Reducing Microbial Contamination in Hematopoietic Stem Cell Products and Quality Improvement Strategy: Retrospective Analysis of 1996-2021 Data

Background@#Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing. @*Methods@#We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples. @*Results@#Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing. @*Conclusions@#The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk.

Efficacy and Safety of Radiofrequency Ablation Performed by an Endocrinologist for Benign Thyroid Nodules

BACKGROUND AND OBJECTIVES: Radiofrequency ablation has recently been used for the treatment of benign thyroid nodules, with outstanding results. However, in most studies, the procedure was usually performed by a radiologist or surgeon. This study aimed to evaluate the efficacy and safety of radiofrequency ablation for nodules >2 cm performed by an endocrinologist with several years of experience performing fine-needle aspiration cytology. MATERIALS AND METHODS: This study was a cross-sectional analysis of 111 patients who received radiofrequency ablation between April 2010 and July 2013. A total of 73 patients with 75 nodules >2 cm in diameter with at least 6 months of follow-up examinations were included. RESULTS: The mean follow-up period was 11.5 months. The mean nodule volume decreased from 17.0+/-15.3 mL preoperatively to 6.0+/-8.5 mL postoperatively, with a mean volume reduction of 69.7%. There were no major complications, and only 1 patient (1.3%) presented with a minor complication (hemorrhaging of the thyroid parenchyma). CONCLUSION: Radiofrequency ablation is a safe method for reducing benign thyroid nodules, and is not associated with any major complications.

Single Nodular Pulmonary Amyloidosis: Case Report / 결핵및호흡기질환

Amyloidosis is defined as the presence of extra-cellular deposits of an insoluble fibrillar protein, amyloid. The pulmonary involvement of amyloidosis is usually classified as tracheobronchial, parenchymal nodular, or diffuse alveolar septal. A single nodular lesion can mimic various conditions, including malignancy, pulmonary tuberculosis, and fungal infection. To date, only one case of nodular pulmonary amyloidosis has been reported in Korea, a case involving multiple nodular lesions. Here, we report and discuss the case of a patient having single nodular amyloidosis.