Immunology of T-cell Response in Tuberculosis

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Questions and Answers

What is the relative risk of TB infection in patients receiving anti-TNF-$ treatment?

5% to 10%

1.5% to 17% (correct)

10% to 20%

0.5% to 5%

Which therapy demonstrates a higher risk of TB infection compared to others?

Corticosteroid therapy

Anti-IL immunobiological therapy

Soluble TNF-$ receptor therapy

Anti-TNF-$ monoclonal antibody therapy (correct)

What is a potential benefit of using anti-IL immunobiological therapies?

Higher efficacy in autoimmune diseases

Better safety profile (correct)

Increased risk of TB reactivation

Broader immunosuppressive effects

What role do Th17-related cytokines play in relation to M.tuberculosis?

They contribute to immunological protection. Signup and view all the answers

Which of the following is a characteristic of soluble TNF-$ receptor therapy?

Lower risk of TB infection. Signup and view all the answers

What is the primary concern with anti-TNF-$ therapies?

Increased risk of TB reactivation. Signup and view all the answers

What factor may contribute to the differing risks of TB infection between treatments?

The selectivity of the treatment. Signup and view all the answers

Which two monoclonal antibodies are mentioned as examples of anti-TNF-$ therapies?

Adalimumab and infliximab Signup and view all the answers

What kind of lesions are typically characterized by central necrosis and ulceration covered by crusts?

Punched-out lesions Signup and view all the answers

Which type of inflammatory infiltrate is found in the upper dermis?

Epithelioid cells Signup and view all the answers

Which condition is NOT included in the differential diagnosis of the lesions described?

Basal cell carcinoma Signup and view all the answers

What characteristic finding occurs after treatment or spontaneous resolution of the lesions?

Varioliform scars Signup and view all the answers

What is a common feature of the histopathology associated with these skin lesions?

Necrosis with dense granulomatous infiltrate Signup and view all the answers

What type of cells may be present in the granulomatous infiltrate?

Multinucleated giant cells Signup and view all the answers

Which organism has been associated with some cases of these lesions as demonstrated by PCR?

Mycobacterium tuberculosis Signup and view all the answers

Who was the first to describe erythema induratum of Bazin?

Ernest Bazin Signup and view all the answers

What is the likelihood of developing tuberculosis for immunocompetent individuals over their lifetime?

10% Signup and view all the answers

Which immune cells play a critical role in the defense against mycobacterial infections?

CD4+ and CD8+ T lymphocytes Signup and view all the answers

What percentage of tuberculosis cases are represented by extrapulmonary TB?

20% Signup and view all the answers

Which of the following conditions is classified as extrapulmonary tuberculosis?

Pleural TB Signup and view all the answers

What is the primary etiological agent of cutaneous tuberculosis?

Mycobacterium tuberculosis Signup and view all the answers

What does lupus vulgaris indicate in terms of immune response in cutaneous tuberculosis?

Active cell immunity Signup and view all the answers

Which statement accurately represents the relationship between T-cells and mycobacterium tuberculosis?

T-cells can eliminate M. tuberculosis Signup and view all the answers

What is a significant feature of scrofuloderma in cutaneous tuberculosis?

Less active cell immunity Signup and view all the answers

What is the preferred location of a painful ulcer due to tuberculous etiology in the lesions described?

On the face Signup and view all the answers

Which of the following is NOT a clinical variant of the lesions described?

Vascular Signup and view all the answers

What initial appearance is noted for the lesions caused by mycobacterioses?

Yellowish erythematous papule or nodule Signup and view all the answers

Which area is NOT commonly affected by mycobacterioses according to the information provided?

Neck Signup and view all the answers

How may oral cavity lesions extend according to the disease description?

By direct inoculation of m. tuberculosis or from expansion of a skin lesion Signup and view all the answers

What serious complication may arise from long-term lesions as described in the literature?

Malignant degeneration Signup and view all the answers

Which of the following is a common feature of the painful ulcers described?

Infiltrated base with irregular edges Signup and view all the answers

What effect does untreated disease have on the affected anatomical sites?

It causes deformities and destruction of structures Signup and view all the answers

What are the typical microscopic findings in EIB/NV?

Lobular or mixed septal/lobular granulomatous panniculitis Signup and view all the answers

Which of the following is NOT identified in EIB/NV lesions?

Ectopic sebaceous glands Signup and view all the answers

What is the purpose of Mycobacterium tuberculosis direct tests?

To detect the microorganism in biological material smears Signup and view all the answers

Which technique is most frequently used in laboratories for detecting AFB?

Ziehl-Neelsen technique Signup and view all the answers

In the context of cutaneous tuberculosis diagnosis, what types of biological material can be analyzed?

Fresh tissue or paraffin-embedded specimens Signup and view all the answers

What is typically observed in chronic lesions of EIB/NV?

Fibrosis Signup and view all the answers

Which condition is NOT part of the differential diagnosis for EIB/NV?

Melanoma Signup and view all the answers

Which of the following histological alterations is commonly associated with EIB/NV?

Areas of caseation necrosis Signup and view all the answers

Study Notes

T-Cell Immune Response and Tuberculosis

10% risk of developing tuberculosis (TB) in immunocompetent individuals over a lifetime; risk increases to 10% annually for HIV-infected individuals.
Extrapulmonary TB accounts for 20% of TB cases, affecting organs like pleura, bones, urinary tract, and meninges.

Cutaneous Tuberculosis (CTB)

CTB is a rare form of TB, representing 1-2% of all forms; primarily caused by Mycobacterium tuberculosis, occasionally by Mycobacterium bovis and the BCG vaccine strain.
First described in 1826 by Théophile Laënnec, who later died from the disease.
Identifies various forms of CTB, including lupus vulgaris (high cell immunity) and scrofuloderma (lower cell immunity).

Clinical Manifestations

Lesions usually present as yellowish erythematous papules/nodules progressing to painful ulcers; can occur in genital, oral, and other areas.
Specific rare cases include painful ulcers on labia majora in young females; lesions often display features like ulceration and scarring.
Multiple skin lesion variants exist: psoriasiform, eczema-like, annular, ulcerative, and hypertrophic lesions, causing significant deformities.

Histopathology

Granulomatous inflammation with epithelioid cells; multinucleated giant cells detected in some cases.
Lack of detectable M. tuberculosis in special stains, though PCR can identify its DNA.

Differential Diagnosis

CTB must be differentiated from conditions like lichen planus, erythema nodosum, and other skin ailments resembling TB.
Ernest Bazin described erythema induratum, with similar granulomatous characteristics requiring differential diagnosis from other inflammatory skin conditions.

Diagnosis of Cutaneous Tuberculosis

Diagnosis may involve the Ziehl-Neelsen technique for staining biological material; sensitivity for detecting bacillus is low.
Risk of TB infection in patients on anti-TNF therapies ranges from 1.5% to 17%, with monoclonal antibodies posing a higher risk than soluble TNF receptor treatments.

Immunological Insights

Th17-related cytokines are suggested to enhance protection against primary M. tuberculosis infections.
New immunobiologicals targeting interleukins aim for better safety in patients, potentially reducing TB reactivation risks compared to TNF-$ inhibitors.

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Description

This quiz explores the T-cell immune response and its significance in defending against tuberculosis, particularly in immunocompetent individuals and those infected with HIV. Understand the roles of dendritic cells and activated macrophages in this critical immune mechanism.