Miliary TB

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Miliary TB
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Review of Pathogenesis

• Inhaled bacilli implant in distal airspace,
  inflammatory reaction often with caseous necrosis
  develops forming Ghon focus
• Bacilli drain to regional lymph node and caseate
• Parenchymal lesion plus lymph node involvement is
  called Ghon complex
• 95 of cases, the development of cell-mediated
  immunity controls the infection and the Ghon
  complex undergoes progressive fibrosis, Latent TB

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Miliary TB

• Miliary TB develops when a Mycobacterium focus
  ruptures into a vascular channel
• Can occur during primary disease acute, and has a
  rapid clinical course, with septic shock,
  multiorgan system failure, ARDS
• Can develop from latent TB and has a variable
  presentation that can be acute, but more often is
  subacute or chronic

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Chronic Presentation

• Late miliary TB has a non-specific presentation
  including,
• Fever and/or night sweats 83-96
• Anorexia 78-92
• Weight loss 66-92
• Weakness or malaise 92
• Signs, symptoms, and lab abnormalities of an
  organ system involvedorgans with high blood flow
  are commonly affected
• lungs, liver, spleen, bone marrow, kidney,
  adrenals, meninges

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Series of 109 Pts from South Africa from 1978-1987

• Fever 96
• Pulmonary (rales, rhonchi, rubs, effusions) 72
• Hepatomegaly 52
• Splenomegaly 15
• Neurologic 20
• Positive PPD 42
• Anemia 52
• Leukopenia 15
• Leukocytosis 14

• Thrombocytopenia 23
• Thrombocytosis 24
• Elevated alkaline phosphatase 83
• Transaminitis 42
• Hyperbilirubinemia 15
• Elevated ESR 50 - 68
• Hypoxemia (pO2

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Diagnosis

• One proposed criteria for diagnosis includes
• Clinical presentation consistent with TB
  evening rise of temp, night sweats, anorexia,
  weight loss greater than 6 weeks
• Miliary pattern on CXR or CT
• Microbiological and/or histopathological evidence
  of TB

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Imaging

• CXR Miliary pattern fairly uniform, faint,
  reticulonodular infiltrate
• Pattern may become apparent days or weeks after
  presentation
• However, 50 of patients with a confirmed
  diagnosis of disseminated miliary TB had normal
  CXR
• CT is more sensitive

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Microbiology/Histology

• Probability of a positive smear increases with
  the number of sites sampled
• Sputum, gastric aspirate, urine, pleural fluid,
  ascities
• Bronchoscopy with BAL does not add significantly
  to the diagnostic yield
• Tissue samples demonstrating granulomas or
  caseating granulomas
• Liver 91-100
• Transbronchial biopsies 63-72
• Bone marrow biopsies 31-82

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Treatment

• Miliary TB is uniformly fatal without treatment
• Miliary TB does not require respiratory isolation
• Therapeutic regimes are generally similar to
  pulmonary TB, but should be individually
  tailored, and longer therapy is considered in the
  following pt types
• Children and immunocompromised
• Lymphadenitis
• Large organism burder
• Slow mirobiologic or clinical response

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Basic Treatment

• Initial phase 2 months
• Always use 4 drugs which reduces development of
  resistance
• Isoniazid, rifampin, ethambutol, pyrazinamide
• Continuation phase 4 - 7 months
• Isoniazid and rifampin