Single-center, real-world experience with granulocyte colony-stimulating factor for management of leukopenia following kidney transplantation.

BACKGROUND: Leukopenia is a frequent complication following kidney transplantation. Granulocyte colony-stimulating factor (G-CSF) has been used to accelerate white blood cell (WBC) count recovery; however, published experience in kidney transplantation is limited. METHODS: We retrospectively reviewed our kidney transplant recipients from January 2012 to September 2016 with a G-CSF order to evaluate leukopenia management (defined as WBC <3000 cells/µL). RESULTS: Thirty-six recipients were included. On average, G-CSF treatment began at 98 ± 38 days. At G-CSF initiation, mean WBC count was 1240 ± 420 cells/µL and absolute neutrophil count (ANC) was 653 ± 368 cells/µL. Mean G-CSF dose was 4.6 ± 1.2 mcg/kg/dose (total 11.8 ± 9.0 mcg/kg), 77.8% of recipients were prescribed G-CSF as outpatients, and overall, median time to WBC count recovery was 9 (IQR 4-14) days. Changes in immunosuppression and prophylaxis regimens for leukopenia were also common. Within 1 month following leukopenia onset, no patients experienced acute rejection and 5 (14%) developed infection requiring hospitalization or opportunistic infection. CONCLUSION: In kidney recipients with leukopenia, G-CSF may be helpful to achieve WBC count recovery in addition to changes in immunosuppression and prophylaxis medications. Prospective, randomized data are still needed to determine optimal G-CSF dosing in this population.

Targeting Glycoprotein NMB With Antibody-Drug Conjugate, Glembatumumab Vedotin, for the Treatment of Osteosarcoma.

BACKGROUND: Cure rates for children and young adults with osteosarcoma have remained stagnant over the past three decades. Targeting glycoprotein non-metastatic b (GPNMB) with the antibody-drug conjugate glembatumumab vedotin has improved outcomes for patients with melanoma and breast cancer. The potential utility of targeting GPNMB in osteosarcoma was explored. METHODS: GPNMB protein expression was evaluated by immunohistochemistry in human osteosarcoma tumor samples and by enzyme-linked immunosorbent assay (ELISA) in osteosarcoma cell lines. mRNA expression was measured by quantitative PCR in primary osteosarcoma samples and cell lines. Surface GPNMB expression was evaluated by flow cytometry and correlated with in vitro and in vivo cytotoxicity of glembatumumab vedotin. RESULTS: Sixty seven human osteosarcoma samples were evaluated by immunohistochemistry, including 12 samples from initial biopsy, 38 samples from definitive surgery, and 17 from the time of disease recurrence. GPNMB was expressed in 92.5% (62/67) of osteosarcoma samples. All primary osteosarcoma samples expressed high levels of GPNMB mRNA. Glembatumumab induced cytotoxic effects in 74% (14/19) of osteosarcoma cell lines, and GPNMB protein levels correlated with glembatumumab in vitro cytotoxicity (r = -0.46, P = 0.04). All osteosarcoma cell lines demonstrated surface GPNMB expression. CONCLUSIONS: GPNMB is expressed in osteosarcoma and targeting GPNMB with the antibody-drug conjugate glembatumumab vedotin demonstrates osteosarcoma cytotoxic activity. Clinical trials are indicated to assess the efficacy of targeting GPNMB in patients with osteosarcoma.

A case of failure to thrive secondary to primary hyperoxaluria type 1.

Primary hyperoxaluria type 1 is a rare genetic condition characterized by oxalate deposition in the kidneys. We report findings of an 8-month old female presenting with failure to thrive, poor oral intake, and kidney stones resulting in the diagnosis of primary hyperoxaluria type 1. The patient exhibits a unique presentation without renal failure at the time of diagnosis suggesting a previously unreported comorbidity in early stages of disease.