Lymphogranuloma venereum (LGV) of the anorectum: evaluation of clinicopathological associations and the utility of a novel RNA in-situ hybridisation stain

Markedly increased duodenal villous surface apoptosis in patients taking pre-exposure prophylaxis (PrEP) against human immunodeficiency virus

AIMS

Pre-exposure prophylaxis (PrEP) consists of combination antiretroviral therapy and is increasingly utilized to prevent human immunodeficiency virus (HIV) in high-risk populations. Two index cases noted during routine care showed markedly increased duodenal villous surface apoptosis in patients on PrEP. We sought to examine the prevalence of this finding and identify any clinicopathologic correlations.

METHODS

Gastrointestinal biopsy specimens from 23 male patients aged 18-40 years taking PrEP and 23 control patients were reviewed. Patients with HIV, inflammatory gastrointestinal diseases, and celiac disease were excluded. Apoptoses were counted on surface epithelium and deep crypts. The highest apoptotic body count per tissue fragment was recorded. Clusters were defined as groups of ≥5 apoptoses. Apoptotic counts between patients taking PrEP and controls were compared using t-tests.

RESULTS

In PrEP patients, the median age was 35 years (range 25-40) and 83% (19/23) were white. The control patients were demographically similar (median age: 32 years [range 23-40]; 70% [16/23] white). Duodenal apoptosis in villous surface epithelium was increased in PrEP patients, with 14/23 (60.9%) patients having ≥10 surface apoptoses compared to 2/23 (8.7%) controls (P = 2.1 × 10-3 ) and 14/23 (61%) having clusters compared to 3/23 (13%) controls (P = 2.0 × 10-3 ). There was no significant association between increased surface apoptosis or clusters and clinical symptoms or duration of PrEP use.

CONCLUSION

Markedly increased villous surface apoptosis, particularly in clusters, is often seen in the duodenum of patients taking PrEP. Although the mechanism and significance are unknown, knowledge of this peculiar finding may prevent unnecessary additional testing.

The Histopathology of Anorectal Neisseria gonorrhoeae Infection

OBJECTIVES

Neisseria gonorrhoeae infection of the anorectal tract is often asymptomatic and infrequently biopsied, but pathologists can be tasked with identifying the histologic features of possible infection. The study was undertaken to better characterize clinical and morphologic features of confirmed anorectal gonococcal infection.

METHODS

From 2011 to 2020, 201 positive gonococcal nucleic acid amplification testing samples from 174 patients collected from the distal colorectum and/or anus were matched to eight patients with concurrent biopsy specimens of the distal anorectum. Complete demographic, clinical, and infectious information was collected for each biopsied patient. The histomorphologic features of each biopsy were systematically tabulated.

RESULTS

All eight gonococcal cases were obtained from men who have sex with men. Each case showed at least mild acute inflammation with moderate activity identified in one case with concurrent cytomegalovirus infection. Intense lymphoplasmacytic infiltration was not commonly seen (two of eight). Half of the cases showed mucosal ulceration, and seven of eight cases demonstrated lymphoid aggregates.

CONCLUSIONS

The microscopic features are mild compared with other well-described types of infectious proctitis, with most cases displaying mild acute inflammation and scattered lymphoid aggregates. These findings highlight the importance of obtaining a complete patient history and recommending additional infectious workup even when only subtle changes are present.

Histologic features of colonic infections

Background

The histopathologic diagnosis of infectious colitis remains relevant despite recent advances in microbiologic techniques.

Objective

This article aims to describe the histologic features of selected infectious diseases of the colon.

Materials and methods

Existing reports on histopathologic and clinical aspects of colonic infectious agents were reviewed.

Results

While histology alone may not be as sensitive as current microbiologic methods, tissue identification of infectious agents still plays an important role in patient care. Infectious colitis can have a variety of clinical manifestations, ranging from strongyloidiasis, which can cause a smoldering, subclinical infection for decades, to syphilis, which can clinically mimic cancer or inflammatory bowel disease. Therefore, the histopathologic identification of infection as the cause of a patient’s colitis has a considerable impact on treatment decisions. Morphologic overlap can occur between infection and other diseases, however. Moreover, some infections can elicit various tissue responses beyond acute colitis. Immunosuppressed patients may not mount an inflammatory response to pathogens such as cytomegalovirus or adenovirus. Sexually transmitted proctocolitis can cause plasma-cell-rich inflammation. Gastrointestinal histoplasmosis is more likely to cause diffuse histiocyte infiltration rather than the expected granuloma formation. In some cases, ancillary tests are useful, but equivocal results can cause diagnostic dilemmas.

Conclusion

Given the range with which colonic infectious disorders can manifest, pathologists should be aware of the typical features of infectious colitis, as well as findings beyond the classic morphologies.