Bis(monoacylglycerol)phosphate as a non-invasive biomarker to monitor the onset and time-course of phospholipidosis with drug-induced toxicities

IMPORTANCE TO THE FIELD: Drug-induced phospholipidosis (PL) is a phospholipid storage disorder characterized by the accumulation of multi-lamellar bodies (myeloid bodies) in tissues. A major unanswered question is whether PL represents a benign adaptive response, symptom or early event in drug toxicity. The absence of a non-invasive biomarker to monitor tissue PL has made it difficult to determine the prevalence and implications of PL in the clinic. As a result, the interpretation of PL in risk assessment remains uncertain in preclinical and clinical drug development. AREAS COVERED IN THIS REVIEW: This review describes the rationale for bis(monoacylglycerol)phosphate (BMP) as a biomarker of PL and explores the potential links between PL and the toxicities of drugs. WHAT THE READER WILL GAIN: The similarities between the hypothesized roles of BMP in PL and Niemann-Pick type C disease are discussed. The potential implications of PL for cellular function are described in the context of drug-induced QT prolongation, myopathy and renal toxicity. TAKE HOME MESSAGE: A specific species of BMP, di-docosahexaenoyl-BMP, should be investigated further as a non-invasive biomarker to monitor the onset and time course of PL and to better understand the functional consequences which could contribute to the toxicities of drugs.