Detection of lenalidomide metabolites in urine to discover drug-resistant compounds.

Lenalidomide is the first-line drug for the clinical treatment of multiple myeloma. However, its efficacy differs significantly among patients. Clinically, after lenalidomide treatment, few patients' conditions worsened, whereas others remained stable or improved. To clarify the reasons for this difference in efficacy, 20 patients with multiple myeloma who received maintenance treatment with lenalidomide were retrospectively included in this study. Lenalidomide metabolic compounds were detected in patient urine using mass spectrometry. A rapid and accurate ultra-performance liquid chromatography-time-of-flight tandem mass spectrometry (UPLC-TOF-MS/MS) method was used to characterize metabolites in the urine of different patients. Eleven metabolites, including four new compounds, were identified and characterized in all the samples. Among these, two metabolites were found to have obvious discrepancies in different groups of patients. One metabolite named Denitrified-2 glutarimide, a new potential compound, was only detected in the urine of ineffective and stable patients, whereas the other metabolite named 5-Hydroxy-lenalidomide was found only in the urine of effective patients.

A case of Bloom syndrome with uncommon clinical manifestations confirmed on genetic testing.

Bloom syndrome, a rare autosomal-recessive disorder, characteristically presents with photosensitivity, telangiectatic facial erythema, and growth deficiency. We present a case of Bloom syndrome with uncommon clinical manifestations including alopecia areata, eyebrow hair loss, flat nose, reticular pigmentation, and short sharpened distal phalanges with fingernails that were wider than they were long. We detected the Bloom syndrome gene, BLM, which is one of the members of the RecQ family of DNA helicases, and found changes in 2 heterozygous nucleotide sites in the patient as well as her father and mother.