Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (316 page)

   
D
-dimer and fibrinogen degradation products (FDPs): elevated if DIC is present.

   Plasma Hb and urine hemosiderin: elevated.

   Plasma haptoglobin: decreased.

Suggested Reading

Mohandas N, Gallagher PG. Red cell membrane: past, present, and future.
Blood.
2008;112:3939–3948.

EVANS SYNDROME

   Definition

Evans syndrome is characterized by the simultaneous (or sequential) development of autoimmune hemolytic anemia and immune thrombocytopenia (ITP) and/ or immune neutropenia, without a demonstrable underlying etiology. Evans syndrome may be associated occasionally with SLE lymphoproliferative neoplasms or primary immune deficiencies.

   Laboratory Findings

As described for autoimmune hemolytic anemias (see p. 377 under Anemia, hemolytic) and immune thrombocytopenias (see p. 442 under Platelets, thrombocytopenias). When neutropenia is present, studies for antileukocyte antibodies should be undertaken.

Suggested Reading

Michel M, Chanet V, Dechartres A, et al. The spectrum of Evans syndrome in adults: new insight into the disease based on the analysis of 68 cases.
Blood.
2009;114:3167–3172.

ERYTHROCYTOSIS

   Increased red cell mass (>25% above predicted hemoglobin, or >18.4 g/dL in males, or >16.4 in females)

   Causes of erythrocytosis (see algorithm on Figure
9-2
)

   Clonal: polycythemia vera

   Nonclonal:

   Relative erythrocytosis (hemoconcentration)

   Hypoxia, high altitude, pulmonary disease, right to left shift, sleep apnea, high affinity hemoglobin, carbon monoxide poisoning

   Renal disease