Cytological clues of bone marrow findings in Kala-Azar

Elucidating the role played by bone marrow in visceral leishmaniasis

Leishmaniasis is a widespread group of infectious diseases that significantly impact global health. Despite high prevalence, leishmaniasis often receives inadequate attention in the prioritization of measures targeting tropical diseases. The causative agents of leishmaniasis are protozoan parasites of the Leishmania genus, which give rise to a diverse range of clinical manifestations, including cutaneous and visceral forms. Visceral leishmaniasis (VL), the most severe form, can be life-threatening if left untreated. Parasites can spread systemically within the body, infecting a range of organs, such as the liver, spleen, bone marrow and lymph nodes. Natural reservoirs for these protozoa include rodents, dogs, foxes, jackals, and wolves, with dogs serving as the primary urban reservoir for Leishmania infantum. Dogs exhibit clinical and pathological similarities to human VL and are valuable models for studying disease progression. Both human and canine VL provoke clinical symptoms, such as organ enlargement, fever, weight loss and abnormal gamma globulin levels. Hematologic abnormalities have also been observed, including anemia, leukopenia with lymphocytosis, neutropenia, and thrombocytopenia. Studies in dogs have linked these hematologic changes in peripheral blood to alterations in the bone marrow. Mouse models of VL have also contributed significantly to our understanding of the mechanisms underlying these hematologic and bone marrow abnormalities. This review consolidates information on hematological and immunological changes in the bone marrow of humans, dogs, and mice infected with Leishmania species causing VL. It includes findings on the role of bone marrow as a source of parasite persistence in internal organs and VL development. Highlighting gaps in current knowledge, the review emphasizes the need for future research to enhance our understanding of VL and identify potential targets for novel diagnostic and therapeutic approaches.

Diagnostic model of visceral leishmaniasis based on bone marrow findings. Study of patients with clinical suspicion in which the parasite is not observed

BACKGROUND

Visceral Leishmaniasis (VL) is a serious protozoal disease endemic in diverse areas, including the southern area of Madrid (Spain), where an outbreak was detected in 2009. The objective of this work is to analyze bone marrow alterations in VL patients and elaborate a diagnostic model with the aim to improve the early detection of this disease. The usual diagnostic methods, as the observation of the parasite on a bone marrow aspirate, have frequent false negatives, and the high sensitivity methods, as PCR and ELISA, are delayed or are not always available.

METHODS

This observational study evaluated bone marrow parameters of adult patients with clinical suspicion of VL, in which a bone marrow aspiration was performed but Leishmania was not directly observed, during the period 2009-2014. The patients finally diagnosed of VL by other methods (VL group, n=41), and the patients in which the VL was not diagnosed (non-VL group, n=20) were compared. A multivariant model was elaborated and externally validated.

RESULTS

The final multivariant model includes percentage of myeloid series, percentage of plasma cells and quantification of megakaryocytes in the bone marrow, with an area under the ROC curve of 0.87 (0.78-0.96). The model performed well in the external validation.

CONCLUSION

In cases of VL suspicion and when the parasite is not observed in the bone marrow aspiration, the proposed model could be useful in discriminating between patients with and without VL, allowing to take a therapeutic decision while awaiting the definitive diagnosis.

Spectrum of clinicohematological profile and its correlation with average parasite density in visceral leishmaniasis

Background:

Leishmaniasis is the prevalent in tropical and subtropical regions of the world. Demonstration of Leishman-Donovan (LD) bodies in the bone marrow aspirates (BMA) is vital to diagnosis of visceral leishmaniasis (VL). In the present study, we studied the clinicohematological parameters encountered in VL and correlated them with parasite load on BMA.

Methods:

Retrospective analysis over 3 years was done; clinical details, biochemical profile, complete hemogram with peripheral smear findings, and BMA smears were reviewed and average parasite density (APD) calculated in each case. Multivariate analysis and tests of significance were applied.

Results:

The study included 28 patients. Splenomegaly showed a positive trend with APD. rK39 antigen detection test was 100% positive in select cases. A strong negative correlation was observed between albumin to globulin ratio and grade of APD. BMA revealed hemophagocytosis (HPS) in 78.57% cases and it had a significant strong correlation with APD (P = 0.014). A significant correlation was also observed between APD and bone marrow plasma cell percentage (P = 0.01). LD bodies were noted in unusual locations such as within myelocytes (14.2%), plasma cells (7.1%), and megakaryocytes (10.7%).

Conclusion:

HPS and bone marrow plasmacytosis were two statistically significant findings, which showed positive correlation with parasite load. The presence of these two findings should prompt hematopathologists for more focused search of hemoparasites in BMA to arrive at a definitive diagnosis. This will avoid unnecessary workups and improve the prognosis. To the best of our knowledge, a statistical correlation between APD and clinicohematological parameters has never been previously studied.

An association of leishmaniasis and dyserythropoiesis in children

Visceral leishmaniasis results in hematological problems such as cytopenias and coagulopathies. This disorder also has morphological effects on the bone marrow. Dyserythropoiesis is one of the most prominent seen with changes like multilobed nuclear cells and the appearance of bridges between nuclei and cytoplasms. Approximately half of the children with leishmaniasis showed dyserythropoietic findings in bone marrow aspirate slides. Because this in endemic regions, physicians of these countries must be alert to correctly diagnose disease and discriminate from other dyserythropoietic disorders.

Dry type leishmanial lymphadenitis presented as two large parotid and cervical masses

BACKGROUND

Cutaneous leishmanisis (CL) is a common disease in Iran, particularly in Kerman and Bam and Kerman province. Lymphadenitis resulting from leishmania tropica (dry type) with, or without, cutaneous lesion is rare. Localized leishmanial lymphadenitis (LLA) is a specific clinico-pathologic presentation of inflammatory changes caused by leishmanial parasites or antigen within an isolated lymph node without any systemic manifestation.

CASE REPORT

A 55-year-old Iranian woman presented with two slow growing large nodules (masses) on the left preauricular and the left cervical areas. The nodules were large, painless, mobile, multilobulated, and associated with a small skin papule on the left-side of the cheek distal to the masses.

RESULTS

Histopathologic examination of both the skin lesion and the lymph nodes suggested the leishmanial etiology of skin papule and lymphadenitis. The Leishman-bodies (amastigotes) were demonstrated in two lymph nodes and a skin lesion. The clinical picture plus pathological finding and the response to meglumine-antimoniate confirmed LLA.

CONCLUSION

Lymph node involvement is another rare manifestation of dissemination of infection with dermotropic leishmania. This presentation of CL should not be treated with the ordinary local treatments such as curettage, cryotherapy or surgical excision.

Visceral leishmaniasis: bone marrow biopsy findings

Visceral leishmaniasis (VL) or Kala-azar is a common parasitic infection among children in Iran. The records of 249 children with VL were evaluated retrospectively. The clinical, hematologic, and bone marrow biopsy findings were studied. In particular, we assessed whether there was an association between bone marrow biopsy findings and prognosis. Five major groups were identified: (1) hypercellular marrow with many Leishman Donovan (LD) bodies, (2) multiple noncaseating granulomas with a few LD bodies, (3) diffuse fibrosis with rare LD bodies, (4) benign lymphoid nodules with many LD bodies, and (5) marrow necrosis with many LD bodies. The patients with hypercellular marrow and benign lymphoid nodules were alive and responded well to glucantime therapy. The patients with marrow fibrosis and marrow necrosis died and were resistant to any type of therapy. Patients with granulomas did not respond to glucantime therapy but responded to amphotericin B. However, less than half of the patients died owing to malnutrition and misdiagnosis. We correlated the bone marrow biopsy findings with the treatment outcomes and prognosis. The outcome was excellent in cases of hypercellular marrow, very poor in cases of fibrosis and necrosis, and intermediate in cases of granulomas. As a result, we believe that bone marrow biopsy findings can be helpful for assessing the prognosis of VL patients.

Unstable Plasma Thalidomide Concentration in Patients with Refractory Multiple Myeloma

In this study, we analyzed the relationship between the plasma concentration of thalidomide and the therapeutic effect obtained by using thalidomide alone in patients with refractory multiple myeloma. The safety and effect of thalidomide was examined in 12 cases of refractory multiple myeloma. Four cases (33%) achieved partial response (PR) and 3 cases (25%) achieved minimal response. These effects were achieved with only 200 mg/day of thalidomide and maintained with 100-200 mg/day. The concentration of thalidomide in the blood was measured in 7 cases; dose-dependency was not recognized. In 5 cases in which complete or partial response was obtained, the effect was obtained with a mean thalidomide concentration in blood of 0.5 microg/mL or less. However, in 2 cases in which the mean blood concentration of thalidomide was 2 microg/mL or higher, an M-protein-reducing effect was not obtained. The frequency of various side effects was increased when the concentration of thalidomide was higher than 2 microg/mL. In conclusion, low-dose thalidomide therapy may effectively treat refractory myeloma, and the measurement of thalidomide concentration in the blood may not be a marker of therapeutic effect, but rather a marker of adverse effects.

A description of parasite-harbouring cells in localized lymphadenitis in dry type cutaneous leishmaniasis

Lymphadenitis with or without dry-type cutaneous leishmaniasis is rare. The lesion might self heal or show excellent response to antimonial therapy. Routine histopathological changes of localized leishmaniasis lymphadenitis are non-caseating to suppurative granulomata mostly in paracortical areas, some with extension to germinal centres, medullary cords and/or pericapsular spaces which have to be distinguished from other causes of lymphadenitis such as tuberculosis, cat-scratch disease and toxoplasmosis. Dense lymphoplasmocytic infiltrate was observed surrounding the necrotizing granuloma together with dense capsular fibrosis with multiple granulomata in subcapsular and pericapsular areas. Immunostaining of lymph nodes showed that a few macrophages were harbouring Leishman bodies. Dispersed Langerhans cells were also harbouring Leishman bodies in the parasitophorous vacuoles between their cytoplasmic pseudopods. In conclusion multiple noncaseating to suppurative granulomata with dense pericapsular and capsular granulomo-sclerotic changes should be considered in the differential diagnosis of leishmaniasis lymphadenitis.