Precocious Line Research Articles

Transcriptomic analysis uncovers a biphasic response to precocious Eimeria acervulina infection in chicken duodenal tissue

Live anticoccidial vaccines, either formulated with unattenuated or attenuated Eimeria parasites, are powerful stimulators of chicken intestinal immunity. Little is known about the dynamics of gene expression and the corresponding biological processes of chicken responses against infection with precocious line (PL) of Eimeria parasites. In the present study, we performed a time-series transcriptomic analysis of chicken duodenum across 15 time points from 6 to 156 hours post-infection (p.i.) with PL of E. acervulina. A high-quality profile showing two distinct changes in chicken duodenum mRNA expression was generated during the infection of Eimeria. Early response revealed that activation of the chicken immune response was detectable from 6 h.p.i., prominent genes triggered during the initiation of asexual and sexual parasite growth encompass immune regulatory effects, such as interferon gamma (IFN-γ), interferon regulatory factor 1 (IRF1), and interleukin-10 (IL10). The late response was identified significantly associating with maintaining cellular structure and activating lipid metabolic pathways. These analyses provide a detailed depiction of the biological response landscape in chickens infected by the PL of E. acervulina, contributing significant insights for the investigation of the host-parasite interactions and the management of parasitic diseases.

Transcriptomic Insights into the Developmental Dynamics of Eimeria acervulina: A Comparative Study of a Precocious Line and the Wild Type.

Coccidiosis, a parasitic disease caused by single or multiple Eimeria species, leads to significant economic losses in the poultry industry. The Eimeria life cycle includes schizogony, gametogony, and sporogony. To investigate the dynamics of gene expression and regulatory networks during the development of Eimeria acervulina, we employed time-course transcriptomics to rigorously compare the gene expression patterns between a precocious line (PL) and the wild type (WT) of E. acervulina. The results revealed that the PL enters into gametogony 12 h earlier than the WT, and both the PL and WT exhibited distinct clustering patterns during the development phase. A weighted gene co-expression network analysis (WGCNA) identified genes specifically expressed at four distinct developmental stages, schizogony, gametogony, sporulated oocysts, and unsporulated oocysts, clarifying the key biological processes at each stage. This study used global transcriptome profiling to elucidate molecular variations throughout the E. acervulina life cycle, providing critical insights into molecular characterization and valuable resources for investigating other apicomplexan parasites of public health importance.

Transcriptomic responses of rabbits to infections by precocious line and wild-type Eimeria media: revealing molecular signatures and pathway differences in liver and duodenum during the peak and terminal phases of oocyst production.

Eimeria media is a principal pathogen responsible for rabbit coccidiosis, targeting the rabbit's intestinal epithelial cells. This parasitism damages the intestinal mucosal barrier, initiating a systemic immune and inflammatory response that jeopardizes the sustainable growth of rabbit farming. To understand the implications of infection on the host's immune and metabolic responses, we employed RNA-Seq to analyze RNA from the liver and duodenum tissues of post-infected rabbits infected with both the precocious line and wild-type strain of E.media. Comprehensive transcriptomic analysis revealed that the two parasites exhibit divergent transcriptomic imprints on host tissues. While the precocious line predominantly modulates immune-centric pathways with significant differential gene enrichment, wild-type strain favors pathways that affect metabolism. In addition, our study pinpointed a set of genes that undergo significant modifications in response to these effects. These revelations grant a fresh avenue to probe deeper into the symbiotic intricacies of the E.media and its rabbit host.

Biological characteristics of a precocious line of Eimeria tenella.

The Eimeria tenella Yulin strain (EtYL), which is sensitive to most anti-coccidial drugs, was isolated in the Yulin area of Guangxi, China. Then, Eimeria tenella Yulin precocious line (pEtYL), a precocious line with a prepatent period of 108h, was obtained through early selection. The biological characteristics of pEtYL, including its morphology, purity, oocyst excretion curve, reproductive capacity, pathogenicity, immunogenicity, and preservation time, were comprehensively analyzed. The results showed that the isolated precocious line of E. tenella exhibited high purity, relatively weak pathogenicity, and good immunogenicity and can be used as a live vaccine line for chicken coccidiosis.

A bivalent vaccine of Eimeria media and Eimeria intestinalis yields protective immunity against coccidiosis during rabbit production

Coccidiosis is the costliest disease in the rabbit industry. The kits do not obtain maternal immunity against the diseases and therefore suckling to weaning period being the riskiest time of infection. To date, control of coccidiosis is relied on the use of chemical coccidiostat as a drug or as the substance in feed. Whilst, continuous exposure to antibiotics develops resistance and contamination in the carcass. There is no commercially provided vaccine to prevent rabbit coccidiosis cases. In this report, we processed precocious lines from the strain of Yogyakarta origin by using selection pressure to attenuate Eimeria spp. The vaccine candidate composed of 50% of each Eimeria media and Eimeria intestinalis were given orally to initiate protective immunity against rabbit coccidiosis. The vaccinated groups with 5 x 102 oocyst dosage exhibited 95% less total oocyst excretion compared to the non-vaccinated group. Our experiment showed no mortality and without any significantly detrimental response of vaccinated rabbits during the observation time (P<0.0001). Since the oocysts in the vaccinated rabbits are excreted in dropped faecal samples, it provides recirculation and provokes a group immunity within the flock. A vaccine candidate is a promising tool as a more environmentally friendly strategy for sustainable rabbit production.

A new landscape of rabbit gut microbiota shaped by the infection of precocious parasites of Eimeria intestinalis

Rabbit intestinal coccidiosis is caused by one or several Eimeria species, which cause intestinal damage and secondary bacterial infection. However, the impact of Eimeria infection on gut microbiota is much unknown. To evaluate the influence, we detected the feces flora of SPF rabbits infected with the 1 × 104 oocysts of E. intestinalis wild type (WT) and a precocious line (EIP8), a highly pathogenic species, by 16S rRNA sequencing. The microbiota of newly weaned rabbits post vaccination with low doses of EIP8 oocysts was also detected. In SPF rabbits, while Ruminococcaceae, Lachnospiraceae, and Bacteroidaceae were dominant families in all groups, EIP8 infection induced less changes in beta-diversity. In EIP8-infected rabbits, the intestinal flora whose abundance changed post infection accounted for less than 5.23 % of the entire flora. In comparison, it accounted for 27.18 % in WT group on d14 PI, while it was more than 20 % in diclazuril control group on d7 or d10 PI. The amount of fecal IgA and the abundance of IgA-production-related bacteria were similar in either EIP8 or WT infected rabbits. In the newly weaned rabbits, vaccination with EIP8 provided sufficient protection against challenge with WT parasites, as the body weight gain of vaccinated rabbits was similar to that of untreated animals, as well as more than 80 % reduction of oocyst output was detected when compared with unimmunized and challenged animals. Moreover, the vaccination had no significant impact on rabbit microbiota. Together, our findings suggested that the precocious line of E. intestinalis, compared with WT, induced a new fecal microbiota biodiversity in rabbits.

The results of the assessment of self-pollinated precocious lines of maize (Zea mays L.) on the main economically valuable traits at two sowing dates

Purpose. Comprehensive study, selection, evaluation and systematization of self-pollinated lines of maize (Zea mays L.) obtained on the basis of material of diffe­rent genetic structure from endosperm of flint and dent maize were implemented according to the main economically valuable traits and precocity in order to select the best genotypes for selection. Methods. Hybridization, inbreeding were used in the process of creating the initial material; visual method – for phenological observations; laboratory and field – to determine the morphobiological characteristics of self-pollinated lines of maize; measuring and weighing – to account the harvest and determine the metric characteristics of plants; mathematical and statistical – to determine the validity of the results, indicators of trait variability, correlation dependence of traits; analysis of variance; comprehensive assessment of morphobiological and economically valuable traits of self-pollinated maize lines of the most common germplasms. Results. As a result of assessment of self-pollinated lines of the most common germplasms, it was revealed that the highest level of grain yield was obtained under both sowing periods – Iodent germplasm; the minimum grain moisture content – Flint and Mix germplasms; the shortest average duration of the emergence – flowering of 50% of male and female inflorescences stage – Flint germplasm; steadily high va­lues ​​of plant height for germplasm Mix – under the optimal sowing date, and Iodent plasma – under the late sowing date. Steadily high values ​​of the ear insertion height at both sowing dates were obtained for lines based on Iodent germplasm. The number of the most precocious and the best by the economically valuable traits germplasms of self-pollinated lines were identified. Conclusions. The DK239 lines – Flint germplasm, DK7174, DK2285, DK305, DK2613, DK5568 – Iodent germplasm, DK2332 and DK2659 – Mix germplasm were the most precocious and the best by the economically valuable traits. They are promising for the selection of ultra-early hybrids of maize adapted to the conditions of the Steppe of Ukraine.

Vaccine of live attenuated Eimeria coecicola boosts immunity against coccidiosis for sustainable rabbit production in Yogyakarta, Indonesia

Coccidiosis is one of the prominent problems in the rabbit industry. Control of coccidiosis is mainly used chemical coccidiostat as drug or as substances in feed which induce resistance development and antibiotic contamination. To date, there is no commercially available vaccine to prevent rabbit coccidiosis cases. We used live-attenuated Eimeria coecicola to induce protective immunity against rabbit coccidiosis in Yogyakarta. Pressure selection was performed to attenuate wild-type E. coecicola with lower pathogenicity but possessing the ability to induce an immune response to coccidia infection. The precocious line had reduced the prepatent period to 165 hours and 65% less oocyst production compared to wildtype. The group vaccinated with the precocious line exhibited significantly reduced total oocyst excretion compared to the non-vaccinated group (P < 0.0001) when challenged with homolog infection. Our trial showed no mortality rate and without detrimental responses of vaccinated rabbits (P < 0.0001). The excreted oocysts in post-vaccinated rabbits were found since the dosage of 5 x 102 which was presenting fecundity and the ability of E. coecicola precocious line to recirculate. Later, the recirculate oocysts may provoke a continuous flock immunity. The vaccine candidate is useful as the more environmentally friendly approach and disease prevention management for sustainable rabbit production.

Genetic Dissection of a Precocious Phenotype in Male Tiger Pufferfish (Takifugu rubripes) using Genotyping by Random Amplicon Sequencing, Direct (GRAS-Di)

The novel non-targeted PCR-based genotyping system, namely Genotyping by Random Amplicon Sequencing, Direct (GRAS-Di), is characterized by the simplicity in library construction and robustness against DNA degradation and is expected to facilitate advancements in genetics, in both basic and applied sciences. In this study, we tested the utility of GRAS-Di for genetic analysis in a cultured population of the tiger pufferfish Takifugu rubripes. The genetic analyses included family structure analysis, genetic map construction, and quantitative trait locus (QTL) analysis for the male precocious phenotype using a population consisting of four full-sib families derived from a genetically precocious line. An average of 4.7 million raw reads were obtained from 198 fish. Trimmed reads were mapped onto a Fugu reference genome for genotyping, and 21,938 putative single-nucleotide polymorphisms (SNPs) were obtained. These 22 K SNPs accurately resolved the sibship and parent–offspring pairs. A fine-scale linkage map (total size: 1,949 cM; average interval: 1.75 cM) was constructed from 1,423 effective SNPs, for which the allele inheritance patterns were known. QTL analysis detected a significant locus for testes weight on Chr_14 and three suggestive loci on Chr_1, Chr_8, and Chr_19. The significant QTL was shared by body length and body weight. The effect of each QTL was small (phenotypic variation explained, PVE: 3.1–5.9%), suggesting that the precociousness seen in the cultured pufferfish is polygenic. Taken together, these results indicate that GRAS-Di is a practical genotyping tool for aquaculture species and applicable for molecular breeding programs, such as marker-assisted selection and genomic selection.

Precocious maturation in male tiger pufferfish Takifugu rubripes: genetics and endocrinology

Testes of the tiger pufferfish Takifugu rubripes are a delicacy in Japan, and selective breeding for a male precocious phenotype, i.e., with early initiation of testes development, is desirable. However, it is unknown if precocious gonad development in this species is under genetic control. Here, we investigated genetic involvement in precociousness by using progeny tests with sires from two cultured populations, including a family line anecdotally known for its precociousness, and a wild population. Progeny derived from the “precocious” line consistently had greater testes weight than that from the other lines, even after accounting for effects of body weight, which indicates that precociousness is truly heritable. We also compared chronological changes in plasma steroid hormones between progenies sired by males from the precocious line and a wild population, and found that the precocious family line had higher levels of plasma estradiol-17β (E2) prior to the initiation of testicular development. Our findings suggest that selective breeding for testes precociousness in the tiger pufferfish is feasible, and that plasma E2 may be an indicator of this phenotype, which would allow for phenotype evaluation without the need to sacrifice specimens.

Comparison of the host cells apoptosis induced by precocious strains and virulent strains of Eimeria tenella

The present study aims to investigate the similarities and differences between the host cells apoptosis induced by virulent line of Eimeria tenella (Tsx) and precocious line (PTsx), which can provide a theoretical basis for the study of drugs and vaccines against coccidiosis. HE staining, Hoechst 33342/AnnexinV-FITC/PI composite staining, and ELISA were used to detect the infection rate, apoptosis rate, and Caspase-3 enzyme activity of host cells infected by PTsx or Tsx, respectively. The apoptotic rates and Caspase-3 absorbance of the inoculation groups were lower (P < 0.05 or P < 0.01) than those of the control group at 4h, whereas the apoptotic rates and Caspase-3 absorbance of the inoculation groups were higher (P < 0.05 or P < 0.01) than those of the control groups at 24 to 120h. At the same inoculation dose, there was no significant difference in the infection rate, apoptosis rate or Caspase-3 absorbance between Tsx groups and PTsx groups after E. tenella inoculation for 4 to 72h (P > 0.05). However, these indicators of PTsx groups were lower (P < 0.01) than those of the same dose inoculated Tsx groups at 120h. The apoptosis rates of cecal and glandular epithelial cells in the inoculated groups were higher (P < 0.01) than those in the control group after inoculated E. tenella 5 D in vivo, and the apoptosis rates of cecal and glandular epithelial cells in PTsx group was lower (P < 0.01) than that in the same dose inoculated Tsx group. These observations indicate that both Tsx and PTsx inhibit host cell apoptosis in the early development of E. tenella, induce host cell apoptosis in the middle and late stages, and the apoptosis-inducing effect on host cells increases with increasing dose. However, when the same dose of oocysts was inoculated, the amount of apoptosis induced by PTsx in late development was less than Tsx.

Immune protection provided by a precocious line trivalent vaccine against rabbit Eimeria

A pilot study was conducted to evaluate the pathogenicity and immunogenicity of vaccinated rabbits with different doses of oocysts (5 × 102, 1 × 103, 1 × 104, and 5 × 104) of a precocious line, including Eimeria magna, E. intestinalis or E. media following the challenge with their corresponding parent strains. Our results showed that each precocious line had weak pathogenicity but good immunogenicity in terms of clinical symptoms, average daily weight gains (ADGs), and oocyst outputs. Therefore, a precocious line trivalent vaccine, including E. magna, E. intestinalis, and E. media was formulated. A total of sixty 40-day-old coccidia-free rabbits were allocated to ten treatments with a 2 × 3 factorial arrangement that included 2 vaccination doses (5 × 102 or 1 × 103 oocysts of the precocious line). Groups I to Ⅷ and Unimmunized Challenged Control group were challenged with mixed oocysts of their corresponding parent strains (1 × 104 oocysts of each parent strain) 14 days after vaccination. No clinical symptoms were observed in the immunized groups after vaccination. Average daily weight gains (ADGs) were similar to those of unimmunized unchallenged controls (P > 0.05) after vaccination or after challenge. Oocyst outputs in the vaccinated challenged groups were significantly different from those of unimmunized challenged controls (P < 0.01) after challenge. These results indicated that the trivalent vaccine could provide immune protection against coccidiosis and therefore, it could be used as a candidate vaccine.

Selection and characterization of a precocious line of Eimeria media.

Coccidiosis, caused by the infection of Eimeria parasites, is one of the most common diseases in domestic rabbits. Live anticoccidial vaccine formulated with attenuated precocious lines of pathogenic eimerian parasites is expected to be valuable for the control of rabbit coccidiosis as a similar strategy to produce anticoccidial vaccines against chicken coccidiosis has being used for several decades. Eimeria media, moderate pathogenic, is widespread in China. Therefore, attenuated anticoccidial vaccines against rabbit coccidiosis should contain vaccine strain(s) of E. media. In this study, a precocious line of E. media (Empre) was selected by collecting and propagating the early excreted oocysts with 16 successive generations. The prepatent period of Empre reduced from 108h of its parental strain (Emwt) to 70h. The fecundity of Empre was about 1/10 to 1/3 lower than that of Emwt. Each sporocyst of Empre sporulated oocyst contained only one large refractile body instead of two smaller ones seen in the parental strain. When vaccinated with 1 × 103 or 1 × 104 precocious line oocysts, the rabbits were completely protected against homologous challenge with the parental strain 14days post challenge by terms of body weight gain and oocyst output counting, indicating the efficacy of Empre. Meanwhile, all immunized rabbits showed no clinical sign post immunization, indicating the safety of Empre. For co-immunization, 1 × 103Empre oocysts and 5 × 102 oocysts of a precocious line of E. intestinalis (EIP8) were inoculated to each rabbit in a trial. No diarrhea or mortality was found after vaccination, and the weight gains of the vaccinated group were similar to that of unvaccinated-unchallenged control (UUC) group, while the weight gains of the vaccinated group were similar to that of unvaccinated-unchallenged control (UUC) group (P > 0.05), but significantly higher than that of UCC group (P < 0.01) after challenge, indicating it is safe and effective when using co-immunization. These results together show that Empre, as a precocious line, is a good candidate of precocious line of E. media for anticoccidial vaccine development.

Transitions in morphological forms and rapid development of the asexual schizonts of Eimeria tenella through serial passaging in chicks

Attenuated strains of avian Eimeria parasites, generated by the selection of precocious lines through serial passaging in chicks, have been used widely as live vaccines. Detailed morphological transitions including their life cycle depending on the passages remain poorly understood. Here, we showed early development and acceleration of transitions in morphological forms of the asexual schizonts of E. tenella that had been attenuated for virulence by serial passaging. Our results may be helpful in understanding parasitism, facilitating further molecular analyses such as comparative genomic or transcriptomic tests.

Selection and identification of a precocious line of Eimeria intestinalis with enlarged oocysts and deletion of one generation of schizogony.

Rabbit coccidiosis is a common parasitic disease and responsible for enormous economic losses in the rabbit industry. Eimeria intestinalis, one of the highly pathogenic and common Eimeria species infecting rabbits, is considered as an indispensable species for the development of live oocyst vaccines against rabbit coccidiosis. In this study, we report the successful selection of a precocious line (EIP8) from a wild-type strain of E. intestinalis (WT) by successively collecting and propagating the early excreted progeny oocysts. The EIP8 line had a prepatent period of only 132h compared to 204h for the WT. Oocysts of EIP8 were notably different from those produced by the WT strain by their significantly larger size (mean length: 29.3 vs 27.6μm and mean width 20.5 vs 19.8μm). Examination of tissue sections prepared from EIP8-infected rabbits revealed that this precocious line undergoes only two generations of schizogony before differentiating into gametocytes by 120h post-infection. In contrast, WT parasites undergo three generations of schizogony and gametocytes are present by 168h post-infection. EIP8 multiplication capacity reduced by more than 35-fold and a concomitant decrease in pathogenicity was detected. Interestingly, immunization with 103 or 104 EIP8 oocysts provided sufficient protection against homologous challenge with wild-type parasites, as body weight gain of immunized and challenged rabbits was similar to that of untreated animals, as well as more than 90% reduction of oocyst output was detected in immunized and challenged animals when compared to unimmunized and challenged animals. Together, these results show that the EIP8 precocious line of E. intestinalis is an attenuated immunogenic strain and a suitable candidate for the development of a live vaccine against rabbit coccidiosis.

Comparative transcriptome analysis of Eimeria maxima (Apicomplexa: Eimeriidae) suggests DNA replication activities correlating with its fecundity

BackgroundChicken coccidiosis, caused by the infection of Eimeria species, leads to important economic losses to the poultry industry. Vaccination with attenuated live parasites seems to be the best way to control this disease. Attenuated eimerian parasites with shortened prepatent times show great changes in intracellular development compared to their parent strains but the mechanisms involved in these biological differences are still unclear.ResultsIn this study, we obtained a precocious line of E. maxima by sequential selection of 22 generations of early shed oocysts in chickens and performed a comparative transcriptome analysis of three different developmental stages of the precocious line and its parent strain using Illumina high-throughput sequencing. Our E. maxima precocious line showed decreased pathogenicity, reduced fecundity and a greatly shorted prepatent time of only 98 h. We found that typical gene changes in the stage development from unsporulated to sporulated oocyst and from sporulated oocyst to merozoite were marked by upregulated organelle genes and protein translation related genes, respectively. Additionally, major differences between the precocious line and its parent strain were detected in the merozoite stage, characterized by downregulated genes involved in protein cleavage and DNA replication activities.ConclusionsOur study generated and characterized an E. maxima precocious line, illustrating gene expression landscapes during parasite development by transcriptome analysis. We also show that the suppressed DNA replication progress in the merozoite stage in the precocious line may result in its reduced fecundity. These results provide the basis for a better understanding of the mechanism of precocity in Eimeria species, which can be useful in studies in early gametocytogenesis in apicomplexan parasites.

A vaccination trial with a precocious line of Eimeria magna in Algerian local rabbits Oryctolagus cuniculus

Coccidiosis is a major health problem in rabbits. A vaccine using Eimeria with perfect safety and effectiveness seems to be necessary to face this parasitosis. To assess the safety and the efficacy of a vaccine based on the Algerian precocious line of Eimeria magna against rabbit coccidiosis, twenty eight young rabbits from six litters of Coccidia free females were used to monitor oocystal excretion and body weights, they were distributed into four groups (vaccinated-challenged group, double challenged non vaccinated group, simple challenged non vaccinated group and control group). Three other Coccidia free rabbits served for the necropsy in order to compare the effect of the wild and the precocious strains of Eimeria magna at the histological level. Following the challenge inoculation, a statistically significant decrease of about 97% in the oocyst excretion was noticed in the vaccinated rabbits as a sign of a good immune response acquired by the vaccination associated to a good growth rate. Moreover, a statistically significant increase in oocyst output following the challenge in both double challenged non vaccinated group and simple challenged non vaccinated one was noticed: (1.2 × 108 and 1.5 × 108vs 4.6 × 106 oocysts/rabbit respectively). Taking the control group showing a steady growth as a reference, the vaccinated rabbits showed a good growth during the experiment (p < 0.05). Globally the challenged groups showed a normal growth compared with the control group except for a temporary decrease in weights. No case of diarrhea was recorded in the vaccinated – challenged group and the control one (neither vaccinated nor challenged) whereas more than 50% of the young rabbits from both simple and double challenged – non vaccinated groups presented diarrhea. Consequently, the Algerian precocious strain of Eimeria magna constitute a good candidate for anticoccidian vaccine in the future.

Observation of the excretion pattern of a precocious line of Eimeria necatrix and the strengthening of immune homogeneity

The excretion frequencies of cecal and intestinal droppings of Chinese Lingnan yellow chickens were observed for 10 consecutive days. The chickens were then orally inoculated with a precocious line of Eimeria necatrix, and the oocysts present in the cecal and intestinal droppings were separately collected and monitored using the McMaster method. The results showed that the excretion frequency of cecal droppings was significantly lower than that of intestinal droppings, and the oocysts of E. necatrix were distributed primarily in the cecal droppings. This distribution affects the homogeneity of the second and third generation of oocysts ingested by the chickens and therefore affects the immune effect observed during E. necatrix immunization. To artificially strengthen the immunologic homogeneity against E. necatrix, a method of artificially strengthening the second immunization was applied, and the immune effect was evaluated based on oocyst excretion, body weight gain, fecal scores, intestinal lesion scores and survival percentages. The results showed that no significant intestinal damage was caused by immunization reactions in the chickens. In addition, the number of excreted oocysts in the immunized chicken groups could be significantly increased, and the immunologic homogeneity of the immunized chickens could be improved by artificially strengthening the second immunization, which could in turn improve the immune protective effect.

Potency of Attenuated Eimeria tenella in Protective Immunity Induction on Homologous and Heterologous Challenges

The aim of this study was to know the protective immunity of broilers immunized with attenuated Eimeria tenella (E. tenella) on homologous and heterologous challenges. The protective immunity was represented by oocyst production and histopathological changes of cecum. The previous experiment already produced attenuated E. tenella through serial passages of precocious lines in naive chicken. Four groups of chickens were separately divided into two non-immunized control groups and two immunized with attenuated E. tenella groups, and each group was challenged with homologous and heterologous strains. The results showed significant difference in oocysts production (p<0.01) and histopathological changes between control and immunized groups.

A Combination of Lenalidomide and Rituximab (ReRi) As Salvage Therapy in Elderly Patients Affected By Diffuse Large B Cells (DLBCL) Lymphoma Relapsed and Refractory

BACKGROUNDThe incidence of non Hodgkin's lymphoma (NHL) increases with age, over one third of NHL cases involves elderly patients >70 years of age.As a matter of fact, many elderly patients (pts) are not enrolled in controlled studies because they do not meet the inclusion criteria. This is the reason why the data from trials on elderly cases are not representative for the whole elderly population. Consequently, many of these patients do not benefit of new therapeutic progresses and the treatment is not yet adequate.Moreover in case of relapse, salvage therapy in the elderly is virtually absent, and the prognosis is extremely poor.Lenalidomide is an immunomodulatory drug with anti-angiogenetic and anti-neoplastic action on cancer cells and also has other anti-tumor activity by acting on the neoplastic microenvironment. Both monotherapy and combination of Lenalidomide with rituximab have shown efficacy in terms of overall response rate (ORR, Overall Response Rate) in the setting of salvage therapy in relapsed/refractory DLBCL, with an acceptable rate of hematologic and extra-hematological toxicitiesPATIENTS AND METHODSIn the period 2013-2014 we consecutively treated 12 elderly patients affected by advanced DLBCL relapsed/refractory.Median age at the start of treatment was 79 years (yrs) (62-86), 5 out 12 was over 80 yrs and 4 out 12 over 75 yrs. The median number of previous treatment was 3 (2-4), 3 pts were transplanted and 4 patients was refractory to previous line of therapy.The treatment scheme included at first cycle: Rituximab 375 mg/m2 i.v. days 1, 8, 15, 22, Desametasone 5 mg p.o. days 1, 8, 15, 22 and Lenalidomide 15 mg/die p.o. from day 2 to 22. From the second to the sixth cycle we administered Rituximab 375 mg/m2 i.v. days 1, 14, Lenalidomide 20 mg/die p.o. from day 2 to 22RESULTSThe overall response rate has been 75% (CR,PR,SD), 3 patients out 12 (25%) achieved a CR and 3 PR (25%).The median PFS was 6 months and with a median follow up of 1 year the overall survival is 25%.(fig.1)All deaths are due to lymphoma progression and the 3 patients in CR are still alive in CCR.CONCLUSIONSIn this elderly and heavily pretreated group of patients our scheme containing Lenalidomide-Rituximab has shown an high rate of response with a good rate of CR and a promising trend in overall survival.The treatment appears feasible and safe also in this particular group of frail patients and even if we need more data to confirm we think it will be possible to extend this therapy in frail elderly patients in a most precocious line of treatment. [Display omitted] DisclosuresOffidani:Celgene, Janssen: Honoraria.