Carnitine palmitoyl transferase II deficiency in an adolescent presenting with rhabdomyolysis and acute renal failure

Experience with carnitine palmitoyltransferase II deficiency: diagnostic challenges in the myopathic form

OBJECTIVES

Carnitine palmitoyltransferase II (CPT II) deficiency is an autosomal recessive disorder of long-chain fatty acid oxidation. Three clinical phenotypes, lethal neonatal form, severe infantile hepatocardiomuscular form, and myopathic form, have been described in CPT II deficiency. The myopathic form is usually mild and can manifest from infancy to adulthood, characterised by recurrent rhabdomyolysis episodes. The study aimed to investigate the clinical features, biochemical, histopathological, and genetic findings of 13 patients diagnosed with the myopathic form of CPT II deficiency at Ege University Hospital.

METHODS

A retrospective study was conducted with 13 patients with the myopathic form of CPT II deficiency. Our study considered demographic data, triggers of recurrent rhabdomyolysis attacks, biochemical metabolic screening, and molecular analysis.

RESULTS

Ten patients were examined for rhabdomyolysis of unknown causes. Two patients were diagnosed during family screening, and one was diagnosed during investigations due to increased liver function tests. Acylcarnitine profiles were normal in five patients during rhabdomyolysis. Genetic studies have identified a c.338C>T (p.Ser113Leu) variant homozygous in 10 patients. One patient showed a novel frameshift variant compound heterozygous with c.338C>T (p.Ser113Leu).

CONCLUSIONS

Plasma acylcarnitine analysis should be preferred as it is superior to DBS acylcarnitine analysis in diagnosing CPT II deficiency. Even if plasma acylcarnitine analysis is impossible, CPT2 gene analysis should be performed. Our study emphasizes that CPT II deficiency should be considered in the differential diagnosis of recurrent rhabdomyolysis, even if typical acylcarnitine elevation does not accompany it.

Acute Renal Failure Secondary to an Unusual Familial Metabolic Myopathy

Rhabdomyolysis is a major cause of acute kidney failure. The etiology is diverse, from full-blown crush syndrome to less frequent causes, such as metabolic myopathy. We describe the case of a 35-year-old male with a history of intermittent myalgias who was admitted to hospital with acute renal failure secondary to rhabdomyolysis. Moderate to intense diffuse uptake of technetium-99m was seen in soft tissues at scintigraphy. The diagnosis of metabolic myopathy was confirmed after careful workup and genetic testing.

Pediatric Rhabdomyolysis

Pediatric rhabdomyolysis is a common diagnosis that pediatricians need to be able to recognize because prompt treatment can prevent potential complications, such as acute kidney injury. The triggers for rhabdomyolysis are extensive, with viruses being the most common cause in pediatric patients. The pathophysiology behind rhabdomyolysis is complex and still being researched, but having a firm understanding of the cascade that results when muscle injury occurs is essential for proper management. Guidelines for managing pediatric rhabdomyolysis currently do not exist, but this article aims to review the available literature and give clinicians a general approach to aid in history taking, physical examination, diagnosis, acute management, follow-up, and prevention.

Exertional rhabdomyolysis leading to acute kidney injury: when genetic defects are diagnosed in adult life

Rhabdomyolysis is a common cause of acute kidney injury (AKI) that is usually triggered by trauma. However, less common causes of rhabdomyolysis may precipitate AKI as well, possibly representing a diagnostic challenge even for the experienced nephrologist. Genetic defects of muscle metabolism represent one of these causes and can be overlooked in adults, since these diseases usually become apparent in childhood. We present here a case in which an adult patient with severe exertional rhabdomyolysis leading to AKI was finally diagnosed with a genetic defect of lipid metabolism. A 41-year-old patient was brought to our attention because of AKI and pigmenturia after strenuous physical effort. At admission, the patient was over-hydrated with a weight increase of 3 kg in few days. Laboratory examination showed creatinine of 8.7 mg/dl, along with increased myoglobin and CPK. Urinalysis was positive for haemoglobin and proteins, while urinary sediment analysis did not demonstrate any red blood cell but rather "muddy-brown" casts and tubular cells. Urine output was forced and the patient completely recovered renal function. Genetic analysis later demonstrated the presence of a common mutation of Carnitine Palmitoyl-Transferase II (CPTII). When facing rhabdomyolysis of obscure origin, nephrologists must keep in mind the possibility that even adult patients may have a genetic defect of energy metabolism. In these cases, patients usually experience rhabdomyolysis during exertion, fasting, or infection. CPTII deficiency often has a subtle presentation and might be unrecognized until AKI develops. Therefore, it is important to consider a genetic defect of muscle metabolism even in adult patients when a history of rhabdomyolysis of unclear origin is present.

Sudden infant death from neonate carnitine palmitoyl transferase II deficiency

A full-term female baby born to parents who gave birth three years prior to a girl who survived only 31h postpartum died 36h after birth. An autopsy showed that the heart was markedly hypertrophic (32g). Microscopically, the myocardium, liver and kidney cells exhibited extensive vacuolar degeneration. Sudan III staining was positive in cardiac muscle, liver and kidney tissue. Tandem mass spectrometry analysis revealed that the deceased patient had a carnitine palmitoyl transferase II (CPT2) deficiency or a carnitine-acylcarnitine translocase deficiency. Genetic testing of the parents revealed heterozygous CPT2 mutations, indicating that their offspring would have a 25% chance of having a CPT2 deficiency. Therefore, we speculated that CPT2 deficiency might be the cause of death based on the results of staining, tandem mass spectrometry analysis and parental genetic testing.

An ignored cause of red urine in children: rhabdomyolysis due to carnitine palmitoyltransferase II (CPT-II) deficiency

Carnitine palmitoyltransferase II (CPT-II) deficiency is an autosomal recessively inherited disorder involving the β-oxidation of long-chain fatty acids, which leads to rhabdomyolysis and subsequent acute renal failure. The clinical phenotype varies from a severe infantile form to a milder muscle form. Here, we report a 9-year-old boy referred to our hospital for the investigation of hematuria with a 2-day history of dark urine and malaise. As no erythrocytes in the microscopic examination of the urine and hemoglobinuria were present, myoglobinuria due to rhabdomyolysis was the most probable cause of dark urine. After excluding the other causes of rhabdomyolysis, with the help of metabolic investigations, the patient was suspected to have CPT-II deficiency, the most common cause of metabolic rhabdomyolysis. Our aim in presenting this case is to emphasize considering rhabdomyolysis in the differential diagnosis of dark urine in order to prevent recurrent rhabdomyolysis and renal injury.

[Acute renal failure caused by rhabdomyolysis in children: a clinical analysis of 26 cases]

OBJECTIVE

To investigate the clinical features and prognosis of acute renal failure (ARF) caused by rhabdomyolysis (RM) in children.

METHODS

A retrospective analysis was performed for the clinical data, laboratory examination, and prognosis of 26 RM children with ARF.

RESULTS

The causes for all 26 RM children with ARF were non-traumatic diseases, and the three most common causes were infection (69%), diabetes (12%), and metabolic disease (8%). In the RM children with ARF, the five most frequent clinical manifestations were fever (69%), multiple organ dysfunction syndrome (69%), convulsion (46%), oliguria or anuria (35%), and tea-colored urine (27%). All 26 children had a serum creatine kinase (CK) level of >1 000 IU/L, among whom 26 had increased aspartate aminotransferase, 25 had increased alanine aminotransferase, 25 had increased creatine kinase isoenzyme, and 23 had increased lactate dehydrogenase. Serum myoglobin (Mb) was measured in 22 children and was found to increase in all these children. The mean time for CK to decrease to below 1 000 IU/L was 10±5 d. There was no significant difference in the time to CK recovery between the 10 children who were treated with conventional treatment as well as continuous venous-venous hemofiltration and those who were not treated with blood purification (P>0.05). Of all 26 RM children with ARF, 7 were withdrawn from the treatment, and 19 had normal renal function after treatment.

CONCLUSIONS

ARF and multiple organ dysfunction syndrome are major complications in RM children. The major primary disease for RM children with ARF is infectious disease. CK is the major marker for the diagnosis of RM. Early diagnosis and appropriate treatment may reverse ARF and improve prognosis.

Heat stroke with bimodal rhabdomyolysis: a case report and review of the literature

BACKGROUND

Severe heat stroke tends to be complicated with rhabdomyolysis, especially in patients with exertional heat stroke. Rhabdomyolysis usually occurs in the acute phase of heat stroke. We herein report a case of heat stroke in a patient who experienced bimodal rhabdomyolysis in the acute and recovery phases.

CASE PRESENTATION

A 34-year-old male patient was found lying unconscious on the road after participating in a half marathon in the spring. It was a sunny day with a maximum temperature of 24.2 °C. His medical and family history was unremarkable. Upon arrival, his Glasgow Coma Scale score was 10. However, the patient's marked restlessness and confusion returned. A sedative was administered and tracheal intubation was performed. On the second day of hospitalization, a blood analysis was compatible with a diagnosis of acute hepatic failure; thus, he received fresh frozen plasma and a platelet transfusion was performed, following plasma exchange and continuous hemodiafiltration. The patient's creatinine phosphokinesis (CPK) level increased to 8832 IU/L on the fifth day of hospitalization and then showed a tendency to transiently decrease. The patient was extubated on the eighth day of hospitalization after the improvement of his laboratory data. From the ninth day of hospitalization, gradual rehabilitation was initiated. However, he felt pain in both legs and his CPK level increased again. Despite the cessation of all drugs and rehabilitation, his CPK level increased to 105,945 IU/L on the 15th day of hospitalization. Fortunately, his CPK level decreased with a fluid infusion. The patient's rehabilitation was restarted after his CPK level fell to <10,000 IU/L. On the 31st day of hospitalization, his CK level decreased to 623 IU/L and he was discharged on foot. Later, a genetic analysis revealed that he had a thermolabile genetic phenotype of carnitine palmitoyltransferase II (CPT II).

CONCLUSIONS

Physicians should pay special attention to the stress of rehabilitation exercises, which may cause collapsed muscles that are injured by severe heat stroke to repeatedly flare up.