Prisco Francesco, Vaccaro Emanuela, Cardillo Lorena, Fusco Giovanna, Papparella Serenella, Santoro Pasquale, Fonfara Sonja, Kipar Anja, Paciello Orlando
Unit of Pathology, Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy.
Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Vet Pathol. 2025 Nov;62(6):928-938. doi: 10.1177/03009858251338849. Epub 2025 May 23.
Inflammatory myopathy (IM) and myocarditis are relevant complications of human immunodeficiency virus (HIV) infection. IM has also been reported in adult cats with experimental feline immunodeficiency virus (FIV) infection. The present study investigated naturally FIV-infected cats for IM and myocarditis and further characterized the inflammatory processes and their potential pathogenesis. Snap-frozen skeletal muscle (quadriceps femoris (QF) and triceps brachii (TB) muscles) and myocardial samples from naturally FIV-infected cats and controls were examined histologically and by immunohistochemistry for leukocytes and FIV-p24-gag, and by quantitative reverse transcription PCR (qRT-PCR) for the relative transcription of inflammatory mediators. Sera from FIV antibody-positive cats were tested for anti-skeletal muscle autoantibodies by indirect immunofluorescence (IIF). Inflammatory infiltrates were observed in 9/31 (35%) QF and TB muscles and 11/30 (37%) myocardial samples from FIV-infected cats, frequently in combination. The infiltrates were dominated by T-cells, with rare B-cells and macrophages; several leukocytes harbored FIV-p24-gag. The T-cell count in the QF was positively correlated with the T-cell count in TB and myocardium. Skeletal muscle of FIV-positive animals showed significantly higher transcription of , , , and than the controls, whereas the myocardium exhibited significantly higher and lower mRNA levels. IIF showed anti-skeletal muscle autoantibodies in sera of FIV positive cats up to a dilution of 1:1000. The results show that natural FIV infection is frequently associated with IM and myocarditis and driven by T-cells, with Th1/Th17 polarization of the response. The presence of circulating anti-muscle autoantibodies suggests an underlying autoimmune pathogenesis.
炎症性肌病（IM）和心肌炎是人类免疫缺陷病毒（HIV）感染的相关并发症。在实验性感染猫免疫缺陷病毒（FIV）的成年猫中也有IM的报道。本研究调查了自然感染FIV的猫是否患有IM和心肌炎，并进一步对炎症过程及其潜在发病机制进行了表征。对自然感染FIV的猫和对照猫的速冻骨骼肌（股四头肌（QF）和肱三头肌（TB））以及心肌样本进行组织学检查，并通过免疫组织化学检测白细胞和FIV-p24-gag，通过定量逆转录PCR（qRT-PCR）检测炎症介质的相对转录水平。通过间接免疫荧光法（IIF）检测FIV抗体阳性猫血清中的抗骨骼肌自身抗体。在感染FIV的猫的9/31（35%）的QF和TB肌肉以及11/30（37%）的心肌样本中观察到炎症浸润，且常合并出现。浸润细胞以T细胞为主，B细胞和巨噬细胞少见；部分白细胞含有FIV-p24-gag。QF中的T细胞计数与TB和心肌中的T细胞计数呈正相关。FIV阳性动物的骨骼肌显示、、和的转录水平显著高于对照组，而心肌则显示mRNA水平显著升高和降低。IIF显示FIV阳性猫血清中存在抗骨骼肌自身抗体，最高稀释度可达1:1000。结果表明，自然感染FIV常与IM和心肌炎相关，并由T细胞驱动，反应呈Th1/Th17极化。循环抗肌肉自身抗体的存在提示潜在的自身免疫发病机制。
