Histopathologic pattern analysis of human intracutaneous tuberculin reaction

IFN-γ Release Assay Result Is Associated with Disease Site and Death in Active Tuberculosis

RATIONALE

The IFN-γ release assays and tuberculin skin tests are used to support the diagnosis of both latent and active tuberculosis. However, we previously demonstrated that a negative tuberculin test in active tuberculosis is associated with disseminated disease and death. It is unknown whether the same associations exist for IFN-γ release assays.

OBJECTIVES

To determine the association between these tests and site of tuberculosis and death among persons with active tuberculosis.

METHODS

We analyzed IFN-γ release assays and tuberculin test results for all persons with culture-confirmed tuberculosis reported to the U.S. National Tuberculosis Surveillance System from 2010 to 2014. We used logistic regression to calculate the association between these tests and site of disease and death.

MEASUREMENTS AND MAIN RESULTS

A total of 24,803 persons with culture-confirmed tuberculosis had either of these test results available for analysis. Persons with a positive tuberculin test had lower odds of disseminated disease (i.e., miliary or combined pulmonary and extrapulmonary disease), but there was no difference in the odds of disseminated disease with a positive IFN-γ release assay. However, persons who were positive to either of these tests had lower odds of death. An indeterminate IFN-γ release assay result was associated with greater odds of both disseminated disease and death.

CONCLUSIONS

Despite perceived equivalence in clinical practice, IFN-γ release assays and tuberculin test results have different associations with tuberculosis site, yet similar associations with the risk of death. Furthermore, an indeterminate IFN-γ release assay result in a person with active tuberculosis is not unimportant, and rather carries greater odds of disseminated disease and death. Prospective study may improve our understanding of the underlying mechanisms by which these tests are associated with disease localization and death.

Tuberculine reaction measured by infrared thermography

SETTING

The infection with Mycobacterium tuberculosis gives a delayed immune response, measured by the tuberculine skin test. We present a new technique for evaluation based on automatic detection and measurement of skin temperature due to infrared emission.

DESIGN

34 subjects (46.8±16.9 years) (12/22, M/F) with suspected tuberculosis disease were examined with an IR thermal camera, 48 h after tuberculin skin injection.

RESULTS

In 20 subjects, IR analysis was positive for tuberculine test. Mean temperature of injection area was higher, around 1°C, for the positive group (36.2±1.1°C positive group; 35.1±1.6°C negative group, p<0.02 T test for unpaired groups).

CONCLUSION

IR image analysis achieves similar estimation of tuberculin reaction as the visual evaluation, based on higher temperature due to increased heat radiation from the skin lesion.

Inflammatory and immune reactions associated with stratum corneum and neutrophils in sterile pustular dermatoses

In this review we present our own experimental findings as well as those from the literature related to the pathomechanisms for the inflammatory changes in psoriasis and its related diseases. A growing body of evidence has indicated that T cell-mediated immunity plays an important role in triggering and maintenance of psoriatic lesions. It has been revealed that lymphokines produced by activated T cells in psoriatic lesions have a strong influence on the proliferation of the epidermis. Characteristic neutrophil accumulation under the stratum corneum can be observed in the highly inflamed areas of psoriatic lesions. These neutrophils are chemotactically attracted and activated there by synergistic action of chemokines, IL-8 and Gro-alpha released by stimulated keratinocytes, and particularly by C5a/C5a des arg produced via the alternative complement pathway activation. We demonstrated that the infiltrating neutrophils adhere to iC3b-opsonized corneocytes to produce active oxygen and probably lysosomal enzymes. From a close relationship observed between neutrophil accumulation and high mitotic ratio of the lesional epidermis, we think that these stimulated neutrophils influence the growth and differentiation of epidermal keratinocytes. Aberrant expression of HLA-DR on neutrophils suggests their activation of infiltrating T cells in the presence of bacterial superantigen. These T cells in turn influence the transepidermal neutrophil migration through the effect of their cytokines on the keratinocyte production of proinflammatory mediators including IL-8 and C3. In this review we discuss the pivotal roles played by stratum corneum and neutrophils in several skin diseases, where neutrophils accumulate beneath the stratum corneum in a sterile condition.

Immunohistochemical characterization of mononuclear cells in delayed hypersensitivity reactions to Paracoccidiodes brasiliensis (paracoccidioidin test)

The density and distribution of T cells, T helper cells, macrophages and B cells at the site of skin tests with a cytoplasmic Paracoccidioides brasiliensis antigen (paracoccidioidin) was studied at 24 and 48 h post-challenge in 10 patients with the chronic form of paracoccidioidomycosis and in 5 non-infected individuals. The in situ study was carried out using immunoperoxidase techniques and monoclonal antibodies. The controls showed negative skin test. In the patients, the great majority of the cells in the perivascular foci were T cells (CD43-positive cells) making up 47% and 48.6% of the total number of cells at 24 and 48 h respectively. Most of the T cells showed a T helper phenotype (CD45RO-positive cells). Approximately 25% of the cells were macrophages (CD68-positive cells) and there were very few B lymphocytes (CD20-positive cells). The present data on the microanatomy of paracoccidioidin skin test sites were consistent with a delayed type hypersensitivity pattern. Our results were comparable to those reported on skin tests for other granulomatous chronic diseases.

Skin test to assess immunity against cottontail rabbit papillomavirus antigens in rabbits with progressing papillomas or after papilloma regression

This study analyzed in vivo antiviral cellular immune reactions in the Shope rabbit papilloma-carcinoma model. Antigens studied in experimentally infected domestic rabbits were cottontail rabbit papillomavirus particles produced with the athymic (nu/nu) mouse xenograft system and bacterial fusion proteins containing the major or minor capsid protein. Recall reactions to antigens were tested by classic intracutaneous tests. Positive reactions had a biphasic course. Histopathology of skin test biopsy specimens showed infiltrating polymorphonuclear cells during the early stages. Later they were replaced by predominantly perivascular infiltrates composed of mononuclear cells. Time course of swelling and infiltrates resembled a delayed-type hypersensitivity reaction. Ten of 11 regressor rabbits (p = 0.00006) and 10 of 20 progressors (p = 0.009) had positive skin tests with intact and/or denaturated virus particles and individual capsid proteins also could elicit specific skin reactions. Skin reactivity to the cottontail rabbit papillomavirus particles was also greater (p = 0.042) in regressor rabbits (8 of 11) when compared to progressors (7 of 20). Recall reactions remained detectable at post-regression times, ranging from several months up to more than 2 years. We conclude that specific skin reactions against the cottontail rabbit papillomavirus in infected domestic rabbits exist, and are strongly positive to intact particles of this papillomavirus in animals (regressors) clinically free of disease.

Characterization of cellular infiltrates and cytokine production during the expression phase of the anticryptococcal delayed-type hypersensitivity response

Cryptococcosis, an increasingly important opportunistic infection caused by the encapsulated yeast-like organism Cryptococcus neoformans, is limited by an anticryptococcal cell-mediated immune (CMI) response. Gaining a thorough understanding of the complex anticryptococcal CMI response is essential for developing means of controlling infections with C. neoformans. The murine cryptococcosis model utilizing footpad swelling to cryptococcal antigen (delayed-type hypersensitivity [DTH]) has proven to be a valuable tool for studying the induction and regulation of the anticryptococcal CMI response, but this technique has limitations with regard to evaluating the role of the final effector cells recruited by an ongoing CMI response. The purpose of this study was to assess the types of cells and cytokines induced into the site of cryptococcal antigen deposition in C. neoformans-infected and -immunized mice compared with those for control mice. We used a gelatin sponge implant model to examine the cells and cytokines present at the site of an anticryptococcal DTH response. Sponges implanted in infected mice and injected with cryptococcal culture filtrate antigen (CneF) 24 h before assessment had significantly increased numbers of infiltrating leukocytes compared with saline-injected sponges in the same animals. Exaggerated influxes of neutrophils and mononuclear cells were the major contributors to the increase in total numbers of cells in the DTH-reactive sponges. The numbers of CD4+ and LFA-1+ cells were found to be significantly increased in the CneF-injected sponges of infected and immunized mice over the numbers in control sponges. The numbers of large granular lymphocytes were also increased in DTH-reactive sponges compared with control sponges. Gamma interferon, interleukin 2 (IL-2), and IL-5 are clearly relevant cytokines in the anticryptococcal CMI response, since they were produced in greater amounts in the CneF-injected sponges from C. neoformans-infected and -immunized mice than in control sponges. IL-4 was not associated with the expression of DTH to cryptococcal antigen. The gelatin sponge model is an excellent tool for studying cells and cytokines involved in specific CMI responses.

Histoanalytical study of the cellular infiltrate in the tuberculin reaction

In contrast to the generally held view, in previous studies it has been found that the histopathological changes in delayed-type hypersensitivity reactions to intradermal purified protein derivative of tuberculin (PPD) in humans were not uniform. These were classified into three types based on their resemblance to features seen in other dermatoses, i.e.: (i) perivascular dermatitis type; (ii) basal spongiotic dermatitis type; and (iii) erythema multiforme type. These histopathological patterns correlated well with the clinical response seen in tuberculin hypersensitivity of tested subjects. In the present study, the immunohistopathological features in 44 skin biopsy specimens were assessed quantitatively by using multivariate analysis. The numbers of infiltrating cells in the epidermis and in the dermis which were immunohistologically positive to monoclonal antibodies against various mononuclear cells were counted separately to determine if there was any statistical correlation between the histopathological patterns and the phenotypes of infiltrating cells. As a result, a significant correlation was found between the histopathological patterns and the phenotypes of cells infiltrating the epidermis, such as CD8+ cells, CD4+ cells, CD11c+ cells and interleukin 2 receptor positive cells. All these cells showed a high correlation coefficient to the expression of HLA-DR antigen by keratinocytes. Next, factors that might regulate the inflammation and interaction among the infiltrating cells were assessed.(ABSTRACT TRUNCATED AT 250 WORDS)

Histometric studies on cellular infiltrates of tuberculin tests in patients with sarcoidosis

The density and microanatomical location of CD4 and CD8 lymphocytes and of monocytes/macrophages at the site of a tuberculin test were measured in 13 patients with sarcoidosis, and the results were compared with those seen in a group of healthy controls. The cellular infiltrate was significantly reduced in the sarcoid subjects compared with the controls for all cell phenotypes studied; the ratio of CD4 positive:CD8 positive lymphocytes was significantly increased in the sarcoid group. Clinically negative reactions showed substantial numbers of infiltrating mononuclear cells, although not as great as in clinically apparent reactions. A clinically negative tuberculin reaction does not necessarily imply anergy to the test substance and should not be termed "negative".

Predominantly indurated reactions to sensitizers may not cause keratinocytes to express HLA-DR

Dermal reactions to primary intradermal or appendageal sensitization are compared to predominantly dermal reactions to standard patch tests and to intradermal antigen tests. In contrast to epicutaneous spongiotic contact dermatitis, HLA-DR was only seen on skin appendages and nearby basal keratinocytes in indurated tissue reactions with the exception of the reactions with focal basal cell layer disruption and an indurated patch test performed one week post angry back syndrome. Other intradermal skin tests showed only minimal epidermal HLA-DR expression despite spongiotic epidermal changes. Predominantly dermal hypersensitivity reactions can be induced by intradermal or epicutaneous routes. They can evoke hypersensitivity responses which do not cause most epidermal keratinocytes to express HLA-DR.

Abnormal cutaneous topobiology: the molecular basis for dermatopathologic mononuclear cell patterns in inflammatory skin disease

Because of the identification and characterization of various adhesion molecules (lymphocyte function associated antigen-1, intercellular adhesion molecule-1), chemotactic factors (interleukin-8, monocyte chemotactic/activating factor), and their modulatory cytokines (gamma interferon, tumor necrosis factor), it is possible to begin to ascribe specific molecules to cutaneous cellular reaction patterns. The abnormal topobiology, or altered spatial distribution, of mononuclear cells, which gives rise to disease-specific patterns, was described in molecular terms. A large number of diverse skin diseases were classified into six different groups, with each group highlighting distinctive cell types, adhesion molecules, chemotactic factors, and cytokines. The diseases within each group, which share functional anatomical reaction zones, were postulated to share common pathophysiologic pathways. Thus, it is now possible, as one scans the microscopic field, to look past the static images of red- and blue-stained cells and appreciate a dynamic and detailed medley of molecularly defined events emanating from the eyepiece.