Age and Epstein-Barr viral load at diagnosis of post-transplant lymphoproliferative disease are associated with patient survival in kidney transplant recipients.

INTRODUCTION: This study investigated variables associated with mortality in kidney transplant recipients (KTRs) diagnosed with post-transplant lymphoproliferative disease (PTLD) and a simultaneous Epstein-Barr virus (EBV) viremia. METHODS: This was a retrospective cohort study enrolling KTRs diagnosed with PTLD between 2018 and 2020. Outcome: death within two years after diagnosis. RESULTS: Among 1,625 KTRs who collected EBV viremia (by PCR, 2018-2020) for any reason, 238 (14.6%) had a positive viral load and 41 (17.2%) simultaneous PTLD. These 41 patients were 40.1 years old at diagnosis and 8.6 years after transplantation; 26.8% were induced with rATG and 92.7% were maintained on tacrolimus and azathioprine (TAC/AZA) as immunosuppressive regimen. Lymph nodes (75.6%) was the most common site of PTLD, followed by the gastrointestinal tract (48.8%), with 61.0% at Lugano stage IV and 80.5% monomorphic PTLD. The mean EBV viral load was 12,198 IU/mL. One- and two-year patient survival post-diagnosis was 60.4% and 46.8%, respectively. In the Cox regression analysis, age at PTLD diagnosis (HR for each year = 1.039; p < 0.001) and EBV viral load (HR for each log = 1.695; p = 0.026) were associated with risk of death. CONCLUSION: This study suggests that in patients predominantly on TAC/AZA, PTLD with simultaneous EBV positive viral load is a late event, and worse survival is associated with older age and EBV viral load at diagnosis.

Intraoral CD30+ T-Cell Lymphoproliferative Disorder with Lymphomatoid Papulosis Type C Features Mimics Lymphoma Histopathologically and Immunohistochemically.

BACKGROUND: Previous studies have shown that at least a of intraoral eosinophilic ulcer is best classified as a CD30 + T-cell lymphoproliferative disorder (LPD), with histopathology reminiscent of lymphomatoid papulosis (LyP) of the skin. Microscopically, a mixed population of inflammatory cells, often including eosinophils and varying numbers of atypical lymphoid cells, frequently expressing CD30, is typical for LyP, whose clinicopathological spectrum includes type A, B, C, D, E, and LyP with DUSP22/IRF4 rearrangement. To date, about 27 intraoral LyP cases have been reported. Of them, 7 cases were diagnosed as LyP type C, which is frequently confused with anaplastic large cell lymphoma (ALCL) on histopathology. METHODS: A 60-year-old male was referred for a one-month history of a tongue ulcer. RESULTS: Microscopy showed numerous subepithelial atypical large lymphoid cells, which expressed CD4 (with partial loss of CD3, CD5, and CD7), CD8 (few cells), CD30 (about 50%, in non-diffuse pattern with size variability), TIA-1, and Ki-67 (85%), without staining for CD56, ALK, LMP1, and EBER1/2, concerning for a diagnosis of ALCL. However, after three weeks, the lesion completely healed. CONCLUSION: We present here a rare case of intraoral CD30+ T-cell LPD that we believe is the oral counterpart of cutaneous LyP type C.

CD62-L down-regulation after L18-MDP stimulation as a complementary flow cytometry functional assay for the diagnosis of XIAP deficiency.

X-linked inhibitor of apoptosis (XIAP) deficiency is an infrequent inborn error of immunity caused by mutations in XIAP gene. Most cases present with absence of XIAP protein which can be detected by flow cytometry (FC), representing a rapid diagnostic method. However, since some genetic defects may not preclude protein expression, it is important to include a complementary functional test in the laboratory workup of these patients. L-selectin (CD62-L) is a molecule that is cleaved from the surface membrane of leukocytes upon stimulation of different receptors such as toll like receptors (TLRs) and nucleotide-binding oligomerization domain-like receptors (NLRs), including NOD2. Considering that XIAP deficiency impairs NOD2 signaling, we decided to assess CD62-L down-regulation by FC post-stimulation of neutrophils and monocytes with L18-muramyl Di-Peptide (L18-MDP), a NOD2 specific agonist, in order to develop a novel assay for the functional evaluation of patients with suspicion of XIAP defects. Whole blood samples from 20 healthy controls (HC) and four patients with confirmed molecular diagnosis of XIAP deficiency were stimulated with 200 ng/mL of L18-MDP for 2 h. Stimulation with 100 ng/mL of lipopolysaccharide (LPS) was carried out in parallel as a positive control of CD62-L shedding. CD62-L expression was evaluated by FC using an anti CD62-L- antibody and down-regulation was assessed by calculating the difference in CD62-L expression before and after stimulation, both in terms of percentage of CD62-L expressing cells (Δ%CD62-L) and median fluorescence intensity (ΔMFI%). Neutrophils and monocytes from XIAP deficient patients displayed a significantly diminished response to L18-MDP stimulation compared with HC (p < 0.0001), indicating a severely altered mechanism of CD62-L down-regulation following activation of NOD2-XIAP axis. On the other hand, the response to LPS stimulation was comparable between patients and heathy controls, suggesting preserved CD62-L shedding with a different stimulus. FC detection of CD62-L down-regulation in monocytes and neutrophils after whole blood stimulation with L18-MDP results in an effective and rapid functional test for the identification of XIAP deficient patients.

Intraoral primary syphilis mimicking lymphoproliferative disorder.

Syphilis can mimic, clinically and microscopically, many other diseases. By microscopy, typically syphilis presents with plasma cell infiltration, admixed with lymphocytes and macrophages, in lichenoid and/or perivascular/perineural distribution pattern. When exuberant, this inflammatory infiltrate can mimic a lymphoproliferative disorder (LPD), notably plasma cell neoplasia or lymphoma. To date, about 12 cases of secondary syphilis, all but one in extraoral location, suggesting initially a LPD, have been published. Here, to our knowledge, we report an unusual case of intraoral primary syphilis initially suggesting LPD, notably lymphoid hyperplasia (pseudolymphoma); however, mucosa-associated lymphoid tissue (MALT) lymphoma and follicular lymphoma could not be disregarded. Polyclonality of plasma cells on immunohistochemistry, in strict clinical correlation, was essential to arrive at the correct diagnosis.

FDG PET/CT Findings of Renal Cell Carcinoma Arising From a Transplanted Kidney in a Pediatric Patient.

ABSTRACT: A 12-year-old girl presented with a history of kidney transplant complicated by posttransplant lymphoproliferative disease. A solid mass was found in the lower pole of the transplanted kidney, concerning for posttransplant lymphoproliferative disease. However, biopsy confirmed papillary renal cell carcinoma. FDG PET/CT showed increased activity in the known renal cell carcinoma in the renal allograft.

Single-center "Argentine" analysis of post-transplant lymphoproliferative disorders: incidence, histopathological characteristics and EBV status

ABSTRACT Introduction: Post-transplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations occurring after solid organ or bone marrow transplantation. The primary aims of our study were to characterize cumulative incidence of PTLDs, clinical and pathological features according to the Epstein-Barr virus (EBV) status and survival. Methods: This was a retrospective cohort study on adult and pediatric patients, from January 2001 to December 2017. The cumulative incidence of PTLD was calculated by analyzing all the patients transplanted at our hospital, based on the database of the Organ Donation and Ablation Authority of Argentina (INCUCAI). The Kaplan-Meier method was used to plot the survival. Results: Fifty-eight cases of biopsy-confirmed PTLD were identified and 12 cases of clinical data were incomplete and these patients were excluded. The median age at the time of the PTLD diagnosis was 17.5 years (interquartile range [IQR] 9 - 57). The median interval between transplant and PTLD diagnosis was 39 months (IQR 9 - 113). The most commonly transplanted organ was the liver (24 cases, 52.2%), followed by kidney (20 cases, 43.5%). The Epstein-Barr encoding region in situ hybridization (EBER ISH) was positive in 29 (69.8%) of the 43 evaluable biopsies. The PTLD cumulative incidence was 1.84% (95%CI 1.77 - 1.91) for solid organ and 0.84% (95%CI 0.48 - 1.2) for bone marrow transplant patients. The overall survival rate at 5 years was 0.77 (95%CI 0.61 - 0.87). Subgroups by the EBV EBER status, transplant type, PTLD subtype and age group (adult vs. pediatric) showed no statistically significant association with the overall survival. Conclusion: The PTLD incidence was similar to that of previous series and the EBER did not appear as a relevant factor in our patient survival.

Post-transplant lymphoproliferative disorder myeloradiculopathy.

A 56-year-old woman developed progressive subacute lower limb weakness with sensory and autonomic abnormalities. She had received a living-donor kidney transplantation 21 years before for end-stage chronic kidney disease and took mycophenolate mofetil and prednisolone. MR scan of the spinal cord showed bilateral cauda equina gadolinium enhancement and MR scan of the brain showed enhancing nodular hyperintensities in the internal capsule and globus pallidus. Cerebrospinal fluid (CSF) showed a pleocytosis with extremely low glucose, and positive DNA-PCR for Epstein-Barr virus. Her condition worsened despite empirically guided antimicrobial treatment. CSF immunophenotyping later identified mature, clonal B lymphocytes of large size, expressing CD19, CD20, CD200 antigens, and kappa light chain immunoglobulin, with absent CD5 and CD10 expression. We diagnosed a myeloradiculopathy from a monomorphic post-transplant lymphoproliferative disorder. This condition occurs after kidney transplantation and falls on the lymphoma spectrum. We review its clinical features, diagnosis and management.

Indicación de amigdalectomía en pacientes pediátricos por sospecha de trastorno linfoproliferativo postrasplante / Indication for tonsillectomy in pediatric patients with suspected post-transplant lymphoproliferative disorder

Un sitio común de hiperplasia linfoidea en los trastornos linfoproliferativos postrasplante (TLPT) son las amígdalas palatinas. Sin embargo, la hipertrofia amigdalina es extremadamente común en niños, lo que dificulta la sospecha de estos trastornos. Se realizó un estudio de una serie de casos de pacientes trasplantados intervenidos de amigdalectomía por sospecha de TLPT en un hospital pediátrico de alta complejidad en Argentina desde enero de 2014 hasta diciembre de 2021. El objetivo de este trabajo es exponer las características clínicas de los pacientes trasplantados a los que se les indicó amigdalectomía con fin diagnóstico de TLPT.

A common site of lymphoid hyperplasia in post-transplant lymphoproliferative disorders (PTLD) is the palatine tonsils. However, tonsillar hypertrophy is extremely common in children, which hinders the suspicion of PTLD. A case series of transplanted patients undergoing tonsillectomy for suspected PTLD was conducted at a tertiary care children's hospital in Argentina between January 2014 and December 2021. The objective of this study is to expose the clinical characteristics of transplanted patients who underwent a tonsillectomy to diagnose PTLD

Indication for tonsillectomy in pediatric patients with suspected post-transplant lymphoproliferative disorder. / Indicación de amigdalectomía en pacientes pediátricos por sospecha de trastorno linfoproliferativo postrasplante.

A common site of lymphoid hyperplasia in post-transplant lymphoproliferative disorders (PTLD) is the palatine tonsils. However, tonsillar hypertrophy is extremely common in children, which hinders the suspicion of PTLD. A case series of transplanted patients undergoing tonsillectomy for suspected PTLD was conducted at a tertiary care children's hospital in Argentina between January 2014 and December 2021. The objective of this study is to expose the clinical characteristics of transplanted patients who underwent a tonsillectomy to diagnose PTLD.

Un sitio común de hiperplasia linfoidea en los trastornos linfoproliferativos postrasplante (TLPT) son las amígdalas palatinas. Sin embargo, la hipertrofia amigdalina es extremadamente común en niños, lo que dificulta la sospecha de estos trastornos. Se realizó un estudio de una serie de casos de pacientes trasplantados intervenidos de amigdalectomía por sospecha de TLPT en un hospital pediátrico de alta complejidad en Argentina desde enero de 2014 hasta diciembre de 2021. El objetivo de este trabajo es exponer las características clínicas de los pacientes trasplantados a los que se les indicó amigdalectomía con fin diagnóstico de TLPT.

Indolent NK-Cell Lymphoproliferative Disorder of the Gastrointestinal Tract - a Report of two Cases of a new Provisional Entity on the World Health Organization Classification of Hematolymphoid Tumors.

Indolent NK-cell lymphoproliferative disorder of the gastrointestinal tract is a new provisional entity listed in the structure of the forthcoming fifth edition of the World Health Organization (WHO) Classification of Hematolymphoid Tumors. It was first named as "NK-cell enteropathy" and "Lymphomatoid gastropathy" by two independent series a decade ago. Molecular or cytogenetic studies have lent support to the clonal/neoplastic nature of this entity. Herein we add two of such cases that still challenge pathologists and were previously diagnosed as aggressive lymphomas of NK/T derivation.

Hydroa vacciniforme-like lymphoproliferative disorder in Ecuadorian children: A case series.

We report the clinical and histopathological features of hydroa vacciniforme-like lymphoproliferative disorder in five indigenous and Mestizo children. All the children resided at higher altitudes, experiencing maximal solar exposure. All cases presented with prurigo along with Epstein-Barr virus infection. Histopathologic examination showed an atypical, CD30 + lymphocytic infiltrate with angiocentricity in all, while three cases demonstrated panniculitis-like infiltrate.

Análise dos Critérios Imunofenotípicos por Citometria de Fluxo para Definição das Doenças Linfoproliferativas Crônicas de Células B / Analysis of Immunophenotypic Criteria by Flow Cytometry to Define B-Cell Chronic Lymphoproliferative Diseases / Análisis de Criterios Inmunofenotípicos por Citometría de Flujo para Definir Enfermedades Linfoproliferativas Crónicas de Células B

Introdução: A citometria de fluxo é uma metodologia importante para o diagnóstico das doenças linfoproliferativas crônicas de células B (DLPCB), contudo, por vezes, o citometrista não encontra subsídios suficientes para a definição exata da entidade patológica envolvida. Objetivo: Analisar os laudos emitidos a pacientes com doenças linfoproliferativas crônicas (DLPC) atendidos em um laboratório particular de Belém-PA, segundo os critérios de classificação estabelecidos pelos estudos de Matutes et al. e Craig e Foon. Método: Estudo retrospectivo com laudos de pacientes que realizaram imunofenotipagem por citometria de fluxo para diagnóstico de DLPCB no período entre setembro de 2015 a dezembro de 2019. Resultados: Depois de aplicados os critérios de Matutes et al. e Craig e Foon para os laudos analisados, observou-se concordância em: 45,24% casos de leucemia linfoide crônica de células B/linfoma linfocítico de pequenas células B; 14,29% casos de linfoma folicular; 4,76% casos de leucemia de células pilosas; e 21,43% de casos definidos como "outras DLPCB não classificáveis por citometria de fluxo". Entretanto, o teste de hipóteses de Hotelling (p=0,0409) mostrou haver diferença estatística para a definição das DLPCB segundo os critérios aplicados. Conclusão: Os resultados ressaltam que, mesmo sendo a citometria de fluxo importante para a caracterização das DLPCB, por vezes, o citometrista necessita incluir no laudo a categoria "outras doenças linfoproliferativas crônicas de células B não classificadas por citometria de fluxo" para induzir o prescritor a solicitar mais exames complementares.

Introduction: Flow cytometry is an important methodology for the diagnosis of chronic B-cell lymphoproliferative diseases (CBCLPD), however, sometimes the cytometrist does not find sufficient elements for the exact definition of the pathological entity involved. Objective: To analyze the reports issued to patients with chronic lymphoproliferative diseases (CLPD) tested at a private laboratory in Belém-PA, according to the classification criteria established by the studies by Matutes et al. and Craig and Foon. Method: Retrospective study with reports of patients who underwent immunophenotyping by flow cytometry for the diagnosis of CBCLPD from September 2015 to December 2019. Results: After applying the criteria by Matutes et al. and Craig and Foon to the reports analyzed, agreement was reached for 45.24% of the cases of chronic b-cell lymphocytic leukemia/small B-cell lymphocytic lymphoma, 14.29% of the cases of follicular lymphoma, 4.76% of the cases of hairy cell leukemia and 21.43% of the cases defined as "other CBCLPDs not classifiable by flow cytometry". However, Hotelling's hypothesis test (p=0.0409) showed a statistical difference for the definition of CBCLPD according to the criteria adopted. Conclusion: The results emphasize that even though flow cytometry is important for the characterization of CBCLPD, sometimes the cytometrist needs to include the category "other chronic B-cell lymphoproliferative diseases not classified by flow cytometry" in the report to induce the prescriber to request additional complementary exams.

Introducción. La citometría de flujo es una metodología importante para el diagnóstico de enfermedades linfoproliferativas crónicas de células B (ELPCB), sin embargo, en ocasiones el citometrista no encuentra suficientes subsidios para la definición exacta de la entidad patológica involucrada. Objetivo: Analizar los informes emitidos a pacientes con enfermedades linfoproliferativas crónicas (ELPC) tratados en un laboratorio privado en Belém-PA, de acuerdo con los criterios de clasificación establecidos por los estudios de Matutes et al. y Craig y Foon. Método: Retrospectivo con relatos de pacientes que se sometieron a inmunofenotipificación por citometría de flujo para el diagnóstico de ELPC de septiembre de 2015 a diciembre de 2019. Resultados: Tras aplicar los criterios de Matutes et al. y Craig y Foon a los informes analizados, se observó concordancia en: 45,24% de los casos de leucemia linfocítica crónica de células B/linfoma linfocítico de células B pequeñas; 14,29% casos de linfoma folicular; 4,76% casos de leucemia de células peludas; y 21,43% de los casos definidos como "otros ELPCB no clasificables por citometría de flujo". Sin embargo, la prueba de hipótesis de Hotelling (p=0,0409) mostró diferencia estadística para la definición de ELPCB según los criterios aplicados. Conclusión: Nuestros resultados enfatizan que si bien la citometría de flujo es importante para la caracterización de ELPCB, en ocasiones el citometrista necesita incluir en el informe la categoría "otras enfermedades linfoproliferativas crónicas de células B no clasificadas por citometría de flujo" para inducir al prescriptor a solicitar más exámenes complementarios.

Epidemiological characterization of patients with sarcoidosis in a high complexity hospital in southwestern Colombia

Introduction: Epidemiological studies on sarcoidosis in Colombia are scarce, and although recent reports from the north of the country have been published, clinical-epidemiological associations are not clear. Our aim was to characterize patients with sarcoidosis diagnosed at Fundación Valle del Lili in Cali, Colombia. Methods: A retrospective study of a series of sarcoidosis cases was conducted between 2011 and 2019. Demographic, clinical, laboratory, imaging, histopathological, and treatment variables were analyzed. Results: A total of 34 patients with a diagnosis of sarcoidosis were found. The majority were women (n = 25; 73%), and the mean age was 50 years. The main symptoms of onset were erythema nodosum (n = 11; 33%), arthritis (n = 10; 30%), and cough (n = 9; 27%). In 64% of the cases, there was pulmonary involvement, with pulmonary nodules, mediastinal adenopathy, and interstitial lung disease found in 54%, 50%, and 36% of cases, respectively. In 85% of cases, there were extrapulmonary manifestations, mainly cutaneous (50%). Angiotensin-converting enzyme (ACE) was elevated in 62% of the cases in which it was measured (n = 16; 47%). During the diagnostic process, 23 biopsies were performed, of which 95% showed granulomas with noncaseating necrosis. Most of the patients (76%) were controlled with prednisolone, at an average dose of 20 mg (7.5-50 mg) per day. Conclusions: Sarcoidosis was more frequent in women and mestizos, and it presented earlier in men. Elevated ACE was not associated with extrapulmonary involvement. Calcium-phosphorus profile and antinuclear antibodies were not useful to establish the diagnosis.

Introducción: En Colombia son escasos los estudios epidemiológicos sobre la sarcoidosis; aunque recientemente se han publicado reportes del norte del país, son grupos muestrales pequeños, por lo que no quedan claras las asociaciones clínico-epidemiológicas. Nuestro objetivo fue caracterizar pacientes con sarcoidosis en la Fundación Valle del Lili, en Cali, Colombia. Métodos: Se realizó un estudio retrospectivo de una serie de casos de sarcoidosis entre el 2011 y el 2019. Se analizaron variables demográficas, clínicas, de laboratorio, imagenológicas, histopatológicas y de tratamiento. Resultados: Se encontraron 34 pacientes con diagnóstico de sarcoidosis, la mayoría fueron mujeres (n = 25; 73%), y la edad promedio fue 50 anos. Los principales síntomas de inicio fueron eritema nudoso (n = 11; 33%), artritis (n = 10; 30%) y tos (n = 9; 27%). En el 64% de los casos hubo compromiso pulmonar, y se encontraron nódulos pulmonares, adenopatías mediastinales y enfermedad pulmonar intersticial en un 54, 50 y 36% de los casos, respectivamente. En el 85% de los casos hubo manifestaciones extrapulmonares, principalmente cutáneas (50%). Los niveles de enzima conversora de angiotensina estuvieron elevados en el 62% de los casos en los que fue medida (n = 16; 47%). Durante el proceso diagnóstico se realizaron 23 biopsias, de las cuales el 95% evidenció granulomas con necrosis no caseificante. La mayoría de los pacientes (76%) fueron controlados con prednisolona, a una dosis promedio de 20 mg (7,5-50 mg) por día. Conclusiones: La sarcoidosis fue más frecuente en mujeres y mestizos. La presentación fue más temprana en hombres. La enzima conversora de angiotensina no se relacionó con compromiso extrapulmonar. Ni el perfil fósforo-calcio ni los anticuerpos antinucleares fueron útiles para establecer el diagnóstico.

The Epstein-Barr Virus Hacks Immune Checkpoints: Evidence and Consequences for Lymphoproliferative Disorders and Cancers.

The Epstein-Barr Virus (EBV) is a gammaherpesvirus involved in the etiopathogenesis of a variety of human cancers, mostly of lymphoid and epithelial origin. The EBV infection participates in both cell transformation and tumor progression, also playing an important role in subverting immune responses against cancers. The homeostasis of the immune system is tightly regulated by inhibitory mechanisms affecting key immune effectors, such as T lymphocytes and NK cells. Collectively known as immune checkpoints, these mechanisms rely on a set of cellular receptors and ligands. These molecules may be candidate targets for immune checkpoints blockade-an emergent and promising modality of immunotherapy already proven to be valuable for a variety of human cancers. The EBV was lately suspected to interfere with the expression of immune checkpoint molecules, notably PD-1 and its ligands, found to be overexpressed in cases of Hodgkin lymphoma, nasopharyngeal, and gastric adenocarcinomas associated with the viral infection. Even though there is compelling evidence showing that the EBV interferes with other immune checkpoint regulators (e.g., CTLA-4, LAG-3, TIM-3, and VISTA), the published data are still scarce. Herein, we discuss the current state of the knowledge on how the EBV interferes with the activity of immune checkpoints regulators, as well as its implications considering the immune checkpoints blockade for clinical management of the EBV-associated malignancies, notably lymphomas.

Anemia hemolítica autoimune na doença de Castleman multicêntrica: relato de caso / Autoimmune hemolytic anemia in multicentric Castleman's disease: case report

A doença de Castleman é um distúrbio linfoproliferativo raro, podendo se manifestar sob a forma de massas localizadas ou como doença multicêntrica. A doença de Castleman multicêntrica é caracterizada por adenopatias generalizadas, visceromegalias, manifestações autoimunes e infecções recorrentes. Este artigo apresenta o relato de caso de anemia hemolítica autoimune por anticorpos quentes em paciente com doença de Castleman multicêntrica. Resposta eficaz foi obtida com uso de corticoterapia sistêmica e tocilizumabe.

Castleman disease is a rare lymphoproliferative disorder that can manifest as localized masses or as multicentric disease. Multicentric Castleman disease is characterized by generalized adenopathies, visceromegaly, autoimmune manifestations, and recurrent infections. This article presents the case report of a patient with multicentric Castleman's disease and autoimmune hemolytic anemia by warm antibodies. Effective response was obtained with systemic corticotherapy and tocilizumab.

Linfoma renal primário em cão / Primary kidney lymphoma in a dog

Background: Lymphoma is a malignant lymphoid tumor originating in the lymph nodes or other solid organs and comprises90% of all hematopoietic tumors in dogs. However, primary kidney lymphoma is rare and is associated with nonspecificclinical signs. Tumor invasion in both kidneys can cause severe clinical signs due to renal failure, complicating the patientstreatment and prognosis. The aim of this case was to report the case of a dog affected by bilateral primary kidney lymphoma. In addition, to characterize the clinical and histopathological presentation due to the intense morphological changes.Case: A 5-year-old male Poodle dog was admitted showing apathy and emesis for 5 days. On physical examination, thedog showed 10% of dehydration, reddish oral mucous membranes, poor body condition (score 1/5), uremic breath, andpain in the kidney area. Complementary tests revealed severe low white blood cells count, high BUN levels, high levels ofpotassium, calcium, and phosphorus (serum biochemistry). Abdominal ultrasound showed bilateral kidney enlargement.Fine needle aspiration of the mass (guided by ultrasound) revealed round cell tumor. Radiographs showed no alterations.The dog died due to his poor condition and necropsy was performed. On post-mortem examination, the kidneys were bothenlarged, pale, and with an irregular subcapsular surface. The histopathological diagnostic was primary renal lymphoma.Immunohistochemical staining revealed that neoplastic cells were strongly positive for anti CD20 and PAX5, while negative for CD3, supporting the diagnosis of B-cell lymphoma.Discussion: The diagnosis was based on clinical, complementary tests, fine needle aspiration, histopathological andimmunohistochemical findings. In dogs, primary kidney tumors are uncommon and usually malignant. The presence ofvomiting, uremic breath, dehydration, weight loss, and erosive and ulcerative lesions on the tongue (uremic glossitis)...(AU)

Seropositivity for cytomegalovirus and PCR-EBV monitoring: Protective factors for posttransplant lymphoproliferative disorder in pediatric liver transplant.

BACKGROUND: PTLD is a clinical condition with high mortality. Monitoring EBV replication can be a useful tool to avoid the development of PTLD. MATERIALS AND METHODS: This was a retrospective analysis of 428 pediatric patients who underwent liver transplantation between 1989 and 2016. The patients were divided into 2 groups (transplanted before 2006, when PCR-EBV was not monitored, and after 2006, when PCR-EBV monitoring was started). Patients with continuous PCR measurements for EBV were evaluated for the impact of a reduction in immunosuppression or a change in immunosuppressants on the number of viral copies. A logistic regression model was applied to evaluate factors related to PTLD. RESULTS: The prevalence of PTLD was 4.2%. After monitoring patients with PCR for EBV levels, a predominance of the most severe, monomorphic form of lymphoproliferative disorder was observed (p = .009). The PTLD mortality was 5%. There was a change in the PCR level after tacrolimus reduction (p = .002) and after tacrolimus exchange for mTOR (p = .008). The number of EBV copies was significantly higher (p = .029) in patients who developed PTLD. In the multiple regression model, seropositivity for CMV was an independent protective factor for lymphoproliferative disorder (OR=0.09; 95% CI 0.02-0.42), reducing the chance of having PTLD adjusted by serology for EBV by 91%. CONCLUSIONS: Monitoring the EBV viral load by PCR seems to prevent the emergence of milder forms of lymphoproliferative disorder. Pretransplant seropositivity for CMV is a protective factor for PTLD.