Report of a clinical and laboratory management of cell therapy for knee cartilage in the face of mycoplasma contamination

ABSTRACT To describe a case of autologous chondrocyte implantation after cell culture contamination by Mycoplasma pneumoniae and the measures taken to successfully complete cell therapy in a patient with focal chondral lesion. A 45-year-old male patient, complaining of chronic pain on the knee and no history of trauma. He had a chondral lesion in the trochlear region of the femur and clinical tests compatible with pain in the anterior compartment of the knee. Conservative treatment failed to alleviate symptoms. Surgical treatment was indicated, but due to the size of the lesion, membrane-assisted autologous chondrocyte implantation was the technique of choice. Cartilage biopsies were collected from the intercondylar region of the distal femur. After isolation, chondrocytes were expanded ex vivo in a trained laboratory, for three weeks, and seeded onto a commercially available collagen membrane prior to implantation in the knee. Two days before surgery, a cell culture sample tested positive for Mycoplasma pneumoniae. The source of contamination was found to be autologous blood serum, extracted from the patient´s peripheral vein, and used to supplement the cell culture medium. After treating the patient with antibiotics, all procedures were repeated and the new final cell product, free from contaminants, was successfully implanted. We discuss the strategies available to deal with this situation, and describe the results of this particular case, which led to modifications in the autologous chondrocyte implant protocol.

摘要 本研究旨在报告1例局灶性软骨病变患者在细胞培养被肺炎支原体（Mycoplasma pneumoniae）污染后，仍成功完成自体软骨细胞植入细胞治疗的病例及所采取的应对措施。患者为45岁男性，主诉膝关节慢性疼痛，无外伤史。其股骨滑车区存在软骨病变，临床检查提示膝关节前室疼痛。保守治疗未能缓解症状，遂拟行手术治疗；鉴于病变范围，膜辅助自体软骨细胞植入术成为首选术式。从股骨远端髁间区采集软骨活检组织。分离软骨细胞后，于资质齐全的实验室中进行体外扩增培养三周，随后将细胞接种于市售胶原膜（collagen membrane），准备用于膝关节植入。术前两日，细胞培养样本检测结果呈肺炎支原体阳性。经排查，污染来源为从患者外周静脉采集、用于补充细胞培养基的自体血清。对患者使用抗生素治疗后，重新开展全部操作流程，最终获得无污染物污染的全新细胞产品，并成功完成植入手术。本文讨论了应对此类情况的可行策略，并详述本病例的相关结果——该病例推动了自体软骨细胞植入方案的修订。