Recent advances in molecular technologies enable sensitive and quantitative assessment of circulating tumor DNA, offering a noninvasive disease monitoring tool for patients with malignant disorders. Here, we demonstrated on four follicular lymphoma cases that circulating tumor DNA based EZH2 mutation analysis performed by a highly sensitive droplet digital PCR method may be a valuable treatment monitoring approach in EZH2 mutant follicular lymphoma. EZH2 variant allele frequencies changed in parallel with the volume of metabolically active tumor sites observed on 18F-fluorodeoxyglucose positron emission tomography combined with computer tomography (PET-CT) scans. Variant allele frequencies of EZH2 mutations decreased or were eliminated rapidly upon successful treatment, with treatment failure being associated with elevated EZH2 variant allele frequencies. We also demonstrated spatial heterogeneity in a patient with two different EZH2 mutations in distinct anatomical sites, with both mutations simultaneously detected in the liquid biopsy specimen. In summary, circulating tumor DNA based EZH2 mutation analysis offers a rapid, real-time, radiation-free monitoring tool for sensitive detection of EZH2 mutations deriving from different anatomical sites in follicular lymphoma patients receiving immunochemotherapy.

Lyophilization is a cost-effective method for biological specimen preservation but detailed tissue-specific reference protocols are still lacking. Moreover, data are limited on the long-term stability of proteins and nucleic acids in lyophilized samples.Here, we offer lyophilization protocols for various rat and mouse tissues (kidney, heart, liver, lung, aorta, and skin) coupled with technical hints for optimal sample preparation. We demonstrate that lyophilized samples stored at 4 °C for 20 months can yield protein and RNA of similar quantity and quality to −80 °C storage, while phosphorylated proteins are preserved as well. Freeze-dried and subsequently pulverized samples can provide more consistent, more reliable data especially when investigating focal injuries, such as fibrosis. We developed a protocol for the concentration of biological solutions and achieved 20-times concentration in human peritoneal dialysis effluent solution which enables the previously unattainable detection of proteins in these samples. We established a method for water removal as well as accurate water content measurement of fecal samples, which can be valuable for gut metabolome analysis.Taken together, lyophilization is a valuable tool for the preservation of biological samples with many advantages. We aim to draw attention to the wide range of possibilities offered by freeze drying in pre-clinical or basic research.

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has revolutionised the therapeutic landscape of chronic lymphocytic leukaemia (CLL). Acquired mutations emerging at position C481 in the BTK tyrosine kinase domain are the predominant genetic alterations associated with secondary ibrutinib resistance. To assess the correlation between disease progression, and the emergence and temporal dynamics of the most common resistance mutation BTK C481S , sensitive (10 À4 ) time-resolved screening was performed in 83 relapsed/refractory CLL patients during single-agent ibrutinib treatment. With a median follow-up time of 40 months, BTK C481S was detected in 48Á2% (40/83) of the patients, with 80Á0% (32/40) of them showing disease progression during the examined period. In these 32 cases, representing 72Á7% (32/44) of all patients experiencing relapse, emergence of the BTK C481S mutation preceded the symptoms of clinical relapse with a median of nine months. Subsequent Bcl-2 inhibition therapy applied in 28/32 patients harbouring BTK C481S and progressing on ibrutinib conferred clinical and molecular remission across the patients. Our study demonstrates the clinical value of sensitive BTK C481S monitoring with the largest longitudinally analysed real-world patient cohort reported to date and validates the feasibility of an early prediction of relapse in the majority of ibrutinib-treated relapsed/refractory CLL patients experiencing disease progression.

The oral, highly selective Bcl2 inhibitor venetoclax has substantially improved the therapeutic landscape of chronic lymphocytic leukemia (CLL). Despite the remarkable response rates in patients with relapsed/refractory (R/R) disease, acquired resistance is the leading cause of treatment failure, with somatic BCL2 mutations being the predominant genetic drivers underpinning venetoclax resistance. To assess the correlation between disease progression and the most common BCL2 mutations G101V and D103Y, sensitive (10−4) screening for the most common BCL2 mutations G101V and D103Y was performed in 67 R/R CLL patients during venetoclax single-agent or venetoclax–rituximab combination therapy. With a median follow-up time of 23 months, BCL2 G101V and D103Y were detected in 10.4% (7/67) and 11.9% (8/67) of the cases, respectively, with four patients harboring both resistance mutations. Ten out of eleven patients carrying BCL2 G101V and/or D103Y experienced relapse during the follow-up period, representing 43.5% of the cases (10/23) showing clinical signs of disease progression. All BCL2 G101V or D103Y variants were detected in patients receiving venetoclax as a continuous single-agent treatment while these mutations were not observed during or after fixed-duration venetoclax therapy. Targeted ultra-deep sequencing of BCL2 uncovered three additional variants in four patient samples obtained at relapse, suggesting convergent evolution and implying a cooperating role of BCL2 mutations in driving venetoclax resistance. This cohort is the largest R/R CLL patient population reported to date in which BCL2 resistance mutations were investigated. Our study demonstrates the feasibility and clinical value of sensitive screening for BCL2 resistance mutations in R/R CLL.

A krónikus limfocitás leukémia a nyugati világban leggyakrabban előforduló felnőttkori leukémiatípus, mely heterogén klinikai lefolyással és változatos genetikai háttérrel társul. A széles körben alkalmazott kemo-immunoterápiák mellett az elmúlt években új, célzott kezeléseket biztosító kis molekulájú gyógyszerek váltak elérhetővé, mint a kinázgátló ibrutinib, acalabrutinib és idelalisib, valamint a BCL2 antagonista venetoclax. Jelenleg hazánkban a krónikus limfocitás leukémia terápiáját forradalmasító, korszerű kezelések közül az ibrutinib monoterápia nemcsak relabáló vagy refrakter betegeknél, hanem rossz prognózisú, TP53-defektust hordozó betegeknél első vonalban is alkalmazható. A látványos klinikai sikerek ellenére a betegek egy részében rezisztencia alakul ki ibrutinibkezelés mellett, melynek hátterében álló genetikai változásokhoz és molekuláris mechanizmusokhoz kapcsolódóan egyre több adat áll rendelkezésre a nemzetközi irodalomban. Közleményünkben ismertetjük a B-sejt receptor jelátviteli útvonalnak a krónikus limfocitás leukémia patogenezisében betöltött szerepét, mely egyúttal az ibrutinibkezelés célpontjaként is szolgál. Továbbá bemutatjuk az ibrutinibterápia hatásmechanizmusát és sajátosságait, valamint a kezelés során megjelenő, klinikai rezisztenciát kísérő genetikai változásokat. Végül áttekintjük a terápiás rezisztencia molekuláris módszerekkel való monitorozásának és korai kimutatásának lehetőségeit és korlátait, valamint a rezisztencia megjelenését követően alkalmazható kezelési lehetőségeket.