Low-Specificity and High-Sensitivity Immunostaining for Demonstrating Pathogens in Formalin-Fixed, Paraffin-Embedded Sections

Abstract

The present review describes a part of the author's own experience in applying immunoperoxidase staining to routine histopathological diagnosis. The target disorder was focused on infection. In the practice of pathology diagnosis services, it is important for us diagnostic pathologists to judge whether the lesion is caused by an infection or not. When an infectious disease is highly likely, the visualization of pathogens within the inflammatory lesion is required to suggest a causative agent. Two main approaches the author would like to introduce include (1) the use of commercially available antisera showing wide cross-reactivity to a variety of bacteria and (2) the use of diluted patients' sera. These immunohistochemical studies employing "low-specificity" and "high-sensitivity" probes are useful for confirming the localization of pathogen within the infectious lesion.

Cutaneous Coinfection of Cytomegalovirus and Mycobacterium chelonae Accelerated by Immunosuppression

“…T. pallidum antiserum also showed weak cross-reactivity. Positive signals with low background staining were observed not only on the mycobacteria in the lipid droplets but also in the cytoplasm of macrophages, so that the detection sensitivity was very high [ 5 ]. Similar results were observed in granulomatous mastitis [ 29 ].…”

“…Similar results were observed in granulomatous mastitis [ 29 ]. The visualization of microbes within the lesion is essentially important for making a histopathological diagnosis of infection [ 5 ]. Another important point of our findings includes the cross-reactivity of antibodies against MPT64, LAM, and PAB to M. chelonae .…”

“…An amino acid polymer method (Simple Stain Max-PO, Nichirei Biosciences, Tokyo) was employed. As reported in the previous article describing a low-specificity and high-sensitivity immunostaining with widely cross-reactive antibacterial antisera [ 5 ], the mycobacteria were visualized in formalin-fixed, paraffin-embedded sections. The antibodies gave clearly positive signals in the cytoplasm of macrophages infiltrating in the lesion, in addition to long rods labeled with Gram and Ziehl-Neelsen stains.…”

“…The antibodies gave clearly positive signals in the cytoplasm of macrophages infiltrating in the lesion, in addition to long rods labeled with Gram and Ziehl-Neelsen stains. Figure 6 illustrates positive findings with rabbit antisera to Bacillus Calmette-Guérin (BCG) [ 6 ], Bacillus cereus [ 5 ], MPT64 (also called as protein Rv1980c, M. tuberculosis -specific 24 kDa secretory antigen) [ 7 ], and monoclonal antibodies to LAM ( M. tuberculosis -related lipoarabinomannan) [ 8 ] and PAB ( Propionibacterium acnes -specific lipoteichoic acid) [ 9 ]. Antiserum to Treponema pallidum gave weak immunoreactivity.…”

Pathology of Gangrene

“…Immunostaining using rabbit antisera raised against Bacillus Calmette-Guérin (BCG; Mycobacterium bovis), Bacillus cereus, Treponema pallidum, and Escherichia coli is employed. These low-specificity (widely cross-reactive) antimicrobial antisera effectively yield clear high-sensitivity signals with a low background [3,4]. Please visit the author's Website at https://pathos223.…”