Immunohistochemical detection of chlamydia trachomatis in sexually transmitted infectious proctitis - BMC Gastroenterology - BMC Gastroenterology

Recently STI proctitis has gained worldwide attention. This study reports 54 cases of this proctitis in young homosexual men with an average age of 32 years. These findings are in agreement with previous studies, only age is slightly lower compared to other publications, which reported an average of approximately 43 years [9, 10]. These young patients typically present anal pain, tenesmus, constipation, and rectal bleeding [11]. In our study it was not possible to estimate the prevalence of these symptoms due to the lack of systematized information in the medical records, a problem that is quite common in our country.

The coexistence of HIV in patients with STI proctitis has been reported in many publications. Indeed, 70% of cases are considered to be HIV [12] positive. In the present study a similar rate of 69% of HIV positive patients was found. However it must be noted that there was a lack of HIV testing in 13 cases.

The mechanism underlying the association between HIV and STI proctitis is still unknown. It does not seem to be an opportunistic infection because most cases are HIV positive patients who receive antiretroviral treatment (HAART). This could be verified in 20% of our HIV positive cases. Infection with an STD has been considered to enhance HIV transmission, which should be of concern in HIV-negative patients. It is worthy to mention that some HIV positive patients showed lack of interest to avoid infecting their partner, even though they were aware of their contagious disease.

There is a wide range of endoscopic findings in STI proctitis and the most common finding is the ulcerated lesion [2]. In our study more than half of the cases presented as multiple or single ulcers. Garg [13] reported a case of Chlamydia related proctitis described as multiple discontinuous ulcers in the rectum. In Madrid, López-Vicente [14], reported 04 cases of Chlamydia also described as ulcers. Likewise, Arnold reported rectal ulcers as the most frequent presentation of STD proctitis in 7 of their 10 reported cases. Gopal [10] also reported rectal ulcer as the most frequent presentation in 3 of their 4 published cases. The ulcers of our patients were mostly multiple and 04 were suspicious for malignancy but none required surgical management.

The mass or pseudo tumor type lesion is another interesting but unusual endoscopic presentation. Zhao [15] in China reported the case of a patient with rectal syphilis with a mass that occupied the entire circumference of the rectal wall, the diagnosis in this case avoided unnecessary surgery. Taylor [16] in the United Kingdom published a case of Lymphogranuloma venereum described as a friable mass that occupied the entire rectal circumference. Dhawan [12], reported a case of Chlamydia proctitis described as a single proliferative ulcer mass in the rectum. Gopal [10] reported a case of syphilis as an ulcerated multilobed mass highly suspicious of malignancy. Garcia [17] in Spain reported a case associated with Chlamydia with a multilobular and ulcerated pseudo-tumor aspect in the anorectal region. We found 6 cases (11%) described as masses or stenosing lesions, none of them required surgery.

According to Arnold [2], the main histological findings for the diagnosis of STI proctitis are: (a) mild distortion of the crypts; (b) dense and basal lymphoplasmacytic infiltrate and (c) scarcity of eosinophils.

In this study all cases showed these 3 features. The crypts were elongated and dilated in all cases and only occasionally focal branched (30%). Basal lymphoplasmacytic inflammation was usually severe and extending into submucosa in a third of cases. Perivascular plasmacytic infiltrate and endothelitis, which are described mainly in syphilis, were also found in a third of cases [18]. A normal average of 2.5 eosinophils by high—power field was found. These histological features could aid to discriminate from ulcerative colitis which is characterized by a striking architecture distortion with many branched crypts, unaffected submucosa and usually a rise in the number of eosinophils.

Neutrophils could be observed in all patients, cryptitis and microabscess was also found in some of them. According to different authors, the presence of neutrophils is predictive of chlamydial infection [16, 19]. Arnold et al. reported cryptitis in 80% of cases of STI proctitis. Levy [20] found microabscess in 58% of cases of lymphogranuloma venereum. In this regard, our findings are in accordance with the recommendation that neutrophilic activity does not help distinguish STI related proctitis from ulcerative colitis which also shows neutrophilic infiltrate, cryptitis and microabscess.

In 03 cases, clusters of macrophages with incomplete granulomas could be identified. Granulomas have been described as part of inflammatory response associated with syphilis and chlamydia [10, 21]. However, we did not find studies that estimate the prevalence of this finding in STI related proctitis. Sony et al. [19] found granulomas in 5 of 12 cases of chlamydia trachomatis. Tuberculosis is an important pathology to rule out in these cases. In fact, 2 of our cases were first studied as tuberculosis. The appearance of the granuloma is a helpful feature in distinguishing tuberculosis from STI related proctitis, which is deep and accompanied by caseous necrosis and giant cells in tuberculosis, whereas chlamydia or syphilis infection exhibit smaller granulomas and are devoid of caseous necrosis.

Definitive diagnosis of Chlamydia trachomatis requires culture or PCR. The culture could be difficult to obtain and has a low sensitivity [4]. At present, nucleic acid amplification test represents the gold standard for the diagnosis of Chlamydia. Even more, this technique through genotyping can identify the specific chlamydia serovars L1, L2 and L3 [12]. In this regard it has been established that L2 serovar has been the most frequently serovar found in recent epidemic outbreaks [22]. None of these complementary tests were found in our patients medical records. Thus, our study required immunohistochemistry study that helped us to identify retrospectively chlamydia infection.

Immunohistochemical study for Chlamydia trachomatis has been used sporadically and mainly in genitourinary pathology. In this regard, Chlamydia has been identified in cystitis [23] chronic endometritis [7] and placentas [24] of women with a history of recurrent miscarriage. However, in gastrointestinal pathology there is scarce information about this topic. In 2016 Van kruninjen [21] using immunohistochemistry showed positive staining for Chlamydia trachomatis in the cytoplasm of macrophages in submucosa and serosa of colon and ileum of 5 of 19 patients with crohn's disease. Further, Borel [25] using real time PCR detected chlamydia in the colon of 4 patients, 2 of them also stained positive for Chlamydia using immunohistochemistry.

In our study a third of STI related proctitis cases were positive for chlamydia using immunohistochemistry. We did not find similar published studies to compare our results. However, there is an investigation in Tel Aviv carried out using PCR [20] in 17 patients with STI related Proctitis, which demonstrated chlamydia infection in 82% of their cases. This difference highlights the greater sensitivity of molecular tests in relation to immunohistochemistry, but it also shows the importance of Chlamydia in the etiology of these lesions. It should be mentioned that a subset of 09 of Chlamydia positive cases also tested positive for syphilis by serology, this co-infection is not surprising given both germs share the same risk factors.

Adblock test (Why?)