ABSTRACT
Idiopathic renal hypouricemia (iRHUC) is a rare hereditary disease caused by a defect in urate handling of renal tubules. Type 1 renal hypouricemia (RHUC1) is diagnosed with confirmation of a mutation in SLC22A12 gene which encodes a renal urate-anion exchanger (URAT1). The majority of iRHUC patients are asymptomatic, especially during childhood, and thus many cases go undiagnosed or they are diagnosed late in older age with complications of hematuria, renal stones, or acute kidney injury (AKI). We report a case of a 7-year-old boy with subtle symptoms such as general weakness and dizziness and revealed hypouricemia and incidental nephrolithiasis. Homozygous mutations were detected in the SLC22A12(c.774G>A) by molecular analysis. The present case suggests that fractional excretion of uric acid (FEUA) screening could be better followed by the coincidental discovery of hypouricemia, to prevent conflicting complications of iRHUC, even with normal urine uric acid to creatinine ratio (UUA/UCr), and sequential genetic analysis if needed.
ABSTRACT
Idiopathic renal hypouricemia (iRHUC) is a rare hereditary disease caused by a defect in urate handling of renal tubules. Type 1 renal hypouricemia (RHUC1) is diagnosed with confirmation of a mutation in SLC22A12 gene which encodes a renal urate-anion exchanger (URAT1). The majority of iRHUC patients are asymptomatic, especially during childhood, and thus many cases go undiagnosed or they are diagnosed late in older age with complications of hematuria, renal stones, or acute kidney injury (AKI). We report a case of a 7-year-old boy with subtle symptoms such as general weakness and dizziness and revealed hypouricemia and incidental nephrolithiasis. Homozygous mutations were detected in the SLC22A12(c.774G>A) by molecular analysis. The present case suggests that fractional excretion of uric acid (FEUA) screening could be better followed by the coincidental discovery of hypouricemia, to prevent conflicting complications of iRHUC, even with normal urine uric acid to creatinine ratio (UUA/UCr), and sequential genetic analysis if needed.
ABSTRACT
Lymphocytic interstitial pneumonia (LIP) is a benign lymphoproliferative disorder characterized histologically by diffuse infiltration with predominantly mature lymphocytes, plasma cells and reticuloendothelial cells in the alveolar septae and along the lymphatic vessels. LIP is an uncommon disease frequently associated with autoimmune diseases such as Sj?gren's syndrome, systemic lupus erythematosus, chronic active hepatitis, thyroiditis, myasthenia gravis, autoimmune hemolytic anemia and Human Immunodeficiency Virus (HIV) or Epstein- Barr virus (EBV) infection. LIP can progress to pulmonary or systemic lymphoma. LIP in children has variable disease courses such as spontaneous resolution, episodic worsening or progression to frank respiratory failure. Intravenous immunoglobulin and corticosteroids yield variable results, and some children may respond to them for several years. We report herein a case of EBV-associated, HIV-negative LIP diagnosed by thoracoscopic lung biopsy and a clonality study in a 5 year-old boy who was admitted with recurrent coughing and dyspnea. The patient was treated and fully recovered with methylprednisolone and high dose acyclovir. At the 3-year follow-up, he showed no clinical symptom despite increased EBV copy in bronchoalveolar lavage and progressive bronchiectasis in the right middle lobe.