Coxiella burnetii causing haemophagocytic syndrome: a rare complication of an unusual pathogen

Hemophagocytic Lymphohistiocytosis (HLH) in Patients with Tick-Borne Illness: A Scoping Review of 98 Cases

Hemophagocytic lymphohistiocytosis (HLH) secondary to tick-borne infections is a rare but potentially life-threatening syndrome. We performed a scoping review according to PRISMA guidelines to systematically analyze the existing literature on the topic. A total of 98 patients were included, with a mean age of 43.7 years, of which 64% were men. Most cases, 31%, were reported from the USA. Immunosuppression was present in 21.4%, with the most common cause being previous solid organ transplantation. Constitutional symptoms were the most common, observed in 83.7% of the patients, while fever was reported in 70.4% of cases. Sepsis was present in 27.6%. The most common laboratory abnormalities in this cohort were thrombocytopenia in 81.6% of patients, while anemia, leukopenia, and leukocytosis were observed in 75.5%, 55.1%, and 10.2%, respectively. Liver enzyme elevation was noted in 63.3% of cases. The H-score was analyzed in 64 patients, with the mean value being 209, and bone marrow analysis was performed in 61.2% of patients. Ehrlichia spp. was the main isolated agent associated with HLH in 45.9%, followed by Rickettsia spp. in 14.3% and Anaplasma phagocytophilum in 12.2%. Notably, no patient with Powassan virus infection or Lyme borreliosis developed HLH. The most common complications were acute kidney injury (AKI) in 35.7% of patients, shock with multiple organ dysfunction in 22.5%, encephalopathy/seizure in 20.4%, respiratory failure in 16.3%, and cardiac complications in 7.1% of patients. Treatment included antibiotic therapy alone in 43.9%, while 5.1% of patients were treated with immunosuppressants alone. Treatment with both antibiotics and immunosuppressants was used in 51% of patients. Appropriate empiric antibiotics were used in 62.2%. In 43.9% of cases of HLH due to tick-borne disease, patients received only antimicrobial therapy, and 88.4% of those recovered completely without the need for immunosuppressive therapy. The mortality rate in our review was 16.3%, and patients who received inappropriate or delayed empiric therapy had a worse outcome. Hence, we suggest empiric antibiotic treatment in patients who are suspected of having HLH due to tick-borne disease or in whom diagnostic uncertainty persists due to diagnostic delay in order to minimize mortality.

Zoonotic Bacterial Infections Triggering Cytokine Storm Syndrome

Zoonotic infections can result in life-threatening complications that can manifest with hemophagocytic lymphohistiocytosis (HLH)/cytokine storm syndrome (CSS). Bacteria constitute the largest group of zoonotic infection-related HLH cases. The growing list of zoonotic bacterial infections associated with HLH/CSS include Brucella spp., Rickettsia spp., Ehrlichia, Coxiella burnetii, Mycobacterium spp., and Bartonella spp. Patients most commonly present with fever, cytopenias, hepatosplenomegaly, myalgias, and less frequently with rash, jaundice, and lymphadenopathy.

Bacteria-Associated Cytokine Storm Syndrome

While viruses are considered the most common infectious triggers for cytokine storm syndromes (CSS), a growing list of bacterial pathogens, particularly intracellular organisms, have been frequently reported to be associated with this syndrome. Both familial and sporadic cases of CSS are often precipitated by acute infections. It is also important to note that an underlying precipitating infection might not be clinically obvious as the CSS clinical picture can mimic an infectious process or an overwhelming septicemia. It is important to detect such an underlying treatable condition. In addition, infections can also be acquired during the course of CSS due to the concurrent immune suppression with treatment. Optimal CSS outcomes require treating bacterial infections when recognized.CSS should always be suspected in patients presenting with a sepsis-like or multi-organ dysfunction picture. There are many criteria proposed to diagnose CSS in general, with HLH-2004 being the most commonly used. Alternatively, criteria have been proposed for CSS occurring in specific underlying conditions such as systemic lupus erythematosus (SLE) or systemic juvenile idiopathic arthritis (sJIA). However, waiting for many of these criteria to be fulfilled could lead to significant delay in diagnosis, and the physician needs a high index of suspicion for CSS in critically ill febrile hospitalized patients in order to properly recognize the condition. Thus, there should be diagnostic equipoise between CSS and infections, including bacterial, in this population. In this chapter, we discuss the more common bacterial precipitants of CSS with many of the cases being discussed in the pediatric age group.

Anaplastic Large Cell Lymphoma Presenting as Haemophagocytic Lymphohistiocytosis with Underlying Coxiella burnetii and Bartonella henselae Seropositivity

A 44-year-old woman with no significant medical history presented with a 3-week history of high-grade fevers, fatigue and shortness of breath. Laboratory investigation was significant for lymphopenia and thrombocytopenia which progressively worsened during her hospital stay, along with new-onset anaemia, and elevated ferritin, transaminase and triglycerides. A computerized tomography (CT) scan of the abdomen revealed retroperitoneal lymphadenopathy. A bone marrow biopsy confirmed the diagnosis of haemophagocytic lymphohistiocytosis (HLH). Extensive infectious work-up revealed high IgG titres for Bartonella henselae and Coxiella burnetii. Interestingly, the left supraclavicular node was negative for both microbes by polymerase chain reaction (PCR), but the biopsy revealed anaplastic large T-cell lymphoma.

LEARNING POINTS

Haemophagocytic lymphohistiocytosis (HLH) is an important differential diagnosis to consider for fever of unknown origin in adults, especially in the setting of pancytopenia and hyperferritinaemia.Q fever resulting from Coxiella burnetii can cause HLH and is also postulated to increase the risk of lymphoma.Bartonella henselae infection can also trigger HLH, but the risk of lymphoma following infection by B. henselae is unknown.

Q fever as a rare cause of hemophagocytic lymphohistiocytosis: Case report

Hemophagocytic Lymphohistiocytosis (HLH) is a reactive disorder of the mononuclear phagocytic system characterized by increased histiocytic proliferation, activation and hemaphagocytosis. The underlying etiology may be genetic (primary) or acquired (secondary). Secondary causes include drugs, autoimmune diseases, malignancies and infections of which EBV is the most common. A 28-year old male patient who was a shepherd with no known concomitant comorbid disease was admitted to the Emergency Department with the complaints of abdominal pain, fever, severe fatigue. Physical examination revealed high fever, hepatosplenomegaly and laboratory examination revealed pancytopenia, hyperferritinemia and hypertriglyceridemia. Hemophagocytes were observed in the bone marrow biopsy and the patient was diagnosed as HLH. The patient was treated with cyclosporine A, dexamethasone, intravenous immunoglobulin (IvIg) and etoposide according to the HLH 2004 protocol. Coxiella burnetii was detected in the serological evaluation of the etiology and doxycycline was added to the current treatment. Fever was controlled in the second week of the treatment and the patient was discharged after complete recovery of the cytopenia in the fourth week. In the outpatient setting, treatment was completed in 8 weeks and follow-up of the patient is still ongoing without medication. To the best of our knowledge, this is the first case from Turkey of HLH secondary to Q-fever which was treated and managed successfully. Since the mortality of HLH is quite high, the etiology should be determined as soon as possible to be able to provide appropriate treatment.

Hemophagocytic lymphohistiocytosis complicating invasive pneumococcal disease: a pediatric case report

Background

Hemophagocytic lymphohistiocytosis (HLH) is an infrequent but life-threatening disease due to excessive immune activation. Secondary HLH can be triggered by infections, autoimmune diseases, and malignant diseases. Streptococcus pneumoniae is a pathogenic bacterium responsible for invasive pneumococcal disease (IPD) such as meningitis and bacteremia. Although the pneumococcal conjugate vaccine (PCV) has led to reductions in IPD incidence, cases of IPD caused by serotypes not included in PCV are increasing. There are few reports of secondary HLH caused by IPD in previously healthy children. We herein report a rare case of a previously healthy boy with secondary HLH complicating IPD of serotype 23A, which is not included in the pneumococcal 13-valent conjugate vaccine (PCV-13).

Case presentation

An 11-month-old boy who had received three doses of PCV-13 was hospitalized with prolonged fever, bilateral otitis media, neutropenia and elevated C-reactive protein (CRP) levels. Blood culture on admission revealed S. pneumoniae, leading to a diagnosis of IPD. HLH was diagnosed based on a prolonged fever, neutropenia, anemia, hepatosplenomegaly, hemophagocytosis in the bone marrow, and elevated serum levels of triglycerides, ferritin, and soluble interleukin-2 receptor. He received broad-spectrum antibiotics and intravenous immunoglobulins for IPD and high-dose steroid pulse therapy and cyclosporine A for HLH; thereafter, his fever resolved, and laboratory findings improved. The serotype of the isolated S. pneumoniae was 23A, which is not included in PCV-13.

Conclusions

It is important to consider secondary HLH as a complication of IPD cases with febrile cytopenia or hepatosplenomegaly, and appropriate treatment for HLH should be started without delay.

Tuberculosis-Associated HLH in an 8-Month-Old Infant: A Case Report and Review

Hemophagocytic lymphohistiocytosis (HLH) is a rare immunological disease, which can be mistaken for sepsis easily. Among the infectious causes that may trigger secondary HLH, tuberculosis (TBC), a rather rare pathogen nowadays, is typical. To our knowledge, this is the first case report of an infant suffering from TBC-associated HLH-induced acute respiratory failure who was treated successfully using extracorporeal membrane oxygenation. An 8-month-old boy with fever (over the last 8 wk) and pancytopenia was transferred to our institution with acute respiratory failure and for extracorporeal membrane oxygenation therapy. Bone marrow biopsy revealed hemophagocytosis. Immunological work-up for familial HLH was negative. In a desperate search for the cause of secondary HLH, an interferon-gamma release assay for TBC returned positive. However, microscopy for acid-fast bacteria as well as polymerase chain reaction for TBC were initially negative. Despite this, the child was treated with tuberculostatic therapy. TBC was finally confirmed. The child remained on extracorporeal membrane oxygenation for 28 d. Further work-up showed typical lesions of disseminated TBC. The mother was identified as the source of TBC. The boy presents with mild sequelae (fine motor skills). In infants with suspected septicemia, TBC should be considered as differential diagnosis even if the results are initially negative.

Fatal case of hemophagocytic lymphohistiocytosis associated with group B streptococcus sepsis: A case report

RATIONALE

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by an excessive systemic inflammatory response. HLH is classified as primary or secondary, where the latter may occur in association with many infections. However, no case of HLH has been previously associated with group b streptococcus (GBS) sepsis.

PATIENT CONCERNS

We present a fatal case of HLH in a 5-year-old girl with GBS sepsis.

DIAGNOSIS

The present patient met 5 of the HLH criteria: fever, splenomegaly, bicytopenia, hypertriglyceridemia and/or hypofibrinogenemia, and hyperferritinemia. GBS was identified in 2 sets of peripheral blood bacterial cultures.

INTERVENTIONS

Empirical antibiotics, inotropes, and immunoglobulins were administered.

OUTCOMES

The clinical course of the patient was fulminant and the patient died of septic shock 10 hours after admission to the hospital.

LESSONS

We suggest GBS infection can cause HLH and early awareness of HLH associated with GBS infection and proper effective treatment are necessary to reduce mortality.

Hemophagocytic Lymphohistiocytosis in the Elderly

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease of massive, dysregulated cytokine release and secondary multiorgan failure and is associated with high mortality. Primary HLH occurs predominately in infants and young children with a genetic predisposition. Acquired HLH is less well characterized and usually occurs in younger adults in the setting of severe inflammation triggered by infection or malignancy. Little is known about the disease in elderly. We report 3 patients >50 years old who presented with multiorgan failure and shock without an identifiable source and were ultimately diagnosed with acquired HLH. We performed a literature review of HLH in adults >50 years of age and identified an additional 68 cases. Mean age was 62 years, with male predominance. Most cases were triggered by infection (49%) followed by malignancy (27%). Nineteen patients were treated with the HLH-94 protocol, 11 received corticosteroids and the remainder received non-HLH specific interventions. Overall mortality was 62%.

Macrophage Activation Syndrome

Hemophagocytic lymphohistiocytosis (HLH), or termed macrophage activation syndrome (MAS) when associated with rheumatic disorders, is a frequently fatal complication of infections, rheumatic disorders, and hematopoietic malignancies. Clinically, HLH/MAS is a life-threatening condition that is usually diagnosed among febrile hospitalized patients (children and adults) who commonly present with unremitting fever and a shock-like multiorgan dysfunction scenario. Laboratory studies reveal pancytopenia, elevated liver enzymes, elevated markers of inflammation (ESR, CRP), hyperferritinemia, and features of coagulopathy. In about 60% of cases, excess hemophagocytosis (macrophages/histiocytes engulfing other hematopoietic cell types) is noted on biopsy specimens from the bone marrow, liver, lymph nodes, and other organs. HLH/MAS has been hypothesized to occur when a threshold level of inflammation has been achieved, and genetic and environmental risk factors are believed to contribute to the hyperinflammatory state. A broad variety of infections, from viruses to fungi to bacteria, have been identified as triggers of HLH/MAS, either in isolation or in addition to an underlying inflammatory disease state. Certain infections, particularly by members of the herpesvirus family, are the most notorious triggers of HLH/MAS. Treatment for infection-triggered MAS requires therapy for both the underlying infection and dampening of the hyperactive immune response.

Sepsis due to Streptococcus pneumoniae associated with secondary hemophagocytic lymphohistiocytosis in a splenectomized patient for spherocytosis: A case report

RATIONALE

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome that is characterized by an inappropriate hyperinflammatory immune response - primary, as a consequence of a genetic defect of NK cells and cytotoxic T lymphocytes or - secondary, in the progression of infections, rheumatic or autoimmune diseases, malignancies or metabolic diseases.

PATIENT CONCERNS

We present the case of a secondary HLH due to Streptococcus pneumoniae infection in a splenectomised patient for spherocytosis, a 37-year-old patient who was splenectomised in childhood for spherocytosis, without immuneprophylaxis induced by antipneumococcal vaccine.

OUTCOMES

He developed a severe pneumococcal sepsis associated with secondary HLH, with unfavorable outcome and death.

LESSONS

To our knowledge, just 2 similar cases had been published in the literature, none in which the secondary HLH was the consequence of an invasive pneumococcal infection in a splenectomized patient for spherocytosis, and the association of splenectomy with HLH is surprizin.

From Q Fever to Coxiella burnetii Infection: a Paradigm Change

Coxiella burnetii is the agent of Q fever, or "query fever," a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between "acute" and "chronic" Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.

Coxiella burnetii Infection With Severe Hyperferritinemia in an Asplenic Patient

Q fever is an uncommon but likely underreported zoonotic infection. Severe hyperferritinemia has been associated with hemophagocytic lymphohistiocytosis and other infectious diseases. In this study, we report a case of Coxiella burnetii infection in an asplenic patient complicated by severe hyperferritinemia and bone marrow infiltration. In this case, the marked ferritin elevation may have been an indicator of profound systemic macrophage activation due to preferential intracellular infection of this cell type by C burnetii, perhaps exacerbated by altered mononuclear phagocyte system function in the setting of asplenia.

Hemophagocytic lymphohistiocytosis: review of etiologies and management

Hemophagocytic lymphohistiocytosis (HLH) covers a wide array of related life-threatening conditions featuring ineffective immunity characterized by an uncontrolled hyperinflammatory response. HLH is often triggered by infection. Familial forms result from genetic defects in natural killer cells and cytotoxic T-cells, typically affecting perforin and intracellular vesicles. HLH is likely under-recognized, which contributes to its high morbidity and mortality. Early recognition is crucial for any reasonable attempt at curative therapy to be made. Current treatment regimens include immunosuppression, immune modulation, chemotherapy, and biological response modification, followed by hematopoietic stem-cell transplant (bone marrow transplant). A number of recent studies have contributed to the understanding of HLH pathophysiology, leading to alternate treatment options; however, much work remains to raise awareness and improve the high morbidity and mortality of these complex conditions.