The use of polymerase chain reaction to confirm diagnosis in skin biopsies consistent with American tegumentary leishmaniasis at histopathology: a study of 90 cases

Comparison between Colorimetric In Situ Hybridization, Histopathology, and Immunohistochemistry for the Diagnosis of New World Cutaneous Leishmaniasis in Human Skin Samples

New world cutaneous leishmaniasis (NWCL) is an anthropozoonosis caused by different species of the protozoan Leishmania. Colorimetric in situ hybridization (CISH) was shown to satisfactorily detect amastigote forms of Leishmania spp. in animal tissues, yet it was not tested for the diagnosis of human NWCL. The aim of this study was to compare CISH, histopathology (HP), and immunohistochemistry (IHC) techniques to diagnose NWCL in human cutaneous lesions. The sample comprised fifty formalin-fixed, paraffin-embedded skin biopsy specimens from patients with NWCL caused by L. (V.) braziliensis. These specimens were analyzed by CISH, using a generic probe for Leishmania, IHC, and HP to assess the sensitivity of these methods by using a parasitological culture as a standard reference. Additional specimens from three patients diagnosed with cutaneous mycoses were also included to evaluate cross-reactions between CISH and IHC. The sensitivities of IHC, CISH, and HP for detecting amastigotes was 66%, 54%, and 50%, respectively. IHC, unlike CISH, cross-reacted with different species of fungi. Together, these results demonstrate that CISH may be a complementary assay for the detection of amastigote in the laboratorial diagnosis routine of human NWCL caused by L. (V.) braziliensis.

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.

Reemergence of zoonotic cutaneous leishmaniasis in an endemic focus, northeastern Iran

Zoonotic cutaneous leishmaniasis (ZCL) is a form of disease, which is mostly caused by Leishmania major (L.major) in the Old World with high incidence through early life. Recently, the high incidence of CL has been reported in Jajarm County, northeastern Iran. The aim of the present study was to investigate the epidemiological aspects of CL and to identify Leishmania spp. in the area. Between 2012 and 2018, patients with active lesions suspected of CL were examined. Diagnosis was performed by methods of clinical examination and direct smears. Conventional kDNA polymerase chain reaction (PCR) was used to identify species of Leishmania. During the seven-year study period, 629 subjects were diagnosed as CL cases by clinical and microscopic examination. Considering the population of the study area, the average incidence rate was 237.8 per 100,000 population. Most (29.4%) of the subjects with ZCL were aged <10 years. Most of the patients (58.7%) were male and the rest were female. Most ulcers were observed on the face (32.2%) and hands (23.7%), respectively. Most patients (90%) had two or more ulcers on their body. The highest incidence was in the autumn in October (32%). Our data revealed that an ongoing reemergence of ZCL focus caused by L.major has arisen in the study area. Moreover, direct PCR on the smears for identifying Leishmania showed 100% specificity, and the species was identified as L. major using species -specific kDNA PCR. The use of conventional PCR on skin smears seems to provide a valuable method for confirming the clinical diagnosis of ZCL, which is very specific and sensitive particularly for clinical correlative studies. Further investigations are needed to improve planning strategies of vectors and reservoirs populations.

Cutaneous leishmaniasis: A pathological study of 360 cases with special emphasis on the contribution of immunohistochemistry and polymerase chain reaction to diagnosis

BACKGROUND

Traditional methods for the diagnosis of leishmaniasis yield poor sensitivity, which limits its effectiveness in lesions with a low parasite burden.

METHODS

Retrospective pathologic study of 360 cases of cutaneous leishmaniasis and analysis of the different diagnostic methods used.

RESULTS

In 93% of the lesions, histopathology showed a dense and diffuse inflammatory infiltrate, consisting of lymphocytes, histiocytes and plasma cells, which occupied the superficial and mid dermis and variably extended to deep dermis and superficial subcutis (standard pattern). The remaining cases exhibited atypical features, such as perivascular, interstitial or perifollicular inflammatory patterns, folliculitis or panniculitis. Granulomas were identified in 84% of biopsies, most of them as small, poorly formed, non-necrotizing histiocytic aggregates. Amastigotes were visualized by routine histopathologic exam in 36% of biopsies. Immunohistochemistry stained 17 of 26 lesions (65%) negative by conventional stains. PCR provided the correct diagnosis in 218 cases (58% of the series) negative for Leishmania by other techniques.

CONCLUSIONS

Biopsies negative for Leishmania by traditional diagnostic methods that show the histopathologic standard pattern, those with atypical features from patients with clinical suspicion of cutaneous leishmaniasis in endemic areas, should be studied by immunohistochemistry and/or PCR for Leishmania in order to reach the definitive diagnosis.

Identification of Leishmania species by high-resolution DNA dissociation in cases of American cutaneous leishmaniasis

Background

American cutaneous leishmaniasis is an infectious dermatosis caused by protozoa of the genus Leishmania, which comprises a broad spectrum of clinical manifestations depending on the parasite species involved in the infections and the immunogenetic response of the host. The use of techniques for amplification of the parasites DNA based on polymerase chain reaction polymerase chain reaction and the recent application of combined techniques, such as high-resolution DNA dissociation, have been described as a viable alternative for the detection and identification of Leishmania spp. in biological samples.

Objectives

To identify the Leishmania species using the polymerase chain reaction high-resolution DNA dissociation technique in skin biopsies of hospital-treated patients, and compare with results obtained by other molecular identification techniques.

Methods

A retrospective study assessing patients with suspected American cutaneous leishmaniasis seen at a hospital in São Paulo/Brazil was conducted. The paraffin blocks of 22 patients were analyzed by polymerase chain reaction high-resolution DNA dissociation to confirm the diagnosis and identify the species.

Results

Of the 22 patients with suspected American cutaneous leishmaniasis, the parasite was identified in 14, comprising five cases (35.6%) of infection by L. amazonensis, four (28.5%) by L. braziliensis, two (14.4%) by L. amazonensis + L. infantum chagasi, two (14.4%) by L. guyanensis, and one (7.1%) by Leishmania infantum chagasi. In one of the samples, in which the presence of amastigotes was confirmed on histopathological examination, the polymerase chain reaction high-resolution DNA dissociation technique failed to detect the DNA of the parasite.

Study limitations

The retrospective nature of the study and small number of patients.

Conclusions

The method detected and identified Leishmania species in paraffin-embedded skin biopsies with a sensitivity of 96.4% and could be routinely used in the public health system.

Case Report: Mucosal Leishmaniasis Presenting with Nasal Septum Perforation after Almost Thirty Years

Mucosal leishmaniasis (ML) is associated with progressive tissue destruction and granuloma formation, often after a considerable period of latency from an initial cutaneous infection. We report a case of recurrent epistaxis of 3 years duration and nasopharyngeal obstruction in a woman with treated cutaneous leishmaniasis nearly 30 years before and with no further exposure to Leishmania. Computed tomography revealed nasal septal perforation and histopathology demonstrated chronic inflammation. Microscopy was negative for amastigotes, but molecular testing of nasal mucosa biopsy detected Leishmania (Viannia) braziliensis. The patient underwent 28 days of treatment with IV sodium stibogluconate and her symptoms improved significantly. Sixteen months after treatment, she continues to have episodic epistaxis and detectable parasite load in her nasal lesion. Although ML is known to take years to decades to develop, there are few reported cases in the literature of such a long latency period. This report highlights the importance of considering ML in the differential diagnosis of chronic epistaxis in countries where leishmaniasis is endemic or in immigrants from these countries, even when presentation occurs decades after leaving an endemic region.

The Role of Histopathology and Immunohistochemistry in the Diagnosis of Cutaneous Leishmaniasis Without "Discernible" Leishman-Donovan Bodies

BACKGROUND

Histopathology plays an important role in the diagnosis of cutaneous leishmaniasis (CL) but Leishman-Donovan (LD) bodies may not always be discernible. Recently, anti-CD1a antibody (Ab), clone MTB1, was found to decorate LD bodies immunohistochemically.

OBJECTIVE

Can histopathology without discernible LD bodies be used to diagnose CL, and can immunohistochemistry using anti-CD1a Ab, clone MTB1, detect LD bodies in these cases.

METHODS

Suspected CL lesions were studied histopathologically and immunohistochemically, and the patients' clinical files were reviewed.

RESULTS

Of the 196 patients with suspected CL, direct smear demonstrated LD bodies in 50 (25.5%). Of the remaining 146 patients, 118 underwent biopsy. In 56 (47.5%) patients, the hematoxylin-eosin-stained sections revealed LD bodies. In 47 (39.8%) patients, LD bodies were not discerned but the histopathology demonstrated histiocytic infiltrates with varying numbers of plasma cells along with other inflammatory cells, and negative Ziehl-Neelsen and periodic acid-Schiff stains. This pattern was termed "histopathology consistent with leishmaniasis." The history, clinical findings, and response to anti-leishmania therapy supported the diagnosis of CL in all of them, and immunostains for CD1a, clone MTB1, detected LD bodies in 11 (23.4%) of these 47 patients.

CONCLUSIONS

"Histopathology consistent with CL" along with appropriate clinical findings supports the diagnosis of CL in an endemic area, and immunostains with CD1a Ab, clone MTB1, may help in the minority of the cases.

Cutaneous and mucocutaneous leishmaniasis: Differential diagnosis, diagnosis, histopathology, and management

The diagnosis of leishmaniasis can be challenging because it mimics both infectious and malignant conditions. A misdiagnosis may lead to an unfavorable outcome. Using culture, histologic, and/or polymerase chain reaction study results, a diagnosis of leishmaniasis can be established and treatment initiated. Appropriate management requires an accurate diagnosis, which often includes identification of the specific etiologic species. Different endemic areas have varying sensitivities to the same medication, even within individual species. Species identification may be of practical value, because infections with select species have a substantial risk of visceral involvement. In addition, HIV and otherwise immunocompromised patients with leishmaniasis have a propensity for diffuse cutaneous leishmaniasis. For most New World Leishmania species, parenteral antimonial drugs remain the first line of therapy, while Old World species are easily treated with physical modalities. Historically, live organism vaccination has been used and is effective in preventing leishmaniasis, but results in an inoculation scar and an incubation period that may last for years. A more effective method of vaccination would be welcome.

Efficacy and Safety of Liposomal Amphotericin B for the Treatment of Mucosal Leishmaniasis from the New World: A Retrospective Study

The standard treatment of mucosal leishmaniasis (ML) is pentavalent antimonials, agents with serious adverse effects. Alternative agents include amphotericin B deoxycholate and liposomal amphotericin B. We performed a retrospective study including 29 patients treated with liposomal amphotericin B, most of whom had comorbidities, history of previous treatment of ML, and contraindications to the use of antimonial pentavalent or amphotericin B deoxycholate. We observed a cure rate of 93.1%. Kidney failure was the most important side effect, reported in five patients (17.2%). This study showed a good efficacy and safety profile of liposomal amphotericin B in patients with ML and contraindications to the use of other agents.

American cutaneous leishmaniasis: epidemiological profile of patients treated in Londrina from 1998 to 2009

BACKGROUND

American cutaneous leishmaniasis is a dermatozoonosis of compulsory notification with relevant morbidity. The disease is considered endemic in northern Paraná.

OBJECTIVES

To evaluate the clinical, laboratory and epidemiological aspects of patients with American cutaneous leishmaniasis treated at Clinics Hospital, State University of Londrina, Brazil (Paraná).

METHODS

This was an observational, cross-sectional, retrospective and descriptive study. The medical records of patients with American cutaneous leishmaniasis treated at the University Hospital of Londrina - Paraná, from 1998 to 2009 were evaluated.

RESULTS

A total of 470 patients, with prevalence of 8.72 cases / 100,000 inhabitants, participated in the study. Most patients were male, aged 21-40 years, with a single ulcerated lesion as the most common clinical presentation, located mainly in an exposed area of the body. With regard to immunological tests, the Montenegro intradermal reaction was positive in 84.4% of cases. Treatment with pentavalent antimony was well tolerated, and patient follow-up for a year occurred in 59% of cases.

CONCLUSION

American cutaneous leishmaniasis is still an endemic disease in the region, with a high potential for morbidity, but with a cure rate of around 95% after treatment. The use of immunological techniques facilitates the diagnosis of clinically suspicious cases.

Applicability of kDNA-PCR for routine diagnosis of American tegumentary leishmaniasis in a tertiary reference hospital

SUMMARY

This study evaluated the applicability of kDNA-PCR as a prospective routine diagnosis method for American tegumentary leishmaniasis (ATL) in patients from the Instituto de Infectologia Emílio Ribas (IIER), a reference center for infectious diseases in São Paulo - SP, Brazil. The kDNA-PCR method detected Leishmania DNA in 87.5% (112/128) of the clinically suspected ATL patients, while the traditional methods demonstrated the following percentages of positivity: 62.8% (49/78) for the Montenegro skin test, 61.8% (47/76) for direct investigation, and 19.3% (22/114) for in vitro culture. The molecular method was able to confirm the disease in samples considered negative or inconclusive by traditional laboratory methods, contributing to the final clinical diagnosis and therapy of ATL in this hospital. Thus, we strongly recommend the inclusion of kDNA-PCR amplification as an alternative diagnostic method for ATL, suggesting a new algorithm routine to be followed to help the diagnosis and treatment of ATL in IIER.

Detection of microorganisms in granulomas that have been formalin-fixed: review of the literature regarding use of molecular methods

Granuloma is an organized aggregate of immune cells that under the microscope appear as epithelioid macrophages. A granuloma can only be diagnosed when a pathologist observes this type of inflammation under the microscope. If a foreign body or a parasite is not observed inside the granuloma, stains for acid-fast bacilli and fungi are ordered since mycobacteria and fungi are frequently the cause of this type of inflammation. It is calculated that 12 to 36% of granulomas do not have a specific etiology and many have wondered if with new molecular methods we could reduce this number. This paper will summarize the frequently known causes of granulomas and will present the recent literature regarding the use of molecular techniques on tissue specimens and how these have helped in defining causative agents. We will also briefly describe new research regarding formation and function of granulomas and how this impacts our ability to find an etiologic agent.