ACSQHC-ARCR-034

Thrombotic Microangiopathies (TMAs) are characterised by platelet aggregation within small blood vessels. This consumes platelets (causing thrombocytopenia), and the damaged/narrowed vessels cause mechanical destruction of red blood cells (microangiopathic haemolytic anaemia). The consequent disruption to blood flow within small vessels leads to end organ damage/dysfunction (e.g. kidney failure or stroke). Thrombotic microangiopathies can occur as a result of a variety of inherited and acquired conditions, and are now seen (and recognised) more commonly, particularly as they can occur as a result of new medications, such as some of the newer anti-cancer agents. 

Thrombotic thrombocytopenic purpura (TTP) is long recognised as a TMA affecting primarily the central nervous system and kidneys. TTP is a rare, life threatening disorder that had an almost universally fatal outcome till the introduction of plasmapheresis in the late 1980s and early 1990s. Haemolytic Uraemic Syndrome (HUS) is another rare TMA often preceded by a diarrhoeal illness caused by Shiga toxin-producing organisms (especially Escherichia coli (STEC) or Shigella bacteria). Atypical HUS (aHUS) has been used to encompass a group of TMAs that are neither TTP or HUS, and which are most commonly associated with acquired or inherited defects in the complement pathway or complement regulatory proteins.

The relative rarity of the individual types of TMA is a barrier to accrual of data and material to support scientific studies and randomised clinical trials. A national registry for all Australian patients with TMA provides an important community resource.

The aims of the TMA Registry are to:

• Determine the incidence, natural history, specific clinical characteristics, and clinical outcome of patients with TMAs, particularly TTP, HUS and aHUS
• Provide information on the range of therapies employed in the treatment of TMA patients
• Explore factors influencing clinical outcomes
• Help define optimal management of patients with TTP and HUS
• Inform and inspire future hypothesis-driven research in this area

The TMA Registry is a register of patients who develop TTP or HUS in any clinical setting. Clinical data collection is undertaken by clinicians in specialist units at participating hospitals.  Data management and analysis is undertaken by the Department of Epidemiology and Preventive Medicine (DEPM), Monash University and interpreted with the input of specialist clinicians on the steering committee.