The morphological spectrum of lymphadenopathy in HIV infected patients

Macrophage immunophenotypes in Jorge Lobo's disease and lepromatous leprosy- A comparative study

Jorge Lobo's disease (JLD) and lepromatous leprosy (LL) share several clinical, histological and immunological features, especially a deficiency in the cellular immune response. Macrophages participate in innate and adaptive inflammatory immune responses, as well as in tissue regeneration and repair. Macrophage function deficiency results in maintenance of diseases. M1 macrophages produce pro-inflammatory mediators and M2 produce anti-inflammatory cytokines. To better understand JLD and LL pathogenesis, we studied the immunophenotype profile of macrophage subtypes in 52 JLD skin lesions, in comparison with 16 LL samples, using a panmacrophage (CD68) antibody and selective immunohistochemical markers for M1 (iNOS) and M2 (CD163, CD204) responses, HAM56 (resident/fixed macrophage) and MAC 387 (recently infiltrating macrophage) antibodies. We found no differences between the groups regarding the density of the CD163, CD204, MAC387+ immunostained cells, including iNOS, considered a M1 marker. But HAM56+ cell density was higher in LL samples. By comparing the M2 and M1 immunomarkers in each disease separately, some other differences were found. Our results reinforce a higher M2 response in JLD and LL patients, depicting predominant production of anti-inflammatory cytokines, but also some distinction in degree of macrophage activation. Significant amounts of iNOS + macrophages take part in the immune milieu of both LL and JLD samples, displaying impaired microbicidal activity, like alternatively activated M2 cells.

The Diagnostic Challenge of an Infrequent Spectrum of Cryptococcus Infection

Cryptococcal infection results from inhalation of fungal spores and usually is confined to the lungs, but may disseminate systemically. Radiologically, cryptococcal infection has multiple forms of presentation. The diagnosis is usually based on fungal isolation from cultured clinical specimens. Long term antifungal therapy is recommended, but surgical procedures may eventually be necessary when large thoracic symptomatic masses are present. We report a case of a 41-year-old male, immunocompetent, investigating a palpable mass in the left supraclavicular region associated with unintentional weight loss over the last three months. He also reported chest pain in this period. Chest X-ray, ultrasonography, and computed tomography were performed, which diagnosed a mediastinal and left supraclavicular mass, interpreted as lymph node conglomerates of unknown etiology. He also underwent a biopsy of the left supraclavicular mass for etiological determination by histopathology, which confirmed cryptococcosis infection. Although very infrequent, mediastinal cryptococcal infection (simulating masses) is a challenging but important differential diagnosis of benign and malignant lesions, since its treatment is usually clinical.

HIV-1 and the Mycobacterium tuberculosis granuloma: A systematic review and meta-analysis

Infection with HIV-1 greatly increases the risk of active tuberculosis (TB). Although hypotheses suggest HIV-1 disrupts Mycobacterium tuberculosis (Mtb) granuloma function, few studies have examined this directly. The objective of this study was to determine what evidence exists about the effect HIV-1 co-infection has upon Mtb granulomas. A systematic search of PubMed, Web of Science, and Medline up to 20 March 2015 was conducted, to identify studies comparing Mtb-infected tissue from HIV-1 infected and uninfected persons, or HIV-1 infected persons with stratified peripheral CD4 T cell (pCD4) counts. We summarized findings that focused on how HIV-1 changes granuloma formation, bacterial presence, cellular composition, and cytokine production. Nineteen studies with a combined sample size of 899 persons were included. Although studies frequently were limited by variable or inadequately described definitions of outcomes and analytical methods, HIV-1 was found to be associated with increased bacillary load within Mtb-infected tissue. Reductions in pCD4 counts within co-infected persons associated with both poorer granuloma formation and higher bacterial load. The high degree of heterogeneity among studies combined with experimental limitations made it difficult to conclusively support previously published and prevalent hypotheses about HIV-1/Mtb co-infection granulomas. To elucidate the validity of these hypotheses we have described areas that can be improved in future studies in order to clarify the influence HIV-1 co-infection has upon the Mtb granuloma.

Utility of endobronchial ultrasound-guided transbronchial needle aspiration in diagnosis of intrathoracic lymphadenopathy in patients with human immunodeficiency virus infection

Objective. Intrathoracic lymphadenopathy (LAD) in patients with Human Immunodeficiency Virus (HIV) infection is common, with wide-ranging diagnoses, from benign to malignant causes. Endobronchial Ultrasound-guided Transbronchial Needle Aspiration (EBUS-TBNA) is a relatively new technology with established applications in lung cancer, sarcoidosis, and tuberculosis. We sought to find out whether the addition of EBUS-TBNA to the diagnostic algorithm for LAD in HIV patients will reduce the need for mediastinoscopy. Methods. Retrospective chart review of all EBUS-TBNA procedures performed in our centre from August 2008 to December 2012. Results. 513 patients had EBUS-TBNA performed during this period. We identified nine HIV-infected patients who had LAD of unknown cause and underwent EBUS-TBNA. The procedure reduced the need for mediastinoscopy in eight patients (89%). Conclusions. Potential mediastinoscopies can be avoided by utilising EBUS-TBNA in HIV patients with LAD.

Frequncy and etiology of lymphadenopathy in Iranian HIV/AIDS patients

OBJECTIVE

To estimate and outline the frequency and etiology of lymphadenopathy in HIV/AIDS patients.

METHODS

This study was conducted on 178 consecutive HIV/AIDS patient files for etiologies (categorized into three sub-groups: definite, probable and possible) and associated factors of local and generalized lymphadenopathy.

RESULTS

Seventy-two (40.45%) patients including 63 male patients (87.5%) developed lymphadenopathy. HIV in lymphadenopathy(+) patients was most commonly transmitted intravenously (n=49). Generalized and localized lymphadenopathy respectively occurred in 27 (37.50%) and 45 (62.50%) patients, mainly in the cervical region (28.9% for local and 63% for generalized lymphadenopathy). The most common causes of lymphadenopathy were tuberculosis (n=24, 33.3%) and lymphoma (n=12, 16.6%). The frequency of lymphadenopathy was non-significantly higher in patients with AIDS (CD4 count <200 cell/µL) vs. HIV(+) patients (CD4 count >200 cell/µL).

CONCLUSIONS

Lymphadenopathy in HIV/AIDS patients may reflect a serious condition, most likely tuberculosis and lymphoma. Since patients might underestimate lymphadenopathy, physicians would rather list these entities for diagnosis.

Infectious lymphadenitis in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma: a rare, but important, complication

The differential diagnosis of rapidly progressive or symptomatic lymphadenopathy in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) includes infectious lymphadenitis. We studied 286 (9%) of 3040 patients with CLL seen between 2003 and 2012 at Mayo Clinic Rochester who had 356 diagnostic lymph node biopsies to evaluate rapidly progressive or symptomatic lymphadenopathy. Most (85.4%) biopsies showed progressive CLL, 8.9% a second lymphoid malignancy, 3.9% infectious lymphadenitis, 1.1% reactive adenitis and 0.6% non-hematological malignancies. Of the 12 patients (14 biopsies) with infectious lymphadenitis, five patients had never been treated for their CLL, and seven had a specific microbiological diagnosis (herpes simplex n=3, Cryptococcus neoformans n=1, Mycobacterium n=1, coagulase negative Staphylococcus n=2). We conclude that infectious lymphadenitis is a rare complication of CLL with clinical characteristics similar to progressive CLL and transformation to a more aggressive lymphoma. Early recognition and antimicrobial therapy treatment of infectious lymphadenitis can be highly effective in these patients.

[Infectious lymphadenitis]

Infectious lymphadenitis is often biopsied in the differential diagnoses of malignant disease. Since the repertoire of lymph nodes which react to exogenous stimuli is limited, malignant lymphomas may enter the clinical and morphological differential diagnosis. In a morphological sense, infectious lymphadenitis is defined as an infection of lymph node tissue. Therefore, the effector phase of the inflammatory reaction will act against lymphatic tissue, in contrast to common physiological hyperplasia. Follicular reactions, in addition to follicular hyperplasia, are seen in HIV-associated lymphadenopathy. Other viruses, such as infectious mononucleosis, give rise to a cytotoxic T-cell reaction. Most infections, however, induce a histiocytic reaction; depending on the microorganism, this varies morphologically from a small clustered epithelioid cell reaction or histiocytic abscesses to epithelioid necrotizing granulomata.