273. Low Positive Predictive Value of β-d-Glucan in Hematology Patients Receiving Antimold Prophylaxis

Background

Detection of β-D-glucan (BDG) in serum is recognized as the mycological evidence in the diagnosis of invasive fungal infection (IFI). However, its diagnostic value in low prevalence of IFI has not been elucidated. We aimed to examine the performance of BDG in hematology patients receiving antimold prophylaxis.

Methods

We retrospectively reviewed all BDG results performed for the purpose of diagnosis or surveillance for IFI in hematology patients receiving posaconazole or micafungin prophylaxis from January 2017 to February 2019 in a tertiary hospital. At least two consecutive positive results of BDG were regarded as positive BDG. All the episodes were classified into true-positive (TP, positive BDG with probable/proven IFI), true-negative (TN, negative BDG without probable/proven IFI), false-positive (FP, positive BDG without probable/proven IFI), false-negative (FN, negative BDG with probable/proven IFI), and nonevaluable (could not be determined for the occurrence of breakthrough IFI). When BDG test was performed in the setting of persistent fever ≥72 hours in spite of broad-spectrum antibiotics or with a suspicion of IFI, it was defined as a diagnostic BDG episode, while others were defined as a surveillance BDG episode.

Results

Of a total of 140 episodes, 24 episodes were non-evaluable. Among 116 evaluable episodes, 75 received induction chemotherapy for acute leukemia or myelodysplastic syndrome, 35 underwent stem cell transplantation, and 10 had intensive treatment for graft-vs.-host disease. There were three episodes of probable/proven IFI (2.6%). Ninety-one (78.4%) were performed with diagnostic purpose, while 25 (21.6%) were performed for surveillance. TP, TN, FP, and FN were 2 (1.7%), 91, 22, and 1, respectively. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value were 66.7%, 80.5%, 8.3% and 98.9%, respectively. PPV was 13.3% and 0% in diagnostic and surveillance BDG episodes, respectively.

Conclusion

The PPV of BDG was low in hematology patients receiving antimold prophylaxis, even in the diagnostic-driven episodes. The routine screening of BDG is not helpful, and the BDG test may be used for exclusion of IFI rather than for diagnosis in these patients.

Disclosures

All authors: No reported disclosures.

Quantitative comparison of structure and dynamics of elastin following three isolation schemes by 13C solid state NMR and MALDI mass spectrometry

Methods for isolating elastin from fat, collagen, and muscle, commonly used in the design of artificial elastin based biomaterials, rely on exposing tissue to harsh pH levels and temperatures that usually denature many proteins. At present, a quantitative measurement of the modifications to elastin following isolation from other extracellular matrix constituents has not been reported. Using magic angle spinning (13)C NMR spectroscopy and relaxation methodologies, we have measured the modification in structure and dynamics following three known purification protocols. Our experimental data reveal that the (13)C spectra of the hydrated samples appear remarkably similar across the various purification methods. Subtle differences in the half maximum widths were observed in the backbone carbonyl suggesting possible structural heterogeneity across the different methods of purification. Additionally, small differences in the relative signal intensities were observed between purified samples. Lyophilizing the samples results in a reduction of backbone motion and reveals additional differences across the purification methods studied. These differences were most notable in the alanine motifs indicating possible changes in cross-linking or structural rigidity. The measured correlation times of glycine and proline moieties are observed to also vary considerably across the different purification methods, which may be related to peptide bond cleavage. Lastly, the relative concentration of desmosine cross-links in the samples quantified by MALDI mass spectrometry is reported.

Activation of HIF-1α (hypoxia inducible factor-1α) prevents dry eye-induced acinar cell death in the lacrimal gland

The pathogenesis of immune-mediated lacrimal gland (LG) dysfunction in Sjögren's syndrome has been thoroughly studied. However, the majority of dry eye (DE) is not related to Sjögren type, and its pathophysiology remains unclear. The purpose of this study was to determine and investigate the protective mechanisms against DE stress in mice. DE induced prominent blood vessel loss without apoptosis or necrosis in the LG. Autophagic vacuoles, distressed mitochondria, and stressed endoplasmic reticulum were observed via electron microscopy. Immunoblotting confirmed the increase in autophagic markers. Glycolytic activities were enhanced with increasing levels of succinate and malate that, in turn, activated hypoxia-inducible factor (HIF)-1α. Interestingly, the areas of stable HIF-1α expression overlapped with COX-2 and MMP-9 upregulation in LGs of DE-induced mice. We generated HIF-1α conditional knockout (CKO) mice in which HIF-1α expression was lost in the LG. Surprisingly, normal LG polarities and morphologies were completely lost with DE induction, and tremendous acinar cell apoptosis was observed. Similar to Sjögren's syndrome, CD3⁺ and CD11b⁺ cells infiltrated HIF-1α CKO LGs. Our results show that DE induced the expression of HIF-1α that activated autophagy signals to prevent further acinar cell damage and to maintain normal LG function.

Receptor activator of nuclear factor kappa B ligand-mediated osteoclastogenesis is elevated in ankylosing spondylitis

OBJECTIVE

Ankylosing spondylitis (AS) is an inflammatory arthritis involving the axial skeleton. Decreased bone mineral density has also been reported in AS patients. This study sought to determine whether osteoclastogenesis and osteoclast activity are increased in AS.

METHODS

Twenty patients with AS were evaluated using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and other clinical parameters. Mononuclear cells were separated out from peripheral blood samples taken from AS patients and normal healthy controls and cultured with monocyte colony stimulating factor and receptor activator of the nuclear factor kappa B ligand (RANKL). Multi-nucleated, tartrate-resistant acid phosphatase stain-positive osteoclasts were counted after 9 days, and the areas of calcium absorption on calcium-coated plates were determined.

RESULTS

Osteoclastogenesis was significantly greater in AS patients than in normal controls (number of osteoclasts/1106 mononuclear cells, median, 518.0 vs. 362.5, p=0.036). No differences were observed between AS patients and controls in terms of calcium absorption areas or the serum concentrations of tumor necrosis factor and RANKL. Osteoclastogenesis was greater in AS patients with sacroiliac joint ankylosis than in those without. Osteoclastogenesis and the calcium absorption area were not found to be correlated with BASDAI nor with other clinical parameters including age, erythrocyte sedimentation rate, and C-reactive protein levels.

CONCLUSION

Osteoclastogenesis is elevated in AS patients, especially in those with sacroiliac joint ankylosis. Increased osteoclastogenesis may be related to osteopenia in AS patients.

A genome-wide microarray analysis reveals anti-inflammatory target genes of paeonol in macrophages

OBJECTIVE

Paeony root has long been used for its anti-inflammatory effects. In this study, the effects of albiflorin, paeoniflorin, and paeonol, compounds from paeony root, on gene expression profiles were examined in macrophages challenged with the inflammation inducer lipopolysaccharide (LPS).

METHODS

The RAW264.7 macrophages were treated with LPS in the presence or absence of albiflorin, paeoniflorin, or paeonol. Global mRNA expression levels were detected by using an oligonucleotide microarray platform covering the mouse whole genome.

RESULTS

Treatment with LPS caused expression level changes in 1,270 genes by 2 folds or more. Paeonol attenuated the induction level of 355 LPS-responsive genes. Classification of the genes targeted by paeonol according to the Panther group analysis revealed 20 biological processes, 24 molecular functions, and 22 signaling pathways. The Panther signaling pathways highly affected by paeonol included the 'inflammation mediated by chemokine and cytokine signaling', 'interleukin signaling', and 'Toll receptor signaling'.

CONCLUSION

Our results demonstrate that paeonol has extensive inhibitory effects on the regulation of inflammation associated gene expression by LPS in macrophages. In addition, the predominant effect of paeonol among the tested compounds suggests that paeonol may be a major ingredient for the anti-inflammatory effect of paeony root.

Effect of tacrolimus on the production of oxygen free radicals in hepatic mitochondria

OBJECTIVES

Cyclosporine (CsA) causes side effects that occur mainly in the kidney but also in the liver. Several reports have strongly suggested that the production of oxygen free radicals (OFRs) is a common mechanism of CsA toxicity. However, tacrolimus is believed to suppress the production of OFRs.

METHODS

We obtained the mitochondrial fraction with 96% purity from rat liver using a sucrose density gradient solution. Zero to 100 micromol/L tacrolimus was incubated with the mitochondrial fraction for 6 hours at 37 degrees C. OFRs were evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2,7-dichlorefluorescein using a VICTOR3 multilabel counter.

RESULTS

The fluorescence units for OFR production were increased as the time of exposure to tacrolimus passed from 1 to 6 hours. The fluorescence units in 0.1 micromol/L tacrolimus were 6.0 x 10(5) at 1 hour, 7.8 x 10(5) at 2 hours, 9.0 x 10(5) at 3 hours, 10.0 x 10(5) at 4 hours, 11.1 x 10(5) at 5 hours, and 11.4 x 10(5) at 6 hours. However, the fluorescence units were similar although the tacrolimus concentration increases from 0.1 to 100 micromol/L.

CONCLUSIONS

The results in this experiment suggested that tacrolimus induced the production of OFRs depending on the exposure time.

Apoptosis by cyclosporine in mesangial cells

INTRODUCTION

The immunosuppressive agent cyclosporine (CsA) is widely used to treat allograft rejection and various autoimmune disorders. A major limiting factor in the use of CsA is chronic nephrotoxicity. The pathogenesis of CsA-induced nephrotoxicity is not fully understood. Several recent studies have suggested that CsA treatment directly induces apoptosis in several cell types. The present study was undertaken to investigate the effects of CsA on apoptosis of cultured rat mesangial cells (RMCs).

METHODS

RMCs were treated with CsA at concentrations of 0.1 to 40 mumol/L. Cell viability was determined by MTT assay. Apoptotic protein expression was determined by Western blot analysis.

RESULTS

Cell viability was decreased with increasing concentrations of CsA in dose-dependent manner. CsA produced dose-dependent induction of p53, caspase-6, and Bax protein expression. CsA treatment caused proteolytic cleavage of caspase-3 and induced the degradation of 116-kDa PARP into 89-kDa fragment. RMCs with CsA reduced Bcl-2 and cIAP expression.

CONCLUSIONS

In this study, CsA induced apoptosis by up-regulating proapoptotic factors, caspase-3 and -6, p53, Bax, cleaving PARP, and down-regulating antiapoptotic factor, Bcl-2, and cIAP. These results suggested that the increased cell apoptosis exerted by CsA may be one of the mechanisms promoting CsA-induced nephrotoxicity.

Total antioxidant status and oxygen free radicals during hepatic regeneration

OBJECTIVES

The damage induced by oxygen free radicals (OFRs) is caused by an imbalance of the production of versus the antioxidant defenses against OFRs.

METHODS

To understand hepatic damage induced by oxygen free radicals after hepatectomy in rats, total antioxidant status and total production of oxygen free radicals were serially measured in regeneration liver. At 1, 2, 3, 7, and 10 days after hepatectomy of Sprague-Dawley rats, blood was obtained into a capillary tube from a tail vein. Total antioxidant status and total production of oxygen free radicals were measured using the Randox kit, a colorimetric method, and the Free Radical Analytical System. We also measured the amount of malonyldialdehyde, which provides an indirect index of oxidative injury.

RESULTS

The level of malonyldialdehyde after hepatectomy was higher compared with that before hepatectomy. The level of total oxygen free radicals after hepatectomy was higher compared with that before hepatectomy. Total antioxidant status after hepatectomy was lower compared with that before hepatectomy.

CONCLUSIONS

The results suggested that the damage by OFRs to the regenerating liver was caused by increased production of OFRs and decreased antioxidant defense against OFRs.

Effects of cyclosporine and tacrolimus on the oxidative stress in cultured mesangial cells

OBJECTIVES

Cyclosporine (CsA) and tacrolimus (Tac) are two primary immunosuppressive agents used for the prevention of graft rejection. However, their use is associated with significant side effects, most notably nephrotoxicity. The mechanisms of this toxicity are not fully understood, but they seem to be associated with increases in the production of oxygen free radicals (OFRs). This present work examined the effect of CsA and Tac on the production of OFRs in cultured rat renal mesangial cells (RMCs).

METHODS

Varying concentrations of CsA and Tac (0 to 40 micromol/L) were added to RMCs and incubated for 60 minutes at 37 degrees C. The production of OFRs was evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2', 7'-dichlorofluorescin.

RESULTS

At 60 minutes, the relative fluorescence units (RFU) for OFRs production in RMCs exposure to CsA were increased by 2.5%, 11.5%, 22.5%, 57.2%, and 174% at 2.5, 5, 10, 20, and 40 micromol/L, respectively. Tac increased the RFU by 15.9%, 13.6%, 14.8%, 13.2%, 21.4%, 13.2%, and 28.1% at 0.1, 1, 2.5, 5, 10, 20, and 40 micromol/L, respectively. In RMCs, the RFU produced by CsA was higher than that by Tac.

CONCLUSIONS

The results of this experiment suggest that CsA and Tac induced renal injury by OFRs.

Cyclosporine-Induced Apoptosis in Osteosarcoma Cells

INTRODUCTION

Posttransplant bone disease is one of the complications of cyclosporine (CsA), which is widely used as an immunosuppressive agent in the field of kidney transplantation. Cyclosporine treatment causes osteopenia as a result of altered bone turnover, but the pathogenic mechanisms of this process remain unclear. This study examined the ability of CsA to induce apoptosis in a rat osteoblast cell line.

RESULTS

We induced apoptosis in rat osteoblastic ROS 17/2.8 cells by exposure to CsA. MTT assay showed that CsA exhibited significant cytotoxic effects on ROS 17/2.8 cells in a dose-dependent manner. Western blot analysis showed enhanced processing of caspase-8, Bax, and p53 after CsA treatment. Expression of cleaved poly (ADP-ribose) polymerase (PARP) was elevated by CsA treatment. Pro-caspase-3 and Bcl-2 proteins were decreased by CsA.

CONCLUSIONS

These results suggested that CsA induced apoptosis of osteoblasts.

Effects of epigallocatechin gallate on the hemolysis induced by cyclosporine

INTRODUCTION

Hemolysis is one of the side effects of cyclosporine (CsA) therapy, in part due to, increased production of free radical species by CsA. Epigallocatechin gallate (EGCG), which acts as a highly efficient free radical scavenger, may have a protective effect on CsA-induced hemolysis. In this study, we measured the degree of hemolysis of as well as the amounts of hydrogen peroxide level and malondialdehyde produced by normal human erythrocytes (RBCs) incubated with CsA and with EGCG.

METHODS

Human RBCs were incubated as follows. In group 1, 4.2 x 10(6)/mL RBCs were incubated with Cremophore EL. In group 2, the RBCs were incubated with only 167 microg/mL EGCG. In group 3, the RBCs were incubated with 1.67 mg/mL CsA. In group 4, the RBCs were incubated with CsA plus EGCG.

RESULTS

The degree of hemolysis in group 2 (53.8 +/- 3.8) was significantly higher than that in group 1 (7.0 +/- 1.0). The degree of hemolysis in group 3 (86.2 +/- 2.2) was significantly higher than that in group 1 and group 2. The degree of hemolysis in group 4 (74.9 +/- 2.9) was significantly higher than in group 1 and in group 2, but lower than that in group 3. The hydrogen peroxide and malondialdehyde levels paralleled the degree of hemolysis.

CONCLUSIONS

These results suggest that CsA can induce free radical-mediated hemolysis, which can be partially prevented with EGCG.

Effects of polyhemoglobin-antioxidant enzyme complex on ischemia-reperfusion in kidney

INTRODUCTION

The kidney suffers ischemia-reperfusion (I/R) injury during transplantation. The purpose of the present study was to investigate the therapeutic effect of artificials cells on renal I/R injury through biochemical assays and histological examination.

METHODS

We prepared artificial cells using cross-linked hemoglobin (Hb), superoxide dismutase (SOD), and catalase. Normal male Sprague-Dawley rats were divided into 6 groups: the sham-operated control group, the group treated with polyHb,and the group treated with polyHb-SOD-catalase (PSC) (per groups were subjected to ischemia for 1 hour or 2 hours). After reperfusion for 4 hours, kidney and blood samples were obtained.

RESULTS

The levels of SOD and catalase in the PSC group were 15 and 50 times higher than those of the control group, respectively. In the polyHb group, the levels of blood urea nitrogen (BUN), serum creatinine, renal hydrogen peroxide, and renal malondialdehyde were increased. However, their levels were significantly decreased by PSC administration. Renal SOD activity did not show any significant changes in the polyHb group, but renal catalase activity was decreased by polyHb treatment in comparison with the control group. The activities of renal SOD and catalase were increased using PSC treatment. In the histological findings, the PSC group showed no evidence of acute tubular necrosis in proximal convoluted tubules; their microvilli and cytoplasmic microorganelles were relatively well preserved.

CONCLUSIONS

These results show that PSC effectively reduces renal damage via diminished oxygen free radical-mediated injury after I/R.

Effect of epigallocatechin gallate on renal function in cyclosporine-induced nephrotoxicity

INTRODUCTION

Nephrotoxicity is a clinically important side effect of cyclosporine (CsA). CsA-induced nephrotoxicity results from increased production of free radical species in the kidney. Epigallocatechin gallate (EGCG) acts as an antioxidant, thus, EGCG may have a protective effect on the alteration of renal function resultant from oxygen free radicals. The purpose of the present study was to investigate the protective effect of EGCG in a rodent model.

METHODS

Experiments were performed on 3 groups. The normal control group (group 1) received normal saline solution. The CsA-treated group (group 2; 15 mg/kg body weight/d for 14 days) received subcutaneous injections. The EGCG-treated group (group 3) in addition received 25 mg of EGCG/kg body weight by intraperitoneal injection.

RESULTS

There were significant increases in levels of blood urea nitrogen (BUN)(42.8 +/- 8.2 mg/dL; P < .001), serum creatinine (1.18 +/- 0.60 mg/dL; P < .05), and serum malondialdehyde (3.09 +/- 0.20 nmol/mL; P < .001), and a significant decrease in CCr(0.07 +/- 0.02 mL/min; P < .001) in group 2 compared with group 1. Levels of BUN (30.2 +/- 0.7 mg/dL; P < .01)and CCr (0.12 +/- 0.08 mL/min) were lower in group 3 than in group 2. Serum creatinine (0.71 +/- 0.04 mg/dL) and serum malondialdehyde level (2.13 +/- 0.15; P < .001 nmol/mL) were lower in group 3 than in group 2. There was no significant difference in CsA levels between group 2 (6.86 +/- 1.48 mug/mL) and group 3 (6.69 +/- 0.62 mug/mL).

CONCLUSIONS

EGCG treatment significantly protected renal function and free radical-mediated injury in the kidney from CsA-induced changes.

Effect of melatonin on the malondialdehyde level of neutrophils in cyclosporine-treated rats

INTRODUCTION

Cyclosporine (CsA) may contribute to oxygen free radical metabolism in neutrophils, thus resulting in the damage to these cells. This damage may be mitigated by antioxidants such as melatonin. In this study, we measured the malondialdehyde level, which was used as a marker of free radical-induced tissue damage from neutrophils in rats treated with CsA and melatonin.

METHODS

The experiments included the following: (1) normal controls (group 1) that received Cremophor EL and 0.5 mL of 5% ethanol-saline solution; (2) CsA alone-treated (group 2) rats that received 15 mg/kg of body weight per day for 14 days by subcutaneous injection; and (3) melatonin-treated (group 3) rats received CsA as for group 2 plus melatonin (715 mug).

RESULTS

Malondialdehyde level was significantly higher among group 2 (13.34 +/- 7.54 nmol/10(7) neutrophils) than group 1 animals (7.33 +/- 2.63 nmol/10(7) neutrophils; P < .05). The level was significantly lower in group 3 (5.58 +/- 1.59 nmol/10(7) neutrophils) than group 2 (P < .01). CsA levels were not significantly different between group 2 (6.25 +/- 1.60 mug/mL) and group 3 (6.09 +/- 2.01 mug/mL).

CONCLUSIONS

In this experiment, the malondialdehyde level in neutrophils was increased after CsA treatment, suggesting that damage resulted from oxygen free radicals by CsA. This damage was reduced by melatonin. Thus, CsA-induced neutrophils oxidative damage may be protected by melatonin in transplant recipients.

Effect of artificial cells on hepatic function after ischemia–reperfusion injury in liver

BACKGROUND

The liver suffers from ischemia/reperfusion injury during transplantation. Reactive oxygen species generated by xanthine oxidase during reperfusion of the ischemic liver may be partially responsible for the hepatic injury. Oxygen free radicals are removed by antioxidant enzymes such as superoxide dismutase (SOD), catalase, and glutathione peroxidase. Using glutaraldehyde and lysine we constructed crosslinked hemoglobin, containing SOD and catalase, and assessed its ability to protect against ischemia/reperfusion injury during transplantation.

METHODS

In contrast to the sham-operated control groups, blood was exchanged using crosslinked hemoglobin (polyHb) a PolyHb-SOD-catalase (PSC) group. After ischemia/reperfusion injury, several parameters of hepatic damage and oxygen free radicals were measured as well as microscopic examination.

RESULTS

Alanine aminotransferase, aspartate aminotransferase, superoxide production, hydrogen peroxide, and malondialdehyde levels were higher among the PolyHb group than sham-operated controls. The PolyHb group revealed a few apoptotic bodies, some acute inflammatory infiltrates in the sinusoids, nuclear fragmentations, cell shrinkage, and chromatin clumping with formation of apoptotic bodies in the apoptotic cells under microscopic examination. Alanine aminotransferase, aspartate aminotransferase, superoxide production, and hydrogen peroxide levels were lower in the PSC than the PolyHb group. Hepatic structures were well preserved in the PSC group.

CONCLUSIONS

Reactive oxygen species contribute to hepatic dysfunction with morphologic changes. PSC is effective to reduce hepatic damage by lowering oxygen free radical-mediated injury after ischemia/reperfusion in the liver.

Fluorescent monitoring of kinase activity in real time: development of a robust fluorescence-based assay for Abl tyrosine kinase activity

Fluorescent biosensors hold great promise for drug discovery. Using a solid-phase version of protein semi-synthesis, we incorporated two fluorophores at specific sites within a truncated version of the c-Crk-II protein. The resulting fluorescent protein biosensor permits the real-time monitoring of Abl kinase activity and provides a robust and rapid method for assaying Abl kinase inhibitors.

Antimicrobial characteristics of chitosans against food spoilage microorganisms in liquid media and mayonnaise

Four different kinds of chitosans were prepared by treating crude chitin with various NaOH concentrations. The antimicrobial activities of the chitosans were tested against four species of food spoilage microorganisms (Lactobacillus plantarum, Lactobacillus fructivorans, Serratia liquefaciens, and Zygosaccharomyces bailii). The initial effect of the chitosans was biocidal, and counts of viable cells were significantly reduced. After an extended lag phase, some strains recovered and resumed growth. The activities of chitosan against these microorganisms increased with the concentration. Chitosan-50 was most effective against L. fructivorans, but inhibition of L. plantarum was greatest with chitosan-55. There was no significant difference among the chitosans in their antimicrobial activity against S. liquefaciens and Z. bailii. The addition of chitosan to mayonnaise significantly decreased the viable cell counts of L. fructivorans and Z. bailii during storage at 25 degrees C. These results suggest that chitosan can be used as a food preservative to inhibit the growth of spoilage microorganisms in mayonnaise.

Population-based study of rotavirus vaccination and intussusception

BACKGROUND

During the first year that the rhesus rotavirus tetravalent vaccine (RRV-TV) was licensed, the Vaccine Adverse Event Reporting System received several reports of intussusception after vaccination. To evaluate the risk of intussusception, we conducted a retrospective cohort study in ten managed care organizations.

METHODS

Cases of intussusception were identified by searching electronic databases for diagnoses of intussusception (ICD-9 Code 560.0) in infants 1 to 11 months of age and confirmed by medical chart review. Vaccination and enrollment data were obtained from administrative databases. Incidence rate ratios (RR) of intussusception were computed by dividing incidence rates in prespecified risk intervals after vaccination by the background rate of intussusception and adjusted for age by Poisson regression. Cox proportional hazard regression was used to evaluate risk by vaccine dose.

RESULTS

Of 463,277 children 56,253 had been vaccinated with a total of 91 371 doses of RRV-TV. The incidence rate of intussusception was 25/100,000 person years among unexposed infants and 340/100,000 person years 3 to 7 days postvaccination. In the interval 3 to 7 days after vaccination, the age-adjusted RR was 16.0 (95% confidence interval, 5.5 to 46.7) for all doses combined and 30.4 (95% confidence interval, 8.8 to 104.9) after the first dose. RRs for the 8- to 14- and 15- to 21-day risk intervals were >1.0, but the confidence intervals substantially overlapped 1.0. The attributable risk was one case of intussusception per 11 073 children vaccinated.

CONCLUSIONS

RRV-TV is associated with an increased risk of intussusception. The risk is greatest 3 to 7 days after the first vaccination dose.