Mielitis transversa aguda asociada con infección por SARS-CoV-2 / Acute Transverse Myelitis Associated to SARS-CoV-2 Infection

Resumen Además de provocar problemas respiratorios, la infección con el SARS-CoV-2 puede causar un espectro amplio de complicaciones neurológicas como son cefalea, ageusia, anosmia, encefalopatía, enfermedad cerebrovascular, síndrome de Guillain-Barré y otras polineuropatías, meningoencefalitis, encefalopatía hemorrágica necrotizante aguda y síndromes del sistema nervioso central asociados a inflamación. En esta revisión presentamos 39 casos de mielitis transversa aguda (MTA) asociados a infección por el SARS-CoV-2, confirmado por una prueba de reacción en cadena de la polimerasa (PCR) por hisopado nasofaríngeo y/o de antígeno en plasma. Los análisis bioquímicos de los pacientes confirmaron la ausencia de otros patógenos y de autoanticuerpos involucrados en inflamación del sistema nervioso, excepto por 2 casos, uno con autoanticuerpos contra la glicoproteína de la mielina de los oligodendrocitos (anti-MOG IgG) y otro con anti-MOG IgG y antidescarboxilasa del ácido glutámico (anti-GAD65), indicativos de una enfermedad autoinmune del sistema nervioso central. Los estudios de imagenología de resonancia magnética (RMN) confirmaron el diagnóstico de MTA. Aunque no se puede inferir causalidad, es muy probable que los casos aislados de MTA sean consecuencia de un proceso para o postinfeccioso en la COVID-19. La comprensión de los mecanismos que desencadenan estos trastornos neurológicos durante o al final de la infección viral, ayudarán a optimizar las estrategias terapéuticas para el manejo del paciente.

Abstract In addition to causing respiratory problems, SARS-CoV-2 can cause a wide spectrum of neurological complications such as headaches, ageusia, anosmia, encephalopathy, cerebrovascular disease, Guillain-Barré syndrome and other polyneuropathies, meningoencephalitis, acute necrotizing hemorrhagic encephalopathy, and central nervous system syndromes associated with inflammation. In this review we present 39 cases of acute transverse myelitis (ATM) associated to SARS-CoV-2 infection. All cases had a positive polymerase chain reaction (PCR) nasopharyngeal swab and/or antigen test. Biochemical analyses confirmed the absence of other pathogens and autoantibody-mediated neuroinflammatory disease, except for two cases, one with autoantibodies against the oligodendrocyte myelin glycoprotein (anti-MOG IgG) and another with anti-MOG IgG and anti-glutamic acid decarboxylase (anti-GAD65). Magnetic Resonance Imaging (MRI) studies confirmed the diagnosis of ATM. Although causality cannot be inferred, it is likely that isolated cases of ATM are the consequence of a para or post-infectious process in SARS-CoV-2. In this work, the probable causes of ATM associated with SARS-CoV-2 are discussed. The understanding of the mechanisms behind these neurological disorders triggered by a viral infection will help to optimize the therapeutic strategies for patient management.

Acidosis tubular renal distal en dos niñas diagnosticadas de hipotiroidismo adquirido / Distal renal tubular acidosis in two children with acquired hypothyroidism

Se presentan dos casos en edad pediátrica diagnosticados de acidosis tubular renal (ATR) asociada a hipotiroidismo de causa autoinmune. El caso 1 desarrolló un íleo intestinal a los 5 años de edad en el seno de un problema respiratorio. En los exámenes realizados se constató acidosis metabólica, hipercloremia, hipopotasemia y nefrocalcinosis. El caso 2 fue diagnosticado de hipotiroidismo a los 11 años de edad y 2 años después, de ATR. En ambos pacientes, se comprobó el diagnóstico de ATR al observarse una pCO2 urinaria máxima reducida. En el caso 2 se constató, además, una fuga proximal de bicarbonato (ATR tipo 3), que constituye el primer caso publicado sobre el tema. Se revisan las causas de ATR en pacientes con hipotiroidismo. El efecto deletéreo sobre el riñón puede ser debido a la propia ausencia de hormona tiroidea y/o a los autoanticuerpos en los casos de hipotiroidismo autoinmune

Two cases of children diagnosed with renal tubular acidosis (RTA) associated with autoimmune hypothyroidism are presented. Case 1 developed an intestinal ileus at the age of five in the context of a respiratory problem. The tests performed confirmed metabolic acidosis, hyperchloraemia, hypokalaemia and nephrocalcinosis. Case 2 was diagnosed with hypothyroidism at the age of 11, and with RTA two years later. In both patients, the diagnosis of RTA was verified when decreased maximum urinary pCO2 was found. In case 2, a proximal bicarbonate leak (type 3 RTA) was also confirmed. This was the first case to be published on the topic. The causes of RTA in patients with hypothyroidism are reviewed. The deleterious effect on the kidneys may be due to the absence of thyroid hormone and/or autoantibodies in the cases of autoimmune hypothyroidism

Distal renal tubular acidosis in two children with acquired hypothyroidism. / Acidosis tubular renal distal en dos niñas diagnosticadas de hipotiroidismo adquirido.

Two cases of children diagnosed with renal tubular acidosis (RTA) associated with autoimmune hypothyroidism are presented. Case 1 developed an intestinal ileus at the age of five in the context of a respiratory problem. The tests performed confirmed metabolic acidosis, hyperchloraemia, hypokalaemia and nephrocalcinosis. Case 2 was diagnosed with hypothyroidism at the age of 11, and with RTA two years later. In both patients, the diagnosis of RTA was verified when decreased maximum urinary pCO2 was found. In case 2, a proximal bicarbonate leak (type 3 RTA) was also confirmed. This was the first case to be published on the topic. The causes of RTA in patients with hypothyroidism are reviewed. The deleterious effect on the kidneys may be due to the absence of thyroid hormone and/or autoantibodies in the cases of autoimmune hypothyroidism.

Distal Renal Tubular Acidosis Screening by Urinary Acidification Testing in Mexican Children.

BACKGROUND: Primary distal renal tubular acidosis is a clinical disorder characterized by hyperchloremic metabolic acidosis, hypercalciuria, hypocitraturia, urinary acidification impairment, hypokalemia, metabolic bone disease, and nephrocalcinosis. Urinary acidification ability may be evaluated by an acidification test or maximum urinary pCO2 assessment with alkaline urine. The maximum urinary pCO2 test using acetazolamide and sodium bicarbonate is an easy test to confirm the lack of urine acidification in distal renal tubular acidosis in children. OBJECTIVE: To determine the urinary acidification ability using the maximum urinary pCO2 assessment in a group of children with a distal renal tubular acidosis diagnosis. MATERIAL AND METHODS: Thirty children were evaluated (13 males and 17 females); 23 children had been diagnosed with distal renal tubular acidosis by other physicians and were under alkali treatment with potassium and sodium citrates (21) and bicarbonate (2), and five children were not under alkali treatment. Two children had been diagnosed with primary distal renal tubular acidosis by our medical group. The maximum urinary pCO2 was determined by the oral intake of acetazolamide and sodium bicarbonate. RESULTS: Two cases with primary distal renal tubular acidosis were found, and they had a history of dehydration episodes during infancy and showed hyperchloremic metabolic acidosis with hypokalemia. They also exhibited urine acidification impairment with furosemide and reduced urinary pCO2 (< 60 mmHg), and the urine-blood pCO2 gradient was reduced in both cases (< 30 mmHg). One of them developed bilateral sensorineural deafness, while the other showed severe hypocitraturia. One case of proximal or type 2 renal tubular acidosis with hyperaminoaciduria was identified. Twenty-eight children displayed normal urinary acidification and did not show signs of distal renal tubular acidosis. CONCLUSIONS: The urinary acidification test with furosemide and urinary pCO2 assessment are reliable tests to identify the renal excretion of hydrogen ions (H+) and allow confirmation of the lack of urine acidification in distal renal tubular acidosis.

Clinical and biochemical findings in Mexican patients with distal renal tubular acidosis.

INTRODUCTION: Renal tubular acidosis (RTA) is a rare disease characterized by a normal serum anion gap, sustained metabolic acidosis, low concentration of plasma bicarbonate, variable hyperchloremia and hypokalemia and conserved glomerular filtration rate. RTA is developed during the first year of life and produces failure to thrive and anorexia. Primary distal RTA (type 1) is a renal syndrome with a reduced ability to excrete the acid load through the collecting ducts and impairment to concentrate the urine causing polyuria and dehydration. OBJECTIVE: Evaluate the current health status and describe the clinical findings and progress of Mexican patients with distal RTA. Demonstrate the distal urinary acidification defect by measuring the urinary pCO2 tension in alkaline urines. MATERIAL AND METHODS: We looked for infants in tertiary care hospitals with a clinical history of normal serum anion gap, metabolic acidosis, hypokalemia, hyperchloremia, nephrocalcinosis, sensorineural hearing loss and inability for urine acidification under systemic metabolic acidosis. Biochemical analysis were performed periodically. Alkali medication was not suspended in one patient to assess urinary acidification with oral administration of sodium bicarbonate (2 mEq/Kg) and acetazolamide (500 mg/1.73 m2 body surface). Urinary pCO2 levels were determined at 60 and 90 min. RESULTS: Three children, one adolescent and one adult with distal RTA were found. They had an infant history of dehydration, failure to thrive, anorexia, vomiting, muscle paralysis, hypercalciuria, urinary infections, polyuria, polydipsia and polyhidramnios during pregnancy. Severe nephrocalcinosis was detected in all patients whereas sensorineural hearing loss was developed in four cases. Under the alkali medication all cases but one were normocalciuric. A patient developed kidney failure. The urinary acidification test confirmed the innability to eliminate the acid load. CONCLUSION: Early diagnosis in infancy and continuos alkali medication were of great benefit for most of the patients. Urinary pCO2 levels in alkaline urine provided an index for collecting duct hydrogen-ion secretion. To our knowledge this is the first report of mexican patients with distal RTA.