Hepatosplenomegaly and pulmonary infiltrates in an infant

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.

Paradoxical upgrading reaction following treatment of disseminated tuberculosis-associated haemophagocytic lymphohistiocytosis in an infant without HIV: a case report and review of the literature

Tuberculosis-associated haemophagocytic lymphohistiocytosis (HLH) is rare in paediatrics and can be fatal if not recognised and treated on time. A 3-month-old infant with tuberculosis and HLH is described. He was successfully treated with anti-tuberculous therapy (ATT) which comprised isoniazid, rifampicin, pyrazinamide, ethambutol, streptomycin and dexamethasone (10 mg/m²/day). On Day 28 of therapy, he developed a paradoxical upgrading reaction to ATT for which he was again treated with (oral) corticosteroids for 4 weeks. He recovered successfully and is now completely well and asymptomatic. To the best of our knowledge, this is the first case of a child having a paradoxical upgrading reaction following treatment for TB-HLH.Abbreviations ATT: anti-tuberculous therapy; CB-NAAT: cartridge-based nucleic acid amplification test; CECT: contrast-enhanced computed tomography; HLH: haemophagocytic lymphohistiocytosis; NK: natural killer, PUR: paradoxical upgrading reaction; sHLH: secondary HLH.

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.

Hemophagocytic syndrome in children: an important diagnostic consideration in fever of unknown origin

To study the evolution of hemophagocytic syndrome (HPS) in children, we performed a retrospective review of 19 patients (median age, 17.4 months) in whom an infectious diseases consultation was requested at Texas Children's Hospital during the period of September 1991 through September 2001. Clinical findings consistent with HPS most frequently presented during days 6-14 of illness, concomitant with laboratory abnormalities. Fever was present for a median of 19 days before the diagnosis of HPS. Elevated serum lactate dehydrogenase and ferritin levels were noted in all patients. An infectious agent was identified in 42% of patients; 16% were found to have immunologic or vasculitic disease. HPS is a rare but often fatal disease that can initially present as fever of unknown origin with varying clinical findings, and it can be recognized by physicians who are familiar with the evolution of HPS. It is likely that many of these cases remain undiagnosed because of the HPS's rapidly fatal course.

Imaging characteristics of hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a nonmalignant disorder of immune regulation, with overproduction of cytokines and diminished immune surveillance. Symptoms are nonspecific and may affect multiple organs, including the central nervous system. Neuroimaging findings have been described in case reports and small series; body imaging findings have not been described extensively. OBJECTIVE. To summarize findings of the most frequently performed imaging studies of the brain, chest and abdomen in patients with HLH.

MATERIALS AND METHODS

Retrospective review of chest radiographs and CT, abdominal ultrasound and CT, brain CT and MRI, skeletal surveys, and autopsy data.

RESULTS

Twenty-five patients were diagnosed and treated for HLH at our institution over an 11-year period; 15 patients (60%) died. Common chest radiograph findings included alveolar-interstitial opacities with pleural effusions, often with rapid evolution and resolution. Hepatosplenomegaly, gallbladder wall thickening, hyperechoic kidneys and ascites were common abdominal findings, which resolved after therapy in some cases. Brain-imaging studies revealed nonspecific periventricular white-matter abnormalities, brain-volume loss and enlargement of extra-axial fluid spaces. Three infant cases, one with intracranial hemorrhage, one with multiple pathologic rib fractures and one with diaphyseal periosteal reaction involving multiple long bones on skeletal survey, raised suspicion of child abuse at presentation. Abuse was not substantiated in any case.

CONCLUSIONS

Clinicians and radiologists should be aware of the radiographic manifestations of HLH, which are nonspecific and overlap with infectious, inflammatory and neoplastic disorders. Findings in the chest (similar to acute respiratory distress syndrome) and abdomen may progress rapidly and then regress with institution of appropriate anti-HLH therapy. CNS findings may be progressive. In some infants, initial imaging findings may mimic nonaccidental trauma.