Ferritin heavy chain supports stability and function of the regulatory T cell lineage.

Regulatory T (TREG) cells develop via a program orchestrated by the transcription factor forkhead box protein P3 (FOXP3). Maintenance of the TREG cell lineage relies on sustained FOXP3 transcription via a mechanism involving demethylation of cytosine-phosphate-guanine (CpG)-rich elements at conserved non-coding sequences (CNS) in the FOXP3 locus. This cytosine demethylation is catalyzed by the ten-eleven translocation (TET) family of dioxygenases, and it involves a redox reaction that uses iron (Fe) as an essential cofactor. Here, we establish that human and mouse TREG cells express Fe-regulatory genes, including that encoding ferritin heavy chain (FTH), at relatively high levels compared to conventional T helper cells. We show that FTH expression in TREG cells is essential for immune homeostasis. Mechanistically, FTH supports TET-catalyzed demethylation of CpG-rich sequences CNS1 and 2 in the FOXP3 locus, thereby promoting FOXP3 transcription and TREG cell stability. This process, which is essential for TREG lineage stability and function, limits the severity of autoimmune neuroinflammation and infectious diseases, and favors tumor progression. These findings suggest that the regulation of intracellular iron by FTH is a stable property of TREG cells that supports immune homeostasis and limits the pathological outcomes of immune-mediated inflammation.

A first-in-class Wiskott-Aldrich syndrome protein activator with anti-tumor activity in hematologic cancers.

Hematological cancers are among the most common cancers in adults and children. Despite significant improvements in therapies, many patients still succumb to the disease. Therefore, novel therapies are needed. The Wiskott-Aldrich syndrome protein (WASp) family regulates actin assembly in conjunction with the Arp2/3 complex, a ubiquitous nucleation factor. WASp is expressed exclusively in hematopoietic cells and exists in two allosteric conformations: autoinhibited or activated. Here, we describe the development of EG-011, a first-in-class small molecule activator of the WASp auto-inhibited form. EG-011 possesses in vitro and in vivo anti-tumor activity as a single agent in lymphoma, leukemia, and multiple myeloma, including models of secondary resistance to PI3K, BTK, and proteasome inhibitors. The in vitro activity was confirmed in a lymphoma xenograft. Actin polymerization and WASp binding was demonstrated using multiple techniques. Transcriptome analysis highlighted homology with drugs-inducing actin polymerization.

Concomitant deletion of Ptpn6 and Ptpn11 in T cells fails to improve anticancer responses.

Anticancer T cells acquire a dysfunctional state characterized by poor effector function and expression of inhibitory receptors, such as PD-1. Blockade of PD-1 leads to T cell reinvigoration and is increasingly applied as an effective anticancer treatment. Recent work challenged the commonly held view that the phosphatase PTPN11 (known as SHP-2) is essential for PD-1 signaling in T cells, suggesting functional redundancy with the homologous phosphatase PTPN6 (SHP-1). Therefore, we investigated the effect of concomitant Ptpn6 and Ptpn11 deletion in T cells on their ability to mount antitumour responses. In vivo data show that neither sustained nor acute Ptpn6/11 deletion improves T cell-mediated tumor control. Sustained loss of Ptpn6/11 also impairs the therapeutic effects of anti-PD1 treatment. In vitro results show that Ptpn6/11-deleted CD8+ T cells exhibit impaired expansion due to a survival defect and proteomics analyses reveal substantial alterations, including in apoptosis-related pathways. These data indicate that concomitant ablation of Ptpn6/11 in polyclonal T cells fails to improve their anticancer properties, implying that caution shall be taken when considering their inhibition for immunotherapeutic approaches.

The Isolated Mucosa of the Rat Colon Decellularization, Microscopy and Cell Cultures.

This project presents the most important findings of the studies, which we carried out in our laboratory on the decellularization of the rat isolated colonic mucosa. We have also included some details of the experiences gathered with the muscle layer as well as the whole wall of the colon. The question of the cytocompatibility of this new substrate has been addressed with the application of primary cultures of human cells and well-established cell lines. The possible applications in experimental and medical settings will be discussed.

Low-level laser effect in patients with neurosensory impairment of mandibular nerve after sagittal split ramus osteotomy. Randomized clinical trial, controlled by placebo.

OBJECTIVE: Evaluate the effect on the application of low level laser therapy, in patients that have been previously intervened with a sagittal ramus split osteotomy and present neurosensory impairment due to this surgery, compared with placebo. STUDY DESIGN: This preliminary study is a randomized clinical trial, with an experimental group (n=17) which received laser light and a control group (n=14), placebo. All participants received laser applications, divided after surgery in days 1, 2, 3, 5, 10, 14, 21 and 28. Neurosensory impairment was evaluated clinically with 5 tests; visual analog scale (VAS) for pain and sensitivity, directional and 2 point discrimination, thermal discrimination, each one of them performed before and after surgery on day 1, and 1, 2 and 6 months. Participants and results evaluator were blinded to intervention. Variables were described with absolute frequencies, percentages and medians. Ordinal and dichotomous variables were compared with Mann Whitney's and Fisher's test respectively. RESULTS: RESULTS demonstrate clinical improvement in time, as well as in magnitude of neurosensory return for laser group; VAS for sensitivity reached 5 (normal), 10 participants recovered initial values for 2 point discrimination (62,5%) and 87,5% recovered directional discrimination at 6 months after surgery. General VAS for sensitivity showed 68,75% for laser group, compared with placebo 21,43% (p-value = (0.0095)). Left side sensitivity (VAS) showed 3.25 and 4 medians for placebo and laser at 2 months, respectively (p-value = (0.004)). CONCLUSION: Low-level laser therapy was beneficial for this group of patients on recovery of neurosensory impairment of mandibular nerve, compared to a placebo.

Hypocitraturia as a biomarker of renal tubular acidosis in patients with Sjögren's disease.

INTRODUCTION: Sjögren's disease (SD) is an immune-mediated chronic inflammatory disease that affects epithelial tissues, mainly salivary and lacrimal glands. It also presents extraglandular manifestations. The main renal manifestation is tubulointerstitial nephritis (TIN), which can manifest as renal tubular acidosis (RTA). Urinary citrate may be a biomarker of RTA in these patients. The objective of this study was to evaluate whether hypocitraturia is a predictive biomarker of RTA in a sample of patients with SD in a tertiary hospital in southern Brazil. METHODS: All patients with SD who met the inclusion criteria and who participated in the rheumatology outpatient clinic of the Irmandade Santa Casa de Misericórdia de Porto Alegre were included. Demographic, SD, serological and urinary data were obtained. RTA was considered in those patients who persistently presented urinary pH above 5.5 and serum pH below 7.35. Patients who persistently had urinary pH above 5.5 underwent a urinary acidification test with furosemide and fludrocortisone. These patients received 1 mg of fludrocortisone and 40 mg of furosemide and had their urine samples tested 2, 4 and 6 h after taking the medications. The test was stopped at any urine sample with pH 5.5 or less. The variables were expressed as mean and standard deviation or interquartile range. The association between hypocitraturia and RTA was assessed using the chi-square. RESULTS: Forty-two patients were included, 95.2% female with a median age of 61.73 years. The prevalence of complete distal RTA was 4.88%. Twenty-eight patients underwent urine acidification testing. Five patients had hypocitraturia, and two of them had complete distal RTA. The association between hypocitraturia and RTA was statistically significant (p < 0.012), with a sensitivity of 100%, specificity of 91.2% and accuracy of 91.7%. The negative predictive value was 100%. The global renal assessment of the population demonstrated two patients with RTA, one patient with decreased renal function and six patients with proteinuria greater than 0.5 g/24 h. CONCLUSION: The prevalence of RTA in the studied population was 4.88%. Hypocitraturia had high sensitivity and accuracy for the diagnosis of RTA.

Pediatric kidney transplantation: outcomes with under and over 6-year-old donors.

OBJECTIVE: Kidney shortage for pediatric kidney transplantation (PKT) entails the need to use low-weight and age donors, despite the apprehension. The aim of this study was to analyze the pediatric deceased donor kidney transplantations (pDDKT) outcomes in the first year after the procedure, stratified by donor age. METHOD: Retrospective cohort of pDDKTs carried out between January 2013, and January 2018, at a PKT reference hospital in Southern Brazil. Donors were divided into group 1 (≤ 6 years), and group 2 (> 6 years); the analysis of the outcomes was carried out in the same period. RESULTS: There were 143 pDDKTs; 51 (35.66%) in group 1; and 92 (64.34%) in group 2. In both groups there were 17 graft losses (11.8%), with vascular thrombosis as the main cause (group 1: 5; group 2: 4). Among the complications, renal artery stenosis (RAS) with indication for angioplasty and stenting was more frequent in group 1 (7.8%; group 2: 2.2%). The 1-year Renal Transplant Recipients' and graft survival did not show significant differences between the groups, (p =  = 0.95). However, the Glomerular Filtration Rate analysis was higher in group 2, reaching, in the 12th month, 79.3 mL/min/1,73m2, compared to 69.7 mL/min/1,73m2 in group 1(p =  = 0.033). CONCLUSIONS: Small donors can be considered for pDDKTs, as long as there is an expert team to perform the transplantation.

The bacterial lysate OM-85 engages Toll-like receptors 2 and 4 triggering an immunomodulatory gene signature in human myeloid cells.

OM-85 is a bacterial lysate used in clinical practice to reduce duration and frequency of recurrent respiratory tract infections. Whereas knowledge of its regulatory effects in vivo has substantially advanced, the mechanisms of OM-85 sensing remain inadequately addressed. Here, we show that the immune response to OM-85 in the mouse is largely mediated by myeloid immune cells through Toll-like receptor (TLR) 4 in vitro and in vivo. Instead, in human immune cells, TLR2 and TLR4 orchestrate the response to OM-85, which binds to both receptors as shown by surface plasmon resonance assay. Ribonucleic acid-sequencing analyses of human monocyte-derived dendritic cells reveal that OM-85 triggers a pro-inflammatory signature and a unique gene set, which is not induced by canonical agonists of TLR2 or TLR4 and comprises tolerogenic genes. A largely overlapping TLR2/4-dependent gene signature was observed in individual subsets of primary human airway myeloid cells, highlighting the robust effects of OM-85. Collectively, our results suggest caution should be taken when relating murine studies on bacterial lysates to humans. Furthermore, our data shed light on how a standardized bacterial lysate shapes the response through TLR2 and TLR4, which are crucial for immune response, trained immunity, and tolerance.

Candida: The Ruthless Opportunist.

Spondylodiscitis is a pathology with a devastating potential for functional limitation in patients, which may involve immobilization for months due to the risk of compression or even spinal cord section. It is a rare type of infection occurring in the vertebrae and discs of the spine, and most are bacterial. Fungal cases are rare. We present the clinical case of a 52-year-old female patient with a past medical history of vesicular lithiasis and degenerative disc disease of the cervical spine and no home medication. The patient was hospitalized in the surgery service for about 3.5 months due to necro-hemorrhagic lithiasic pancreatitis that evolved into septic shock and needed organ support in intensive care for 2.5 weeks. Several cycles of antibiotics and endoscopic retrograde cholangiopancreatography (ERCP) with stent placement were performed. She was readmitted for urgent care to the hospital of residence with fever, sweating, and low back pain with sciatica five days after discharge. Lumbar CT and MRI evidence showed the destruction of about two-thirds of the vertebral bodies L3-L4, L5-S1, and adjacent discs, pointing to the diagnosis of infectious spondylodiscitis. Candida albicans was found in blood cultures and lumbar biopsies. The patient was treated with oral fluconazole 400 mg/day for eight months, and the control MRIs showed slow but favorable bone sclerosis over time. She spent a total of 13.5 months in the hospital, including five months in bedbound status. The patient left the hospital walking without any assistance, with an upright mood and disposition. The most likely main fungal infectious factors were the manipulation of the bile ducts, immunosuppression associated with corticosteroid therapy, and multiorgan septic failure. The authors highlight this clinical case for its rarity, complications leading to candidemia, diagnostic and therapeutic delay, complexity, and risk of irreversible injuries to which the patient was subjected. The total recuperation of the patient after such a long physical and emotional struggle was very gratifying.

Myc controls NK cell development, IL-15-driven expansion, and translational machinery.

MYC is a pleiotropic transcription factor involved in cancer, cell proliferation, and metabolism. Its regulation and function in NK cells, which are innate cytotoxic lymphocytes important to control viral infections and cancer, remain poorly defined. Here, we show that mice deficient for Myc in NK cells presented a severe reduction in these lymphocytes. Myc was required for NK cell development and expansion in response to the key cytokine IL-15, which induced Myc through transcriptional and posttranslational mechanisms. Mechanistically, Myc ablation in vivo largely impacted NK cells' ribosomagenesis, reducing their translation and expansion capacities. Similar results were obtained by inhibiting MYC in human NK cells. Impairing translation by pharmacological intervention phenocopied the consequences of deleting or blocking MYC in vitro. Notably, mice lacking Myc in NK cells exhibited defective anticancer immunity, which reflected their decreased numbers of mature NK cells exerting suboptimal cytotoxic functions. These results indicate that MYC is a central node in NK cells, connecting IL-15 to translational fitness, expansion, and anticancer immunity.

Real-world effectiveness and safety of direct-acting antivirals for the treatment of hepatitis C virus in kidney and liver transplant recipients: experience of a large transplant center in Brazil.

Direct-acting antivirals are the gold-standard treatment for chronic HCV infections, but few studies have investigated their use on kidney and liver transplant recipients. We conducted a real-world study to evaluate the rates of sustained virological response with direct-acting antivirals in kidney and liver transplant recipients. Moreover, it also aimed to evaluate direct-acting antivirals (DAAs) interference with immunosuppressant levels and to describe the frequency of adverse events. As part of this retrospective observational cohort, we included adult patients that had undergone a kidney transplant (KT) or liver transplant (LT) at our center, had a chronic HCV infection, and were treated with DAAs from June 2016 to December 2021. A total of 165 patients were included in the analysis, divided in 108 KT and 57 LT recipients. HCV genotype 1 was more frequent in KT (58.4%), and genotype 3 was more prevalent in LT (57.9%) patients. Sustained virological response was achieved in 89.6% of patients. Adverse effects were reported by 36% of patients. There were significant interactions with immunosuppressants requiring dose adjustments. A total of three episodes of rejection were reported in KT recipients. In conclusion, DAA treatment resulted in high rates of SVR and was well tolerated in both kidney and liver transplant patients. Adverse events were frequent but not severe in most patients, with low treatment drop-out rates. Interactions with immunosuppressants need monitoring since dose adjustments may be required. Reporting real-life experiences is important to help build evidence for patient management in non-controlled environments.

Multi-sensor arrays for online monitoring of cell dynamics in in vitro studies with choroid plexus epithelial cells.

Sensors and multi-sensor arrays are the basis of new technologies for the non-label monitoring of cell activity. In this paper we show that choroid plexus cells can be cultured on silicon chips and that sensors register in real time changes in their activity, constituting an interesting experimental paradigm for cell biology and medical research. To validate the signals recorded (metabolism = peri-cellular acidification, oxygen consumption = respiration; impedance = adhesion, cell shape and motility) we performed experiments with compounds that act in a well-known way on cells, influencing these parameters. Our in vitro model demonstrates the advantages of multi-sensor arrays in assessment and experimental characterization of dynamic cellular events--in this case in choroid plexus functions, however with applicability to other cell types as well.

BK Virus and Cytomegalovirus Coinfections in Kidney Transplantation and Their Impact on Allograft Loss.

We aimed to ascertain the interaction and effects of combined reactivations of BK virus and cytomegalovirus on kidney graft function. All consecutive kidney transplant recipients (KTR) between 2003 and 2016 were included. Of 1976 patients who received a kidney transplant, 23 (1.2%) presented BKV-associated nephropathy (BKVAN). Factors independently associated with BKVAN were diabetes mellitus (odds ratios (OR) 3.895%, confidence intervals (CI) (1.4-10.5)), acute allograft rejection (OR 2.8 95%, CI (1.1-7.6)) and nephrostomy requirement (OR 4.195%, CI (1.3-13)). Cytomegalovirus infection was diagnosed in 19% of KTR patients. Recipients with BKVAN presented more frequently with cytomegalovirus (CMV) infection compared to patients without BKVAN (39% vs. 19%, p = 0.02). Acute allograft rejection (OR 2.95%, CI (1.4-2.4)) and nephrostomy requirement (OR 2.95%, CI (1.2-3)) were independently associated with CMV infection. Sixteen patients (69%) with BKVAN had graft dysfunction at one-year post-transplant and eight of them (35%) lost their graft. Patients presenting with BKVAN and graft loss presented more frequently a cytomegalovirus infection (OR 2.295%, CI (1.3-4.3)). In conclusion, we found a relation between CMV infection and graft loss in patients presenting BKVAN, suggesting that patients with CMV reactivation should be actively screened for BKV.

Latent tuberculosis screening before kidney transplantation in the South of Brazil.

BACKGROUND: Tuberculosis (TB) is a prevalent infection after kidney transplantation (KT) in high-burden countries. Latent tuberculosis infection (LTBI) screening includes previous TB history, chest radiograph findings, and tuberculin test (TST) and/or interferon-gamma release assays (IGRAs) results. We aimed to compare our routine LTBI screening of KT candidates and living donors (LD) with their IGRA results, and evaluate if this would improve isoniazid (INH) treatment referral. METHODS: We evaluated adult KT candidates and LD with complete routine LTBI screening and QuantiFERON-TB® Gold In-Tube (QFT) testing. Blood samples were collected from April 4th, 2014 to October 31st, 2018, with follow-up until October 31st, 2019. RESULTS: There were 116 KT recipients, with 30% QFT-positive results. Positive QFT was associated with past TB history (p=0.007), positive TST (p<0.0001), residual radiographic lesions (p=0.003), and diabetes (p=0.035). There were 25 LD, 40% had positive QFT. Positive QFT was associated with a positive TST (p=0.002). Positive QFT results increased INH referral in 80%. Post-transplant TB incidence was 2.6% in a median follow-up of 2 (1-33) months. No variables were associated with post-transplant TB. TB patients had inferior, although non-significant, 5-year graft survival (66.7% vs. 76.5%) (p = 0.402). CONCLUSION: In the present study, the association of QFT to our routine LTBI screening incremented INH treatment referral, but there was still a high incidence of post-transplant TB, possibly related to other forms of infection, such as new exposure and donor transmission.

Pediatric kidney transplantation: outcomes with under and over 6-year-old donors

Abstract Objective Kidney shortage for pediatric kidney transplantation (PKT) entails the need to use low-weight and age donors, despite the apprehension. The aim of this study was to analyze the pediatric deceased donor kidney transplantations (pDDKT) outcomes in the first year after the procedure, stratified by donor age. Method Retrospective cohort of pDDKTs carried out between January 2013, and January 2018, at a PKT reference hospital in Southern Brazil. Donors were divided into group 1 (≤ 6 years), and group 2 (> 6 years); the analysis of the outcomes was carried out in the same period. Results There were 143 pDDKTs; 51 (35.66%) in group 1; and 92 (64.34%) in group 2. In both groups there were 17 graft losses (11.8%), with vascular thrombosis as the main cause (group 1: 5; group 2: 4). Among the complications, renal artery stenosis (RAS) with indication for angioplasty and stenting was more frequent in group 1 (7.8%; group 2: 2.2%). The 1-year Renal Transplant Recipients' and graft survival did not show significant differences between the groups, (p= = 0.95). However, the Glomerular Filtration Rate analysis was higher in group 2, reaching, in the 12th month, 79.3 mL/min/1,73m2, compared to 69.7 mL/min/1,73m2 in group 1(p= = 0.033). Conclusions Small donors can be considered for pDDKTs, as long as there is an expert team to perform the transplantation.

Ferritin regulates organismal energy balance and thermogenesis.

OBJECTIVE: The ferritin heavy/heart chain (FTH) gene encodes the ferroxidase component of the iron (Fe) sequestering ferritin complex, which plays a central role in the regulation of cellular Fe metabolism. Here we tested the hypothesis that ferritin regulates organismal Fe metabolism in a manner that impacts energy balance and thermal homeostasis. METHODS: We developed a mouse strain, referred herein as FthR26 fl/fl, expressing a tamoxifen-inducible Cre recombinase under the control of the Rosa26 (R26) promoter and carrying two LoxP (fl) sites: one at the 5'end of the Fth promoter and another the 3' end of the first Fth exon. Tamoxifen administration induces global deletion of Fth in adult FthR26Δ/Δ mice, testing whether FTH is required for maintenance of organismal homeostasis. RESULTS: Under standard nutritional Fe supply, Fth deletion in adult FthR26Δ/Δ mice led to a profound deregulation of organismal Fe metabolism, oxidative stress, inflammation, and multi-organ damage, culminating in death. Unexpectedly, Fth deletion was also associated with a profound atrophy of white and brown adipose tissue as well as with collapse of energy expenditure and thermogenesis. This was attributed mechanistically to mitochondrial dysfunction, as assessed in the liver and in adipose tissue. CONCLUSION: The FTH component of ferritin acts as a master regulator of organismal Fe homeostasis, coupling nutritional Fe supply to organismal redox homeostasis, energy expenditure and thermoregulation.

Laser Biophotomodulation in Patients with Neurosensory Disturbance of the Inferior Alveolar Nerve After Sagittal Split Ramus Osteotomy: A 2-Year Follow-Up Study.

OBJECTIVE: To evaluate the effect of the application of photobiomodulation in a 2-year follow-up period in patients who have been intervened with a sagittal ramus split osteotomy and present neurosensory disturbance of the inferior alveolar nerve. BACKGROUND: Photobiomodulation is a common clinical tool in dentistry, for its beneficial effects have been shown in surgical and periodontal wound healing, reducing of swelling and pain, neurosensory recovery, and treatment of temporomandibular joint disorders. METHODS: This is a 2-year follow-up study with an experimental (Laser) group (n = 33) that received photobiomodulation, and a control (Sham) group (n = 9), placebo. All patients from the Laser group received laser applications (continuous wave of 0.353 W/cm2, 27 J in 270 sec per session) on days 1, 2, 3, 5, 10, 14, 21, and 28 after surgery. Neurosensory disturbance was evaluated with five tests: Visual Analog Scale (VAS) for pain and sensitivity, sensitivity threshold test, two-point discrimination, and thermal discrimination. All tests were performed before (24 h before surgery) and after surgery (24 h, 28 days, 60 days, 6 months, 1 year, 2 years, more than 2 years). Participants and evaluator were blinded to intervention. Variables were described with absolute frequencies, percentages, and medians. Ordinal and dichotomous variables were compared with Mann-Whitney's and Fisher's tests, respectively. RESULTS: Clinical improvement was observed during the follow-up period for the Laser group; general VAS for sensitivity was normal in 11 participants from the Laser group at 2 years postsurgery (40.74%), while no participants from the Sham group achieved this (p = 0.0341). Twenty-three participants recovered initial values for two-point discrimination (69.7%) after 2 years of follow-up (p = 0.0025) as well as sensitivity threshold test. General VAS for pain was normal in 31 patients from the Laser group after 2 years of follow-up (93.94%, p = 0.0254). CONCLUSIONS: Photobiomodulation was effective for neurosensory recovery on sample studied.

Real-world effectiveness and safety of direct-acting antivirals for the treatment of hepatitis C virus in kidney and liver transplant recipients: experience of a large transplant center in Brazil

ABSTRACT Direct-acting antivirals are the gold-standard treatment for chronic HCV infections, but few studies have investigated their use on kidney and liver transplant recipients. We conducted a real-world study to evaluate the rates of sustained virological response with direct-acting antivirals in kidney and liver transplant recipients. Moreover, it also aimed to evaluate direct-acting antivirals (DAAs) interference with immunosuppressant levels and to describe the frequency of adverse events. As part of this retrospective observational cohort, we included adult patients that had undergone a kidney transplant (KT) or liver transplant (LT) at our center, had a chronic HCV infection, and were treated with DAAs from June 2016 to December 2021. A total of 165 patients were included in the analysis, divided in 108 KT and 57 LT recipients. HCV genotype 1 was more frequent in KT (58.4%), and genotype 3 was more prevalent in LT (57.9%) patients. Sustained virological response was achieved in 89.6% of patients. Adverse effects were reported by 36% of patients. There were significant interactions with immunosuppressants requiring dose adjustments. A total of three episodes of rejection were reported in KT recipients. In conclusion, DAA treatment resulted in high rates of SVR and was well tolerated in both kidney and liver transplant patients. Adverse events were frequent but not severe in most patients, with low treatment drop-out rates. Interactions with immunosuppressants need monitoring since dose adjustments may be required. Reporting real-life experiences is important to help build evidence for patient management in non-controlled environments.

Latent tuberculosis screening before kidney transplantation in the South of Brazil / Rastreamento de tuberculose latente antes do transplante renal no Sul do Brasil

Abstract Background: Tuberculosis (TB) is a prevalent infection after kidney transplantation (KT) in high-burden countries. Latent tuberculosis infection (LTBI) screening includes previous TB history, chest radiograph findings, and tuberculin test (TST) and/or interferon-gamma release assays (IGRAs) results. We aimed to compare our routine LTBI screening of KT candidates and living donors (LD) with their IGRA results, and evaluate if this would improve isoniazid (INH) treatment referral. Methods: We evaluated adult KT candidates and LD with complete routine LTBI screening and QuantiFERON-TB® Gold In-Tube (QFT) testing. Blood samples were collected from April 4th, 2014 to October 31st, 2018, with follow-up until October 31st, 2019. Results: There were 116 KT recipients, with 30% QFT-positive results. Positive QFT was associated with past TB history (p=0.007), positive TST (p<0.0001), residual radiographic lesions (p=0.003), and diabetes (p=0.035). There were 25 LD, 40% had positive QFT. Positive QFT was associated with a positive TST (p=0.002). Positive QFT results increased INH referral in 80%. Post-transplant TB incidence was 2.6% in a median follow-up of 2 (1-33) months. No variables were associated with post-transplant TB. TB patients had inferior, although non-significant, 5-year graft survival (66.7% vs. 76.5%) (p = 0.402). Conclusion: In the present study, the association of QFT to our routine LTBI screening incremented INH treatment referral, but there was still a high incidence of post-transplant TB, possibly related to other forms of infection, such as new exposure and donor transmission.

Resumo Histórico: Tuberculose (TB) é uma infecção relativamente comum pós-transplante renal (TR) em países com alta prevalência da doença. O rastreamento de infecção latente por tuberculose (ILTB) inclui histórico prévio de TB, achados de radiografia do tórax, resultados do teste tuberculínico (TT) e/ou de ensaio de liberação de interferon-gama (IGRAs). Nosso objetivo foi comparar nossa avaliação de rotina de candidatos ao TR e doadores vivos (DV) com seus resultados de IGRA, avaliando se aumentaria o encaminhamento para tratamento com isoniazida (INH). Métodos: Avaliamos candidatos adultos ao TR e DV com rastreamento para ILTB de rotina completo e coleta de testes QuantiFERON-TB® Gold In-Tube (QFT). Coletamos amostras sanguíneas de 4 de Abril, 2014 - 31 de Outubro, 2018, com acompanhamento até 31 de Outubro, 2019. Resultados: Avaliamos 116 receptores de TR, 30% sendo QFT-positivo. QFT positivo foi associado ao histórico prévio de TB (p=0,007), TT positivo (p<0,0001), lesões radiográficas residuais (p=0,003), diabetes (p=0,035). Avaliamos 25 DV, 40% apresentaram QFT positivo. QFT positivo foi associado a TT positivo (p=0,002). Resultados positivos do QFT aumentaram o encaminhamento para INH em 80%. A incidência de TB pós-transplante foi 2,6% em uma mediana de acompanhamento de 2 (1-33) meses. Nenhuma variável foi associada à TB pós-transplante. Pacientes com TB tiveram sobrevida do enxerto em 5 anos inferior, embora não-significativa (66,7% vs. 76,5%) (p = 0,402). Conclusão: Neste estudo, a associação do QFT à nossa avaliação de ILTB de rotina aumentou o encaminhamento para tratamento com INH, mas ainda houve alta incidência de TB pós-transplante, possivelmente relacionada a outras formas de infecção, como nova exposição e transmissão pelos doadores.