Garg Pankaj, Garg Mohinder K, Agarwal Narinder
Department of Coloproctology, Garg Fistula Research Institute, Panchkula, India; Department of Coloproctology, Indus International Hospital, Mohali, India.
Department of General Surgery, BPS Medical College for Women, Khanpur Kalan, India.
Int J Mycobacteriol. 2016 Dec;5 Suppl 1:S208-S209. doi: 10.1016/j.ijmyco.2016.09.055. Epub 2016 Nov 23.
OBJECTIVE/BACKGROUND: Mycobacterium tuberculosis (MTB) is a known cause of refractory and recurrent fistula-in-ano. Histopathology of fistula tract and acid fast bacillus (AFB) smear of the pus are the standard procedures employed to diagnose MTB. However, they have some drawbacks. Nontubercular mycobacteria (NTM) has also been detected to cause fistula-in-ano and these methods cannot differentiate between MTB and NTM. Secondly, as these methods have low sensitivity, they could possibly be missing out MTB patients. Real-time polymerase chain reaction (RT-PCR) has high sensitivity in detecting mycobacteria. The aim of the study was to compare the sensitivity of RT-PCR, histopathology, and AFB smear in detecting MTB in fistula-in-ano.
The histopathology and RT-PCR of tissue (fistula tract) was done along with AFB smear and RT-PCR of the pus was done in all the cases as per the availability of the specimen. The histopathology, AFB smear and RT-PCR was done by same pathologists in all the cases and all the patients were operated by a single surgeon.
A total of 286 samples were tested in 161 patients of fistula-in-ano who were operated over a period of 1year. The mean age was 38.6±10.5 and male/female ratio was 153/8. Histopathology and RT-PCR of tissue (fistula tract) was done in 131 patients and 141 patients respectively. AFB smear and RT-PCR of pus (fistula) was done in 14 patients. Overall, MTB was detected in total of 17/161 (10.63%) patients. Out of these, MTB was detected in tissue (fistula tract) in 1/131 (0.76%) by histopathology and 14/141 (10%) by RT-PCR tissue. In pus samples, AFB smear was negative in all cases (0/14), whereas RT-PCR detected MTB in four of 14 (28.6%) patients. In 17 patients detected to have MTB, four-drug antitubercular therapy (ATT) was recommended. ATT was started in 15 patients. Nine of 17 patients completed 6months ATT and were cured. Six of 17 patients are currently taking ATT. Two patients did not take ATT; both of these have persistent symptoms of pus formation. Out of nine cured patients, two patients did not start ATT for 2months after detection. Only after the symptoms (persistent pus discharge) continued, did they start ATT and were subsequently cured.
RT-PCR is significantly more sensitive than histopathology and AFB smear in detecting MTB in fistula-in-ano. The routine practice of doing only histopathology and AFB smear in fistula patients might be missing a significant number of MTB cases and could be responsible for many recurrences in fistula patients. RT-PCR should preferably be done in all fistula cases and at least in refractory and recurrent fistulas.
目的/背景：结核分枝杆菌（MTB）是难治性和复发性肛瘘的已知病因。瘘管组织病理学检查和脓液抗酸杆菌（AFB）涂片是诊断MTB的标准方法。然而，它们存在一些缺点。非结核分枝杆菌（NTM）也被检测出可导致肛瘘，而这些方法无法区分MTB和NTM。其次，由于这些方法灵敏度较低，可能会遗漏MTB患者。实时聚合酶链反应（RT-PCR）在检测分枝杆菌方面具有高灵敏度。本研究的目的是比较RT-PCR、组织病理学和AFB涂片在检测肛瘘中MTB的灵敏度。
根据标本的可获得性，对所有病例进行瘘管组织的组织病理学检查和RT-PCR，同时进行脓液的AFB涂片和RT-PCR。所有病例的组织病理学、AFB涂片和RT-PCR均由同一位病理学家完成，所有患者均由同一外科医生进行手术。
在161例肛瘘患者中，共检测了286份样本，这些患者在1年的时间里接受了手术。平均年龄为38.6±10.5岁，男女比例为153/8。分别对131例和141例患者进行了瘘管组织的组织病理学检查和RT-PCR。对14例患者进行了脓液（瘘管）的AFB涂片和RT-PCR。总体而言，共在17/161（10.63%）例患者中检测到MTB。其中，通过组织病理学在1/131（0.76%）例瘘管组织中检测到MTB，通过RT-PCR组织检测在14/141（10%）例中检测到MTB。在脓液样本中，所有病例（0/14）的AFB涂片均为阴性，而RT-PCR在14例中的4例（28.6%）患者中检测到MTB。在检测出患有MTB的17例患者中，推荐进行四联抗结核治疗（ATT）。15例患者开始接受ATT。17例患者中有9例完成了6个月的ATT并治愈。17例患者中有6例目前正在接受ATT。2例患者未接受ATT；这2例患者均有持续的脓液形成症状。在9例治愈的患者中，2例患者在检测后2个月未开始接受ATT。仅在症状（持续脓性分泌物）持续后，他们才开始接受ATT并随后治愈。
在检测肛瘘中的MTB方面，RT-PCR比组织病理学和AFB涂片明显更敏感。仅对肛瘘患者进行组织病理学和AFB涂片的常规做法可能会遗漏大量MTB病例，并可能导致许多肛瘘患者复发。所有肛瘘病例最好都进行RT-PCR检测，至少对于难治性和复发性肛瘘应进行检测。
