Identification of plexin D1 on circulating extracellular vesicles as a potential biomarker of polymyositis and dermatomyositis.

OBJECTIVES: We aimed to identify disease-specific surface proteins on extracellular vesicles (EVs) as novel serum biomarkers of PM/DM. METHODS: We performed liquid chromatography-tandem mass spectrometry (LC/MS) on purified EVs from sera of 10 PM/DM patients, 23 patients with other autoimmune diseases and 10 healthy controls (HCs). We identified membrane proteins preferentially present in EVs of PM/DM patients by bioinformatics and biostatistical analyses. We developed an EV sandwich ELISA for directly detecting serum EVs expressing disease-specific membrane proteins and evaluated their clinical utility using sera from 54 PM/DM, 24 RA, 20 SLE, 13 SSc and 25 Duchenne and Becker types of muscular dystrophy (DMD/BMD) patients and 36 HCs. RESULTS: LC/MS analysis identified 1220 proteins in serum EVs. Of these, plexin D1 was enriched in those from PM/DM patients relative to HCs or patients without PM/DM. Using a specific EV sandwich ELISA, we found that levels of plexin D1+ EVs in serum were significantly greater in PM/DM patients than in HCs or RA, SLE or DMD/BMD patients. Serum levels of plexin D1+ EVs were greater in those PM/DM patients with muscle pain or weakness. Serum levels of plexin D1+ EVs were significantly correlated with levels of aldolase (rs = 0.481), white blood cells (rs = 0.381), neutrophils (rs = 0.450) and platelets (rs = 0.408) in PM/DM patients. Finally, serum levels of plexin D1+ EVs decreased significantly in patients with PM/DM in clinical remission after treatment. CONCLUSION: We identified levels of circulating plexin D1+ EVs as a novel serum biomarker for PM/DM.

MicroRNA-124 inhibits TNF-α- and IL-6-induced osteoclastogenesis.

Receptor activator for nuclear factor κB ligand (RANKL)-independent osteoclastogenic pathway was reported recently. MicroRNA (miR)-124 has been known to suppress RANKL-dependent osteoclastogenesis by inhibiting NFATc1 expression. However, whether miR-124 regulates a RANKL-independent pathway has not been elucidated. In this study, we examined whether a RANKL-independent pathway is regulated by miR-124 in addition to the RANKL-dependent one. Using osteoclastogenic culture and pit-formation assay, we found that a miR-124 mimic inhibited osteoclastogenesis in mouse bone marrow-derived macrophages stimulated by TNF-α, IL-6, and M-CSF in the presence of osteoprotegerin. We also showed that the expression levels of osteoclast-specific genes and NFATc1 protein were suppressed in the miR-124 mimic-transfected cells by performing quantitative-polymerase chain reaction and western blotting. Our results indicate that miR-124 is important in inhibiting both RANKL-dependent and -independent osteoclast differentiation by suppressing NFATc1-mediated pathway.

Efficacy of Valganciclovir Treatment Depends on the Severity of Hearing Dysfunction in Symptomatic Infants with Congenital Cytomegalovirus Infection.

Although earlier studies have shown that antiviral treatment regimens using valganciclovir (VGCV) improved hearing function in some infants with congenital cytomegalovirus (CMV) infection; its efficacy on the severity of hearing dysfunction is unclear. We conducted a prospective study among 26 infants with congenital CMV infections from 2009 to 2018. Oral VGCV (32 mg/kg/day) was administered for 6 weeks (November 2009 to June 2015; n = 20) or 6 months (July 2015 to March 2018, n = 6). Hearing function was evaluated by measuring the auditory brainstem response before VGCV treatment and at 6 months. Hearing dysfunction, defined as a V-wave threshold >40 dB, was categorized into: most severe, ≥91 dB; severe, 61⁻90 dB; and moderate, 41⁻60 dB. Hearing improvement was defined as a decrease of ≥20 dB from the pretreatment V-wave threshold. Of 52 ears in 26 infants with congenital CMV infection, 29 (56%) had hearing dysfunction, and of 29 ears, 16 (55%) improved after VGCV treatment. Although, 16 (84%) of 19 ears with moderate or severe hearing dysfunction improved after treatment (p < 0.001), 10 ears with the most severe form did not. In conclusion, VGCV treatment is effective in improving moderate and severe hearing dysfunction in infants with congenital CMV infection.

Diagnostic Value of Cytomegalovirus IgM Antibodies at Birth in PCR-Confirmed Congenital Cytomegalovirus Infection.

Although cytomegalovirus (CMV) DNA detection in urine is the standard method for diagnosing congenital cytomegalovirus infection (CCMVI), polymerase chain reaction (PCR) is not comprehensively available. Currently, the efficacy of CMV-specific IgM (CMV-IgM) and CMV-specific IgG (CMV-IgG) detection remains unclear. To determine the sensitivity and specificity of CMV-specific antibodies at birth, we investigated CMV-IgM and CMV-IgG titers in CCMVI cases and non-CCMVI controls, with confirmed diagnoses by urine quantitative real-time PCR within 3 weeks after birth. We included 174 infants with suspected CCMVI in whom serological testing was performed within the first 2 weeks after birth during 2012-2018. We classified the participants into a CCMVI group (n = 32) and non-CCMVI group (n = 142) based on their urine PCR results. The CMV-IgM-positive rate was 27/32 (84.4%) in the CCMVI group, compared with 1/142 (0.7%) in the non-CCMVI group (p < 0.0001). The positive CMV-IgG rates were 32/32 (100%) in the CCMVI group and 141/142 (99.3%) in the non-CCMVI group. The positive predictive value for CMV-IgM was high at 96.4% (27/28). This value may be sufficient for clinical use, especially in settings with limited resources where PCR is unavailable. However, CCMVI screening by CMV-IgM alone appears insufficient because of the considerable number of false-negative cases.

Sequence analyses of variable cytomegalovirus genes for distinction between breast milk- and transfusion-transmitted infections in very-low-birth-weight infants.

BACKGROUND: Cytomegalovirus (CMV) transmission to very-low-birth-weight infants (VLBWIs) sometimes induces serious clinical symptoms. Although breast milk is considered a major source of transmission, transfusion-transmitted CMV (TT-CMV) infection is often suspected when CMV disease develops after transfusion. Thus, it is clinically important to distinguish between transfusion-transmitted and breast milk-transmitted CMV infections. STUDY DESIGN AND METHODS: Study A: The incidence of acquired CMV transmission was prospectively investigated in 65 VLBWIs. Study B: To determine the transmission routes in 18 TT-CMV-suspected VLBWIs who had been reported in our hemovigilance system, we performed polymerase chain reaction for CMV DNA in fed breast milk and/or repository blood samples related to transfused leukoreduced blood products. Furthermore, we evaluated the identity of CMV strains in patients' urine/blood samples and fed breast milk by sequence analyses of variable CMV genes UL139 and UL146. RESULTS: Study A: Acquired CMV infection was found in 4 of 65 VLBWIs (6.2%). Study B: CMV DNA was detected in fed breast milk for 12 of 14 TT-CMV-suspected cases, for which breast milk was available. Furthermore, CMV DNA sequence-matching rates between fed breast milk and patients' urine/blood for both UL139 and UL146 genes were 100% or nearly 100% in 11 patients. In contrast, repository blood samples for 11 of 14 patients were CMV DNA negative. CONCLUSION: CMV is principally transmitted through breast milk in VLBWIs. The risk of TT-CMV seems to be extremely low when using leukoreduced blood products. Sequence analyses of the variable CMV genes are useful for evaluating CMV transmission routes.

[Performance Utility of High Sensitivity Quantitative Assay for HBs Antigen].

A high sensitivity quantitative assay for hepatitis B virus (HBV) surface antigen (HBsAg-HQ assay) was recently developed and is useful for earlier detection of HBV reactivation. We created HBsAg-HQ assay operational proce- dures by the sample transport system and laboratory information system. In this study, we evaluated the perfor- mance and utility of the HBsAg-HQ assay based on our operational procedures using internal quality control (IQC) data and 13,762 samples routinely measured for 8 months. The IQC data of the HBsAg-HQ assay demonstrated good accuracy (CV: 1.6-2.7%). The difference in IQC data between two of the same analyzers or several reagent lots had no clinical significance. Of 13,762 samples, HBsAg titer was negative in 12,592(91.5%) and positive in 1,169(8.5%), and HBsAg negative samples were remarkably lower(<0.001 IU/mL) than the cut-off value(0.005 IU/mL). Among 114 HBsAg weakly positive samples ranging from 0.005 to 1.000 IU/mL, false positive results occurred in 12 samples, which were converted into negative results after re-measurement. We could effectively perform carry-over prevention and dilution of high titer samples using our operational procedures. Furthermore, we performed inhibition test in 52 HBsAg weakly positive samples, and 20 samples, most of which were taken from patients with connective tissue disease or malignancy, were judged as non-specific reactivity. Taken together, our operational HBsAg-HQ assay procedures may contribute to efficient workflow for routine testing. Moreover, the HBsAg-HQ assay may be clinically useful for not only highly sensitive assays, but also for reducing false positives.

Coexpression of NUP98/TOP1 and TOP1/NUP98 in de novo Acute Myeloid Leukemia with t(11;20)(p15;q12) and t(2;5)(q33;q31).

The t(11;20)(p15;q11∼12) translocation is a very rare but recurrent cytogenetic aberration that occurs in myelodysplastic syndrome/acute myeloid leukemia (MDS/AML). This translocation was shown to form a fusion gene between NUP98 at 11p15 and TOP1 at 20q12. Here, we describe a new case of de novo AML M2 with t(11;20) which was associated with another balanced translocation. An 81-year-old man was admitted to undergo salvage therapy for relapsed AML. G-banding and spectral karyotyping showed 46,XY,t(2;5)(q33;q31),t(11;20)(p15;q12)[20]. Expression of the NUP98/TOP1 fusion transcript was confirmed: NUP98 exon 13 was in-frame fused with TOP1 exon 8. The reciprocal TOP1/NUP98 fusion transcript was also detected: TOP1 exon 7 was fused with NUP98 exon 14. After achieving hematological complete remission, the karyotype converted to 46,XY,t(2;5)(q33;q31)[19]/46,sl,t(11;20)(p15;q12)[1]. FISH analysis demonstrated that the 5q31 breakpoint of t(2;5) was centromeric to EGR1. In all 10 cases described in the literature, the NUP98 exon 13/TOP1 exon 8 fusion transcript was expressed, indicating that it may be responsible for the pathogenesis of MDS/AML with t(11;20). On the other hand, the TOP1/NUP98 transcript was coexpressed in 4 cases of de novo AML, but not in 3 cases of therapy-related MDS. Thus, this reciprocal fusion may be associated with progression to AML.

Mixed Phenotype Acute Leukemia with t(12;17)(p13;q21)/TAF15-ZNF384 and Other Chromosome Abnormalities.

The t(12;17)(p13;q11∼21) translocation is a very rare but recurrent cytogenetic aberration observed predominantly in early pre-B acute lymphoblastic leukemia (ALL) with CD19+CD10-CD33+ phenotype. This translocation was shown to form a fusion gene between TAF15 at 17q12 and ZNF384 at 12p13. On the other hand, der(1;18)(q10;q10) has been detected as a rare unbalanced whole-arm translocation leading to trisomy 1q in myeloid malignancies. We describe here the first case of mixed phenotype acute leukemia (MPAL) with a t(12;17)(p13;q21)/TAF15-ZNF384, which also had der(1;18)(q10;q10) as an additional abnormality. A 74-year-old woman was diagnosed with MPAL, B/myeloid, because bone marrow blasts were positive for myeloperoxidase, CD19, and CD22. Chromosome analysis showed 46,XX, +1,der(1;18)(q10;q10),t(2;16)(q13;q13),t(12;17)(p13;q21). Expression of the TAF15-ZNF384 fusion transcript was confirmed: TAF15 exon 6 was fused in-frame to ZNF384 exon 3. This type of fusion gene has been reported in 1 acute myeloid leukemia case and 3 ALL cases. Thus, at present, it is difficult to find a specific association between the structure of the TAF15-ZNF384 fusion gene and the leukemia phenotype. The TAF15-ZNF384 fusion may occur in early common progenitor cells that could differentiate into both the myeloid and lymphoid lineages. Furthermore, der(1;18)(q10;q10) might play some role in the appearance of an additional myeloid phenotype.

MicroRNA-124 inhibits the progression of adjuvant-induced arthritis in rats.

OBJECTIVE: MicroRNAs (miRNAs) are small endogenous, non-coding RNAs that act as post-transcriptional regulators. We analysed the in vivo effect of miRNA-124 (miR-124, the rat analogue of human miR-124a) on adjuvant-induced arthritis (AIA) in rats. METHODS: AIA was induced in Lewis rats by injecting incomplete Freund's adjuvant with heat-killed Mycobacterium tuberculosis. Precursor (pre)-miR-124 was injected into the right hind ankle on day 9. Morphological changes in the ankle joint were assessed by micro-CT and histopathology. Cytokine expression was examined by western blotting and real-time RT-PCR. The effect of miR-124 on predicted target messenger RNAs (mRNAs) was examined by luciferase reporter assays. The effect of pre-miR-124 or pre-miR-124a on the differentiation of human osteoclasts was examined by tartrate-resistant acid phosphatase staining. RESULTS: We found that miR-124 suppressed AIA in rats, as demonstrated by decreased synoviocyte proliferation, leucocyte infiltration and cartilage or bone destruction. Osteoclast counts and expression level of receptor activator of the nuclear factor κB ligand (RANKL), integrin ß1 (ITGB1) and nuclear factor of activated T cells cytoplasmic 1 (NFATc1) were reduced in AIA rats treated with pre-miR-124. Luciferase analysis showed that miR-124 directly targeted the 3'UTR of the rat NFATc1, ITGB1, specificity protein 1 and CCAAT/enhancer-binding protein α mRNAs. Pre-miR-124 also suppressed NFATc1 expression in RAW264.7 cells. Both miR-124 and miR-124a directly targeted the 3'-UTR of human NFATc1 mRNA, and both pre-miR-124 and pre-miR-124a suppressed the differentiation of human osteoclasts. CONCLUSIONS: We found that miR-124 ameliorated AIA by suppressing critical prerequisites for arthritis development, such as RANKL and NFATc1. Thus, miR-124a is a candidate for therapeutic use for human rheumatoid arthritis.

Low total IgM values and high cytomegalovirus loads in the blood of newborns with symptomatic congenital cytomegalovirus infection.

AIMS: Neurological outcomes differ considerably between symptomatic and asymptomatic infants with congenital cytomegalovirus (CMV) infection. Our objective was to characterize laboratory markers in symptomatic newborns in comparison with asymptomatic newborns with congenital CMV infection. METHODS: Ten newborns with symptomatic and 13 newborns with asymptomatic congenital CMV infection were included in this 3-year prospective cohort study. Total immunoglobulin M (IgM), CMV-IgM, CMV antigenemia, and CMV-DNA in blood and urine were measured and their positive rates and quantitative values compared between the symptomatic and asymptomatic groups. RESULTS: Fifty percent of newborns in the symptomatic group were positive based on total IgM; this was significantly lower than in the asymptomatic group (100%). Quantitative total IgM values were significantly lower, and there were significantly more copies of CMV-DNA in the blood of symptomatic newborns than in asymptomatic newborns (median values for total IgM: 14 vs. 43 mg/dL and blood CMV-DNA: 3.2×102 vs. 3.5×101 copies/106 white blood cells). CMV-IgM, CMV antigenemia, and urine CMV-DNA did not differ significantly between groups. CONCLUSION: Low total IgM values and high blood CMV loads were associated with the presence of symptoms in newborns with congenital CMV infection.

A novel TRB@/NOTCH1 fusion gene in T-cell lymphoblastic lymphoma with t(7;9)(q34;q34).

BACKGROUND: In T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL), activating mutations of NOTCH1 are observed in more than 50% of cases, whereas the t(7;9)(q34;q34) involving NOTCH1 at 9q34 and TRB@ at 7q34 is an extremely rare but recurrent translocation. PATIENT: A 41-year-old male with a large mediastinal mass, pleural effusion, and lymphadenopathy was diagnosed as having T-LBL. Lymphoma cells were positive for CD4, CD8, CD2, CD3, CD5, CD7, CD10, and TdT. RESULTS: G-banding and spectral karyotyping of pleural effusion cells showed 47,XY,dup(1)(q21q32),t(7;9)(q34;q34),+20. Genomic polymerase chain reaction (PCR) revealed that the 5' end of TRB@ J1-5 was connected with the middle of NOTCH1 exon 25 (434 bp downstream from its 5' end) in a 'head-to-head' configuration on the der(9)t(7;9), although nine extra bases were inserted between the two genes. Reverse transcription-PCR confirmed expression of the TRB@/NOTCH1 fusion transcripts. Similarly, the 5' end of J1-5 was fused to the shortened exon 25 with nine extra bases. The NOTCH1 breakpoint in exon 25 was very close to transcription start sites of deleted Notch1 in murine T-ALL. CONCLUSIONS: The TRB@/NOTCH1 fusion gene with a NOTCH1 breakpoint in exon 25, which has not previously been detected in four other reported cases with t(7;9), could lead to aberrant expression of the truncated NOTCH1 by TRB@ enhancer elements. The resultant NOTCH1 receptor deleting most of the extracellular domain may be implicated in the pathogenesis of T-LBL by ligand-independent, constitutive activation of the NOTCH1 pathway, suggesting avenues for future therapy with γ-secretase inhibitors.

Exosomes derived from synovial fibroblasts from patients with rheumatoid arthritis promote macrophage migration that can be suppressed by miR-124-3p.

Objectives: Exosomes are potent vehicles for intercellular communication. Rheumatoid arthritis (RA) is a chronic systemic disease of unknown etiology. Local administration of miR-124 precursor to rats with adjuvant-induced arthritis suppresses systemic arthritis and bone destruction. Thus, exosomes may be involved in this disease. We aimed to determine the role of exosomes in the pathology of RA. Methods: Fibroblast-like synoviocytes (FLS) were collected from patients with RA and osteoarthritis (OA). miR-124-3p mimic was transfected into the RA FLS (RA miR-124 FLS). Exosomes were collected from the culture medium by ultracentrifugation. Macrophages were produced from THP-1 cells. MicroRNAs in the exosomes were analyzed using real-time PCR. Proteomics analysis was performed using nanoscale liquid chromatography-tandem mass spectrometry. Macrophage migration was evaluated using a Transwell migration assay. SiRNA was used to knockdown proteins of interest. Results: MicroRNAs in the RA FLS, RA miR-124 FLS, and OA FLS exosomes were similar. Proteomics analysis revealed that pentraxin 3 (PTX3) levels were higher in RA FLS exosomes than in RA miR-124 FLS and OA FLS exosomes, and proteasome 20S subunit beta 5 (PSMB5) levels were lower in RA FLS exosomes than in RA miR-124 FLS and OA FLS exosomes. The RA FLS exosomes promoted and the RA miR-124 FLS exosomes suppressed macrophage migration. PTX3-silenced RA FLS exosomes suppressed and PSMB5-silenced OA FLS exosomes promoted macrophage migration. Conclusions: RA FLS exosomes promote macrophage migration via PTX3 and PSMB5, and miR-124-3p suppresses this migration.

SS-A/Ro52 promotes apoptosis by regulating Bcl-2 production.

SS-A/Ro52 (Ro52), an autoantigen in systemic autoimmune diseases such as systemic lupus erythematosus and Sjögren's syndrome, has E3 ligase activity to ubiquitinate proteins that protect against viral infection. To investigate Ro52's role during stress, we transiently knocked it down in HeLa cells by siRo52 transfection. We found that Ro52(low) HeLa cells were significantly more resistant to apoptosis than wild-type HeLa cells when stimulated by H(2)O(2)- or diamide-induced oxidative stress, IFN-α, IFN-γ and anti-Fas antibody, etoposide, or γ-irradiation. Furthermore, Ro52-mediated apoptosis was not influenced by p53 protein level in HeLa cells. Depleting Ro52 in HeLa cells caused Bcl-2, but not other Bcl-2 family molecules, to be upregulated. Taken together, our data showed that Ro52 is a universal proapoptotic molecule, and that its proapoptotic effect does not depend on p53, but is exerted through negative regulation of the anti-apoptotic protein Bcl-2. These findings shed light on a new physiological role for Ro52 that is important to intracellular immunity.

Expression of the novel NUP98/PSIP1 fusion transcripts in myelodysplastic syndrome with t(9;11)(p22;p15).

OBJECTIVES: The t(9;11)(p22;p15) is a very rare but recurrent translocation in acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) blast crisis. The translocation results in a fusion gene between NUP98 at 11p15 and PSIP1 encoding two transcriptional coactivators, p52 and p75, at 9p22. Here, we describe the first case of myelodysplastic syndrome (MDS) with t(9;11)(p22;p15). PATIENT: A 64-yr-old woman presented pancytopenia, trilineage dysplasia, and 9.2% blasts in the bone marrow, indicating the diagnosis of MDS. RESULTS: G-banding and spectral karyotyping showed 46,XX,t(9;11)(p22;p15)[20]. Reverse transcription-polymerase chain reaction (RT-PCR) and nucleotide sequencing detected four types of NUP98/PSIP1-p52 and two types of NUP98/PSIP1-p75 fusion transcripts. Essentially, the NUP98 exon 12 or exon 11 by alternative splicing was fused in-frame with the PSIP1 exon 8. Real-time quantitative (RQ) PCR for NUP98/PSIP1/GAPDH demonstrated a 4-log decrease after cord blood transplantation and a 2-log increase at relapse. CONCLUSIONS: The fusion genes combining NUP98 exon 11/12 with PSIP1 exon 8, which have never been detected in other AML/CML cases, may be implicated in the pathogenesis of MDS. Furthermore, RQ-PCR for NUP98/PSIP1 could be useful to monitor minimal residual disease.

Comparison of 17 serological treponemal and nontreponemal assays for syphilis: A retrospective cohort study.

Objectives: Rapid plasma reagin (RPR) and Treponema pallidum (TP) antibody test kits are often used to diagnose syphilis, although the relationship between their measured values is unclear. We aimed to reveal the relevance of these kits' results. Design and methods: In all, 143 sera from 110 patients were tested using 12 TP kits and 5 RPR kits and the results compared. Results: The specificity and sensitivity of RPR kits were 81-96% and 95-100%, respectively. The correlation coefficients (0.849-0.934) considerably differed between the manual RPR card test and latex agglutination (LA) assay kits. The following sensitivities were obtained: 82-91% for TP fluorescent treponemal antibody absorption assay (FTA-ABS), TP hemagglutination assay (HA), and TP particle agglutination assay (PA); 94-95% for TP LAs; and 92-100% for chemiluminescent immunoassay (CLIA), chemiluminescent enzyme immunoassay (CLEIA), and immunochromatography assay (IC). Correlation coefficients between TP kits were 0.753-0.974, and the measured values varied. Changes in RPR and quantifiable TP kits were the same for patients with reinfected syphilis and with syphilis under treatment. Conclusions: RPR tests had lower specificity than TP antibody tests. RPR card test and RPR LAs had similar specificity and sensitivity, but their measured values were different. RPR should be measured using automatic RPR LA without setting the upper limit of the reported value. RPR LA should also be standardized. The sensitivity of TP antibody was better in CLIA, CLEIA, and IC than in FTA-ABS, HA, PA, and LA. Therefore, TP antibody kits should be standardized and quantified.

Genetic Analysis of UGT1A1 Polymorphisms Using Preserved Dried Umbilical Cord for Assessing the Potential of Neonatal Jaundice as a Risk Factor for Autism Spectrum Disorder in Children.

Neonatal jaundice has been suggested as a perinatal risk factor for autism spectrum disorder (ASD). We examined UGT1A1 polymorphisms to assess the potential of neonatal jaundice as a risk factor for ASD in children by using DNA extracted from preserved umbilical cord. In total, 79 children with ASD were genotyped for UGT1A1*28 (c.-41-40dup), UGT1A1*6 (c.211 G > A), and UGT1A1*27 (c.686 C > A). The allele frequency of UGT1A1*6 (OR = 1.34, p = 0.26) and UGT1A1*28 (OR = 0.80, p = 0.54) and the prevalence of UGT1A1*28/*6 diplotypes did not differ significantly from those in the control population. No UGT1A1*27 allele was detected in the subjects. ASD symptom assessment scores were not associated with UGT1A1*28/*6/*27 genotypes or UGT1A1*28/*6 diplotypes. These results suggest that neonatal jaundice is not significantly associated with ASD.

miR-124a as a key regulator of proliferation and MCP-1 secretion in synoviocytes from patients with rheumatoid arthritis.

MicroRNAs (miRNA) are a class of small endogenous non-coding RNAs that influence the stability and translation of messenger RNA. Synoviocytes from patients with rheumatoid arthritis (RA) were analysed for their miRNA expression profile, and it was found that miR-124a levels significantly decreased in RA synoviocytes as compared with osteoarthritis synoviocytes. Transfection of miR-124a into RA synoviocytes significantly suppressed their proliferation and arrested the cell cycle at the G1 phase. miR-124a directly binds to the 3'-untranslated region of cyclin-dependent kinase 2 (CDK-2) and monocyte chemoattractant protein 1 (MCP-1) mRNA, and the induction of miR-124a in RA synoviocytes significantly suppressed the production of the CDK-2 and MCP-1 proteins. It is proposed that miR-124a is a key miRNA in the post-transcriptional regulatory mechanisms of RA synoviocytes, and has a therapeutic potential.

[Acute myeloid leukemia with t(16;21)(q24;q22) in a child].

The t(16;21)(q24;q22), a rare chromosomal translocation observed mostly in therapy-related acute myelogenous leukemia (AML), produces a RUNX1-CBFA2T3 fusion gene. Here we report a de novo AML case of 1-year-old girl with t(16;21)(q24;q22). In this case, we demonstrated the RUNX1-CBFA2T3 fusion gene and established quantitative RT-PCR for detecting minimal residual disease.

Lymphoplasmacytic lymphoma in a patient with Birt-Hogg-Dubé syndrome.

Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant disease characterized by benign skin hamartomas, pulmonary cysts leading to spontaneous pneumothorax, and an increased risk of renal cancer. BHD syndrome is caused by germline mutations in the folliculin (FLCN) gene, a putative tumor suppressor, which result in loss of function of the folliculin protein and may cause cancer predisposition. In a 45-year-old woman with anemia, lymphadenopathy, and a history of recurrent spontaneous pneumothorax, 18F-FDG PET/CT detected diffuse and slight 18F-FDG accumulation in the bone marrow, enlarged spleen, and systemic multiple enlarged lymph nodes. Genetic examination identified a germline nonsense mutation [c.998C > G (p.Ser333*)] on exon 9 of FLCN. Pathological examination of the lymph node revealed a diffuse neoplastic proliferation of plasmacytoid lymphocytes. The neoplastic lymphoid cells were positive for CD20, CD138, and light chain kappa as per immunohistochemistry and mRNA in situ hybridization, and a MYD88 gene mutation [c.755T > C (p.L252P)] was identified. Accordingly, she was diagnosed with lymphoplasmacytic lymphoma concomitant with BHD syndrome. To the best of our knowledge, this is the first report describing the development of hematological malignancy in a patient with BHD syndrome. The FLCN mutation might contribute lymphomagenesis as an additional mutation cooperating with the MYD88 mutation.