Síndrome de Reacción a drogas con Eosinofilia y Síntomas Sistémicos (DRESS) asociados a Nefritis Túbulo Intersticial Aguda en un adolescente / DRESS síndrome (Drug Reaction with Eosinophilia and Systemic Symptoms) associated with Tubulo Interstitial Nephritis in a adolescent

Resumen El síndrome de DRESS (Reacción a drogas con eosinofilia y síntomas sistémicos) es una patología poco frecuente en Pediatría, descrita por primera vez en 1996, por Bocquet. Puede presentarse en un tiempo variable luego de exposición a algunos medicamentos, se caracteriza por fiebre, compromiso cutáneo y de órganos internos. En este caso, se presenta a un paciente de 13 años, con antecedente de uso de Trimetroprim sulfa desde hace 2 meses, con cuadro de 3 días consistente en fiebre y rash cutáneo, sin compromiso de mucosas, con respuesta no favorable al manejo con esteroide, requiriendo Inmunoglobulina IV. Semanas después del inicio de los síntomas y evolución estable presenta insuficiencia renal aguda que requirió terapia de reemplazo renal. Se descartaron otras patologías subyacentes de índole autoinmune. Hubo recuperación de azoados y normalización de los demás paraclínicos el día 40 de la enfermedad. El paciente continúa asintomático, 4 meses después, con tratamiento con esteroide oral, en descenso lento y gradual. Se debe considerar la evaluación permanente de las pruebas de función renal en los pacientes que presenten Síndrome de DRESS, por su asociación con Nefritis intersticial aguda y complicaciones relacionadas.

Abstract DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms) is a rare pathology in Pediatrics, first described in 1996 by Bocquet. It can appear in a variable period of time after exposure to some medications, it is characterized by fever, skin involvement and internal organs. A 13-year-old patient is presented, with a history of use of Trimethoprim sulfa for two months, with a disease of three days of evolution, consisting of fever and skin rash, without mucosal involvement, with an unfavorable response to steroid management, requiring Intravenous inmunoglobulin. Weeks after the onset of symptoms and stable evolution, he presented acute renal failure that required renal replacement therapy. Other underlying autoimmune pathologies were ruled out. There was recovery of renal function test and normalization of the other paraclinical on day 40 of the disease. Patient remains asymptomatic four months later, with oral steroid treatment, in slow and gradual decline. Permanent evaluation of renal function tests should be considered in patients with DRESS syndrome, due to its association with acute tubulointerstitial nephritis and related complications.

Association of karyomegalic interstitial nephritis with focal segmental glomerulosclerosis

Karyomegalic interstitial nephritis (KIN), first described in 1974, is a rare form of chronic tubulointerstitial nephritis. It is defined by the presence of markedly enlarged, hyperchromatic nuclei with prominent nucleoli, mainly involving tubular epithelial cells of the kidney, accompanied by marked interstitial fibrosis. The disease presents as asymptomatic proteinuria, gradually progresses to chronic kidney disease and eventually leads to end-stage renal disease by 30-40 years. The etiology of the disease remains unclear; however, genetic risk factors and possible association with HLA (B27/35) is proposed by some. It has also been linked to FAN1 (FANCD2/FANC1- associated nuclease 1) mutation. Case Report We present two cases of KIN with associated focal segmental glomerulosclerosis. Both patients presented with nephrotic range proteinuria. The biopsies demonstrated marked enlargement of tubular nuclei (3-5x larger than the uninvolved tubular nuclei, a metric used by some authors in previous studies) in some tubules, meeting the diagnostic criteria of KIN.. Interestingly, case one had a prior biopsy that showed minimal change disease. In the biopsies done at our institution, H&E sections showed patchy tubular attenuation with readily recognizable tubular cell mitotic figures, indicating concurrent acute tubular injury. Electron microscopy showed diffuse podocyte foot process effacement, along with microvillous transformation, podocyte hypertrophy, and cytoplasmic vacuoles, suggesting podocyte injury. This cytoplasmic vacuolization was also observed in the tubular epithelial cells. In both cases, the injury factor appeared to target both podocytes and tubular cells.

Multiple myeloma presenting as acute tubulointerstitial nephritis

Background Acute tubulointerstitial nephritis (ATIN) is a very rare paraneoplastic manifestation in patients with multiple myeloma (MM). It is an uncommon pattern of renal disease in such patients. Case presentation We report a case of an 82-year-old male who was admitted with acute kidney injury. Renal biopsy showed typical findings of light chain-associated ATIN with scattered inflammatory cells in the interstitium and associated active tubulitis. No other common manifestations of MM were present at the time of presentation, including hypercalcemia, hyperuricemia, proteinuria, bone pain or lytic bone lesions. Subsequent immunoassays revealed significant serum lambda light chain burden and Bence Jones protein in urine. Immunofluorescence demonstrated linear tubular basement membranes with positive staining for lambda light chain (3+). Electron microscopy (EM) further showed interstitial edema and inflammation. All the aforementioned findings are consistent with ATIN and supported the diagnosis of MM. Conclusions In conclusion, light chain-associated ATIN should be considered in the differential diagnosis of acute interstitial nephritis. Henceforth, serum free light chains as well as serum and urine protein electrophoresis should be included in the workup of such patients.

Nefritis tubulointersticial aguda. Revisión bibliográfica / Acute interstitial nephritis. Literature review

RESUMEN La nefritis tubulointersticial aguda hace referencia a un tipo de daño renal que afecta principalmente el intersticio y ocasiona la lesión renal aguda, potencialmente reversible. Su curso puede ser subclínico, con deterioro progresivo hasta evolucionar hacia la insuficiencia renal crónica. La nefritis tubulointersticial aguda tiene múltiples etiologías, las más frecuentes son los medicamentos, productos herbales, las infecciones y las enfermedades autoinmunes. Las principales manifestaciones clínicas son la poliuria, polaquiuria, nocturia, dolor lumbar, microhematuria y leucocituria, aunque puede ser totalmente asintomática. El tratamiento depende de la causa de base y los esteroides juegan un papel importante cuando la condición es de origen medicamentoso o autoinmune. El pronóstico generalmente es bueno, si el problema se identifica de forma oportuna y se trata adecuadamente.

SUMMARY Acute tubulointerstitial nephritis is a kidney lesion that mainly affects the interstitium and can lead to a reversible acute kidney injury. It can progress subclinically, with progressive development towards chronic renal failure. Acute tubulointerstitial nephritis has several causes, being the most common medications, herbal products, infections and autoimmune diseases. The main clinical manifestations are polyuria, polaquiuria, nycturia, lumbar pain, microhematuria, leukocyturia, although the patients also can be completely asymptomatic. Treatment is determined by the underlying cause. Steroids play an important role when tubulointerstitial nephritis is caused by medication or autoimmune diseases. The prognosis is usually good if the problem is detected early and treated properly.

Pathophysiological aspects of nephropathy caused by non-steroidal anti-inflammatory drugs / Aspectos fisiopatológicos da nefropatia por anti-inflamatórios não esteroidais

Abstract Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used medications associated with nephrotoxicity, especially when used chronically. Factors such as advanced age and comorbidities, which in themselves already lead to a decrease in glomerular filtration rate, increase the risk of NSAID-related nephrotoxicity. The main mechanism of NSAID action is cyclooxygenase (COX) enzyme inhibition, interfering on arachidonic acid conversion into E2 prostaglandins E2, prostacyclins and thromboxanes. Within the kidneys, prostaglandins act as vasodilators, increasing renal perfusion. This vasodilatation is a counter regulation of mechanisms, such as the renin-angiotensin-aldosterone system works and that of the sympathetic nervous system, culminating with compensation to ensure adequate flow to the organ. NSAIDs inhibit this mechanism and can lead to acute kidney injury (AKI). High doses of NSAIDs have been implicated as causes of AKI, especially in the elderly. The main form of AKI by NSAIDs is hemodynamically mediated. The second form of NSAID-induced AKI is acute interstitial nephritis, which may manifest as nephrotic proteinuria. Long-term NSAID use can lead to chronic kidney disease (CKD). In patients without renal diseases, young and without comorbidities, NSAIDs are not greatly harmful. However, because of its dose-dependent effect, caution should be exercised in chronic use, since it increases the risk of developing nephrotoxicity.

Resumo Os anti-inflamatórios não esteroidais (AINEs) são medicamentos comumente utilizados, associados à nefrotoxicidade, sobretudo quando utilizados cronicamente. Fatores como idade avançada e comorbidades, que por si só já levam à diminuição da taxa de filtração glomerular, aumentam o risco de nefrotoxicidade dos AINEs. O principal mecanismo de ação dos AINEs é a inibição da enzima ciclooxigenase (COX), interferindo na conversão do ácido araquidônico em prostaglandinas E2, prostaciclinas e tromboxanos. Nos rins, as prostaglandinas atuam como vasodilatadoras, aumentando a perfusão renal. Essa vasodilatação atua como uma contrarregulação de mecanismos, como a atuação do sistema renina-angiotensina-aldosterona e do sistema nervoso simpático, culminando com uma compensação para assegurar o fluxo adequado ao órgão. O uso de AINEs inibe esse mecanismo, podendo causar lesão renal aguda (LRA). Altas doses de AINEs têm sido implicadas como causas de LRA, especialmente em idosos. A principal forma de LRA por AINEs é a hemodinamicamente mediada. A segunda forma de apresentação da LRA induzida por AINES é a nefrite intersticial aguda, que pode se manifestar com proteinúria nefrótica. O uso de AINEs em longo prazo pode ocasionar doença renal crônica (DRC). Nos pacientes sem doenças renais, jovens e sem comorbidades, os AINEs não apresentam grandes malefícios. Entretanto, por seu efeito dose-dependente, deve-se ter grande cautela no uso crônico, por aumentar risco de desenvolver nefrotoxicidade.

Pielonefritis y nefritis intersticial / Pyelonephritis and interstitial nephritis

La pielonefritis aguda es una infección frecuente que puede progresar a absceso o pielonefritis enfisematosa (PE); la mayoría de los casos se produce por Escherichia coli. La presentación clínica puede oscilar desde síntomas leves hasta septicemia. La posibilidad de bacteremia depende de factores del huésped: pacientes gravemente enfermos, inmunocomprometidos, con obstrucción del tracto urinario y mayores de 65 años. Más del 90% de PE se presenta en pacientes con diabetes. La nefritis intersticial afecta el intersticio renal, puede ser aguda o crónica, la mayoría de las veces debido a AINES o antibióticos. Ambas patologías son predominantes en mujeres

Acute pyelonephritis is a frequent infection that can progress to abscess or emphysematous pyelonephritis (EP); most cases are caused by Escherichia coli. The clinical onset can range from mild symptoms to septicemia. The possibility of bacteremia depends on host factors: patients who are seriously ill, immunocompromised, with urinary tract obstruction and >65 years of age. More than 90% of EP occurs in patients with diabetes. Interstitial nephritis affecting the renal interstitium, can be acute or chronic, in most cases due to NSAIDs or antibiotics. Both pathologies are predominant in women

Renal and Urinary Manifestations of Inflammatory Bowel Disease / 대한소화기병학회잡지

The incidence of inflammatory bowel disease (IBD) is increasing rapidly and extra-intestinal manifestations in IBD are also increasing. The prevalence of renal and urinary involvement in IBD ranges from 4–23%. Nephrolithiasis is the most common urinary complication in IBD patients. Parenchymal renal disease is rare but has been well documented and presents most commonly as glomerulonephritis or tubulointerstitial nephritis. The overall morbidity of IBD-related renal manifestations is significant. Therefore, a high index of clinical suspicion and optimal monitoring of the renal function are needed for the early diagnosis and prevention of IBD-related renal manifestations and complications.

Acute kidney injury associated with Yersinia pseudotuberculosis infection: Forgotten but not gone

BACKGROUND: Yersinia pseudotuberculosis is known to cause fever, gastroenteritis, or acute kidney injury (AKI). There have been several Y. pseudotuberculosis infection outbreaks to date associated with ingestion of contaminated food or unsterile water. While this disease was considered to have practically been eradicated with the improvement in public health, we encountered several cases of AKI associated with Yersinia infection. METHODS: We retrospectively collected data from medical records of patients with suspected Y. pseudotuberculosis infection who visited Seoul National University Children’s Hospital in 2017. RESULTS: There were nine suspected cases of Yersinia infection (six males and three females; age range 2.99–12.18 years). Among them, five cases occurred in May, and seven patients were residing in the metropolitan Seoul area. Three patients had history of drinking mountain water. Every patient first presented with fever for a median of 13 days, followed by gastrointestinal symptoms and oliguria. Imaging studies revealed mesenteric lymphadenitis, terminal ileum wall thickening, and increased renal parenchymal echogenicity. Creatinine levels increased to 5.72 ± 2.18 mg/dL. Urinalysis revealed sterile pyuria, proteinuria, and glycosuria. Oliguria continued for 4 to 17 days, and two patients required dialysis; however, all of them recovered from AKI. Mucocutaneous manifestations developed later. In the diagnostic work-up, Yersinia was isolated from the stool culture in one patient. Anti-Yersinia immunoglobulin (Ig) A and IgG were positive in 6 patients. CONCLUSION: Y. pseudotuberculosis infection is an infrequent cause of interstitial nephritis presenting with AKI. When a patient presents with fever, gastroenteritis, and AKI not resolving despite hydration, the clinician should suspect Y. pseudotuberculosis infection.

Renal and Urinary Manifestations of Inflammatory Bowel Disease / 대한소화기학회지

The incidence of inflammatory bowel disease (IBD) is increasing rapidly and extra-intestinal manifestations in IBD are also increasing. The prevalence of renal and urinary involvement in IBD ranges from 4–23%. Nephrolithiasis is the most common urinary complication in IBD patients. Parenchymal renal disease is rare but has been well documented and presents most commonly as glomerulonephritis or tubulointerstitial nephritis. The overall morbidity of IBD-related renal manifestations is significant. Therefore, a high index of clinical suspicion and optimal monitoring of the renal function are needed for the early diagnosis and prevention of IBD-related renal manifestations and complications.

Protocolos de Vigilancia Centinela de enfermedad renal crónica y manual de registro guatemalteco de diálisis y trasplante renal. No. 12 / Sentinel Surveillance Protocols of chronic kidney disease and manual of Guatemalan dialysis and renal transplantation. No. 12

Estos protocolos están dirigido a personal médico, paramédico y otros profesionales que realizan acciones gerenciales y operativas de vigilancia epidemiológica en los servicios de salud del país, y están divididos en varios tomos para dar a conocer y actualizar la identificación y medidas de control para diversos padecimientos a fin de continuar con el mejoramiento de las capacidades técnicas de los trabajadores de salud, que permita planificar la prestación de servicios con decisiones partiendo de un enfoque epidemiológico comprobado, para responder a los cambios de tendencias epidemiológicas y con ello contribuir al fortalecimiento de prácticas asertivas de la salud pública de nuestro país. Por otra parte, en el documento se afirma que "en el marco de la "Reunión de Alto Nivel sobre Enfermedad Renal Crónica de Causas no Tradicionales en Centroamérica" (ERCnT), celebrada en abril del 2013, los Estados Miembros de Centroamérica y la República Dominicana, que forman parte del Sistema de la Integración Centroamericana (SICA) y la Comisión de Ministros de Salud de Centroamérica y República Dominicana (COMISCA) a través de la "Declaración de San Salvador" reconocen que la enfermedad renal crónica es un problema de salud pública importante en Centroamérica y requiere de una acción urgente."

Tubulointerstitial nephritis and uveitis syndrome in children: report of three cases / Nefrite tubulointersticial e uveíte em idade pediátrica: descrição de três doentes

ABSTRACT Tubulointerstitial nephritis and uveitis syndrome is a rare and probably underdiagnosed condition. Renal and ocular manifestations may not occur simultaneously, making the diagnosis more difficult. Nephritis may be asymptomatic; therefore, renal function evaluation is essential for diagnosis. Urinary β2-microglobulin levels may be particularly useful. Uveitis, mostly anterior, nongranulomatous and bilateral, occurs usually after the onset of nephritis. Treatment includes corticosteroids and, eventually, other immunosuppressant agents. Renal disease is usually benign and resolves spontaneously or after treatment with systemic corticosteroids. Uveitis, however, may be chronic or recurrent. The authors described the cases of three pediatric patients diagnosed with tubulointerstitial nephritis and uveitis syndrome. The goal of this paper was to warn the medical community over the need to screen patients with uveitis for renal disease.

RESUMO A síndrome nefrite tubulointersticial e uveíte é uma doença rara, provavelmente subdiagnosticada. As manifestações renais e oculares podem não ocorrer simultaneamente, tornando o diagnóstico mais difícil. A nefrite é geralmente assintomática, tornando fundamental a avaliação da função renal em doentes com uveíte. O doseamento da excreção urinária de β2-microglobulina é particularmente útil para o diagnóstico. A uveíte, tipicamente anterior, não granulomatosa e bilateral, manifesta-se após a nefrite na maioria dos casos. O tratamento inclui corticoides e, por vezes, outros imunossupressores. A doença renal tem evolução benigna, resolvendo-se espontaneamente ou com terapêutica com corticoides sistêmicos na maioria dos casos, no entanto, a uveíte pode ser crônica ou recorrente. Os autores descrevem três casos de síndrome nefrite tubulointersticial e uveíte, diagnosticados em idade pediátrica, e pretendem alertar para a necessidade de pesquisar sempre alterações renais nos doentes com uveíte.

Acute kidney injury in childhood-onset nephrotic syndrome: Incidence and risk factors in hospitalized patients

BACKGROUND: Nephrotic syndrome (NS) is the most common glomerulopathy in children. Acute kidney injury (AKI) is a common complication of NS, caused by severe intravascular volume depletion, acute tubular necrosis, interstitial nephritis, or progression of NS. However, the incidence and risk factors of childhood-onset NS in Korea are unclear. Therefore, we studied the incidence, causes, and risk factors of AKI in hospitalized Korean patients with childhood-onset NS. METHODS: We conducted a retrospective review of patients with childhood-onset NS who were admitted to our center from January 2015 to July 2017. Patients with decreased renal function or hereditary/secondary NS, as well as those admitted for management of other conditions unrelated to NS, were excluded. RESULTS: During the study period, 65 patients with idiopathic, childhood-onset NS were hospitalized 90 times for management of NS or its complications. Of these 90 cases, 29 met the Kidney Disease Improving Global Outcomes criteria for AKI (32.2%). They developed AKI in association with infection (n = 12), NS aggravation (n = 11), dehydration (n = 3), and intravenous methylprednisolone administration (n = 3). Age ≥ 9 years at admission and combined use of cyclosporine and renin-angiotensin system inhibitors were risk factors for AKI. CONCLUSION: AKI occurred in one-third of the total hospitalizations related to childhood-onset NS, owing to infection, aggravation of NS, dehydration, and possibly high-dose methylprednisolone treatment. Age at admission and use of nephrotoxic agents were associated with AKI. As the AKI incidence is high, AKI should be considered during management of high-risk patients.

Disseminated adenovirus infection in a 10-year-old renal allograft recipient

Disseminated adenovirus infection can result in high mortality and morbidity in immunocompromised patients. Here, we report the case of a 10-year-old renal allograft recipient who presented with hematuria and dysuria. Adenovirus was isolated from his urine. His urinary symptoms decreased after intravenous hydration and reduction of immunosuppressants. However, 2 weeks later he presented with general weakness and laboratory tests indicated renal failure necessitating emergency hemodialysis. Adenovirus was detected in his sputum; therefore, intravenous ganciclovir and immunoglobulin therapy were initiated. Renal biopsy revealed diffuse necrotizing granulomatous tubulointerstitial nephritis compatible with renal involvement of the viral infection. Adenovirus was detected in his serum. Despite cidofovir administration for 2 weeks, adenovirus was also detected in the cerebrospinal fluid, resulting in generalized tonic-clonic seizure. The patient died 7 weeks after the onset of urinary symptoms. Adenovirus should be considered in screening tests for post-renal transplantation patients who present with hemorrhagic cystitis.

Membranoproliferative glomerulonephritis in a patient with chronic brucellosis

Brucellosis is the most common zoonotic disease in Greece, with an endemic distribution and can affect any organ. Infiltration of the renal parenchyma causes acute and chronic interstitial nephritis with granulomas, whereas renal glomeruli are rarely affected. The disease has been sporadically reported, and it causes various histopathologic patterns. Herein, we describe the case of a 39-year-old stock breeder with a history of recurrent episodes of bacteremia caused by Brucella melitensis over a period of 3 years. Two months after the last episode of bacteremia, he presented with mild renal insufficiency, nephrotic range proteinuria, and microscopic hematuria. A renal biopsy revealed membranoproliferative glomerulonephritis with a pattern of focal-segmental nodular sclerosis and moderate tubulointerstitial fibrosis. The patient received antimicrobial and corticosteroid therapy with partial remission of the nephrotic syndrome.

Interstitial Nephritis Caused by Anorexia Nervosa in Young Male; A Case Report and Literature Review

Severe eating disorders characterized by repetitive episodes of purging and vomiting can occasionally trigger acute kidney injury. However, interstitial nephritis induced by episodes of repeated vomiting has rarely been reported, and the pathophysiology of this entity remains unknown. A 26-year-old man was admitted to our hospital because of known hypokalemia. His serum electrolyte profile showed: sodium 133 mEq/L, potassium 2.6 mEq/L, chloride 72 mEq/L, total carbon dioxide 50 mEq/L, blood urea nitrogen/creatinine ratio (BUN/Cr) 21.9/1.98 mg/dL, and magnesium 2.0 mg/dL. Arterial blood gas analysis showed: pH 7.557, partial pressure of carbon dioxide 65.8 mmHg, and bicarbonate 58.5 mEq/L. His urinary potassium concentration was 73.2 mEq/L, and Cr was 111 mg/dL. Renal biopsy revealed acute tubular necrosis and tubulointerstitial nephritis with a few shrunken glomeruli. Repeated psychogenic vomiting may precipitate acute kidney injury and interstitial nephritis secondary to volume depletion and hypokalemia. Serum electrolyte levels and renal function should be carefully monitored in patients diagnosed with eating disorders to prevent tubular ischemia and interstitial nephritis.

Baicalein alleviates tubular-interstitial nephritis in vivo and in vitro by down-regulating NF-κB and MAPK pathways

Tubular-interstitial nephritis (TIN) is characterized by tubular cell damage and inflammatory lesions of kidneys. Baicalein (BAI) is a flavonoid compound found in the roots of Scutellaria baicalensis Georgi. The present study was undertaken to explore the anti-inflammatory and anti-oxidative effects of BAI on TIN patients and a lipopolysaccharide (LPS)-induced TIN cell model. The expression levels of interleukin-6 (IL-6), IL-10, and tumor necrosis factor α in serum samples of TIN patients and culture supernatants of renal proximal tubular epithelial cells (RPTECs) were evaluated using enzyme-linked immunosorbent assay. Creatinine clearance was calculated using the Cockcroft-Gault equation. Activities of malondialdehyde, superoxide dismutase, and glutathione peroxidase were also determined. Viability and apoptosis of RPTECs were measured using MTT assay and Guava Nexin assay, respectively. qRT-PCR was performed to determine the expressions of Bax, Bcl-2, nuclear factor kappa B (IκBα), and p65. Protein levels of Bax, Bcl-2, IκBα, p65, c-Jun N-terminal kinase, extracellular regulated protein kinases, and p38 were analyzed using western blotting. We found that BAI reduced inflammation and oxidative stress in vivo and in vitro. Moreover, BAI alleviated the LPS-induced RPTECs viability inhibition and apoptosis enhancement, as well as nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) activation. Phorbol ester, an activator of NF-κB, attenuated the effects of BAI on LPS-induced inflammatory cytokine expressions in RPTECs. In conclusion, BAI had anti-inflammatory and anti-oxidative effects on TIN patients and LPS-induced RPTECs by down-regulating NF-κB and MAPK pathways.

Granulomatous intersticial nephritis secondary to sarcoidosis / Nefrite intersticial granulomatose secundária a sarcoidose

ABSTRACT Introduction: Granulomatous interstitial nephritis is a rare condition, in which renal involvement is uncommon. Its etiology is variable, and may be medicinal, infectious or inflammatory origin. Case report: This is a 65-year-old male patient with renal lesions of unknown etiology, associated with hypercalcaemia. During the investigation, cardiac insufficiency with diastolic dysfunction and interstitial lung involvement on chest tomography were evidenced. Renal function (glomerular filtration rate) has partially improved with clinical measures. Renal biopsy was performed, which showed moderate interstitial lesion with tuberculoid granulomas without caseous necrosis. Conclusion: The objective of the article was to describe a case of NIG and to alert to the importance of its clinical investigation. In this case, renal biopsy, associated with systemic clinical manifestations, contributed to the diagnosis of sarcoidosis.

RESUMO Introdução: a nefrite intersticial granulomatosa é uma condição rara, na qual o envolvimento renal é incomum. Sua etiologia é variável e pode ter origem medicinal, infecciosa ou inflamatória. Relato de caso: trata-se de um paciente do sexo masculino, com 65 anos de idade, com lesões renais de etiologia desconhecida, associadas à hipercalcemia. Durante a investigação, evidenciaram-se insuficiência cardíaca com disfunção diastólica e envolvimento pulmonar intersticial à tomografia torácica. A função renal (taxa de filtração glomerular) melhorou parcialmente com medidas clínicas. Foi realizada biópsia renal, que apresentou lesão intersticial moderada com granulomas tuberculoides sem necrose caseosa. Conclusão: o objetivo do artigo foi descrever um caso de GIN e alertar para a importância de sua investigação clínica. Neste caso, a biópsia renal, associada a manifestações clínicas sistêmicas, contribuiu para o diagnóstico de sarcoidose.

Daño renal agudo secundario a nefritis tubulointersticial aguda por uso de medicamentos. Caso clínico / Acute renal damage secondary to acute tubulointerstitial nephritis drug use. Case report

Resumen Introducción: La nefritis tubulointersticial aguda (NTIA) es infrecuente en la edad pediátrica. Se caracteriza por la infiltración del parénquima renal por células mononucleares y/o polinucleares con afectación secundaria de los túbulos sin lesión glomerular, y puede ser producida por infecciones, enfermedades inmunológicas, fármacos, o ser de origen idiopático. Objetivo: Describir un caso de NTIA secundario a antiinflamatorios no esteroidales (AINE) en un lactante, con énfasis en esta aso ciación para ser considerada por los pediatras. Caso clínico: Lactante de 10 meses, sin antecedentes previos, trasladada a nuestro hospital por daño renal agudo estadio 3, clasificación KDIGO 2012. Los tres días previos recibió tratamiento con amoxicilina e ibuprofeno por otitis media aguda. En la exploración física destacaba leve edema palpebral con presión arterial normal. En la orina presentaba proteinuria no nefrótica con componente tubular, microhematuria y leucocituria. La ecografía renal no mostraba alteraciones. Ante la sospecha de NTIA se cambió el antibiótico a cefotaxima intrave nosa y se suspendió el ibuprofeno realizándose manejo conservador del daño renal agudo. Presentó aumento de la creatinina (4.14 mg/dL) y eosinofilia, siendo el estudio inmunológico negativo. Se trató con metilprednisolona, con normalización de la función renal. Conclusión: La NTIA se puede producir por cualquier medicamento mediante una reacción inmunológica idiosincrásica. Entre los medicamentos responsables se identifican fármacos de uso frecuente en la edad pediátrica, como los AINEs, por lo que se necesita una alta sospecha diagnóstica por parte de los pediatras.

Abstract Introduction: Acute tubulointerstitial nephritis (ATIN) is a rare entity in the pediatric age. It is de fined by the infiltration of the renal parenchyma by mononuclear and/or polynuclear cells with se condary involvement of the tubules, without glomerular injury. It can be triggered by infections or immunological diseases, drugs like NSAIDs or be of idiopathic origin. Objective: To raise awareness among pediatricians about the prescription of NSAIDs, especially to patients of less than a year old, since they can provoke renal damage. Case report: A ten month old child, with no nephrological an tecedents of interest, was transferred to our hospital due to acute renal failure stage 3 KDIGO 2012. The three previous days received treatment with amoxicillin and ibuprofen for acute otitis media. Physical examination revealed mild eyelid edema with normal blood pressure. In the urine analysis, there were non-nephrotic proteinuria with tubular component, microhematuria and leukocyturia. Renal ultrasound showed no abnormalities. ATIN was suspected and so the antibiotic was changed to intravenous cefotaxime and ibuprofen was discontinued, opting for conservative management of acute renal damage. There was an increase in the number of creatinine up to 4.14 mg/dL and eosinophilia, with the immunological study being negative. Treatment with methylprednisolone was initiated, achieving normalization of renal function. Discussion: NTIA can be produced by any me dication through an idiosyncratic immune reaction. Among the responsible drugs, there are ones commonly used in the pediatric age, such as NSAIDs. Therefore, the pediatricians should pay special attention during prescriptions and have a high diagnostic suspicion of this disease.