Myeloid & Lymphoid disorders in practice - 2008

Comment: The classification of MPNs: WHO and why?
John Reilly
pp 2-2
The American academic Samuel Hayakawa (1906–92) is quoted as saying, ‘Science seeks only the most generally useful systems of classification; these it regards for the time being, until more useful classifications are invented, as true’. So how does the new 2008 World Health Organization (WHO) classification advance the field and will it be seen as ‘more useful’?
An update on the diagnosis and management of PNH
Richard Kelly, Stephen Richards and Peter Hillmen
pp 3-6
Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal disorder of haemopoietic stem cells (HSCs). It is characterised by haemopoietic clones that harbour somatic mutations of the PIG-A gene. The PIG-A gene is one of over 20 genes needed for the synthesis of the glycophosphatidylinositol (GPI) anchor which is used by a variety of cell surface proteins to attach to blood cells.
Demethylation agents – do they have a future?
Deborah Moulton and Kavita Raj
pp 7-9
The DNA methyltransferase (DNMT) inhibitors (DNMTis) azacitidine and decitabine were developed in the 1960s as chemotherapeutic agents. Their epigenetic modulating activity mediating differentiation has renewed interest in them. Epigenetic changes are reversible and include DNA methylation (addition of a methyl group by DNMT enzymes to cytosine leading to 5- methylcytosine) and histone deacetylation (removal of negatively charged acetyl groups from lysine residues on histone tails), both of which lead to DNA and its associated chromatin being in the closed configuration. Such DNA is inaccessible to the transcriptional machinery and the genes are turned off.
How pretreatment advice can help keep patients on therapy
Heather Rawle, Yvonne Francis, Claire N Harrison and Ann Marie Jahn- Fermor
pp 10-11
There are many key challenges in managing patients with chronic conditions. Assisting patients with medication-related side-effects and assuring patient compliance are two such challenges which are interdependent. Managing these issues with care is crucial to treatment success.
Juvenile myelomonocytic leukaemia – an update
Anupama G Rao and Phil J Ancliff
pp 12-15
Juvenile myelomonocytic leukaemia (JMML) describes a clonal myeloproliferative haematopoietic stem cell disorder presenting in early childhood. It was previously referred to as chronic myelomonocytic leukaemia (CMML) or juvenile chronic myeloid leukaemia – diseases characterised by specific chromosomal translocations – which failed to accurately describe this unique disorder.