Tuberculosis-associated hemophagocytic lymphohistiocytosis in an umbilical cord blood transplant recipient

Genetics of Acquired Cytokine Storm Syndromes : Secondary HLH Genetics

Secondary hemophagocytic lymphohistiocytosis (sHLH) has historically been defined as a cytokine storm syndrome (CSS) occurring in the setting of triggers leading to strong and dysregulated immunological activation, without known genetic predilection. However, recent studies have suggested that existing underlying genetic factors may synergize with particular diseases and/or environmental triggers (including infection, autoimmune/autoinflammatory disorder, certain biologic therapies, or malignant transformation), leading to sHLH. With the recent advances in genetic testing technology, more patients are examined for genetic variations in primary HLH (pHLH)-associated genes, including through whole exome and whole genome sequencing. This expanding genetic and genomic evidence has revealed HLH as a more complex phenomenon, resulting from specific immune challenges in patients with a susceptible genetic background. Rather than a simple, binary definition of pHLH and sHLH, HLH represents a spectrum of diseases, from a severe complication of common infections (EBV, influenza) to early onset familial diseases that can only be cured by transplantation.

Tuberculosis-Associated Hemophagocytic Lymphohistiocytosis: A Review of Current Literature

Hemophagocytic lymphohistiocytosis (HLH) is a condition of immune dysregulation and hyperinflammation, leading to organ failure and death. Malignancy, autoimmune conditions, and infections, including Mycobacterium tuberculosis (TB), are all considered triggers of HLH. The aim of this study was to review all reported cases of TB-associated HLH in English literature, and to summarize the epidemiology, diagnostics, treatment, and mortality in patients with concomitant HLH and TB. A systematic review of described cases with TB-associated HLH, via a structured literature search in the medical database PubMed, is presented. Additional articles were included through cross-referencing with existing review articles. Articles were reviewed based on a predetermined set of criteria. A total of 116 patients with TB-associated HLH were identified with a male:female ratio of about 3:2. The age at presentation ranged from 12 days to 83 years. Malignancy, autoimmunity, and renal failure were the most common comorbid conditions. Most patients received both tuberculostatic and specific immunomodulating treatment, which was associated with a 66% (48/73) survival rate compared to 56% (15/27) in those receiving only tuberculostatic treatment, and 0% (0/13) in those receiving only immunomodulating treatment. The survival rate was 55% overall. The overlapping presentation between disseminated TB and HLH poses challenging diagnostics and may delay diagnosis and treatment, leading to increased mortality. TB should be considered as a potential trigger of HLH; clinicians' knowledge and awareness of this may result in the appropriate investigations needed to ensure diagnosis and proper treatment.

Pediatric isoniazid-resistant tuberculosis of the bone marrow manifesting as hemophagocytic syndrome: A case report

Hemophagocytic syndrome (HPS) is a critical syndrome of ineffective hyperinflammatory immune response resulting in infiltration of lymphocytes and histiocytes in various organs. Causes can be hereditary or due to malignancy, autoimmune disease, or infection. HPS due to Mycobacterium tuberculosis is rare as only a handful of cases are reported, and they are mostly associated with severe disseminated tuberculosis (TB). We reported a 9-year-old boy with tuberculosis of the bone marrow accompanied with hemophagocytic syndrome. The patient presented with manifestation of HPS and had no respiratory symptoms or risk factors for TB but was later diagnosed of isoniazid-resistant TB in the bone marrow. He had a good outcome after receiving anti-TB drugs and corticosteroids on time. This case highlights that bone marrow might be a shelter for Mycobacterium tuberculosis. Concurrent testing for drug susceptibility in TB cases with an uncommon manifestation is recommended even for first episodes. Early diagnosis and etiological confirmation of the infection origin and appropriate treatment are essential to improve survival in this otherwise life-threatening condition.

Granulomatous Tubercular Hepatitis Presenting as Secondary Hemophagocytic Lymphohistiocytosis: A Case Report and Systematic Review of the Literature

Hemophagocytic lymphohistiocytosis is a life-threatening disorder characterized by persistent pathologic activation of cytotoxic T lymphocytes, natural killer cells, and macrophages. We present details of a young patient who presented with high-grade fever, jaundice, and breathlessness. On investigations, he had hepatitis, anemia, neutropenia, and coagulopathy. He also had hypertriglyceridemia, hypofibrinogenemia, and hyperferritinemia. Bone marrow aspiration revealed histiocytosis, and transjugular liver biopsy revealed necrotizing granulomas positive for Mycobacterium tuberculosis on acid-fast bacilli staining. He was successfully managed with a combination of immunosuppressants and antitubercular therapy. Tuberculosis associated hemophagocytosis syndrome is rare and should be considered in patients with unexplained hemophagocytosis syndrome, especially in tuberculosis-endemic regions. Prompt recognition and treatment with antitubercular treatment and immunosuppressants are associated with good outcomes.

An update on Mycobacterium tuberculosis infection after hematopoietic stem cell transplantation in adults

BACKGROUND

Mycobacterium tuberculosis (TB) is common worldwide, but is rarely reported after hematopoietic transplantation (HSCT). We reviewed all TB cases among HSCT since 2010 to provide an update on its epidemiology, clinical presentation, management and outcome.

METHODS

Several databases were reviewed from January 1, 2010 to June 30, 2018 using key words tuberculosis and hematopoietic transplantation.

RESULTS

The 47 cases of TB were reported during the study period. The highest TB frequency was reported from India (2.9%), with a median frequency of 2% (range, 0.18%-2.9%). The majority were recipients of allogeneic transplants (45/47, 95.7%). Pulmonary TB was the most common clinical presentation (20/47, 42.6%). The median time to clinical presentation was 4.6 (range, 3-12.9) and 2.4 (range, 0.6-5) months, based on cohort data and case reports, respectively. Fever was reported in 87.5% (14/16) of patients. First-line quadruple drug therapy was frequently used (29/35, 82.9%), with a median length of 12 and 9 months for cohorts and case reports, respectively. All-cause and attributable mortality was 27.6% (13/47), and 8.5% (4/47), respectively.

CONCLUSIONS

Mycobacterium tuberculosis presents early after HSCT, most commonly as fever. A high index of suspicion is needed for early diagnosis and treatment, to prevent TB-attributable mortality.