Histoplasmosis-Associated Hemophagocytic Lymphohistiocytosis: A Review of the Literature

Haemophagocytic lymphohistiocytosis secondary to disseminated histoplasmosis in an immunocompetent patient

Haemophagocytic lymphohistiocytosis secondary to Histoplasma infection is rare and almost always occurs in immunocompromised hosts. We report a 32-year-old immunocompetent man presenting with a nonspecific febrile illness found to have disseminated histoplasmosis and associated haemophagocytic lymphohistiocytosis. The diagnosis was confirmed on histopathological examination and PCR of liver and bone marrow biopsies. He was successfully treated with steroids, intravenous immunoglobulin and itraconazole.

Survival Against the Odds-Hemophagocytic Lymphohistiocytosis Amidst the Shadows of Disseminated Histoplasmosis: A Case Report and Literature Review

Hemophagocytic lymphohistiocytosis (HLH) secondary to Histoplasma capsulatum is rare, impacting <1% globally, with a mortality rate of up to 31%. Herein, we present a rare case of HLH secondary to H capsulatum, affecting a 57-year-old female with rheumatoid arthritis. Extensive investigations were unrevealing and despite broad-spectrum antibiotics, her condition worsened, leading to respiratory failure requiring extracorporeal membrane oxygenation (ECMO) support, shock requiring multiple vasopressors, and acute kidney injury (AKI) requiring hemodialysis. Diagnosis confirmed disseminated histoplasmosis (DHP), prompting Amphotericin B and methylprednisolone treatment, resulting in significant improvement and discharge with posaconazole therapy. Secondary HLH, primarily arising from severe infections like DHP, is discussed. Limited research exists on this condition in human immunodeficiency virus (HIV)-seronegative individuals. Diagnosis involves HLH-2004 and HScore criteria. Managing histoplasmosis-associated HLH remains challenging due to multiorgan failure risks and treatment complexities and needs further research.

Histoplasmosis: An epidemiological and clinical update in China, review and a case report

Histoplasmosis is a systemic mycosis caused by the dimorphic fungus in the genus Histoplasma. Histoplasmosis is overlooked in China. This study aims to provide an epidemiological and clinical update on histoplasmosis in China by literature review. We reviewed cases of histoplasmosis reported in recent 11 years  and described a case of histoplasmosis-triggered hemophagocytic lymphohistiocytosis (HLH) in an immunocompetent patient. A total of 225 cases of histoplasmosis diagnosed in China between 2012 and 2022 were involved in this study, compared with 300 cases reviewed from 1990 to 2011, an increasing number of cases of histoplasmosis have been diagnosed in the last 11 years. The majority of cases of histoplasmosis were autochthonous cases, mainly from provinces Sichuan (56/225, 24.9%), Hunan (50/225, 22.2%), Guangdong (31/225, 13.8%), and Yunnan (24/225, 10.7%). Higher incidence (52.5%, 53/99) of histoplasmosis occurred in immunocompetent patients which is similar to those from the previous 21 years, and the prevalence of the disease did not vary highly over time. Of note, the number of histoplasmosis cases is increasing, and the geographic distribution is shifting southwards over time. Improved awareness is critically important for informing clinical practice in China.

A Rare Case of Disseminated Histoplasmosis With Hemophagocytic Lymphohistiocytosis Mimicking a Flare of Systemic Lupus Erythematosus in a Middle-Aged Man: A Case Report

Disseminated histoplasmosis is a progressive granulomatous disease caused by Histoplasma capsulatum, which is an intracellular dimorphic fungus endemic to the Ohio and Mississippi River valleys in the United States. It is usually thought to be due to the failure of the activation of the T-cell-mediated immune response. Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal condition, in which histiocytes and lymphocytes build up in and damage organs and other blood cells. We present a 37-year-old man with a past medical history of systemic lupus erythematosus (SLE) complicated by lupus nephritis on immunosuppressive therapy who presented to the emergency department with hypotension and was admitted for acute kidney injury. Prior to the presentation, he had persistent fever, myalgias, cough, mild shortness of breath, and back pain. Computed tomography (CT) chest shows "eggshell" calcification; microbiology evaluation of peripheral blood smear revealed intracellular organism, morphologically consistent with H. capsulatum; and urine histoplasmosis antigen test confirmed the diagnosis of histoplasmosis. HLH diagnosis was made clinically after "clinical and testing criteria" were evaluated. Despite further management, he developed coagulopathy and sepsis, which led to his death. At autopsy, we found organomegaly of the liver, spleen, and kidneys. Microscopically, these enlarged organs show old fibrotic granulomas and granulomatous inflammation with suspected fungal organisms. Gomori's methenamine silver special stain confirmed these fungal organisms to be consistent with Histoplasma species (3-5 micron budding yeasts). This case highlights that physicians should be aware of the diagnostic challenge that disseminated histoplasmosis with HLH could pose in a patient with SLE, especially in patients on immunosuppression. Failure to recognize the infection promptly could lead to grievous complications and possibly death.

Sepsis in Immunocompromised Host and a Hematologic Complication

CASE PRESENTATION

A 43-year-old Puerto Rican man with a kidney transplant presented to the ED with 2 weeks of flu-like symptoms, nausea, and vomiting. He had plasma exchange therapy 2 months before for acute transplant rejection and has been tolerating a heightened immunosuppressive regimen. CT scans characterized opacities as possibly early tree-in-bud opacities (Fig 1A). Patient remained stable throughout hospital stay with an unremarkable workup and was discharged with doxycycline for nonspecific pneumonia.

Management of Complex Infections in Hemophagocytic Lymphohistiocytosis in Adults

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive immune system activation and inflammatory response due to a variety of primary and secondary factors that can cause a range of clinical symptoms and, in severe cases, life-threatening conditions. Patients with HLH are at increased risk of infection due to their abnormal immune function as well as chemotherapy and immunosuppressive therapy at the time of treatment. At the same time, the lack of specific clinical features makes complex infections in HLH challenging to diagnose and treat. The management of complex infections in HLH requires a multidisciplinary and integrated approach including the early identification of pathogens, the development of anti-infection protocols and regimens, and the elimination of potential infection factors. Especially in HLH patients with septic shock, empirical combination therapy against the most likely pathogens should be initiated, and appropriate anti-infective regimens should be determined based on immune status, site of infection, pathogens, and their drug resistance, with timely antibiotic adjustment by monitoring procalcitonin. In addition, anti-infection prophylaxis for HLH patients is needed to reduce the risk of infection such as prophylactic antibiotics and vaccinations. In conclusion, complex infection in HLH is a serious and challenging disease that requires vigilance, early identification, and timely anti-infective therapy.

Ehrlichiosis-Associated Hemophagocytic Lymphohistiocytosis: A Case Series and Review of the Literature

Background

Human monocytic ehrlichiosis (HME) is a potentially life-threatening tick-borne illness. HME-associated hemophagocytic lymphohistiocytosis (HLH) is a rare entity with a paucity of published literature regarding treatment and outcome. We present the clinical features, treatment, and outcomes of 4 patients at our institutions with HME-associated HLH. This review also summarizes the current literature regarding the presentation, treatment, and outcome of this infection-related HLH.

Methods

We searched the PubMed database for case reports and case series. All cases were diagnosed according to the HLH-04 criteria.

Results

Four cases of HME-associated HLH were included from our institutions. The literature review yielded 30 additional cases. About 41% of the cases were in the pediatric population; 59% were female; and all patients had fever, cytopenia, and elevated ferritin. Most patients were immunocompetent; all but one patient with available data were treated with doxycycline, and eight of the patients with available data received the HLH-94 treatment protocol. The mortality rate was 17.6%.

Conclusions

HME-associated HLH is a rare but serious syndrome with significant mortality. Early treatment with doxycycline is critical, but the role of immunosuppressive therapy is individualized.

Two Cases of Hemophagocytic Lymphohistiocytosis Associated with Disseminated Histoplasmosis Presented with Transient Pancytopenia

Transient pancytopenia due to reactive bone marrow suppression often occurs in hemophagocytic lymphohistiocytosis (HLH), a syndrome resulting from excessive immune activation following a severe infection. We reported two cases with pancytopenia and disseminated histoplasmosis accompanied by HLH, initially suspected to be blood malignancies. Our first case documented the relevance between the improvement of pancytopenia and the clearance of Histoplasma capsulatum in serial bone marrow aspirations. The second case showed immense Histoplasma engulfment by the macrophage in relation to a severe clinical condition, followed by improvement of clinical symptoms in accordance with the recovery of pancytopenia. These two cases highlighted the importance of comprehensive and critical analysis for cases with concurrent pancytopenia and severe infection, since it may be that the pancytopenia underlies the severe infection or vice versa.

Travel related histoplasmosis – a diagnostic challenge in a patient with tumor necrosis factor alpha (TNF-α) inhibitor therapy

Introduction

In a non-endemic setting, disseminated histoplasmosis is a rare travel-related health problem of immunosuppressed returnees from endemic regions.

Methods

We describe the case of a 68-year-old man with rheumatoid arthritis and tumor necrosis factor alpha (TNF-α) inhibitor treatment-related immunodeficiency, who suffered from disseminated histoplasmosis after traveling to Brazil. Based on this case, we discuss challenges and pitfalls associated with the diagnosis of disseminated histoplasmosis in a non-endemic setting.

Results

The disease mimicked a hemophagocytic lymphohistiocytosis (HLH) like syndrome. Histoplasma capsulatum was microscopically detected in bronchoalveolar fluid and bone marrow aspirate smears, but was initially misclassified as Leishmania spp., another class of pathogens, which may cause HLH like syndromes in immunocompromised individuals.

Discussion

Since the clinical symptoms of histoplasmosis are nonspecific and physicians in non-endemic regions might not be familiar with this disease pattern, there is a risk of delayed diagnosis of travel related cases. Taking a thorough travel history is key in unclear cases of illness in immunocompromised patients.

Updates on Histoplasmosis in Solid Organ Transplantation

Purpose of Review

Recent Findings

Summary

An Unusual Case of Secondary Hemophagocytic Lymphohistiocytosis in a Patient Diagnosed With Triple Infection: COVID-19, HIV, and Histoplasmosis

In this study, we present a unique instance of a patient who developed hemophagocytic lymphohistiocytosis secondary to a triple infection with coronavirus disease 2019 (COVID-19), HIV, and histoplasmosis. We emphasize the proinflammatory dysregulations driving the severity of COVID-19 infection in this setting and highlight the importance of early diagnosis and targeted therapy of underlying conditions as a method to increase the chance of survival.

Progressive disseminated histoplasmosis in HIV-positive patients

BACKGROUND

Histoplasmosis is the most common endemic mycosis among people living with advanced HIV infection.

PURPOSE

Describe general aspects and challenges of this disease and its association with HIV.

RESEARCH DESIGN

Review of literature.

STUDY SAMPLE

Articles found using different combinations of terms including "disseminated histoplasmosis" and AIDS/HIV or immunosuppression in PubMed, Scopus, WHO Global health library, and Scielo database.

ANALYSIS

We look for information on epidemiology, pathogenesis, diagnosis, and treatment of histoplasmosis in AIDS patients.

RESULTS

Histoplasmosis is caused by Histoplasma capsulatum, a dimorphic fungus encountered throughout the world, mainly in soil enriched with bat and bird excreta. Progressive disseminated histoplasmosis is the main presentation of this mycosis in people living with advanced HIV and is fatal if left untreated. Symptoms include a systemic disease characterized by fever, weight loss, night sweats, skin manifestations, hepatomegaly, splenomegaly, and septic shock. Diagnostic tests include culture, visualization of H. capsulatum by direct and histopathological examination, serology, antigen, molecular, and skin testing. Patients with disseminated disease require aggressive and prolonged treatment to eradicate the pathogen and include amphotericin B and itraconazole. In many low income countries of endemic regions, histoplasmosis in HIV-positive patients is often undiagnosed or misdiagnosed as another opportunistic infection, due to the similarity in clinical manifestations and to the paucity of better diagnostic tests.

CONCLUSION

Histoplasmosis remains a neglected disease. Few studies about the disease and expensive treatments make it difficult to reduce the morbidity and mortality of this condition. Public health services and physicians must be aware of histoplasmosis' burden among the HIV-positive population.

Disseminated histoplasmosis and hemophagocytic lymphohistiocytosis in a patient receiving TNF-alpha inhibitor therapy

Histoplasmosis commonly presents as an asymptomatic or self-limited infection in immunocompetent patients, but immunocompromised hosts may present with severe and disseminated disease. Herein, we present a 26-year-old male with history of ulcerative colitis receiving long-term TNF-alpha inhibitor therapy who presented with six months of diarrhea and recently fever and hematochezia. On admission, he was febrile and hypotensive, with initial workup revealing pancytopenia and imaging reporting pulmonary infiltrates, pancolitis, and enlarged mesenteric lymph nodes. Disseminated histoplasmosis was ultimately diagnosed after examination of the colonic biopsy. Bone marrow biopsy was also consistent with the diagnosis of histoplasmosis but also demonstrated hemophagocytic lymphohistiocytosis. The patient was ultimately treated with amphotericin B, intravenous immunoglobulin, etoposide, and corticosteroids.

Hemophagocytic lymphohistiocytosis secondary to disseminated histoplasmosis, cytomegalovirus viremia, and nontuberculous mycobacteria bacteremia in a patient with recently diagnosed AIDS

A 30-year-old Honduran male with recently diagnosed AIDS presented with a 1-month history of worsening abdominal pain, diarrhea, and fever. Initial investigations were notable for Cytomegalovirus viremia and diffuse lymphadenopathy. Axillary lymph node biopsy demonstrated necrotizing lymphadenitis with disseminated histoplasmosis. Despite aggressive antimicrobial therapy he continued to clinically deteriorate raising suspicion for hemophagocytic lymphohistiocytosis. The patient met 5 of 8 HLH-2004 diagnostic criteria and was successfully treated with dexamethasone and etoposide per the HLH-94 protocol. Despite the high mortality rates and poor clinical outcomes of hemophagocytic lymphohistiocytosis in patients living with HIV/AIDS, this case demonstrates that this high-risk patient population can be successfully treated and survive acquired hemophagocytic lymphohistiocytosis. Furthermore, our case stresses the importance of maintaining a broad differential diagnosis in patients living with HIV/AIDS who present with sepsis.

Hemophagocytic lymphohistiocytosis secondary to progressive disseminated histoplasmosis presenting as cellulitis

Histoplasmosis-associated hemophagocytic lymphohistiocytosis is a rate but lethal disease in immunocompromised hosts. Unusual clinical presentations make diagnosing invasive fungal infection even more challenging. Here we present a case of hemophagocytic lymphohistiocytosis secondary to progressive disseminated histoplasmosis presenting as cellulitis in a patient with systemic lupus erythematous. A high index of suspicion combined with histopathology and molecular diagnostic techniques are important to establish an accurate and timely diagnosis of opportunistic infections in immunocompromised patients.

Histoplasmosis

Histoplasmosis is one of the commonest endemic mycoses in the Americas yet is often underdiagnosed and neglected as a public health priority. This review outlines the evolving understanding of its epidemiology and the clinical syndromes of histoplasmosis, in addition to up-to-date diagnostic and treatment guidelines. A focus on histoplasmosis in advanced HIV is included. The challenges pertinent to histoplasmosis management in Latin America, with recommendations made through international expert consensus are discussed.

Treatment and Prevention of Histoplasmosis in Adults Living with HIV

Histoplasmosis causes life-threatening disseminated infection in adult patients living with untreated HIV. Although disease incidence has declined dramatically in countries with access to antiretroviral therapy, histoplasmosis remains prevalent in many resource-limited regions. A high index of suspicion for histoplasmosis should be maintained in the setting of a febrile multisystem illness in severely immunosuppressed patients, particularly in persons with hemophagocytic lymphohistiocytosis. Preferred treatment regimens for initial therapy include liposomal amphotericin B for severe disease, or itraconazole for mild to moderate disease. Subsequently, itraconazole maintenance therapy should be administered for at least one year and then discontinued if CD4 count increases to ≥150 cells/µL. Antiretroviral therapy, which improves outcome when administered together with an antifungal agent, should be instituted immediately, as the risk of triggering Immune Reconstitution Syndrome is low. The major risk factor for relapsed infection is nonadherence. Itraconazole prophylaxis reduces risk for histoplasmosis in patients with CD4 counts <100/µL but is not associated with survival benefit and is primarily reserved for use in outbreaks. Although most patients with histoplasmosis have not had recognized high-risk exposures, avoidance of contact with bird or bat guano or inhalation of aerosolized soil in endemic regions may reduce risk. Adherence to effective antiretroviral therapy is the most important strategy for reducing the incidence of life-threatening histoplasmosis.

Central Nervous System Histoplasma-Associated Post-infectious Inflammatory Response Syndrome (Histo-PIIRS)

We present a case of central nervous system (CNS) histoplasmosis in a previously healthy adult with hepatitis C (HCV) presenting with neurological symptoms refractory to antifungal therapy and ventriculoperitoneal (VP) shunting 4 months after initial diagnosis. Persistent symptoms were thought to be inflammatory rather than infectious given negative cerebrospinal fluid (CSF) and serum fungal antigens. The patient promptly improved after initiation of corticosteroid therapy. Elevated CSF cytokines and regional enhancement on brain MRI resolved with corticosteroid treatment. This is the first case of Histoplasma-associated post-infectious inflammatory response syndrome (Histo-PIIRS) documented by CSF cytokine reduction in response to corticosteroid therapy.

Hemophagocytic Lymphohistiocytosis During HIV Infection in Cayenne Hospital 2012-2015: First Think Histoplasmosis

Introduction: Haemophagocytic Lymphohistiocytosis (HLH), during HIV infection is a rare complication with a poor prognosis. There are few data on HLH within the Amazon region. The objective was to describe epidemiological, clinical and therapeutic features of HIV-related HLH in French Guiana. Methods: A retrospective analysis of adult HIV patients at Cayenne hospital with HLH between 2012 and 2015. A diagnosis of HLH was given if the patient presented at least 3 of 8 criteria of the HLH-2004 classification. Results: Fourteen cases of HLH were tallied during the study period. The mean age was 46 years with a sex ratio of 1.8. The most frequent etiology of HLH was an associated infection (12/14). Confirmed disseminated histoplasmosis, was found in 10 of 14 cases, and it was suspected in 2 other cases. The CD4 count was below 200/mm3 in 13/14 cases. An HIV viral load >100,000 copies/ml was observed in 13/14 cases. An early treatment with liposomal amphotericin B was initiated in 12/14 cases. The outcome was favorable in 12/14 of all cases and in 10/12 cases involving histoplasmosis. Case fatality was 2/14 among all cases (14.3%) et 1/10 among confirmed disseminated histoplasmosis with HLH (10%). During the study period 1 in 5 cases of known HIV-associated disseminated histoplasmosis in French Guiana was HLH. Conclusion: Histoplasmosis was the most frequent etiology associated with HLH in HIV-infected patients in French Guiana. The prognosis of HLH remains severe. However, a probabilistic empirical first line treatment with liposomal amphotericin B seemed to have a favorable impact on patient survival.

A Case of Hemophagocytic Lymphohistiocytosis Secondary to Disseminated Histoplasmosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition characterized by a pathologic immune dysregulation resulting in extreme inflammation. Clinical manifestations are varied but can include severe multiorgan failure and death. HLH has been associated with malignancies, autoimmune diseases, and infections, such as histoplasmosis. Histoplasmosis commonly has subclinical manifestations but can also present in its disseminated form. We present the case of an immunocompromised patient with worsening liver function caused by hepatic histoplasmosis that later triggered HLH with severe multiorgan dysfunction.

Hemophagocytic Lymphohistiocytosis (HLH) in a Patient with Disseminated Histoplasmosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition characterized by an overwhelming inflammatory cascade activation which is often associated with rapid progression and high mortality. It may be familial with an underlying genetic mutation or triggered by infection, malignancy, and autoimmune disease. Disseminated histoplasmosis caused by histoplasma capsulatum is a granulomatous fungal disease seen typically in immunocompromised patients with varied clinical manifestations and requires long-term antifungal therapy. We present the case of a 61-year-old immunocompromised female with significant travel history who came with fever, pancytopenia, and liver failure raising suspicion for HLH that prompted a bone marrow biopsy procedure. Hemophagocytic figures consistent with HLH and numerous encapsulated fungi resembling histoplasma were visualized. She was treated with intravenous (IV) liposomal amphotericin B. Etoposide chemotherapy and interleukin-1 (IL-1) antagonist anakinra were deferred in order to limit her immunosuppression, and treatment was focused on antifungal therapy.