Case Presentation: An 87-year-old female with a history of bilateral knee osteoarthritis presented to the emergency room with complaints of intermittent fever ongoing at home for two weeks. She recently had a Lipogems injection procedure done to her right knee. She denied any history of recent travel, tick bites or sick contacts. Physical exam was only significant for fever of 102.8F and bilateral knee crepitus. No erythema or edema was noted. Routine blood work, including CBC/CMP were within normal limits. Her ESR was elevated to 61 mm/hr and CRP 14.6 mg/L but RF, ANA, CPK levels were normal. Procalcitonin levels and Lyme antibodies were negative. Repeated blood cultures and synovial fluid gram stain and cultures were negative. A CT chest abdomen and pelvis was unremarkable and infective endocarditis was ruled out with a negative transthoracic and transesophageal echo. Procedure site infection was initially suspected, however, diagnostic arthrocentesis showed only 468 WBCs/HPPF with 60% neutrophils. All infectious, vasculitis, rheumatological and malignancy workups were negative. Therefore, patient’s presentation of fever was suspected to be from adipose tissue infusion to her right knee as this involves cytokine release into the joint.

Discussion: Lipogems™ is a novel technology under development in regenerative medicine. It comprises of a closed-loop, disposable, FDA cleared device used to obtain micro fragmented adipose tissue with intact stromal vascular niche and MSCs. It is then transfused into the place of interest, in our case being the right knee. This procedure claims to relieve osteoarthritic pain through regeneration and paracrine action of MSCs to prime and sustain angiogenic, anti-fibrotic, anti-apoptotic, anti-microbial and immunomodulatory responses. There is not enough data regarding the side effects of this procedure, however, the commonly reported ones include allergic reactions and damage to underlying tissues from the procedure. It is important to note that Lipogems extract not only contains intact stromal vascular niche, pericytes and MSCs but it also contains large amounts of cytokines. Our case presented as a case of recurrent fever and posed a significant diagnostic challenge.

Conclusions: Lipogems has been used widely in the US at present, however, the long-term benefits and adverse effects need to be further examined. Meanwhile, clinicians should be aware of the potential side effects of the novel technologies in treating common ailments. We believe our case would serve as a source for further studies on the molecular effects and side effects of Lipogem.