paroxysmal cold hemoglobinuria (PCH)

Etiology

• viral infection
  • measles & mumps in children
• autoimmune disease
• tertiary syphilis

Epidemiology

rare

Pathology

• complement-mediated hemolysis resulting from IgG autoantibody against RBC (P-antigen) activated by the cold

Clinical manifestations

• attacks precipitated by cold exposure
• fever/chills
• back pain, leg pain, abdominal pain/cramps
• headache following exposure to the cold
• malaise
• nausea/vomiting
• diarrhea
• splenomegaly
• hepatomegaly
• transient jaundice may be observed
• pale fingers, toes & tip of nose
• rapid recovery from acute episode
• generally asymptomatic between episodes
• disorder generally extends over many years

Laboratory

• IgG autoantibody directed against P-antigen on RBC (Donath-Landsteiner antibody)
• hemoglobinemia
• hemoglobinuria
  • hemoglobin in fresh urine without red cells
• methemoglobin in urine
• cold hemolysis of blood in vitro may be observed
• direct antiglobulin test (Coomb's)
  • may show complement, but seldom IgG
  • often negative
• Donath-Landsteiner test:
  • hemolysis activated by exposure of blood to cold
  • hemolysis takes place only after rewarming
• peripheral blood smear may show agglutination

Management

• treat syphilis if present; responds favorably to treatment
• chronic autoimmune PCH may respond to immunosuppression
  • prednisone
  • azathioprine
  • cyclophosphamide
• does NOT respond to splenectomy

More general terms

• hemoglobinuria
• cold antibody autoimmune hemolytic anemia