Warit Saradee, Meesawat Suthirote, Cheawchanlertfa Pattsarun, Makhao Nampueng, Srilohasin Prapaporn, Kaewparuehaschai Machamon, Noradechanon Kirana, Pomcoke Areeya, Kemthong Taratorn, Prammananan Therdsak, Kanitpun Reka, Palaga Tanapat, Malaivijitnond Suchinda, Chaiprasert Angkana
Industrial Tuberculosis Team, Industrial Medical Molecular Biotechnology Research Group, BIOTEC, National Science and Technology Development Agency, Pathum Thani, Thailand.
National Primate Research Center of Thailand- Chulalongkorn University, Saraburi, Thailand.
PLoS One. 2024 Dec 16;19(12):e0302349. doi: 10.1371/journal.pone.0302349. eCollection 2024.
Tuberculosis (TB) is the first infectious disease to be screened-out from specified pathogen-free cynomolgus macaques (Macaca fascicularis; Mf) using in human pharmaceutical testing. Being in either latent or active stage after exposure to the Mycobacterium tuberculosis complex (MTBC), the monkey gamma-interferon release assay (mIGRA) was previously introduced for early TB detection. However, a notable incidence of indeterminate results was observed. In this study, we compared two positive mitogen references, phytohemagglutinin (PHA) that is used in the QuantiFERON-TB Gold Plus kit (QFT-PHA) and a combination of Concanavalin A and Pokeweed mitogen (ConA+PWM), in a cohort of 316 MTBC-exposed Mf. Following a 29-month follow-up of 100 selected animals, we established a new mIGRA interpretation algorithm that demonstrated a significant shift in the negative and indeterminate cases regardless of whether the QFT-PHA or ConA+PWM was used as a mitogen. That is, if the ODNIL value was ≤0.18, ODMIT-NIL > ODNIL, and the ODTB1/2-NIL were ≥0.05 and ≥25% of individual ODNIL, the mIGRA result was interpreted as 'positive'. If the ODNIL value was ≤0.18, ODMIT-NIL > ODNIL, and the ODTB-NIL was <0.05, the mIGRA result was interpreted as 'negative'. If the ODNIL value was >0.18 or the OD of mitogen references [OD(QFT-PHA) and OD(ConA+PWM)] were ≤0.18, the mIGRA result was interpreted as 'indeterminate'. As a result, negative cases increased by 10-50%, indeterminate cases decreased by 40-80%, and the number of TB-positive cases remained unchanged. Our findings highlight the critical role of mitogens as positive controls in mIGRA interpretation. This study provides the mIGRA value for the TB screening of cynomolgus macaques that enables the identification of true positive and suspicious TB cases for quarantine programs.
结核病（TB）是第一种从用于人类药物测试的无特定病原体食蟹猴（猕猴；Mf）中筛查出的传染病。在接触结核分枝杆菌复合群（MTBC）后处于潜伏或活跃阶段，之前引入了猴γ-干扰素释放测定法（mIGRA）用于早期结核病检测。然而，观察到不确定结果的发生率显著。在本研究中，我们在316只接触MTBC的Mf队列中比较了两种阳性促有丝分裂原对照，即用于QuantiFERON-TB Gold Plus试剂盒（QFT-PHA）的植物血凝素（PHA）以及刀豆球蛋白A和商陆有丝分裂原的组合（ConA+PWM）。在对100只选定动物进行29个月的随访后，我们建立了一种新的mIGRA解释算法，无论使用QFT-PHA还是ConA+PWM作为促有丝分裂原，该算法在阴性和不确定病例中都显示出显著变化。也就是说，如果ODNIL值≤0.18，ODMIT-NIL>ODNIL，且ODTB1/2-NIL≥0.05且≥个体ODNIL的25%，则mIGRA结果解释为“阳性”。如果ODNIL值≤0.18，ODMIT-NIL>ODNIL，且ODTB-NIL<0.05，则mIGRA结果解释为“阴性”。如果ODNIL值>0.18或促有丝分裂原对照的OD值[OD（QFT-PHA）和OD（ConA+PWM）]≤0.18，则mIGRA结果解释为“不确定”。结果，阴性病例增加了10 - 50%，不确定病例减少了40 - 80%，而结核病阳性病例数量保持不变。我们的研究结果突出了促有丝分裂原作为mIGRA解释中的阳性对照的关键作用。本研究提供了用于食蟹猴结核病筛查的mIGRA值，能够识别用于检疫计划的真正阳性和可疑结核病病例。
