. The fact that the CMV disease in patients who received letermovir occurred after the discontinuation of the drug, questions whether CMV prophylaxis should be used in patients with high risk for CMV reactivation or disease.

Impact of Early Intrapatient Variability of Tacrolimus Concentrations on the Risk of Graft-Versus-Host Disease after Allogeneic Stem Cell Transplantation Using High-Dose Post-Transplant Cyclophosphamide

Tacrolimus (Tac) is a pivotal immunosuppressant agent used to prevent graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (alloHSCT). Tac is characterized by a narrow therapeutic window and a high inter-patient and intra-patient pharmacokinetic variability (IPV). Although high IPV of Tac concentrations has been associated with adverse post-transplant outcomes following solid organ transplantation, the effects of Tac IPV on alloHSCT recipients have not been determined. Tac IPV was therefore retrospectively evaluated in 128 alloHSCT recipients receiving high-dose post-transplant cyclophosphamide (PTCy) and the effects of Tac IPV on the occurrence of acute GVHD (aGVHD) were analyzed. Tac IPV was calculated from pre-dose concentrations (C0) measured during the first month after Tac initiation. The cumulative rates of grades II-IV and grades III-IV aGVHD at day +100 were 22.7% and 7%, respectively. Higher Tac IPV was associated with a greater risk of developing GVHD, with patients having IPV > 50th percentile having significantly higher rates of grades II-IV (34.9% vs. 10.8%; hazard ratio [HR] 3.858, p < 0.001) and grades III-IV (12.7% vs. 1.5%; HR 9.69, p = 0.033) aGVHD than patients having IPV ≤ 50th percentile. Similarly, patients with IPV > 75th percentile had higher rates of grades II-IV (41.9% vs. 16.5%; HR 3.30, p < 0.001) and grades III-IV (16.1% vs. 4.1%; HR 4.99, p = 0.012) aGVHD than patients with IPV ≤ 75th percentile. Multivariate analyses showed that high Tac IPV (>50th percentile) was an independent risk factor for grades II-IV (HR 2.99, p = 0.018) and grades III-IV (HR 9.12, p = 0.047) aGVHD. Determination of Tac IPV soon after alloHSCT could be useful in identifying patients at greater risk of aGVHD.

High-dose benznidazole in a 62-year-old Bolivian kidney transplant recipient with Chagas central nervous system involvement

There is little published data on benznidazole dosing, or levels in cerebrospinal fluid. In this report, we describe the clinical course of an immunosuppressed patient with Chagas central nervous system involvement. He was treated successfully with larger benznidazole doses than are recommended, in order to reach therapeutically effective concentrations in the brain.

[Assessment of cardiovascular preload and response to volume expansion]

Volume expansion is used in patients with hemodynamic insufficiency in an attempt to improve cardiac output. Finding criteria to predict fluid responsiveness would be helpful to guide resuscitation and to avoid excessive volume effects. Static and dynamic indicators have been described to predict fluid responsiveness under certain conditions. In this review we define preload and preload-responsiveness concepts. A description is made of the characteristics of each indicator in patients subjected to mechanical ventilation or with spontaneous breathing.

Chemical burns: pathophysiology and treatment

Chemical burns continue to pose a variety of dilemmas to the clinician managing such cases. Assessment of burn depth is often difficult and the decision whether to excise the wound early is not always clear-cut. In this updated review, common agents are classified and the basic principles of management and specific recommendations are examined. The complications arising from exposure to these chemicals and the supportive measures needed during treatment are also described.

The AP-2 transcription factor is required for joint formation and cell survival in Drosophila leg development

Flies mutant for the Drosophila homologue of the mammalian transcription factor AP-2 show a severe reduction in leg length and fail to develop joint structures. Presumptive joint cells express dAP-2 in response to Notch signaling. dAP-2 is required for joint cell differentiation and can induce formation of supernumerary joints when misexpressed. Although dAP-2 is expressed only in presumptive joint cells, its activity is required to support cell survival in the entire leg segment. Taken together, our data indicate that dAP-2 is an important mediator of Notch activity in leg development.

Drosophila transcription factor AP-2 in proboscis, leg and brain central complex development

We report loss- and gain-of-function analyses that identify essential roles in development for Drosophila transcription factor AP-2. A mutagenesis screen yielded 16 lethal point mutant alleles of dAP-2. Null mutants die as adults or late pupae with a reduced proboscis, severely shortened legs (~30% of normal length) lacking tarsal joints, and disruptions in the protocerebral central complex, a brain region critical for locomotion. Seven hypomorphic alleles constitute a phenotypic series yielding hemizygous adults with legs ranging from 40–95% of normal length. Hypomorphic alleles show additive effects with respect to leg length and viability; and several heteroallelic lines were established. Heteroallelic adults have moderately penetrant defects that include necrotic leg joints and ectopic growths (sometimes supernumerary antennae) invading medial eye territory. Several dAP-2 alleles with DNA binding domain missense mutations are null in hemizygotes but have dominant negative effects when paired with hypomorphic alleles. In wild-type leg primordia, dAP-2 is restricted to presumptive joints. Ectopic dAP-2 in leg discs can inhibit but not enhance leg elongation indicating that functions of dAP-2 in leg outgrowth are region restricted. In wing discs, ectopic dAP-2 cell autonomously transforms presumptive wing vein epithelium to ectopic sensory bristles, consistent with an instructive role in sensory organ development. These findings reveal multiple functions for dAP-2 during morphogenesis of feeding and locomotor appendages and their neural circuitry, and provide a new paradigm for understanding AP-2 family transcription factors.

DAP-2, the Drosophila homolog of transcription factor AP-2

Transcription factor AP-2 is essential for craniofacial, nervous system, and limb development in the mouse. We report here the cloning and expression pattern analysis of DAP-2, the Drosophila homolog of AP-2 family genes. DAP-2 is expressed in discrete regions of procephalic neuroectoderm, the brain, ventral nerve cord, and maxillary segment during Drosophila embryogenesis, and in the brain, optic lobes, ventral nerve cord, antenno-maxillary complex, and antennal and leg imaginal disks in third instar larvae. Protein sequence conservation and parallels between the embryonic expression patterns of DAP-2 and mammal ian AP-2 family genes indicate that transcription factor AP-2 has been structurally and functionally conserved during metazoan evolution.