All are seen in PNH except-

PNH is paroxysmal nocturnal hemoglobinuria.Its a disease results from acquired mutation in PIGA an enzyme that is essential for the synthesis of ceain membrane associated complement regulatory proteins. Thrombosis is the leading cause of disease related death in PNH.About 40% patient suffer from venous thrombosis of hepatic, poal or cerebral veins. In PNH GPI linked proteins are deficient because of somatic mutation that inactivate PIGA.In RBC proteins are attached to cell membrane through a linkage to a specialised phospholipid called GPI.It is hypothesised that bone marrow cells with PIGA mutation increase in numbers only in rare instances where they have selective advantages such as in setting autoimmune reaction against GPI linked antigens. This explains the frequent association of PNH with aplastic anaemia. Red cell deficient in these GPI linked factors are abnormally susceptible to lysis or injury by complement. Manifest as intravascular hemolysis.PNH is the only hemolytic anaemia caused by an acquired genetic defect. Reference :ROBBINS AND COTRAN PATHOLOGIC BASIS OF DISEASE.SOUTH ASIA EDITION. VOL 1. PAGE NO.642,643