A 40-year-old female visited our hospital because of malaise. She had no history of early loss of primary teeth nor family history of skeletal dysplasia. Laboratory examination showed low serum alkaline phosphatase levels of 18 U/L. In addition, hypozincemia was also observed, but alkaline phosphatase level did not increase after zinc replacement. Mediators, including calcium and phosphorus metabolism, were within normal range. X-ray examination showed no evidence of osteomalacia, but mineral bone density was slightly decreased compared with the young adult mean. Urine phosphoethanolamine level was increased, and we then suspected hypophosphatasia. Genetic tests detected ALPL gene heterozygous missense mutation (c.529G>A p.Ala177Thr and c.670A>G p.Lys224Glu) and adult-onset hypophosphatasia was finally diagnosed. It is important to evaluate alkaline phosphatase levels in the screening of patients with non-specific symptoms.

Background: Arbekacin (ABK) is an aminoglycoside that exhibits anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-Pseudomonas aeruginosa activities. Therefore, for patients with febrile neutropenia (FN) and concurrent pneumonia suspected to be caused by MRSA, ABK may be sufficiently effective even as a single agent. Materials and Methods: Patients with hematologic malignancies treated with ABK who met the following criteria were included: 1) fever during neutropenia or functional neutropenia, 2) FN complicated by pneumonia, and 3) possible infection by antimicrobial-resistant Grampositive cocci. Results: This study encompassed 22 episodes involving 19 patients, of which, 15 (68.2%) were successfully treated with ABK. Of the nine episodes showing inadequate response to other anti-MRSA drugs, eight were successfully treated with ABK. Grade 2 or worse adverse events included acute kidney injury (13.6%) and increased transaminase levels (9.1%). Conclusion The present study demonstrated that ABK is effective and safe in patients with FN and concurrent pneumonia caused by antimicrobial-resistant Gram-positive cocci. ABK may also be effective in patients who are unresponsive to other anti-MRSA drugs. Therefore, ABK may be beneficial in the treatment of pneumonia caused by antimicrobial-resistant Gram-positive cocci in patients with FN.