Hermansky-Pudlak Syndrome

Epidemiology

  • Increased incidence in Puerto Ricans and inhabitants of Southern Holland

Physiology

  • Autosomal recessive
  • Deficiency of unknown enzyme: accumulation of a chromolipid ceroid (related to lipofuscin) in reticuloendothelial system
    • Partial tyrosine-negative albinism
    • Qualitative platelet defect

Pathologic Patterns

  • Desquamative interstitial pneumonia (DIP):
  • Usual interstitial pneumonia (UIP): may be seen
  • Honeycombing

Diagnosis

  • CXR/Chest CT Patterns
    • ILD: reticulonodular infiltrates
    • Honeycombing: small cystic changes (seen best in lower fields) seen late in course
      • Radiographic honeycombing correlates well with pathologic honeycombing
  • FOB
    • BAL may recover ceroid-containing macrophages (which stain with Fontana-Masson silver reduction techniques)
  • OLB: extensive fibrosis of interstitium and filling of alveolar spaces with ceroid-containing macrophages

Clinical

Pulmonary Manifestations

  • Interstitial Lung Disease (see ILD-Etiology, [[ILD-Etiology]])
    • Epidemiology: occurs in females>males
    • Diagnosis
      • CXR/Chest CT: reticular pattern -> may progress to honeycombing
      • PFT’s: restrictive pattern with decreased DLCO
    • Clinical: onset in teens-30’s
    • Treatment and Prognosis: usully slowly progressive and unresponsive to treatment
  • Pulmonary Hypertension (see Pulmonary Hypertension, [[Pulmonary Hypertension]])
    • Occurs late in course

Hematologic Manifestations

  • Platelet Dysfunction:

Derm/Ocular Manifestations

  • Oculocutaneous Albinism (partial): tyrosine-negative

GI Manifestations

  • Granulomatous Colitis

Treatment

  • ILD: usually unresponsive to treatment

References

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