High-risk groups of neonatal lupus erythematosus in term infants: a birth cohort study.

This study aims to analyze the clinical characteristics and risk factors of high-risk groups of neonatal lupus erythematosus (NLE) in term infants. High-risk groups of NLE infants whose mothers were positive for anti-SSA, anti-SSB or anti-U1RNP antibodies during pregnancy were enrolled. They were born between February 2013 and February 2020, with a gestational age not less than 37 weeks. We analyzed their clinical data from birth to 24 months after birth. A total of 105 patients in the NLE high-risk group were included. Among them, 30 patients were diagnosed with NLE (NLE group), and 75 patients were not (non-NLE group). The affected systems of the NLE group included the dermal (13.3%), hepatic (76.0%), and hematological systems (43.3%). Hepatic involvement, anemia and thrombocytopenia did not emerge until 60 days, 41 days and 22 days after birth, respectively, in some cases. Systemic involvement could be cured within 3 to 12 months after birth. The clearance time of specific autoantibodies was 12 months after birth. There was no significant difference in the clinical characteristics of babies and their mothers between the two groups, neither in the positive rate nor in the clearance time of specific autoantibodies. CONCLUSION: After standardized prenatal health care, there is still a high risk of dermal, hepatic, or hematological system involvement for high-risk groups of NLE. There are no specific indicators for the prediction of whether babies will develop NLE. All of these patients need to be followed up closely within one year after birth. WHAT IS KNOWN: • Neonatal lupus erythematosus (NLEs) can affect the cardiac, dermal, hepatic, and hematological systems of infants. WHAT IS NEW: • After standardized prenatal health care employing good multidepartment cooperation in our center, no neonates had cardiac block in this study. However, dermal, hepatic, and hematological system involvement of NLE can still gradually appear (as long as 60 days after birth in some cases) during follow-up, and some of these conditions are serious and require timely and active intervention. No single factor has been found to predict whether offspring at high-risk of NLE whose mothers are positive for anti-SSA, SSB and/or RNP will develop NLE.

Expression characteristics of the cyp19a1b aromatase gene and its response to 17ß-estradiol treatment in largemouth bass (Micropterus salmoides).

To investigate the regulatory role of the cyp19a1b aromatase gene in the sexual differentiation of largemouth bass (Micropterus salmoides, LMB), we obtained the full-length cDNA sequence of cyp19a1b using rapid amplification of cDNA ends technique. Tissue expression characteristics and feedback with 17-ß-estradiol (E2) were determined using quantitative real-time PCR (qRT-PCR), while gonad development was assessed through histological section observations. The cDNA sequence of LMB cyp19a1b was found to be1950 base pairs (bp) in length, including a 5' untranslated region of 145 bp, a 3' untranslated region of 278 bp, and an open reading frame encoding a protein consisting of 1527 bp that encoded 508 amino acids. The qRT-PCR results indicated that cyp19a1b abundantly expressed in the brain, followed by the gonads, and its expression in the ovaries was significantly higher than that observed in the testes (P < 0.05). After feeding fish with E2 for 30 days, the expression of cyp19a1b in the pseudo-female gonads (XY-F) was significantly higher than that in males (XY-M) (P < 0.05), whereas expression did not differ significantly between XX-F and XY-F fish (P > 0.05). Although the expression of cyp19a1b in XY-F and XX-F fish was not significantly different after 60 days (P>0.05), both exhibited significantly higher levels than that of XY-M fish (P<0.05). Histological sections analysis showed the presence of oogonia in both XY-F and XX-F fish at 30 days, while spermatogonia were observed in XY-M fish. At 60 days, primary oocytes were abundantly observed in both XY-F and XX-F fish, while a few spermatogonia were visible in XY-M fish. At 90 days, the histological sections' results showed that a large number of oocytes were visible in XY-F and XX-F fish. Additionally, the gonads of XY-M fish contained numerous spermatocytes. These results suggest that cyp19a1b plays a pivotal role in the development of ovaries and nervous system development in LMB.

The effect of antinuclear antibody titre and its variation on outcomes in children with primary immune thrombocytopenia.

Antinuclear antibody (ANA) can be positive in children with primary immune thrombocytopenia (ITP), but the effect of ANA titre and its variation on outcomes of children with primary ITP remains unclear. Here, we conducted a single-centre retrospective cohort study of children with primary ITP at the Peking Union Medical College Hospital in China. A total of 324 children with primary ITP included in this study were followed for a median time of 25 months. In this cohort, 39.2% had an ANA titre of 1:160 or higher. Results from a generalized estimating equation model revealed that patients with higher ANA titres had lower platelet counts at onset but a higher recovery rate of subsequent platelet counts. Results from Cox regression models adjusted for potential confounders revealed that patients with ANA titres of 1:160 or more were more likely to develop to autoimmune disease (AID) than those without, and the risk of AID development increased with the rise of ANA titres (p value for trend less than 0.001). These data highlight the predictive value of ANA titre for platelet counts and the risk of AID development in children with primary ITP.

A Cohort Study on Deficiency of ADA2 from China.

PURPOSE: Deficiency of adenosine deaminase 2 (DADA2), an autosomal recessive autoinflammatory disorder caused by biallelic loss-of-function variants in adenosine deaminase 2 (ADA2), has not been systemically investigated in Chinese population yet. We aim to further characterize DADA2 cases in China. METHODS: A retrospective analysis of patients with DADA2 identified through whole exome sequencing (WES) at seventeen rheumatology centers across China was conducted. Clinical characteristics, laboratory findings, genotype, and treatment response were analyzed. RESULTS: Thirty patients with DADA2 were enrolled between January 2015 and December 2021. Adenosine deaminase 2 enzymatic activity was low in all tested cases to confirm pathogenicity. Median age of disease presentation was 4.3 years and the median age at diagnosis was 7.8 years. All but one patient presented during childhood and two subjects died from complications of their disease. The patients most commonly presented with systemic inflammation (92.9%), vasculitis (86.7%), and hypogammaglobinemia (73.3%) while one patient presented with bone marrow failure (BMF) with variable cytopenia. Twenty-three (76.7%) patients were treated with TNF inhibitors (TNFi), while two (6.7%) underwent hematopoietic stem cell transplantation (HSCT). They all achieved clinical remission. A total of thirty-nine ADA2 causative variants were identified, six of which were novel. CONCLUSION: To establish early diagnosis and improve clinical outcomes, genetic screening and/or testing of ADA2 enzymatic activity should be performed in patients with suspected clinical features. TNFi is considered as first line treatment for those with vascular phenotypes. HSCT may be beneficial for those with hematological disease or in those who are refractory to TNFi.

Evaluation of belimumab in treatment of Chinese childhood-onset systemic lupus erythematosus: a prospective analysis from multicenter study.

OBJECTIVE: The aim of this study is to identify whether low lupus disease activity status (LLDAS) and clinical remission (CR) of belimumab plus standard of care (SoC) therapy are achievable goals in childhood-onset SLE (cSLE). METHODS: This multicentre, one arm pre-post intervention study was conducted at 15 centers in China. The primary end point was to describe the proportion of patients who achieved LLDAS and CR after 3, 6, and 12 months after treatment with belimumab plus SoC therapy. A multiple regression model was used to impute missing data. A Poisson regression model was used to calculate the effect of belimumab treatment on the reduced risk of serious diseases and the incidence of new damage. RESULT: 193 (92.2% female) with active cSLE from 15 centers were included. At 3, 6 and 12 months, the proportion of LLDAS (CR) was 12.4% (1.0%), 25.6% (4.5%) and 70.3% (29.7%), respectively. The mean SELENA-SLEDAI score decreased from 11.0 at baseline to 3.7, 2.9 and 1.7 at 3, 6, and 12 months. At baseline, all patients received steroids at a mean (SD) prednisone equivalent dose of 31.0 (18.2) mg/day, which decreased to 19.4 (10.8) mg/day at month 3, 12.6 (7.2) mg/day at month 6 and 6.7 (5.3) mg/day at month 12. The symptoms and immunological indicators were also significantly improved. CONCLUSION: This is the first and largest sample size prospective clinical intervention study of cSLE patients treated with belimumab in China. LLDAS and CR were attainable treat-to-target of belimumab plus SoC therapy in cSLE.

Application of cementoplasty in patients with symptomatic benign osteopathy disease.

BACKGROUND: The optimal treatment for some symptomatic, benign osteopathy lesions is yet to be identified. PURPOSE: To investigate the clinical efficiency of cementoplasty in managing symptomatic, benign osteopathy. MATERIAL AND METHODS: Between June 2006 and January 2020, we retrospectively enrolled 31 patients (10 men, 21 women; mean age = 46.5 ± 16.6 years; age range = 20-85 years), accounting for 34 treatment sites, who underwent percutaneous osteoplasty (14 treatment sites) and percutaneous vertebroplasty (20 treatment sites) with digital subtraction angiography (DSA) or DSA combined with computed tomography (CT). All the participants experienced different degrees of clinical symptoms with benign osteopathy lesions. The technical success of the procedure and occurrence of complications were recorded. Follow-up examinations were conducted to assess the treatment outcome using the MacNab criteria. RESULTS: All the participants had a diagnosis of benign osteopathy lesions before or after the cementoplasty. Surgery was successfully completed in all patients. Cement distributions were diffuse and homogeneous, with the complication of cement leakage occurring in 17.6% (6 of 34) of the lesions. The leakage occurred in the intervertebral disc (n = 1), the intra-articular space (n = 1), and the surrounding soft tissue (n = 4). Analysis of the treatment outcome using the MacNab criteria revealed that all patients showed improvement in their clinical symptoms to some extent and in the quality of life. CONCLUSION: Cementoplasty is an effective treatment for symptomatic, benign osteopathy, with the advantage of favorable clinical outcomes, and low complication rate.

Potential risk factors for the development from immune thrombocytopenia to systemic lupus erythematosus: a case-control study in Chinese children.

Immune thrombocytopenia (ITP) patients are at risk developing to systemic lupus erythematosus (SLE) in the future. Our study attempted to explore the potential risk factors for the development from ITP to SLE in Chinese children by statistical analysis. This study was a retrospective case-control study. Patients diagnosed with ITP and developed to SLE after the diagnosis of ITP were defined as the case group. The control group consisted of children with ITP but without developing to SLE was recruited with a ratio of 1:2. Besides univariable analysis, multivariable logistic regression was built to evaluate the potential risk factors. A total of 150 children was included with 50 in the case group and 100 in the control group. Median developing time from ITP to SLE was 34.5 [IQR 12.5, 58.75] months. ANA was found significantly different between the two groups in our study in the univariable analysis but not in the multivariable analysis (OR = 4.50, 95% CI 0.97 to 21.01). Age diagnosed ITP was positively associated with SLE (OR = 1.07 every 5 years, 95% CI 1.01 to 1.15) with alert point at 8 years old (sensitivity 0.82, specificity 0.60). A lower level of complement was also positively associated with SLE (OR = 8.33, 95% CI 1.62 to 42.91). A minimum 3-year of close follow-up for pediatric ITP patients was recommended to monitor the risk for developing SLE. Older age and hypocomplementemia were potential risk factors for the development from ITP to SLE.

Timing of early gonadal differentiation and effects of estradiol-17ß treatments on the sex differentiation in Largemouth bass (Micropterus salmoides).

In this study, an efficient estradiol-17ß (E2)-induced feminization method was established based on the timing of early gonadal differentiation in Largemouth bass (Micropterus salmoides). Histological section results showed that from 20 days post-hatch (dph) to 30 dph, the germ cells gradually differentiated into oogonium and spermatic deferent, respectively. Moreover, female-biased genes Foxl2 and Cyp19a1a were up-regulated to the first peak at 20 dph, while the male-biased genes Dmrt1 were up-regulated to the first peak at 30 dph. These results indicated that the timing of early gonadal differentiation in Largemouth bass was between 20 and 30 dph. Therefore, 15 dph Largemouth bass with a body length of 15.10 ± 0.09 mm were chosen, and four E2-treated diets were set as 0 (E0, control), 50 mg/kg E2 (E50), 100 mg/kg E2 (E100), and 200 mg/kg E2 (E200). After feeding with E2-treated diets for 60 days, female ratios were 55%, 100%, 100%, and 100% in E0, E50, E100, and E200 groups, respectively. No intersex fish were observed in all the groups. However, 30% of females in the E200 group possessed thinner ovaries, with smaller ovary cavity structures and a decreased number of primary oocyte cells than those in other groups. Besides, the Largemouth bass in the E0 group grew more than those in E50, E100, and E200 groups during the E2 treatments period (P < 0.05). In conclusion, our study suggested that 50-100 mg/kg E2-treated diets could effectively induce the feminization of 15 dph Largemouth bass within 60 days duration time, which provided valuable information for the breeding of the all-male Largemouth bass population.

Successful management with Janus kinase inhibitor tofacitinib in refractory juvenile dermatomyositis: a pilot study and literature review.

OBJECTIVES: JDM is a rare autoimmune inflammatory muscle disease with a pronounced IFN signature. Treatment for children with JDM has improved over the years with the use of steroids and immunosuppressive agents. However, there remains a subset of children who have refractory disease. Janus kinase and type I IFN signalling production are suspected to contribute to the pathogenesis of JDM. Our pilot study investigated the use of tofacitinib, a Janus kinase inhibitor, in refractory JDM cases to provide new therapeutic options for better treatment. METHODS: Refractory JDM was defined as patients who failed two or more steroid sparing agents or high-dose steroids. Tofacitinib was given to three refractory JDM patients with a dose of 5 mg twice per day for at least 6 months. Core set measures defined by Pediatric Rheumatology International Trials Organization were evaluated at month 0, 3 and 6 along with other systemic evaluations. A literature review was conducted to identify all the cases using Janus kinase inhibitors in JDM. RESULTS: All three subjects tolerated and responded well to tofacitinib with significant improvement in Child Myositis Assessment Scale, manual muscle testing-8, physician global disease activity and inflammatory indices without occurrence of severe adverse events. CONCLUSION: This pilot study showed improvement of muscle strength, resolution of cutaneous lesions, increased daily quality of life and successful tapering of steroids when tofacitinib used in selected cases. Tofacitinib can be considered with caution when treating refractory JDM cases. Further randomized controlled trials are warranted to assess its efficacy in JDM.

Juvenile Onset Splenomegaly and Oculopathy Due to Germline Mutation in ALPK1.

ROSAH syndrome was recently identified as an autosomal dominant systemic disorder due to mutations in ALPK1. It was characterized by retinal dystrophy, optic nerve edema, splenomegaly, anhidrosis, and migraine headache. We collected and summarized the clinical data of two patients with juvenile onset splenomegaly and oculopathy. Whole exome sequencing (WES) was adapted for genetic analysis. Mutations in ALPK1 were confirmed by Sanger sequencing. Besides juvenile oculopathy and splenomegaly, both patients had intermittent fever and anhidrosis. Patient 2 also experienced recurrent upper respiratory infections in her infancy and developed dental and nail problems in childhood. Elevated TNF-α was their prominent laboratory features. Both patients were found to have a previously reported mutation, c.710C>T, p. T237M (NM_001102406) in ALPK1. Anti-TNF treatment of adalimumab was applied to patient 1, after which her optic disc edema in the left eye continued and the visual acuity deteriorated further. Patient 1 underwent elective splenectomy due to concern for spontaneous rupture of the spleen. Up to date, 18 patients of ROSAH syndrome have been reported. The clinical manifestations were relatively homogeneous, prominently presenting with juvenile onset oculopathy and splenomegaly. As it mainly involves ocular fundus, severe oculopathy deeply affects the quality of life and prognosis of ROSAH patients. Now little has been known about its treatment. As a newly recognized inherited systemic disorder, ROSAH syndrome needs to be paid more attention to, especially for those with juvenile onset splenomegaly and oculopathy.

Association of anti-nuclear matrix protein 2 antibody with complications in patients with idiopathic inflammatory myopathies: A meta-analysis of 20 cohorts.

BACKGROUND: Several complications like calcinosis, interstitial lung disease (ILD) or malignancy, are primary causes leading to poor outcomes in idiopathic inflammatory myopathies (IIM) patients. Specific antibodies might help to indicate the occurrence or absence of these complications. OBJECTIVE: The aim of this study was to evaluate the association of anti-nuclear matrix protein 2 antibody (anti-NXP2) with calcinosis, ILD and malignancy in IIM patients. METHODS: Two investigators independently searched literature about the relation of anti-NXP2 with calcinosis, ILD, malignancy in IIM patients in PubMed, EMBASE, Web of Science databases, then selected eligible articles and extracted data from the included studies. The association between anti-NXP2 and these complications was assessed by odds ratios (OR) and 95% confidence intervals (95% CI). Further quantitative meta-analysis, subgroup analysis, sensitivity analysis and publication bias analysis were conducted with STATA 14.0 software (Stata Corp.; College Station, Texas, USA). A fixed-effects model (the Mantel-Haenszel method) was employed when I2 < 25%, otherwise a random-effects model (the Mantel-Haenszel method) was used. RESULTS: Twenty cohorts with 3064 IIM patients were included in this meta-analysis, among which 9 were about calcinosis in adults, 6 about calcinosis in juvenile patients, 9 about ILD in adults, 3 about ILD in juvenile patients, while 13 about malignancy in adult patients. Anti-NXP2 was more common in patients with calcinosis than those without calcinosis (pooled OR = 4.00, 95% CI: 2.65-6.06 in adults; pooled OR = 1.62, 95% CI: 1.14-2.30 in juvenile patients). On the contrary, this antibody was less common in adult patients with ILD than those without ILD (pooled OR: 0.33, 95% CI: 0.19-0.56). No significant difference concerning the incidence of anti-NXP2 antibody was found in IIM patients between those with and without cancer (pooled OR = 1.42, 95% CI: 0.69-2.91). CONCLUSION: The present study indicates that anti-NXP2 autoantibody is a risk factor for development into calcinosis both in adult and juvenile patients, while a protective factor for ILD in adult patients. Anti-NXP2 had no relation with malignancy in adult patients.

[Clinical features and TTC21B genotype of a child with nephronophthisis type 12].

Nephronophthisis (NPHP) is a group of autosomal recessive tubulointerstitial cystic kidney disorders. This article reports a case of NPHP type 12 caused by TTC21B mutations. The girl had an insidious onset, with moderate proteinuria, renal dysfunction, stage 2 hypertension, situs inversus, and short phalanges when she visited the hospital for the first time at the age of 3 years and 6 months. The renal lesions progressed to end-stage renal disease (ESRD) before she was 4 years old. Urine protein electrophoresis showed glomerular proteinuria. There were significant increases in urinary ß2-microglobulin and α1-microglobulin. Gene detection revealed two compound heterozygous mutations, c.1552T>C (p.C518R) and c.752T>G (p.M251R), in the TTC21B gene, which came from her father and mother respectively. The c.752T>G mutation was a novel mutation. It is concluded that besides typical tubular changes of NPHP, marked glomerular damage is also observed in patients with TTC21B gene mutations.

Subarachnoid Hemorrhage in Patients with Good Clinical Grade: Accuracy of 3.0-T MR Angiography for Detection and Characterization.

Purpose To evaluate the diagnostic accuracy of aneurysm detection and the fidelity of morphologic characterization of three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography at 3.0 T in patients with a Glasgow coma score of 15 and noncontrast material-enhanced computed tomography (CT) findings that showed acute nontraumatic subarachnoid hemorrhage. Materials and Methods The institutional review board approved this prospective study, and patients provided informed consent. A total of 277 patients who had not experienced trauma but in whom nonenhanced CT showed subarachnoid hemorrhage, who had a Glasgow coma score of 15, and who underwent both 3D TOF MR angiography and digital subtraction angiography (DSA) (the reference standard) were included. Three observers who were blinded to clinical and DSA results independently analyzed all 3D TOF MR angiographic data sets. The receiver operating characteristic curve was applied to analysis of the detection of aneurysms with 3D TOF MR angiography by using patient- and aneurysm-based evaluations. Multivariate logistic regression analysis was performed to identify aneurysm-specific variables, including size, shape (daughter sac/lobulation/margin), neck width (wide if > 4 mm or if fundus-to-neck ratio was < 2), and relation to adjacent artery, that significantly affected morphologic assessment with 3D TOF MR angiography. Results Aneurysms were depicted with DSA in 225 patients. In patient- and aneurysm-based evaluations, respectively, 3D TOF MR angiography yielded accuracies of 96.8% (268 of 277) and 96.6% (309 of 320), sensitivities of 98.2% (219 of 223) and 98.1% (260 of 265), specificities of 91% (49 of 54) and 89% (49 of 55), positive predictive values of 97.8% (219 of 224) and 97.7% (260 of 266), and negative predictive values of 92% (49 of 53) and 91% (49 of 54). Accuracy of display of morphologic features was 92.5% (236 of 255) for size, 86.3% (220 of 255) for neck width, 94.5% for shape (241 of 255), and 96.9% (247 of 255) for relationship to adjacent vessel. Width of aneurysm neck was the only variable that significantly affected the morphologic assessment of 3D TOF MR angiography (odds ratio, 0.378; 95% confidence interval: 0.337, 8.347; P = .004). Conclusion Three-dimensional TOF MR angiography can accurately depict cerebral aneurysms and accurately display their morphologic features in stable patients with subarachnoid hemorrhage and a Glasgow coma score of 15. © RSNA, 2017.

Outflow angle measurement: a simple approach for the differential diagnosis of intracranial protrusion with a branch artery arising from its top.

PURPOSE: Magnetic resonance angiography (MRA) is an important diagnosis method for the detection of intracranial aneurysms (IAs), but it is not useful for differentiating between IA and infundibular dilatation (ID) in patients in whom imaging shows an intracranial protrusion with a branch artery at its top. The objective of this study was to introduce a new approach-measurement of the outflow angle (OA)-for differentiating between IA and ID in such cases. METHODS: The study included 7 patients with a total of 9 protrusions. The protrusions were separately reviewed on MRA and DSA images. We first diagnosed the protrusions using OA approach. An OA ≥90° was considered indicative of an IA and an OA <90° was considered indicative of an ID. The diagnosis by the OA method was compared with diagnosis by the gold standard-DSA. RESULTS: Among the 9 intracranial protrusions, 5 were IAs and 4 were IDs. The OAs of 5 IAs were all ≥90°; the average OA of the 5 IAs was 115.20°. The OAs of the 4 IDs were all <90°; the average OA of the 4 IDs was 59.50°. The diagnosis results by the OA method were in agreement with DSA diagnosis in all cases. CONCLUSION: The OA method can discriminate between IA and ID in patients in whom imaging shows an intracranial protrusion with a branch artery at its top. The method is simple and convenient, and can be easily applied in clinical practice. It can be especially useful for novice neuroradiologists.

[A clinical analysis of 15 children with systemic lupus erythematosus accompanied by pulmonary hypertension].

OBJECTIVE: To evaluate the clinical features, laboratory findings, diagnosis and treatment, and prognosis of children with systemic lupus erythematosus (SLE) accompanied by pulmonary hypertension (PH). METHODS: The clinical symptoms, laboratory findings, echocardiographic features, SLE disease activity index, and treatment outcome of 15 hospitalized children with SLE accompanied by PH were retrospectively analyzed. RESULTS: Among the 15 patients, the median interval from diagnosis of SLE to diagnosis of PH was 0.1 year (range: 0-6.5 years). Aside from PH-related symptoms, Raynaud's phenomenon was observed in 6 (40%) of the 15 patients. There was no significant difference in SLE disease activity (evaluated by complements 3 and 4 levels, erythrocyte sedimentation rate, and positive rate of anti-double-stranded DNA) between patients with mild-to-moderate PH and those with severe PH (P<0.05). As for treatment, 13 patients received immunosuppressive therapy with glucocorticoids, and among them 2 patients received PH-targeted therapy. During a median follow-up of 8.0 years (range: 0.5-18.1 years) since the diagnosis of PH, 2 deaths were noted with class III or IV cardiac function (World Health Organization), while the other patients were in a stable condition. CONCLUSIONS: Raynaud's phenomenon is a common clinical manifestation in children with SLE accompanied by pulmonary hypertension (PH). PH severity is not significantly associated with SLE disease activity, and thus greater focus should be placed upon early screening of pulmonary arterial pressure in SLE patients. Early diagnosis and early treatment can improve the prognosis of children with SLE.

Transcriptome analysis between invasive Pomacea canaliculata and indigenous Cipangopaludina cahayensis reveals genomic divergence and diagnostic microsatellite/SSR markers.

BACKGROUND: Pomacea canaliculata is an important invasive species worldwide. However, little is known about the molecular mechanisms behind species displacement, adaptational abilities, and pesticide resistance, partly because of the lack of genomic information that is available for this species. Here, the transcriptome sequences for the invasive golden apple snail P. canaliculata and the native mudsnail Cipangopaludina cahayensis were obtained by next-generation-sequencing and used to compare genomic divergence and identify molecular markers. RESULTS: More than 46 million high quality sequencing reads were generated from P. canaliculata and C. cahayensis using Illumina paired-end sequencing technology. Our analysis indicated that 11,312 unigenes from P. canaliculata and C. cahayensis showed significant similarities to known proteins families, among which a total of 4,320 specific protein families were identified. KEGG pathway enrichment was analyzed for the unique unigenes with 17 pathways (p-value < 10(-5)) in P. canaliculata relating predominantly to lysosomes and vitamin digestion and absorption, and with 12 identified in C. cahayensis, including cancer and toxoplasmosis pathways, respectively. Our analysis also indicated that the comparatively high number of P450 genes in the P. canaliculata transcriptome may be associated with the pesticide resistance in this species. Additionally, 16,717 simple sequence repeats derived from expressed sequence tags (EST-SSRs) were identified from the 14,722 unigenes in P. canaliculata and 100 of them were examined by PCR, revealing a species-specific molecular marker that could distinguish between the morphologically similar P. canaliculata and C. cahayensis snails. CONCLUSIONS: Here, we present the genomic resources of P. canaliculata and C. cahayensis. Differentially expressed genes in the transcriptome of P. canaliculata compared with C. cahayensis corresponded to critical metabolic pathways, and genes specifically related to environmental stress response were detected. The CYP4 family of P450 cytochromes that may be important factors in pesticide metabolism in P. canaliculata was identified. Overall, these findings will provide valuable genetic data for the further characterization of the molecular mechanisms that support the invasive and adaptive abilities of P. canaliculata.