IFI44L as a Forward Regulator Enhancing Host Antituberculosis Responses.

Interferon-induced protein 44-like (IFI44L) gene is a type I interferon-stimulated gene (ISG) that plays a critical role in antiviral activity and constitutes a promising diagnostic marker. However, its precise role and function in tuberculosis have not been unveiled. This study showed that IFI44L acts as an antimicrobial target and positive modulator in human macrophages. Knockdown of IFI44L led to increased Mycobacterium tuberculosis intracellular survival. Moreover, IFI44L was significantly upregulated, and it restricted the intracellular survival of M. tuberculosis H37Rv strains at 72 h after rifampicin treatment. Individuals with cutaneous tuberculosis (CTB) were found to have significantly higher IFI44L expression after 6 months of rifampicin therapy than after only 1 month. These results demonstrated that IFI44L induced positive regulation and clearance of M. tuberculosis from human macrophages. This antimicrobial activity of IFI44L makes it a possible target for therapeutic applications against M. tuberculosis.

Disseminated tuberculosis associated with reactive arthritis of Poncet in an immunocompetent patient

Abstract Cutaneous tuberculosis is a rare extrapulmonary manifestation of tuberculosis which, like disseminated tuberculosis, commonly occurs in immunocompromised patients. Poncet reactive arthritis is a seronegative arthritis affecting patients with extrapulmonary tuberculosis, which is uncommon even in endemic countries. We report a previously healthy 23-year-old male patient with watery diarrhea associated with erythematous ulcers on the lower limbs and oligoarthritis of the hands. Histopathological examination of the skin showed epithelioid granulomatous process with palisade granulomas and central caseous necrosis. AFB screening by Ziehl-Neelsen staining showed intact bacilli, the culture was positive for Mycobacterium tuberculosis, and colonoscopy revealed multiple shallow ulcers. Disseminated tuberculosis associated with reactive Poncet arthritis was diagnosed, with an improvement of the clinical and skin condition after appropriate treatment.

Disseminated tuberculosis associated with reactive arthritis of Poncet in an immunocompetent patient.

Cutaneous tuberculosis is a rare extrapulmonary manifestation of tuberculosis which, like disseminated tuberculosis, commonly occurs in immunocompromised patients. Poncet reactive arthritis is a seronegative arthritis affecting patients with extrapulmonary tuberculosis, which is uncommon even in endemic countries. We report a previously healthy 23-year-old male patient with watery diarrhea associated with erythematous ulcers on the lower limbs and oligoarthritis of the hands. Histopathological examination of the skin showed epithelioid granulomatous process with palisade granulomas and central caseous necrosis. AFB screening by Ziehl-Neelsen staining showed intact bacilli, the culture was positive for Mycobacterium tuberculosis, and colonoscopy revealed multiple shallow ulcers. Disseminated tuberculosis associated with reactive Poncet arthritis was diagnosed, with an improvement of the clinical and skin condition after appropriate treatment.

Pattern of Cross-Reactivity Between Mycobacterial Immunohistochemical Stain and Normal Human Eosinophils: A Potential Pitfall in the Diagnosis of Cutaneous Mycobacterial Infections.

Cutaneous tuberculosis (CTB) is a challenging diagnosis that often requires tissue biopsy and the use of immunohistochemical (IHC) staining, among other special stains. The mycobacterium tuberculosis IHC stain is believed to be specific for mycobacteria and closely related organisms, without documented reactivity to normal human tissue. In this study, we document 4 cases of previously unreported cross-reactivity between the mycobacterium tuberculosis IHC polyclonal antibody and normal eosinophil granules in patients without other evidence of CTB infection. Such cross-reactivity represents a potential pitfall for the use of IHC in the diagnosis of CTB.

A Rare Manifestation of Tuberculosis in a Renal Transplant Patient: A Case Report.

Cutaneous lesions in the presence of fever in patients undergoing immunosuppressive therapy are a diagnostic challenge and may represent manifestations of multiple diseases, such as fungal infections, nocardiosis, lymphoproliferative diseases, zoonosis, and tuberculosis. The authors report a case of a 66-year-old white man with chronic kidney disease since 2014 (chronic pyelonephritis) who had a renal transplant in the previous 6 months. Induction therapy was performed with thymoglobulin, and his current immunosuppression scheme included tacrolimus, mycophenolate mofetil, and prednisolone. The patient had no history of pulmonary tuberculosis. The patient presented with 2 cutaneous lesions, localized on the back and abdomen, that appeared to be firm, painful, subcutaneous, erythematous nodules with an approximately 5 cm diameter overlying an infected focus and purulent material inside. The patient also had a fever and fatigue. Blood analysis showed pancytopenia with an elevation of inflammatory markers and graft dysfunction. Tissue cultures and skin biopsy with histological analysis were performed. Histopathology of the lesion showed a nonspecific inflammatory infiltrate without granulomas, and acid-fast bacillus staining was negative. Nevertheless, serum QuantiFERON testing was positive. But polymerase chain reaction finally confirmed the presence of Mycobacterium tuberculosis, which confirmed the diagnosis of cutaneous tuberculosis. A chest computed tomography scan showed a lung pattern of miliary tuberculosis. The patient was treated with multidrug tuberculosis therapy, resulting in lesion clearance after 3 weeks. Tuberculosis is a serious infection, especially in high-risk patients, such as those in an immunocompromised state. The incidence of cutaneous tuberculosis is rare, but it should be considered in patients presenting with atypical skin lesions suggestive of an underlying infectious etiology.

Tuberculous gummas: Epidemiological, clinical, bacteriological, immunological, and therapeutic features.

Tuberculous gummas are an unusual form of tuberculosis (TB) accounting for 1%-2% of all cutaneous TB cases. The aim of this article was to describe the epidemiological, clinical, bacteriological, immunological, and therapeutic features of this form upon a case report and a literature review. Forty-eight case reports were identified through a PubMed and Google Scholar search using the following keywords: "tuberculous gumma" and "metastatic tuberculous abscesse." Tuberculous gumma can occur at any age. Immunodepression is not a sine qua non condition to the development of the disease. Limbs are the most frequent site for gummas. Tuberculous gummas are associated to another location in only 73% of cases. The most frequent associated locations are lung, nodes, and musculoskeletal apparatus. Mantoux test is negative in 38% of cases. Skin stain is positive in 45% of cases and culture in 85% of cases. Giant epithelioid cell granuloma is present in 82.4% of cases. There is no universally accepted chemotherapy regimen for metastatic tuberculous abscesses. The classic 2RHZE/4RH is highly effective.

Cutaneous and articular tuberculosis in a renal transplant recipient.

Seven months after undergoing kidney transplantation, a 56-year-old woman presented with papules and ulcers in her right forearm. The patient received antibiotics for 8 months with limited improvement. Eleven months after symptom onset, she presented with acute arthritis in her left knee. Asynovial fluid culture yielded Mycobacterium tuberculosis, and a forearm ulcer biopsy showed granulomatous inflammation. After surgical fistulectomy and 12 months of tuberculosis treatment, she was cured. Chronic cutaneous ulcers and articular manifestations in TB are rare, but they should always be considered in the differential diagnosis for immunosuppressed patients. Surgical intervention and prolonged treatment might be necessary.

Cutaneous and articular tuberculosis in a renal transplant recipient

Abstract Seven months after undergoing kidney transplantation, a 56-year-old woman presented with papules and ulcers in her right forearm. The patient received antibiotics for 8 months with limited improvement. Eleven months after symptom onset, she presented with acute arthritis in her left knee. Asynovial fluid culture yielded Mycobacterium tuberculosis, and a forearm ulcer biopsy showed granulomatous inflammation. After surgical fistulectomy and 12 months of tuberculosis treatment, she was cured. Chronic cutaneous ulcers and articular manifestations in TB are rare, but they should always be considered in the differential diagnosis for immunosuppressed patients. Surgical intervention and prolonged treatment might be necessary.

BCG and Kawasaki disease in Mexico and Japan.

Dr. Tomisaku Kawasaki was the first to describe BCG reactivation in Kawasaki Disease (KD), and this sign is present in about 30-50% of KD patients. It is a very specific early sign of the disease and although it has been recognized for decades, its pathophysiology continues to be an enigma. Recently, Yamada et al. reported a severe BCG reaction with tuberculid in 2 Japanese KD patients. We present 2 cases with KD and severe BCG reaction, one from Japan and the other from Mexico and review the policies of administration of BCG in both countries. The BCG vaccine has a worldwide coverage of 88%. Differences in BCG strains and methods of administration may influence BCG reactions in KD. The BCG reaction in the inoculation site may represent the most useful sign in KD.

Effects of MBL-associated serine protease-2 (MASP-2) on liquefaction and ulceration in rabbit skin model of tuberculosis.

Tuberculosis is a chronic infectious disease, which caused by Mycobacterium tuberculosis. It typically affects the functions of the lung and causes high morbidity and mortality rates worldwide. The lectin pathway, one of the complement cascade systems, provides the primary line of defense against invading pathogens. However, what is the specific effection between tuberculosis and complement is unknown. Mannose-binding lectin (MBL), a recognition subunit, binds to arrays of carbohydrates on the surfaces of pathogens, which results in the activation of MBL-associated serine protease-2 to trigger a downstream reaction cascade of complement system. The effects of human MBL-associated serine protease-2 (hMASP-2) were assessed in a rabbit-skin model by intradermal injection of 5 × 106 viable BCG bacilli. The rAd-hMASP-2 accelerated the formation of liquefaction and healing of the granuloma lesions, reduced the bacteria loads of the skin nodules. The serum levels of IL-2 and IFN-γ were significantly increasing during the granuloma and liquefaction phases in the rAd-hMASP-2 group. This study suggests that hMASP-2 can induce a protective efficacy in BCG-infected rabbit skin models, which affects both the progress of lesions and the survival of the mycobacteria within them.

An immunocompetent young patient with tuberculosis of the penis: a challenging case.

Tuberculous chancre is an extremely rare form of cutaneous tuberculosis. The genital area is a possible site of presentation. We present a case of a young male with a persistent balanopreputial ulceration resembling a luetic chancre with negative serology for syphilis. The diagnosis was based on the specific pathologic features and the positive intradermal reaction to tuberculin. A successful treatment was achieved by combining antituberculosis treatment and surgical approach with circumcision. After six months of antituberculosis treatment, the patient developed paradoxical inguinal lymph node enlargement, which, after surgical excision and biopsy, was not followed by a relapse of the disease and needed no further therapy. Tuberculosis should be considered a potential diagnosis in the case of a persistent genital ulcer.

Multifocal tuberculosis verrucosa cutis.

Tuberculosis Verrucosa Cutis (TBVC), a verrucous form of cutaneous tuberculosis, occurs from inoculation of tubercle bacilli into the skin of a previously sensitized patient with moderate to high degree of immunity. This disease is now rare in western countries and in India; the incidence of cutaneous tuberculosis has fallen from 2% to 0.15%. However two recent studies from the Indian subcontinent have reported the prevalence of cutaneous tuebrculosis as 0.7% (Varshney et al) and 0.26% (Patra et al) This case is reported to demonstrate the indolent and extensive nature of tuberculosis verrucosa cutis in an immunocompetent individual and to highlight the importance of histopathology and empirical antitubercular therapy as an adjunct diagnostic tool.

Virulence and immune response induced by Mycobacterium avium complex strains in a model of progressive pulmonary tuberculosis and subcutaneous infection in BALB/c mice.

The genus Mycobacterium comprises more than 150 species, including important pathogens for humans which cause major public health problems. The vast majority of efforts to understand the genus have been addressed in studies with Mycobacterium tuberculosis. The biological differentiation between M. tuberculosis and nontuberculous mycobacteria (NTM) is important because there are distinctions in the sources of infection, treatments, and the course of disease. Likewise, the importance of studying NTM is not only due to its clinical significance but also due to the mechanisms by which some species are pathogenic while others are not. Mycobacterium avium complex (MAC) is the most important group of NTM opportunistic pathogens, since it is the second largest medical complex in the genus after the M. tuberculosis complex. Here, we evaluated the virulence and immune response of M. avium subsp. avium and Mycobacterium colombiense, using experimental models of progressive pulmonary tuberculosis and subcutaneous infection in BALB/c mice. Mice infected intratracheally with a high dose of MAC strains showed high expression of tumor necrosis factor alpha (TNF-α) and inducible nitric oxide synthase with rapid bacillus elimination and numerous granulomas, but without lung consolidation during late infection in coexistence with high expression of anti-inflammatory cytokines. In contrast, subcutaneous infection showed high production of the proinflammatory cytokines TNF-α and gamma interferon with relatively low production of anti-inflammatory cytokines such as interleukin-10 (IL-10) or IL-4, which efficiently eliminate the bacilli but maintain extensive inflammation and fibrosis. Thus, MAC infection evokes different immune and inflammatory responses depending on the MAC species and affected tissue.