Paroxysmal nocturnal haemoglobinuria and pregnancy

DIAGNOSTIC DILEMMAS IN PAROXYSMAL NOCTURNAL HEMOGLOBINURIA

Clinical and hematological parameters in six cases of paroxysmal nocturnal hemoglobinuria (PNH) are presented. The mean delay in diagnosis after onset of symptoms was 3.7 years. Initial diagnoses considered were: (a) hematuria; (b) iron-deficiency; hemolytic; megaloblastic or refractory anemia and (c) myelodysplastic syndrome. Clinical features included; reddish urine (5/6), unexplained abdominal pain (4/6) and pallor (6/6). Laboratory investigations showed anemia (6/6), leucopenia (3/6), thrombocytopenia (3/6), unconjugated hyperbilirubinemia at some stage (6/6), and bone marrow erythroid hyperplasia (6/6). Complications encountered were (a) gall stones needing cholecystectomy, hemosiderosis and proximal tubular acidosis in 1 case, (b) disseminated tuberculosis in 1 case and (c) abortion with congestive cardiac failure in one. PNH may present with atypical features and tests for hemosiderinuria, sucrose lysis test and HAM's test are required to establish the diagnosis.

Paroxysmal nocturnal haemoglobinuria and pregnancy

A woman with paroxysmal nocturnal haemoglobinuria (PNH) who was successfully delivered of 3 healthy infants after 4 pregnancies is reported. The obstetric literature of women with PNH is reviewed and the consequent view presented that judicious advice should not preclude pregnancy in such women.

[Paroxysmal nocturnal hemoglobinuria]

Paroxysmal nocturnal hemoglobinuria, first described in the late 19th century, is an acquired disorder characterized by hemoglobinemia and hemoglobinuria. The major clinical manifestation of PNH is chronic intravascular hemolysis of various severity. Patients-mostly young adults - may also present with episodes of abdominal or back pain. Common cause of death is thrombosis especially of the hepatic veins. Granulocytopenia and thrombocytopenia may be the initial manifestation of PNH, indicating that the disorder is a primary bone-marrow disease, affecting not only the erythrocytes but also other peripheral blood cells and the haematopoietic stem cell. The course of the disease is variable. Partial complete recovery was described, but also fatal thrombosis. The major phenotypic expression of PNH is an increased susceptibility of the erythrocytes to the lytic action of complement in vitro. The enhanced complement susceptibility is most probably due to membrane defects: two membrane proteins regulating the complement cascade in PNH cells were missing, the decay-accelerating factor, DAF, inhibiting the activation of the lytic complement complex and the C8 binding protein, C8bp, which interferes with the lytic process. Aside from the lack of the complement regulators also other membrane defects have been described (e.g. of acetylcholinesterase or alkaline phosphatase). The proteins as well as DAF and C8bp are linked to the cell membrane via a phosphatidylinositol (PI) anchor, leading to the speculation that the disease results from a deficiency in the post-translational PI anchoring mechanism. The diagnosis of PNH is based on the Hamtest, but will be extended to the quantitation of the above described membrane proteins.(ABSTRACT TRUNCATED AT 250 WORDS)