RESUMO
BACKGROUND: Mixed Connective Tissue Disease (MCTD) is a rare condition in children, characterized by a high titer of anti-ribonucleoprotein-U1 (anti-U1 RNP) antibodies, often presenting with overlapping features of two or more rheumatologic disorders, including juvenile idiopathic arthritis (JIA), systemic lupus erythematous (SLE), systemic sclerosis (SSc), and juvenile dermatomyositis/polymyositis (JDM/PM). CASE PRESENTATION: We report the case of an 8-year-old girl with a history of fever, hair loss, lower extremities edema, weakness, oral aphthous ulcers, and a high titer of anti-U1 RNP antibodies, which is consistent with the diagnosis of MCTD. The patient received immunomodulator drugs, and her disease went into remission. CONCLUSION: Diagnosing MCTD in pediatric patients can be challenging. It should be considered especially in cases with recurrent muscular weakness or pain, lupus-like manifestations, and edema. Moreover, serum anti-U1 RNP testing can be a helpful diagnostic tool.
RESUMO
BACKGROUND: Primary immunodeficiencies are immunological disorders caused by gene mutations involved in immune system development and activation. Recently, activated phosphoinositide 3-kinase delta syndrome (APDS) due to mutations in the phosphoinositide 3-kinase (PI3K), phosphatidylinositol-4, 5-bisphosphate 3-kinase, catalytic subunit delta gene (PIK3CD), and phosphoinositide 3-kinase regulatory subunit 1 (PIK3R1) genes have been reported to induce a combined immunodeficiency syndrome leading to senescent T cells, lymphadenopathy, and immunodeficiency. The exact diagnosis of these deficiencies is essential for treatment and prognosis. In recent years, targeted treatment with selective PI3Kd inhibitors has had a significant effect on controlling the symptoms of these patients. CASE PRESENTATION: In this case report, we represent a 27-month-old girl with recurrent fever, an increased level of inflammatory markers, and erythema nodosum, who was referred to the rheumatology clinic. In the course of evaluations, because of the lack of clinical improvement with usual treatments, and a history of frequent respiratory infections, combined immunodeficiency was diagnosed in the immunological investigations. Moreover, whole-exome sequencing was performed for her. CONCLUSION: The genetic analysis found a novel variant of PIK3CD (c.1429 G > A) in the patient. Following daily antibiotic prophylaxis and monthly IV therapy, the patient's frequent infections and fevers were controlled.
