Tubulointerstitial nephritis and uveitis syndrome and SARS-CoV-2 infection in an adolescent: just a coincidence in time?

BACKGROUND: Despite recent well-established kidney tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), usually presenting as acute kidney injury (AKI), there are few published cases with SARS-CoV-2-related tubulointerstitial nephritis (TIN). We report an adolescent with TIN and delayed association with uveitis (TINU syndrome), where SARS-CoV-2 spike protein was identified in kidney biopsy. CASE-DIAGNOSIS/TREATMENT: A 12-year-old girl was assessed for a mild elevation of serum creatinine detected during the evaluation of systemic manifestations including asthenia, anorexia, abdominal pain, vomiting, and weight loss. Data of incomplete proximal tubular dysfunction (hypophosphatemia and hypouricemia with inappropriate urinary losses, low molecular weight proteinuria, and glucosuria) were also associated. Symptoms had initiated after a febrile respiratory infection with no known infectious cause. After 8 weeks, the patient tested positive in PCR for SARS-CoV-2 (Omicron variant). A subsequent percutaneous kidney biopsy revealed TIN and immunofluorescence staining with confocal microscopy detected the presence of SARS-CoV-2 protein S within the kidney interstitium. Steroid therapy was started with gradual tapering. Ten months after onset of clinical manifestations, as serum creatinine remained slightly elevated and kidney ultrasound showed mild bilateral parenchymal cortical thinning, a second percutaneous kidney biopsy was performed, without demonstrating acute inflammation or chronic changes, but SARS-CoV-2 protein S within the kidney tissue was again detected. At that moment, simultaneous routine ophthalmological examination revealed an asymptomatic bilateral anterior uveitis. CONCLUSIONS: We present a patient who was found to have SARS-CoV-2 in kidney tissue several weeks following onset of TINU syndrome. Although simultaneous infection by SARS-CoV-2 could not be demonstrated at onset of symptoms, since no other etiological cause was identified, we hypothesize that SARS-CoV-2 might have been involved in triggering the patient's illness.

Evolución de tubulopatías renales primarias diagnosticadas en edad pediátrica / Outcome of primary tubular tubulopathies diagnosed in pediatric age

ANTECEDENTES Y OBJETIVO: Las tubulopatías primarias son raras y se presentan habitualmente en la edad pediátrica. Avances recientes en diagnóstico genético y tratamiento han cambiado su historia natural. Este estudio presenta el espectro clínico de una serie de tubulopatías primarias diagnosticadas en una Unidad de Nefrología Pediátrica y ofrece datos de seguimiento a largo plazo sobre crecimiento, filtrado glomerular estimado y complicaciones intercurrentes. PACIENTES Y MÉTODOS: Estudio observacional en 53 pacientes con tubulopatías primarias y defecto genético identificado: síndrome de Gitelman (36%), acidosis tubular renal distal (15%), cistinuria (11%), raquitismo hipofosfatémico ligado al X (7%), síndrome de Dent-Lowe (7%), cistinosis (6%), y uno o 2 casos de otras tubulopatías. Se recogieron datos demográficos, analíticos y clínicos al diagnóstico, durante la evolución y en el momento del estudio. RESULTADOS: La edad (mediana y rango intercuartílico) al diagnóstico fue de 5,08 años (1,33-8,50). Las manifestaciones de presentación más frecuentes fueron descompensaciones metabólicas asociadas a procesos intercurrentes (40%) y talla baja (38%). La talla (media ± DE) fue de -1,39 ± 1,49 al diagnóstico y 1,07 ± 1,54 tras un seguimiento de 18,92 (6,25-24,33) años. Dieciséis (32%) desarrollaron filtrado glomerular estimado < 90 mL/min/1,73 m2. Tres pacientes requirieron reemplazo renal sustitutivo. Once enfermos tuvieron descompensaciones metabólicas que requirieron hospitalización, 9 cólicos nefríticos y/o cálculos renales y 10 problemas mentales. Seis de 8 pacientes con acidosis tubular renal desarrollaron sordera neurosensorial. CONCLUSIONES: Las tubulopatías primarias son un grupo heterogéneo de enfermedades que ocasionan afectación del crecimiento, reversible en gran medida con tratamiento, riesgo de reducción de filtrado glomerular estimado e importantes complicaciones extrarrenales derivadas o asociadas

BACKGROUND AND OBJECTIVE: Primary tubulopathies are rare and usually present at pediatric age. Recent advances in genetic diagnosis and treatment have changed its natural history. This study provides the clinical spectrum of a series of primary tubulopathies diagnosed in a Pediatric Nephrology Unit and to offer long-term follow-up data regarding growth, estimated glomerular filtration and intercurrent complications. PATIENTS AND METHODS: Observational study in 53 patients with primary tubulopathies and identified genetic defect: Gitelman syndrome (36%), distal renal tubular acidosis (15%), cystinuria (11%), X-linked hypophosphatemic rickets (7%), Dent-syndrome Lowe (7%), cystinosis (6%), and 1-2 cases of other tubulopathies. Demographic, analytical and clinical data were collected at diagnosis, during evolution and at the time of the study. RESULTS: The age (median and interquartile range) at diagnosis was 5.08 years (1.33-8.50). The most frequent presentation manifestations were metabolic decompensations associated with intercurrent processes (40%) and short stature (38%). Height (mean±SD) was - 1.39 ± 1.49 at diagnosis and 1.07 ± 1.54 after a follow-up of 18.92 (6.25-24.33) years. Sixteen (32%) developed an estimated glomerular filtration < 90 ml / min / 1.73 m2. Three patients required replacement renal replacement. Eleven patients had metabolic decompensations that required hospitalization, 9 renal colic and / or kidney stones and 10 mental problems. Six of 8 patients with distal renal tubular acidosis developed sensorineural deafness. CONCLUSIONS: Primary tubulopathies are a heterogeneous group of diseases that cause growth impairment, largely reversible with treatment, risk of estimated glomerular filtration reduction and significant extrarenal complications derived or associated

Hipertensión arterial en el lactante. Un reto diagnóstico en pediatría / Infantile arterial hypertension: A diagnostic challenge in paediatrics

La prevalencia de la hipertensión arterial ha aumentado considerablemente en la edad pediátrica como consecuencia principal de su detección en niños mayores y adolescentes, en quienes predomina la causa esencial (primaria). En otras etapas de la edad pediátrica la HTA es menos frecuente, en especial en lactantes. En este grupo la hipertensión arterial obedece casi siempre a causas secundarias, en ocasiones potencialmente graves, por lo que resulta imprescindible detectarla, llevar a cabo un proceso diagnóstico etiológico adecuado y proporcionar al paciente un adecuado tratamiento, que suele requerir de un profesional especializado. A las dificultades técnicas propias de la medición de la presión arterial en los lactantes se añade la ausencia de recomendaciones específicas relacionadas con su identificación sistemática y de valores de normalidad bien establecidos en este rango de edad, por lo que su manejo constituye un reto diagnóstico y terapéutico para el profesional. A través de la exposición de 3 casos de hipertensión detectada en la etapa de lactante, se pretende sensibilizar al pediatra sobre esta enfermedad, así como proporcionar información sobre su orientación diagnóstica y terapéutica, incidiendo asimismo en las medidas farmacológicas

Arterial Hypertension prevalence (HTN) has significantly increased in paediatric patients, mainly in older children and teenagers. In these subjects the most common type is essential or primary HTN. However, in infants HTN prevalence is significantly lower and is almost always due to secondary causes, which can be potentially severe. Hence the importance of its detection, in order to establish an etiological diagnosis and provide an appropriate treatment, which usually requires a specialist physician. In addition to the technical difficulties of blood pressure measurement in infants, the lack of recommendations to perform a systematic screening in this age range and the absence of well-established normal values turns infancy-onset HTN into a diagnostic and therapeutic challenge for the physician. By means of the exposition of three infancy-onset HTN cases, the aim is to increase the paediatrician's awareness of this pathology and also to provide information about its diagnostic and therapeutic approach, dealing also with pharmacological measures of treatment

[Infantile arterial hypertension: A diagnostic challenge in paediatrics]. / Hipertensión arterial en el lactante. Un reto diagnóstico en pediatría.

Arterial Hypertension prevalence (HTN) has significantly increased in paediatric patients, mainly in older children and teenagers. In these subjects the most common type is essential or primary HTN. However, in infants HTN prevalence is significantly lower and is almost always due to secondary causes, which can be potentially severe. Hence the importance of its detection, in order to establish an etiological diagnosis and provide an appropriate treatment, which usually requires a specialist physician. In addition to the technical difficulties of blood pressure measurement in infants, the lack of recommendations to perform a systematic screening in this age range and the absence of well-established normal values turns infancy-onset HTN into a diagnostic and therapeutic challenge for the physician. By means of the exposition of three infancy-onset HTN cases, the aim is to increase the paediatrician's awareness of this pathology and also to provide information about its diagnostic and therapeutic approach, dealing also with pharmacological measures of treatment.

Outcome of primary tubular tubulopathies diagnosed in pediatric age. / Evolución de tubulopatías renales primarias diagnosticadas en edad pediátrica.

BACKGROUND AND OBJECTIVE: Primary tubulopathies are rare and usually present at pediatric age. Recent advances in genetic diagnosis and treatment have changed its natural history. This study provides the clinical spectrum of a series of primary tubulopathies diagnosed in a Pediatric Nephrology Unit and to offer long-term follow-up data regarding growth, estimated glomerular filtration and intercurrent complications. PATIENTS AND METHODS: Observational study in 53 patients with primary tubulopathies and identified genetic defect: Gitelman syndrome (36%), distal renal tubular acidosis (15%), cystinuria (11%), X-linked hypophosphatemic rickets (7%), Dent-syndrome Lowe (7%), cystinosis (6%), and 1-2 cases of other tubulopathies. Demographic, analytical and clinical data were collected at diagnosis, during evolution and at the time of the study. RESULTS: The age (median and interquartile range) at diagnosis was 5.08 years (1.33-8.50). The most frequent presentation manifestations were metabolic decompensations associated with intercurrent processes (40%) and short stature (38%). Height (mean±SD) was -1.39±1.49 at diagnosis and 1.07±1.54 after a follow-up of 18.92 (6.25-24.33) years. Sixteen (32%) developed an estimated glomerular filtration<90ml / min / 1.73m2. Three patients required replacement renal replacement. Eleven patients had metabolic decompensations that required hospitalization, 9 renal colic and / or kidney stones and 10 mental problems. Six of 8 patients with distal renal tubular acidosis developed sensorineural deafness. CONCLUSIONS: Primary tubulopathies are a heterogeneous group of diseases that cause growth impairment, largely reversible with treatment, risk of estimated glomerular filtration reduction and significant extrarenal complications derived or associated.