RESUMO
OBJECTIVE: Previous studies suggested a role for the death decoy receptor 3 (DcR3) in the pathogenesis of adult systemic lupus erythematosus (SLE). We investigated the role of DcR3 in juvenile-onset SLE, to identify polymorphisms that might alter the function of this protein. METHODS: DcR3 was measured in the serum of 61 patients with juvenile SLE. The coding region of the DcR3 gene was sequenced in 100 juvenile and 103 adult patients with SLE, together with 500 healthy controls. RESULTS: DcR3 was elevated in the serum of juvenile patients with active SLE disease (440.8 ± 169.1 pg/ml), compared to patients with inactive disease (122.6 ± 28.05 pg/ml; p = 0.0014) and controls (69.27 ± 20.23 pg/ml; p = 0.0009). DNA sequencing identified 2 novel missense mutations: c.C167T (p.T56I) in an adult SLE patient and c.C364T (p.H122Y) in a juvenile patient. Recombinant proteins containing these mutations exhibited altered binding kinetics to FasL and they significantly increased lymphocyte proliferation, compared to the wild-type protein (p < 0.05). The adult patient with SLE carrying the p.T56I mutation had significantly increased lymphocyte proliferation compared to 3 SLE controls matched for age, sex, and disease severity. CONCLUSION: DcR3 may play an etiologic role in SLE through either elevated serum levels of wild-type DcR3 or normal levels of gain-of-function DcR3 proteins that increase lymphocyte proliferation.
Assuntos
Proliferação de Células , Progressão da Doença , Lúpus Eritematoso Sistêmico/genética , Linfócitos/patologia , Mutação de Sentido Incorreto/genética , Membro 6b de Receptores do Fator de Necrose Tumoral/genética , Adolescente , Adulto , Fatores Etários , Idade de Início , Sequência de Aminoácidos , Estudos de Casos e Controles , Criança , Feminino , Humanos , Lúpus Eritematoso Sistêmico/patologia , Masculino , Dados de Sequência Molecular , Índice de Gravidade de Doença , Adulto JovemRESUMO
A 5-month-old female infant who had chronic diarrhea and acute renal failure was referred to Chulalongkorn Hospital for further investigation and management. Laboratory investigation revealed elevated blood urea nitrogen and creatinine level, hypocalcemia, hyperphosphatemia, and hyponatremia. Ultrasonography of the kidneys showed normal size with bilateral hyperechoic kidneys. Eyes examination was compatible with oxalosis maculopathy. Urine organic acid analysis revealed peak of oxalate and glycolate. Clinical impression concluded acute renal failure from hyperoxaluria. The patient underwent continuous venovenous hemodiafiltration (CVVH-DF) with regional citrate anticoagulation and expired on day 13 after admission. Pathological examination of kidney necropsy revealed diffuse intraluminal deposition of oxalate crystals within the renal parenchyma. Primary hyperoxaluria is a very rare disease and has rarely been reported in Thailand. In the presented case, the diagnosis was delayed due to uncommon presentation and unavailability of diagnostic laboratory.