Species-specific immunocytochemical localization of Mycobacterium tuberculosis complex in fine needle aspirates of tuberculous lymphadenitis using antibody to 38 kDa immunodominant protein antigen.
OBJECTIVE
To examine immunocytochemical localization of Mycobacterium tuberculosis (MTB) complex antigen in fine needle aspiration (FNA) smears of tuberculous lymphadenitis (TBLN) using species-specific monoclonal antibody MTSS to 38-kDa immnunodominant protein antigen as a diagnostic adjunct to conventional cytomorphology and its advantage over Ziehl-Neelsen (ZN) microscopy. Study Design FNA smears from 340 cases-174 TBLN; 34 negative controls from nontuberculous, positive controls of 13 known acid-fast bacilli (AFB)-positive sputum smears; 50 blind controls; and 69 other controls (smears from stock cultures of bacterial, atypical mycobacteria and fungal species) were subjected to ZN and immunocytochemical staining using MTSS by the streptavidin-biotin method.


RESULTS
Immunocytochemical staining was positive in 59 of 61 (96.7%) archival and 110 of 113 (97.3%) fresh FNA smears; ZN positivity for AFB was observed in 27 of 61 (44.2%) archival and 48 of 113 (42.4%) fresh FNA smears of TBLN.


CONCLUSIONS
The immunostaining using MTSS showed a definite advantage over conventional ZN staining for detection and specific diagnosis of TBLN in FNA smears with 0% false positive results. Immunostaining of cytosmears with species specific antibody to MTB would prove to be a good diagnostic adjunct to morphologic diagnosis.
Goel
Madhu Mati
MM
Department of Pathology, King George's Medical University, Lucknow, Uttar Pradesh, India. madhukgmc@rediffmail.com
Budhwar
Puja
P
D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial / Q000032:analysis* / Q000276:immunology; D044963:Biopsy, Fine-Needle; D005189:False Positive Reactions; D006801:Humans; D007150:Immunohistochemistry; D008074:Lipoproteins / Q000032:analysis* / Q000276:immunology; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000302:isolation & purification*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013194:Staining and Labeling / Q000379:methods*; D014388:Tuberculosis, Lymph Node / Q000382:microbiology* / Q000473:pathology
C075966:Ag38 antigen, Mycobacterium tuberculosis; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D008074:Lipoproteins