Diagnostic Utility of Biplex/Multiplex Polymerase Chain Reaction in Infectious Granulomatous Dermatitis in North Indian Population.

BACKGROUND: A definite diagnosis of infectious granulomatous dermatitis (IGD) is difficult for both practicing dermatologists and dermatopathologists due to overlapping clinical and histomorphological features. We aimed to explore the role of multiplex polymerase chain reaction (PCR) for identifying a definite etiological agent for diagnosis and appropriate treatment in IGD in formalin-fixed paraffin-embedded tissue. MATERIALS AND METHODS: Sixty-two cases of IGD were included, excluding leprosy. The histochemical stains including Ziehl-Neelsen, periodic acid-Schiff, and Giemsa were performed in all cases. A multiplex PCR was designed for detection of tuberculosis (TB) (IS6110 and mpt64), fungal infections (ITS1, ITS2; ZM1, and ZM3), and leishmaniasis (kDNA). The results of histomorphology, histochemical stains, and multiplex PCR were compared. RESULTS: Among 62 cases, the sensitivity rate of PCR detection for organisms was 16.7%, 0%, 100%, 72%, 75%, and 66.7% in patients with TB, suggestive of TB, leishmaniasis, fungal infections, and granulomatous dermatitis not otherwise specified and granulomatous dermatitis suggestive of fungus, respectively. The TB PCR using IS6110 primers was negative in all cases; however, PCR using mpt64 primers was positive in 33.33% cases of scrofuloderma. The histochemical stains including Ziehl-Neelsen for acid-fast bacilli, periodic acid-Schiff for fungus, and Giemsa for Leishman-Donovan bodies showed positivity in 11.3%, 43.5%, and 3.2%, respectively. CONCLUSION: A multiplex PCR (Mycobacterium tuberculosis, Leishmania, and panfungal) is highly recommended in all cases of IGD where an etiological agent is difficult to establish by skin biopsy and histochemical stains along with a clinicopathological correlation. This will augment in appropriate treatment and will reduce empirical treatment and morbidity in such patients.

Clinicopathological features and the practice of diagnosing infectious cutaneous granulomas in Egypt.

OBJECTIVE: To present the clinicopathological features and the practice of diagnosing infectious cutaneous granulomas in Egypt. METHODS: This study included all cases diagnosed with infectious cutaneous granuloma during the period 2004-2010 at Al-Hussein University Hospital, Cairo. Clinical and histological features were recorded, along with the positivity rate (PR) for each diagnostic method. RESULTS: This study included 233 cases (150 males and 83 females) with a mean age of 47 years. Three groups of infection were recorded: bacterial infections (73.8% Mycobacterium and 3.9% non-Mycobacterium), parasitic infestations (16.7%), and deep fungal infections (5.6%). Tuberculosis cases formed the largest granuloma group (40.8%), followed by leprosy (31.7%) and leishmaniasis (15.9%). A total of 36 cases were diagnosed by direct smear (PR 15.5%), 61 cases by skin biopsy (PR 31.0%), 84 cases by intradermal test (PR 63.6%), 26 cases by serological tests (PR 60.5%), 18 cases by tissue culture (PR 69.2%), and eight cases by PCR (PR 100%). CONCLUSIONS: Mycobacterial infections constitute the most common infectious cutaneous granulomas among Egyptians. Routine methods such as direct smear, skin biopsy, and intradermal tests remain the most commonly applied and economical methods for diagnosis in developing countries, although specific methods such as tissue culture and PCR have higher positivity rates in the diagnosis.

[The 69th annual meeting symposium. II: Mechanism of necrotizing granuloma formation and its function].

Histological features of tuberculosis are caseation necrosis and epithelioid cell granuloma formation. Both phenomena are interpreted as expression of cellular immunity. Caseation necrosis is thought to be immunopathology and epithelioid cell granuloma formation is considered to be expression of protective immunity. Recently roles of cytokines for granuloma formation are gradually elucidated. In this symposium, mechanisms and functions of necrosis and granuloma formation Dr. Akagawa reported differentiation of two types of phenotypically different macrophages from human monocytes by GM (granulocyte-macrophage)-CSF or M (macrophage)-CSF. Interestingly such a basic differentiation induced by CSF was affected by IL-4 (interleukin-4). Langerhans-like dendritic cells were generated by cooperation of GM-CSF and IL-4, and multinucleated cells were generated by cooperation of IL-4 and M-CSF. Dr. Fukuda reported human Langerhans cell granulomatosis (LCG) from the pathological and immunohistochemical standpoints. In situ proliferation of LCs in the LCG was demonstrated by immunohistochemistry using antibody to PCNA (proliferating cell nuclear antigen) which is used to detect proliferating cells. In the course of granuloma formation, damage and disruption of lung structure such as alveolar basement membrane and elastic tissue framework, and reactive intraluminar fibrosis was observed. Mechanism of cystic dilation was also reported. Cytokines might play important roles in these events. Dr. Ina demonstrated experimental epithelioid cell granuloma formation. Extract (granuloma inducing factor, GIF) from Schistosoma mansoni Egg-induced granuloma, TNF -alpha, or IL-1 beta were coated, individually on the surface of beads, then these beads were inoculated to rat's skins or cultured with rat's monocytes. Four weeks later, epithelioid cell granuloma was demonstrated histologically and electronmicroscopically around beads in vitro and in vivo. GIF-induced granuloma was more organized than cytokine-induced ones. In vitro using human monocytes, activated macrophages accumulated around beads of which cytokines or GIF were coated. It was suspected that many cytokines or other factors are needed to make epithelioid cell granuloma. Dr. Sakamoto showed the presence of acid fast bacilli and various inflammatory cells including lymphocytes and macrophages in the tuberculous caseous necrosis after exudative reaction (E-necrosis) by immunohistochemistry. But no acid fast bacilli or inflammatory cells were found in the caseous necrosis after productive reaction (P-necrosis). TNF-alpha (tumor necrosis factor-alpha) and IL-4 were stained in the E-necrosis and IL-4 and ICAM-1 (intercellular adhesion molecule-1) were positively stained in the cytoplasm of epithelioid cells by immunohistochemistry. It was suspected that many cells and cytokines were involved in epithelioid cell granuloma formation and caseous necrosis formation.(ABSTRACT TRUNCATED AT 400 WORDS)