Gaucher disease prevalence in 600 patients affected by monoclonal gammopathy of undetermined significance.

BACKGROUND: Gaucher disease (GD) is a rare autosomal recessive inherited disorder caused by the lysosomal enzyme acid ß-glucosidase deficiency. Many patients experience a critical delay in the diagnosis of up to 8-10 years due to its rarity and variability in signs and symptoms, with the consultation of several specialists. PATIENTS AND METHODS: This prospective observational study analyzed the prevalence of GD in 600 patients with monoclonal gammopathy of uncertain significance (MGUS) from January 2018 until February 2022. RESULTS: The mean age of participants was 66 years, with a mean monoclonal component of 0.58 g/dL. In 433 MGUS patients with available data, anemia (hemoglobin level < 10 g/dL) was present in 31 patients (7%), and thrombocytopenia (platelet count <100.000/mm3 ) in 24 (5.5%). Of 600 MGUS patients tested for acid ß-glucosidase enzyme activity, 7 patients (1.2%) had activity below 2.5 nmol/h/mL. In comparison, GBA gene analysis was executed in 110 patients. It revealed 4 patients (0.7%) affected by GD (3 patients with compound heterozygous mutation and 1 with homozygous mutation), with a prevalence of 1 every 150 MGUS patients. Furthermore, 12 out of the remaining 106 evaluated patients (11%) were carriers of a single heterozygous mutation while having regular enzyme activity. CONCLUSIONS: The clinical heterogeneity of GD and frequent lack of awareness among physicians often lead to diagnostic delays and severe clinical manifestations. The role of MGUS in the presence of at least one clinical sign, such as low platelet count, organomegaly, bone pain, or bleeding tendency, could aid in initiating GD screening with DBS, thus reducing the period between symptom onset and the diagnosis of this rare disease.

Lenalidomide in International Prognostic Scoring System Low and Intermediate-1 risk myelodysplastic syndromes with del(5q): an Italian phase II trial of health-related quality of life, safety and efficacy.

In lower-risk myelodysplastic syndromes (MDS) with del(5q), lenalidomide induces erythroid responses associated with better survival. In a phase II, single-arm trial, 45 patients with anemia and lower-risk del(5q) MDS received lenalidomide 10 mg/day to evaluate quality of life (QoL) changes, measured by QOL-E, safety, responses and survival. Lenalidomide was well tolerated, with 80% completing ≥ 24 weeks of treatment. Earlier study discontinuation was related to disease progression (n = 5), death (n = 1) and withdrawal of consent (n = 3). Within 24 weeks, 82% obtained erythroid responses, durable in 69% at 52 weeks. Cytogenetic responses occurred in 29 patients (64%), with 10 patients achieving a complete cytogenetic response. QoL-E scores correlated with hemoglobin levels and improved in erythroid responders. Erythroid responders had an 86% reduced risk of disease progression and an 80% reduction in mortality risk compared with non-responders. These findings corroborate earlier studies and give further support to the use of lenalidomide in lower-risk MDS and del(5q).

Biological activity of lenalidomide in myelodysplastic syndromes with del5q: results of gene expression profiling from a multicenter phase II study.

In vitro studies suggest that haploinsufficiency is involved in the pathogenesis of myelodysplastic syndromes (MDS). In patients with del5q cytogenetic abnormality, RPS-14 and microRNAs (miRNAs) play a major role. In a multicenter phase II single-arm trial with lenalidomide in anemic primary del5q MDS patients with low- or int-1 risk IPSS, biological changes from baseline were investigated. Gene expression profiling of selected genes was performed (TaqMan® Low Density Array Fluidic card, Applied Biosystems PRISM® 7900HT) and normalized against the expression of the 18S housekeeping gene from a pool of healthy subjects. Thirty-two patients were evaluated at baseline and after 3 and 6 months of treatment. RPS-14, miR-145, and miR-146 were downregulated at baseline and significantly increased during treatment. Nuclear factor kappa B, IL-6, interferon regulatory factor-1, IFNγ-R2, IL-2, and many genes in the apoptotic pathways (TNF, IL-1B, and IL-10) were upregulated at baseline and significantly downregulated during lenalidomide treatment, while forkhead box P3, FAS, IFNγ, IL-12A, and IL-12B were downregulated at baseline and progressively upregulated during treatment. The crucial role of aberrant immunological pathways and haploinsufficiency in the pathogenesis of del5q MDS is confirmed in the present patient setting. Our results indicate that lenalidomide may act through defined immunological pathways in this condition.