Gential Tuberculosis- newer trends in the diagnostic

modalities

Dr Anusha Rao P

PGY 2

CAIMS

Varied incidence depending on the SES and the environment.

1% among the patients at gynec OP in India.

5 – 10 % amongst the patients with infertility.

Pathogenesis

• Mycobacterium tuberculosis of human type.

• Rarely M.bovine.

• Almost always of secondary type.

• Fallopian tubes are invariably the primary sites of pelvic TB.

• Mode of spread : Hematogenous (90%)

Lymphatic/ Direct

Ascending

ORGAN FREQUENCY

Fallopian tubes 90-100%

Endometrium 50-60%

Ovaries 20-30%

Cervix 5-15%

Vulva and Vagina 1%

Pelvic peritonitis:

• Wet type

• Dry type

Microscopic appearance of the granuloma:

• Multinucleated giant cells, Langhans cells

• Chr. Inflammatory cells

• Epithelioid cells

• Central area of caseation necrosis.

Clinical features

• High index of suspicion• 20% give family history• 30-50% might have had some form of TB and give H/o

ATT.

Symptomatology: • Systemic• Infertility• Menstrual disturbances• Abdominal swelling , postcoital bleeding, vaginal

discharge,dyspareunia

Signs:• Normal 35- 50 %• Abdominal mass• Pelvic mass• Adnexal mass/ tenderness• Ascites• Excessive Vaginal discharge• Ulcer vagina/ cervix/ vulva

Investigations

• Culture : Gold standard, but very low positive rates.BD MGIT: more rapid and sensitive than other

methods of culture.

• Egg based media 3-8 weeks eg Lowenstein Jensen media

• Agar based < 3 weekseg- BACTEC medium

• BacT/ALERT 3D MBmodified Middlebrook 7H9 broth with supplements

Tuberculin (Mantoux) tests0.1 ml PPD is injected intradermally

• Not 100 % sensitive or specific

• A positive test is read as discrete wheal > 10mm between 48 -78 hrs

• Mantoux test in women with laparoscopicallydiagnosed tuberculosis

sensitivity - 55% specificity - 80%

• Blood

• Chest X ray

• Diagnostic uterine curettage: Optimal time of sampling, at the end of the menstrual cycle or within 12 hrs after the onset of menstrual flow.

HPE

culture in L-J media

AFB microscopy

Nucleic acid amplification (PCR)

Guinea pig inoculation

Endometrial curettage

• Frequent first diagnostic test

• False negetive because of sampling errors

• Diagnosis by either MTB isolation or histological Granulomata.

Negative biopsy does not exclude GTB

• Cornual curettage yields atleast 50% possibility of rapid histological diagnosis

• positive culture was seen in 25 % cases of Tb endometritis.

• Menstrual blood: low sensitivity

- collected on D2 of her cycle

Mycobacterial culture, nucleic acid amplification and guinea pig inoculation.

Positive report supports the diagnosis but a negative report doesn’t rule out the infection.

• Sputum and urine

• Lymph node biopsy

• CT/ MRI abdominal, pelvic

• Laparoscopy

• Endoovarian tissue biopsis and Pelvic aspiration fluids.

Hysterosalpingography (HSG)• Vascular or lymphatic extravasation of the dye• Rigid (lead-pipe) tubes with nodulations• Tobacco-pouch appearance• Beaded appearance of the tube• Distal tube obstruction• Coiling/ calcified shadows• Bilateral cornual block• Irregular, honey-comb appearance of the uterine

cavity

Rigid pipe

Calcification with irregular uterine cavity

Clubbing of ampulla

Intravasation of dye

Filling defect

Tobacco pouch

Hysteroscopysmall cavity with adhesion

3D ultrasound fundal adhesions..

Detection and identification of mycobacteria directlyfrom clinical samples

• Genotypic Methods :

• PCR

• NAA

Dr.T.V.Rao MD 27

•PCR-based genetic tests

• Detection is based on multiplication not of whole bacilli, as in culture, but of their genetic material, chromosomal DNA or ribosomal RNA.

• In principle, from one target sequence, of one bacillus, the reaction can produce millions of copies and thus yield a positive result

Dr.T.V.Rao MD 28

Sensitivity 85-95%,specificity 90-97%

NAA techniques

• Gen –probe M.tuberculosis test –transcription mediated amplification of rRNA

good in smear positive samples

• Ampiclor test – PCR amplification of DNA

Different types of PCR

• Real time PCReg: Mycosure Dr.Lal Pathlabdetects both mycobacterium tuberculosis and Non tuberculosis mycobacteria

• Multiplex PCReg TB PCR –SRL laboratorydetects mycobacteria tuberculosis complex

• Nested DNA PCR

Eg. Reliance laboratorytargets IS61110 gene region in TB DNA

• False positive PCR may be due to NTM

• False negative due tosampling errorblood contamination paucibacillary specimensPCR inhibitorsineffective primers

• new class of in vitro assay that measure interferon (IFN-γ) released by sensitized T cells after stimulation by M. tuberculosis antigens.

• Measures immune reactivity to M.tb.

Quantiferon-GOLD

35

Conventional methods for the diagnosis of TB include microscopy and culture.Ziehl-Neelsen (ZN) staining of AFB requires 104-106

bacilli/ml of tissue or fluid specimens to give a positive result.Although culture for Mycobacterium is more sensitive, it still needs 10-100 bacilli/ml of sample for the diagnostic yield and requires 2-4 weeks for the growthof Mycobacterium. A diagnostic method that is less time-consuming and at the same time has high sensitivity and specificity istherefore desirable.

Nucleic acid amplification (NAA) tests

represent a major advance in the diagnosis of

TB.

PCR based methods: very useful for rapid diagnosis and require bacteria as less as

10 bacteria/ ml of the specimen.

DNA-PCR unable to differentiate between viable and non viable organisms,

But is reliable even in the absence of activity at the site of sample collection, with the primary foci elsewhere in the body..hence is useful in the detection of early tubercular involvement.

• Reverse Transcriptase PCR (RT PCR): detection of viable organisms possible because bacterial mRNA with a mean half-life of 3-5 minutes is more prone for destruction than genomic DNA, hence positive mRNA signal would indicate the presence of viable organisms.

• STN RT-PCR more sensitive as it can detect even a single copy of MTB gene

Results from a study by Srivastava et al as published in the Journal of Human Reproductive Sciences / Volume

7 / Issue 1 / Jan - Mar 2014

Total samples Total positive samples

Only Microscopy +

Only culture + Only PCR +

227 133 (58.5%) 0 7 (5.2%) 115 (86.4%)

Microscopy +Culture +

Microscopy +PCR +

Microscopy +Culture +PCR +

0 11 (8.2%) 2 (1.5%)

• Overall sensitivity:

PCR assay: 31.3%

Microscopy: 5.1%

Culture: 4.2%

HPE: 2.4%

Differential diagnosis:

• Pyogenic tubo-ovarian mass

• Pelvic endometriosis

• Adherent ovarian cyst

• Chronic disturbed ectopic pregnancy