A 24-year-old male visited our hospital because of pain in both flanks. His biochemistry profile showed an elevated serum creatinine level and low serum uric acid level. History taking revealed that he had undertaken exercise prior to the acute kidney injury (AKI) event, and he stated that family members had a history of urolithiasis. His renal profile improved after hydration and supportive care during hospitalization. Although the patient was subsequently admitted again due to AKI, his status recovered with similar treatment. Since the diagnosis of the patient was familial renal hypouricemia with exercise-induced AKI, we performed genotyping of SLC22A12, which encodes human urate transporter 1. The diagnosis was confirmed by the detection of a homozygous mutation of W258X. We herein, report a case of familial renal hypouricemia confirmed by genotyping of SLC22A12, and review the relevant literature.

Crohn's disease (CD) is a chronic inflammatory bowel disease (IBD) that presents with abdominal pain, weight loss, and diarrhea. Although the etiology has not been fully elucidated, both environmental and genetic causes are known to be involved. In chronic inflammatory conditions such as IBD, B lymphocytes are chronically stimulated, and they induce monoclonal expansion of plasma cells, sometimes resulting in monoclonal gammopathy of undetermined significance. Immunomodulators that are commonly used to control inflammation, such as tumor necrosis factor-α (TNF-α) blockers could increase the possibility of hematologic malignancy. The pathogenesis of multiple myeloma in association with TNF-α inhibitor therapy is attributed to decreased apoptosis of plasma cell populations. Here, we describe a case of a 36-year-old male patient who was diagnosed with immunoglobulin A subtype smoldering multiple myeloma during the treatment for CD with infliximab and adalimumab. We report this case along with a review of the literature on cases of multiple myeloma that occurred in conjunction with CD.

HACEK is a rare cause of prosthetic valve endocarditis (PVE). We describe 42-year-old male patient who presented with Aggregatibacter aphrophilus PVE and cerebral infarct. A. aphrophilus was isolated from his blood cultures as the sole pathogen, which was confirmed by subsequent 16S rRNA sequencing. He was treated with valve replacement surgery and an 8 week course of pathogen-directed antibiotic therapy and followed for 20 months without recurrence.

Patients with diabetes undergo bariatric surgery to improve sugar metabolism and to achieve weight loss. However, possible complications after bariatric surgery must be carefully considered. We report a case of uncontrolled blood sugar after bariatric surgery despite weight loss in a severely obese patient with diabetes. The patient underwent bariatric surgery in 2009 in order to lose weight and improve glycemic control. Six months after the surgery, the patient experienced dumping syndrome. The patient did actually lose weight; however, as the visceral fat/subcutaneous fat+visceral fat ratio increased, insulin resistance was not improved, and glycemic control was aggravated. The patient received proper medication for dumping syndrome including nutritional support and exercise education. Due to these efforts, the patient has maintained her weight loss, and her blood sugar level was controlled within the target range.