In fall 2009 the emergency department of a clinic in Greece with increased patient visits due to influenza-like illness observed a particular pattern in the complete blood count (CBC) of these patients. In 90% of all patients with probable influenza, lymphopenia and/or monocytosis were present. Relative lymphopenia with or without monocytosis appears to be a laboratory marker for H1N1 virus inf...

Purine Nucleoside Phosphorylase (PNP) deficiency is a rare autosomal recessive metabolic disorder. In PNP-deficiency disorder, the deficient enzyme leads to accumulation of toxic metabolites, especially in lymphocytes and the metabolites exert toxic effect on T-cell generation. Purine nucleoside phosphorylase deficiency causes decreased numbers of T cells and lymphopenia. The patients suffering...

Background Dimethyl fumarate (DMF) is a disease modifying therapy (DMT) used to manage Multiple Sclerosis (MS). The recently revised Summary of Product Characteristics (SPC) recommends increased monitoring or cessation this medication for persistent (> 6 months) lymphopenia, because an risk Progressive Multifocal Leukoencephalopathy. Awareness the frequency lymphopenia will guide clinical de...