Loss of phospholipase PLAAT3 causes a mixed lipodystrophic and neurological syndrome due to impaired PPARγ signaling.

Phospholipase A/acyltransferase 3 (PLAAT3) is a phospholipid-modifying enzyme predominantly expressed in neural and white adipose tissue (WAT). It is a potential drug target for metabolic syndrome, as Plaat3 deficiency in mice protects against diet-induced obesity. We identified seven patients from four unrelated consanguineous families, with homozygous loss-of-function variants in PLAAT3, who presented with a lipodystrophy syndrome with loss of fat varying from partial to generalized and associated with metabolic complications, as well as variable neurological features including demyelinating neuropathy and intellectual disability. Multi-omics analysis of mouse Plaat3-/- and patient-derived WAT showed enrichment of arachidonic acid-containing membrane phospholipids and a strong decrease in the signaling of peroxisome proliferator-activated receptor gamma (PPARγ), the master regulator of adipocyte differentiation. Accordingly, CRISPR-Cas9-mediated PLAAT3 inactivation in human adipose stem cells induced insulin resistance, altered adipocyte differentiation with decreased lipid droplet formation and reduced the expression of adipogenic and mature adipocyte markers, including PPARγ. These findings establish PLAAT3 deficiency as a hereditary lipodystrophy syndrome with neurological manifestations, caused by a PPARγ-dependent defect in WAT differentiation and function.

Identification of chloramphenicol in human hair leading to a diagnosis of factitious disorder.

Introduction: Chloramphenicol (2,2-dichloro-N-[1,3-dihydroxy-1-(4-nitrophenyl)porpan-2-yl]acetamide) is a bacteriostatic antibiotic of the phenicolated family, used in the past to treat meningitis, plague, cholera, or typhoid fever. Treatment with chloramphenicol can have life threatening side effects, the most serious of which is aplastic anemia, which may be fatal. For this reason, the antibiotic was removed from the French market in 2008.Case report: In this paper, the authors report the case of a woman consuming chloramphenicol possibly in the context of factitious disorder. After a capsule containing chloramphenicol was discovered in her hospital bed, a hair specimen (about 16 cm, brown, not oriented) was collected and sent to the toxicological laboratory in order to document exposure to chloramphenicol.Results: The drug was identified in the hair specimen of the subject at 13.7 ng/mg.Discussion: Identification of chloramphenicol in hair has not been reported in the literature. As consequence, the interpretation of the concentration, the dosage and the frequency of abuse are difficult to establish.Conclusion: Given the context, physicians considered the case as a possible factitious disorder, thus being a unique observation of using chloramphenicol in such a context.

Efficacy of everolimus in patients with metastatic insulinoma and refractory hypoglycemia.

BACKGROUND: Refractory hypoglycemia in patients with metastatic insulinoma is an important cause of morbidity and mortality. Everolimus could be a new therapeutic option. METHODS: Within the French Group, we conducted a retrospective, multicentric study of endocrine tumors to evaluate the time to the first recurrence of symptomatic hypoglycemia, after everolimus initiation, in patients with metastatic insulinoma and refractory hypoglycemia. Ongoing hyperglycemic medical options, tumor response, and safety information were recorded. RESULTS: Twelve patients with metastatic insulinoma and refractory hypoglycemia who were treated with everolimus between May 2007 and June 2011 were reviewed. Everolimus (starting dose, 10 mg/day, except in one patient, 5 mg/day) was given after a median of four previous therapeutic lines. Medication aimed at normalizing blood glucose levels in 11 patients. After a median duration of 6.5 months (range 1-35+ months), median time to the first recurrence of symptomatic hypoglycemia was 6.5 months (range 0 to 35+ months). Three patients discontinued everolimus because of cardiac and/or pulmonary adverse events at 1, 1.5, and 7 months after initiation, which led to two deaths. Three patients discontinued everolimus because of tumor progression at 2, 3, and 10 months after initiation, without recurrence of hypoglycemia. CONCLUSION: Everolimus appears to be a new effective treatment for patients with metastatic insulinoma and refractory hypoglycemia. Tolerance should be carefully monitored.