Clinical Long-Term Outcomes of Patient-Reported Outcomes in the Prospective Real-World Tofacitinib Response in Ulcerative Colitis Registry

INTRODUCTION

We previously reported the results of tofacitinib induction therapy in the prospective multisite US real-world Tofacitinib Response in Ulcerative Colitis registry. We now assessed patient-reported outcomes (PROs) and predictors of success during tofacitinib maintenance therapy.

METHODS

Tofacitinib Response in Ulcerative Colitis included 103 patients with refractory ulcerative colitis (UC); 67% had failed ≥ 2 biologics. Patients reported the Simple Clinical Colitis Activity Index (SCCAI), Patient-Reported Outcome Measurement Information System measures for anxiety, depression, social satisfaction, and adverse events between weeks 8 and 52 using a web-based system. Paired t test and P for trend were used to compare changes in PRO measures over time. Bivariate analyses and logistic regression models were used to determine factors associated with response (SCCAI <5) or remission (SCCAI <2) at week 52.

RESULTS

Of 103 patients, 82.5% entered the maintenance phase and 43.7% remained on tofacitinib at week 52. Tofacitinib de-escalation to 5 mg BID occurred in 15% of patients. At week 52, 42.7% and 31.1% of all patients reported an SCCAI <5 and SCCAI ≤2, respectively. Normalization of bowel frequency, rectal bleeding, and urgency occurred in 79%, 61%, and 48% of patients remaining on maintenance therapy. Social satisfaction improved significantly ( P < 0.001), while anxiety and depression scores only numerically improved. No consistent predictors for tofacitinib long-term treatment efficacy were identified, and safety findings were consistent with the known safety profile of tofacitinib.

DISCUSSION

Tofacitinib is an effective maintenance therapy in patients with refractory UC. Dose reductions infrequently occurred during maintenance. Unmet needs in UC maintenance include improvement of urgency and psychosocial factors (NCT03772145).

Tofacitinib Response in Ulcerative Colitis (TOUR): Early Response After Initiation of Tofacitinib Therapy in a Real-world Setting

BACKGROUND

Tofacitinib is an oral, small-molecule JAK inhibitor for the treatment of ulcerative colitis (UC). Using a novel electronic reporting tool, we aimed to prospectively describe the onset of tofacitinib efficacy during induction therapy in a real-world study.

METHODS

Patient-reported outcome data (PROs) including the simple clinical colitis activity index (SCCAI), PRO Measurement Identification Systems (PROMIS) measures, and adverse events were collected daily for the first 14 days and at day 28 and 56. Paired t tests and P for trend were utilized to compare changes in SCCAI over time. Bivariate analyses and logistic regression models were performed to describe response (SCCAI <5) and remission (SCCAI ≤2) by clinical factors.

RESULTS

Of all included patients (n = 96), 67% had failed ≥2 biologics, and 61.5% were on concomitant steroids. Starting at day 3, PROs showed significant and persistent decline of the mean SCCAI (-1.1, P < 000.1) including significantly lower SCCAI subscores for stool frequency (-0.3; P < .003), bleeding (-0.3; P < .0002) and urgency (-0.2; P < .001). Steroid-free remission at day 14, 28, and 56 was achieved in 25%, 30.2%, and 29.2% of patients, respectively. Neither prior biologics nor endoscopic severity were independently predictive of response or remission in multivariate models. Numeric improvements in all PROMIS measures (anxiety, depression, social satisfaction) were seen through day 56. Rates of discontinuation due to adverse events were low.

CONCLUSIONS

In this prospective real-world study, tofacitinib resulted in a rapid and persistent improvement in UC disease activity PROs. The safety findings were consistent with the established safety profile of tofacitinib.

Direct endoscopic placement of percutaneous endoscopic gastrostomies with jejunal extension tubes (PEG-J) using ultra-thin endoscopes - long-term outcomes from a U.S. tertiary referral center

INTRODUCTION

Several techniques for PEG-J tube placement have been described, commonly requiring fluoroscopic guidance and/or fixation of the jejunostomy tube (J-tube) into the small intestine. We describe a modified technique for placing jejunostomy tubes under direct visualization through a PEG with the use of ultra-thin endoscopes and steel guidewire.

METHODS

A retrospective study at a single tertiary academic center evaluating patients who underwent PEG-J placement between 2010 and 2020. All PEG tubes were placed with a pull-through technique. The Olympus GIF-N180 endoscope was advanced through the PEG to the jejunum and a Savary-Gilliard guidewire was used for placement of the J-tube extension.

RESULTS

Fifty-eight patients underwent PEG-J placement (median age 61 years; women 52%). Surgically altered gastric anatomy was observed in 11 patients (19%). Median procedure time was 44 min for new PEG-J tube placement (range 26-103) and 20 min for placement of a J-tube extension through an existing PEG tube (range 9-86) or gastrostomy tract. Technical success rate was in 100%. Sixty-two repeat procedures were performed for J-tube exchange in 27 patients (46%, range 1-9 per patient), of which 51 procedures (82%) were done using the same technique. The most common indication for tube replacement was tube dysfunction (63%, n = 39). The median procedure time for tube exchange was 20 min (range 2-62). No major adverse events were encountered.

CONCLUSION

PEG-J tubes can be placed effectively, rapidly, and safely using an ultra-thin caliber endoscope and a stiff steel wire through the PEG tube or mature gastrostomy site, precluding the need for fluoroscopy or oral access. J-tubes can be easily replaced utilizing the same technique.

Exploring Cost Savings with Specialty Biologic Drugs Administered to Adult Inpatients with Inflammatory Bowel Disease

Background: Specialty infusion and self-injectable biologic drugs for the treatment of inflammatory bowel disease (IBD) are high-cost medications. When administered to hospital-admitted patients, these medications are not reimbursed on an individual basis but rolled into a per diem payment by most payers in the United States (US). Therefore, choosing to administer these medications in the inpatient setting may reveal negative financial implications for some health care institutions. Selecting an alternative site of care to administer these medications during the clinical management process may lead to cost savings. Objective: Review the clinical necessity of inpatient specialty biologic administrations for the treatment of IBD to identify and quantify potential cost saving opportunities. Methods: Using patient medical records at a US academic medical center, we retrospectively identified inpatient administrations of specialty infusion and self-injectable biologic medications for IBD treatment from June 1, 2016 to May 31, 2017. Guided by a standardized form, an evaluation team consisting of 3 of the investigators determined the clinical necessity of each specialty biologic medication administration within the inpatient setting. Costs and reimbursement rates for administration in both the inpatient and outpatient settings were procured and tabulated. Results: Seventeen inpatient specialty biologic administrations for IBD during the 12 month study period were identified. Of these, 11 administrations were given for the treatment of Crohn's disease (CD) and 6 for ulcerative colitis (UC). The evaluation team determined that 65% of these administrations were clinically necessary as inpatient administrations, and that 35% were not. The sum of the wholesale acquisition costs (WAC) for clinically necessary inpatient biologic administrations totaled $54 737, and the WAC for those administrations deemed not clinically necessary totaled $43 702. Further analysis of administration events revealed that the institution could have realized an estimated $13 817 in additional revenue above the cost of the drug if eligible inpatient biologic administrations had been received in the institution's outpatient clinic setting instead. Conclusion: Administering specialty biologic drugs for the treatment of IBD in the care setting best aligned with existing reimbursement structures may lead to institutional cost savings.

OR19-05 Steroid:Corticosteroid-Binding Globulin Interactions; Effects of Neutrophil Elastase Cleavage, Pyrexia and Acidosis

Context Corticosteroid-binding globulin (CBG) transports cortisol and other steroid hormones^1,2. High-affinity CBG (haCBG) undergoes proteolysis of the reactive centre loop (RCL) by neutrophil elastase (NE) at inflammatory sites, liberating immunomodulatory cortisol and altering conformation to low-affinity CBG (laCBG). Pyrexia reduces CBG:cortisol binding affinity, an interaction at the RCL is speculated³. Objective To measure the equilibrium binding constants of a panel of steroids to glycosylated haCBG and laCBG over temperature and pH ranges mimicking the pathophysiological conditions of septic shock. Design Surface plasmon resonance was used to determine the binding profiles of 19 steroid ligands to haCBG and laCBG at temperatures 25°C, 37°C and 39°C and pH 7.4 and 7.0. The RCL-recognizing 9G12 antibody was used to assess cleavage and epitope availability of the RCL across conditions. Results A 4–8 fold reduction in affinity for cortisol, cortisone, corticosterone, 11-deoxycortisol, progesterone, 17-hydroxyprogesterone and prednisolone occurred with NE-mediated haCBG-to-laCBG conversion, cortisol expectedly displayed the highest binding affinity. Binding affinity consistently decreased at higher temperatures and at acidic pH for both haCBG and laCBG. 9G12 antibody RCL binding was preserved for haCBG across temperatures. Conclusions These studies reveal that steroid binding to CBG is selective and in all cases reduced upon NE-mediated haCBG-to-laCBG transition. Moreover, reduced CBG:cortisol binding affinity at elevated temperature occurs with an intact and accessible RCL epitope, suggesting a non-RCL mechanism for the delivery of anti-inflammatory cortisol in pyrexia. Synergy of NE cleavage and pyrexia/acidosis may serve for local inflammatory site cortisol delivery and increase free cortisol. These findings demonstrate the modifiable hormone binding characteristics of CBG in (patho-)physiological conditions, supporting its significance in cortisol delivery in obviating systemic inflammation and multiorgan-organ failure in patients with septic shock and its association with mortality⁴.

1. Pemberton PA, Stein PE, Pepys MB, et al. Hormone binding globulins undergo serpin conformational change in inflammation. Nature. 1988;336(6196):257–258.

2. Pugeat MM, Dunn JF, Nisula BC. Transport of steroid hormones: interaction of 70 drugs with testosterone-binding globulin and corticosteroid-binding globulin in human plasma. J Clin Endocrinol Metab. 1981;53(1):69–75.

3. Cameron A, Henley D, Carrell R, et al. Temperature-responsive release of cortisol from its binding globulin: a protein thermocouple. J Clin Endocrinol Metab. 2010;95(10):4689–4695.

4. Meyer EJ, Nenke MA, Rankin W, et al. Total and high-affinity corticosteroid-binding globulin depletion in septic shock is associated with mortality. Clin Endocrinol (Oxf). 2019;90(1):232–240.

Methotrexate Is Not Superior to Placebo in Maintaining Steroid-Free Response or Remission in Ulcerative Colitis

BACKGROUND & AIMS

Parenteral methotrexate induces clinical remission but not endoscopic improvement of mucosal inflammation in patients with ulcerative colitis (UC). We performed a randomized, placebo-controlled trial to assess the efficacy of parenteral methotrexate in maintaining steroid-free response or remission in patients with UC after induction therapy with methotrexate and steroids.

METHODS

We performed a 48-week trial, from February 2012 through May 2016, of 179 patients with active UC (Mayo score of 6-12 with endoscopy subscore ≥ 2) despite previous conventional or biological therapy. The study comprised a 16-week open label methotrexate induction period followed by a 32-week double-blind, placebo-controlled maintenance period. Patients were given subcutaneous methotrexate (25 mg/wk) and a 12-week steroid taper. At week 16, steroid-free responders were randomly assigned to groups that either continued methotrexate (25 mg/wk, n = 44) or were given placebo (n = 40) until week 48. We compared the efficacy of treatment by analyzing the proportion of patients who remained relapse free and were in remission at week 48 without use of steroids or other medications to control disease activity.

RESULTS

Ninety-one patients (51%) achieved response at week 16, and 84 patients were included in the maintenance period study. During this period, 60% of patients in the placebo group (24/40) and 66% in the methotrexate group (29/44) had a relapse of UC (P = .75). At week 48, 30% of patients in the placebo group (12/40) and 27% of patients in the methotrexate group (12/44) were in steroid-free clinical remission without need for additional therapies (P = .86). No new safety signals for methotrexate were detected.

CONCLUSIONS

Parenteral methotrexate (25 mg/wk) was not superior to placebo in preventing relapses of UC in patients who achieved steroid-free response during induction therapy. ClinicalTrials.gov, Number: NCT01393405.

Indigenous Health: ACTION on Prevention - 50th annual Australian Society for Medical Research National Scientific Conference

The 50th annual National Scientific Conference of the Australian Society for Medical Research was held in Cairns, Queensland, 13-16 November 2011. The theme, 'Indigenous Health: ACTION on Prevention' highlighted the direct action being undertaken by health and medical researchers, as well as allied health professionals, to improve long-term health outcomes for Indigenous Australians.

Identification of adeno-associated viral vectors suitable for intestinal gene delivery and modulation of experimental colitis

Effective gene transfer with sustained gene expression is an important adjunct to the study of intestinal inflammation and future therapy in inflammatory bowel disease. Recombinant adeno-associated virus (AAV) vectors are ideal for gene transfer and long-term transgene expression. The purpose of our study was to identify optimal AAV pseudotypes for transduction of the epithelium in the small intestine and colon, which could be used for studies in experimental colitis. The tropism and transduction efficiencies of AAV pseudotypes 1-10 were examined in murine small intestine and colon 8 wk after administration by real-time PCR and immunohistochemistry. The clinical and histopathological effects of IL-10-mediated intestinal transduction delivered by AAVrh10 were examined in the murine IL-10⁻/⁻ enterocolitis model. Serum IL-10 levels and IL-10 expression were followed by ELISA and real-time PCR, respectively. AAV pseudotypes 4, 7, 8, 9, and 10 demonstrated optimal intestinal transduction. Transgene expression was sustained 8 wk after administration and was frequently observed in enteroendocrine cells. Long-term IL-10 gene expression and serum IL-10 levels were observed following AAV transduction in an IL-10-/- model of enterocolitis. Animals treated with AAVrh10-IL-10 had lower disease activity index scores, higher colon weight-to-length ratios, and lower microscopic inflammation scores. This study identifies novel AAV pseudotypes with small intestine and colon tropism and sustained transgene expression capable of modulating mucosal inflammation in a murine model of enterocolitis.

Randomized, controlled trial of standard, large-capacity versus jumbo biopsy forceps for polypectomy of small, sessile, colorectal polyps

BACKGROUND

Polypectomy with cold biopsy forceps is a frequently used technique for removal of small, sessile, colorectal polyps. Jumbo forceps may lead to more effective polypectomy because of the larger size of the forceps cup.

OBJECTIVE

To evaluate the efficiency of cold jumbo biopsy forceps compared with standard forceps for polypectomy of small, sessile, colorectal polyps.

DESIGN

Randomized, controlled trial.

SETTING

Outpatient endoscopy center.

PATIENTS

This study involved 140 patients found to have at least one eligible polyp defined as a sessile polyp measuring ≤6 mm.

INTERVENTION

Polypectomy with cold biopsy forceps.

MAIN OUTCOME MEASUREMENTS

Complete visual polyp eradication with one forceps bite.

RESULTS

In 140 patients, a total of 305 eligible polyps were detected (151 removed with jumbo forceps and 154 with standard forceps). Complete visual eradication of the polyp with one forceps bite was achieved in 78.8% of the jumbo forceps group and 50.7% of the standard forceps group (P < .0001). Biopsies from the polypectomy sites of adenomatous polyps thought to be visually completely eradicated with one bite showed a trend toward a higher complete histologic eradication rate with the jumbo forceps (82.4%) compared with the standard forceps (77.4%), but the difference did not reach statistical significance (P = .62). The withdrawal time for visual inspection of the colon and time to perform polypectomies were significantly shorter in the jumbo forceps group (mean 21.43 vs 18.23 minutes; P = .02).

LIMITATIONS

Lack of blinding to the type of forceps used.

CONCLUSION

The jumbo biopsy forceps is superior to the standard forceps in removing small, sessile polyps. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT00855790.).

Diagnostic value of noninvasive combined fluorine-18 labeled fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography enterography in active Crohn's disease

BACKGROUND

The role of combined localized positron emission tomography (lPET) and computed tomography enterography (CTe) in Crohn's disease is unclear. We examined if this imaging modality using fluorine-18 labeled-fluoro-2-deoxy-D-glucose (FDG) could more effectively identify disease activity.

METHODS

52 lPET-CTe scans were analyzed in this retrospective study. CTe scores and FDG uptake were quantified. Correlations of CTe scores and standard uptake value (SUV) with C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), short Inflammatory Bowel Disease Questionnaire (sIBDq), and Harvey-Bradshaw index (HBI) were estimated using Pearson analysis. Imaging scores were compared to medical outcome by logistics regression model.

RESULTS

CTe scores correlated with SUV, but additional abnormal segments of small bowel were not identified. In all, 38 (79%) abnormal CTe segments demonstrated increased FDG uptake with mean SUVmax 4.77; 10 (21%) abnormal CTe segments lacked FDG accumulation, with mean SUVmax 1.27. There was no correlation between SUVmax and CRP, ESR, sIBDq, or HBI. There were no significant differences in clinical indices, biochemical parameters, and presence of multiple abnormal segments between medical responders and uptake were associated with failed medical therapy (P = 0.001).

CONCLUSIONS

PET scanning added to CTe did not identify additional abnormal segments when compared to CTe alone. Abnormal segments with mucosal enhancement on CTe that did not accumulate FDG were significantly associated with failure of medical therapy. A larger trial is warranted to confirm if combined lPET-CTe has an important role in the clinical management of stricturing Crohn's disease.

Colorectal cancer surveillance in inflammatory bowel disease: The search continues

Patients with inflammatory bowel disease (IBD) are at increased risk for colorectal cancer (CRC). Risk factors for the development of CRC in the setting of IBD include disease duration, anatomic extent of disease, age at time of diagnosis, severity of inflammation, family history of colon cancer, and concomitant primary sclerosing cholangitis. The current surveillance strategy of surveillance colonoscopy with multiple random biopsies most likely reduces morbidity and mortality associated with IBD-related CRC. Unfortunately, surveillance colonoscopy also has severe limitations including high cost, sampling error at time of biopsy, and interobserver disagreement in histologically grading dysplasia. Furthermore, once dysplasia is detected there is disagreement about its management. Advances in endoscopic imaging techniques are already underway, and may potentially aid in dysplasia detection and improve overall surveillance outcomes. Management of dysplasia depends predominantly on the degree and focality of dysplasia, with the mainstay of management involving either proctocolectomy or continued colonoscopic surveillance. Lastly, continued research into additional chemopreventive agents may increase our arsenal in attempting to reduce the incidence of IBD-associated CRC.

Gene delivery to intestinal epithelial cells in vitro and in vivo with recombinant adeno-associated virus types 1, 2 and 5

Intestinal disorders such as inflammatory bowel disease (IBD) result in chronic illness requiring lifelong therapy. Our aim was to evaluate the efficacy of recombinant adeno-associated virus (AAV) vector-mediated gene delivery to intestinal epithelial cells in vitro and in vivo. Human colon epithelial cell lines and colon biopsies were transduced using AAV pseudotypes 2/1, 2/2, and 2/5 encoding green fluorescence protein (GFP). Mice were administered the same vectors through oral, enema, intraperitoneal (IP) injection and superior mesenteric artery (SMA) injection routes. Tropism and efficiency were determined by microscopy, flow cytometry, immunohistochemistry and PCR. Caco2 cells were more permissive to AAV transduction. Human colon epithelial cells in organ culture were more effectively transduced by AAV2/2. SMA injection provided the most effective means of vector gene transfer to small intestine and colonic epithelial cells in vivo. Transgene detection 80 days post AAV treatment suggests transduction of crypt progenitor cells. This study shows the feasibility of AAV-mediated intestinal gene delivery, applicable for the investigation of IBD pathogenesis and novel therapeutic options, but also revealed the need for further studies to identify more efficient pseudotypes.

Endoscopy/surveillance in inflammatory bowel disease

Patients with chronic colitis from inflammatory bowel disease (IBD) have an increased risk of colorectal cancer (CRC). Previously, to ameliorate this, prophylactic total colectomy was offered to patients who had chronic ulcerative colitis (UC); however, research has identified less invasive management options through better understanding of the pathogenesis of cancer in chronic inflammation, a more uniform histologic diagnosis by pathologists, and proper surveillance colonoscopy techniques. This article reviews the pathogenesis of neoplasia in IBD, and then reviews the risk factors for CRC in IBD, surveillance guidelines and their limitations, surveillance techniques, ileal pouch dysplasia, and chemoprevention. Although data for CRC risk in Crohn's disease (CD) are not as extensive, it has been suggested that the risks are comparable to UC.

A multi-protein complex containing cold shock domain (Y-box) and polypyrimidine tract binding proteins forms on the vascular endothelial growth factor mRNA. Potential role in mRNA stabilization

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis and post-transcriptional regulation plays a major role in VEGF expression. Both the 5'- and 3'-UTR are required for VEGF post-transcriptional regulation but factors binding to functional sequences within the 5'-UTR have not been fully characterized. We report here the identification of complexes, binding to the VEGFmRNA 5'- and 3'-UTR, that contain cold shock domain (CSD) and polypyrimidine tract binding (PTB) RNA binding proteins. Analysis of the CSD/PTB binding sites revealed a potential role in VEGF mRNA stability, in both noninduced and induced conditions, demonstrating a general stabilizing function. Such a stabilizing mechanism had not been reported previously for the VEGF gene. We further found that the CSD/PTB-containing complexes are large multiprotein complexes that are most likely preformed in solution and we demonstrate that PTB is associated with the VEGF mRNA in vivo. Complex formation between CSD proteins and PTB has not been reported previously. Analysis of the CSD/PTB RNA binding sites revealed a novel CSD protein RNA recognition site and also demonstrated that CSD proteins may direct the binding of CSD/PTB complexes. We found the same complexes binding to an RNA-stabilizing element of another growth factor gene, suggesting a broader functional role for the CSD/PTB complexes. Finally, as the VEGF gene is also regulated at the transcriptional level by CSD proteins, we propose a combined transcriptional/post-transcriptional role for these proteins in VEGF and other growth factor gene regulation.

Impaired class II expression and antigen uptake in monocytic cells after HIV-1 infection

Using the human macrophage hybridoma cell line 43 and primary monocytes, we investigated the regulation of class II expression and intracellular Ag trafficking after HIV-1 infection. The HIV-1-infected human macrophage hybridoma cell line, 43HIV, lost class II Ag expression, as determined by immunofluorescence, immunoprecipitation, and Northern blot analysis, 2 wk after infection. Class II expression could be restored by transfection with the full-length HLA-DR4 cDNA driven by a CMV IE promotor. However, even after transfection, the 43HIV cells were incapable of presenting Ag to MHC-matched Ag-specific T cells. This defect was associated with decreased formation of class II-Ag complexes, and similar findings were observed in primary HIV-1BaL-infected monocytes. We investigated Ag uptake using FITC-labeled tetanus, OVA, and keyhole limpet hemocyanin. There was decreased uptake of all three Ags after HIV-1 infection at different time points after Ag pulsing in the 43HIV cells and in primary HIV-1BaL-infected monocytes. There was colocalization of the FITC-labeled Ags with early (cathepsin D) and late endosomal markers (anti-mannose-6-phosphate receptor), lysosomal markers (CD-63), and acidic compartment markers (3-(2,4-dinitroanilino)-3'-amino-N-methyldipropylamine) in the uninfected cells, but the level of colocalized Ag was reduced in the 43HIV cells and HIV-1BaL-infected monocytes. Our data suggest that class II expression, formation of class II-Ag complexes, and Ag uptake are impaired in chronically HIV-1-infected monocytic cells, which may contribute to the global immunosuppression observed in AIDS.

Impaired class II expression and antigen uptake in monocytic cells after HIV-1 infection

Using the human macrophage hybridoma cell line 43 and primary monocytes, we investigated the regulation of class II expression and intracellular Ag trafficking after HIV-1 infection. The HIV-1-infected human macrophage hybridoma cell line, 43HIV, lost class II Ag expression, as determined by immunofluorescence, immunoprecipitation, and Northern blot analysis, 2 wk after infection. Class II expression could be restored by transfection with the full-length HLA-DR4 cDNA driven by a CMV IE promotor. However, even after transfection, the 43HIV cells were incapable of presenting Ag to MHC-matched Ag-specific T cells. This defect was associated with decreased formation of class II-Ag complexes, and similar findings were observed in primary HIV-1BaL-infected monocytes. We investigated Ag uptake using FITC-labeled tetanus, OVA, and keyhole limpet hemocyanin. There was decreased uptake of all three Ags after HIV-1 infection at different time points after Ag pulsing in the 43HIV cells and in primary HIV-1BaL-infected monocytes. There was colocalization of the FITC-labeled Ags with early (cathepsin D) and late endosomal markers (anti-mannose-6-phosphate receptor), lysosomal markers (CD-63), and acidic compartment markers (3-(2,4-dinitroanilino)-3'-amino-N-methyldipropylamine) in the uninfected cells, but the level of colocalized Ag was reduced in the 43HIV cells and HIV-1BaL-infected monocytes. Our data suggest that class II expression, formation of class II-Ag complexes, and Ag uptake are impaired in chronically HIV-1-infected monocytic cells, which may contribute to the global immunosuppression observed in AIDS.

Altered cytokine production and accessory cell function after HIV-1 infection

We investigated cytokine production and accessory cell function in human macrophage hybridoma cell lines and primary monocytes after infection with HIV-1. HIV-1 infection induced IL-10 production in the macrophage hybridoma cell line with loss of IL-12 1 wk after infection. There were also significant increases in production of IL-10 (537 +/- 521 vs 687 +/- 625 pg/ml) while there was a reduction in IL-12 (6.3 +/- 3.1 vs 1.2 +/- 1.0 pg/ml, p = 0.021) in the primary monocytes 5 days after HIV-1 infection. In addition, the hybridoma cell lines and primary monocytes failed to support PHA, Con A, PWM, or anti-CD3- induced T cell proliferation 1 wk after infection. The viability of the T cells cocultured with the HIV-1-infected macrophage cell lines or the primary monocytes as determined by propidium iodide staining was unaltered and there was no increase in apoptosis-specific DNA strand breaks or increased expression of Bcl-2 in the T cells. No soluble suppressor factor was present, since UV-inactivated supernatants from the hybridoma cell line and primary monocytes failed to inhibit mitogen- and anti-CD3-induced T cell proliferation. Early events in T cell activation, including calcium flux and phosphotyrosine kinase activity, were intact in the T cells cocultured with the HIV-1- infected hybridomas and monocytes but there was reduced IL-2 production. Addition of exogenous IL-2 restored the proliferative responses. Taken together, these data suggest that alteration of cytokine production and accessory cell function for mitogens and anti-CD3-induced T cell proliferation independent of induction of apoptosis, suppressor factor production, or inhibition of T cell signaling occurs very early after HIV-1 infection and may contribute to the global immunosuppression observed in AIDS.

Altered cytokine production and accessory cell function after HIV-1 infection

We investigated cytokine production and accessory cell function in human macrophage hybridoma cell lines and primary monocytes after infection with HIV-1. HIV-1 infection induced IL-10 production in the macrophage hybridoma cell line with loss of IL-12 1 wk after infection. There were also significant increases in production of IL-10 (537 +/- 521 vs 687 +/- 625 pg/ml) while there was a reduction in IL-12 (6.3 +/- 3.1 vs 1.2 +/- 1.0 pg/ml, p = 0.021) in the primary monocytes 5 days after HIV-1 infection. In addition, the hybridoma cell lines and primary monocytes failed to support PHA, Con A, PWM, or anti-CD3- induced T cell proliferation 1 wk after infection. The viability of the T cells cocultured with the HIV-1-infected macrophage cell lines or the primary monocytes as determined by propidium iodide staining was unaltered and there was no increase in apoptosis-specific DNA strand breaks or increased expression of Bcl-2 in the T cells. No soluble suppressor factor was present, since UV-inactivated supernatants from the hybridoma cell line and primary monocytes failed to inhibit mitogen- and anti-CD3-induced T cell proliferation. Early events in T cell activation, including calcium flux and phosphotyrosine kinase activity, were intact in the T cells cocultured with the HIV-1- infected hybridomas and monocytes but there was reduced IL-2 production. Addition of exogenous IL-2 restored the proliferative responses. Taken together, these data suggest that alteration of cytokine production and accessory cell function for mitogens and anti-CD3-induced T cell proliferation independent of induction of apoptosis, suppressor factor production, or inhibition of T cell signaling occurs very early after HIV-1 infection and may contribute to the global immunosuppression observed in AIDS.

Radiocesium body burdens in immigrants to Israel from areas of the Ukraine, Belarus and Russia near Chernobyl

Of the 500,000 immigrants from the former Soviet Union who came to Israel during 1990-1993, about 100,000 are estimated to have come from radiocontaminated areas near Chernobyl. These people were subject to chronic uptake of environmental radiocesium over protracted periods. During October-November 1991, a joint Israeli-Canadian investigation measured radiocesium body burdens in immigrants to Israel from the Ukraine, Belarus, and the southern Russian republic in order to provide factual information on radiocesium levels to concerned immigrants and to relate the body burdens to the geographic area of residence before coming to Israel. Assessments were made of 137Cs body burdens in 1,228 volunteer men, women, and children. These measurements were accompanied by medical assessments based on clinical histories and examinations. Radiocesium levels were strongly dependent on the duration of residence in Israel, with the highest levels being found in the most recent immigrants. The maximum level, extrapolated back to the time of leaving the former Soviet Union, was estimated to be about 0.83 kBq (10.3 Bq kg-1). Of the most recent immigrants from the Kiev region (< 101 days in Israel), only 15% had back extrapolated body burdens > 50 Bq, whereas 53% of those coming from Gomel and other towns in the contaminated zones (> 3.7 x 10(10) Bq km-2 of radiocesium) had detectable levels > 50 Bq. People coming from the latter region had significantly higher body burdens as compared to those from the former, in accordance with the higher degree of ground radiocesium contamination reported for the latter region. Women and children showed considerably lower total radiocesium content in comparison to men. All radiocesium body burdens at the time of measurement were too low to be of health concern.

Reticulo-fibroblastoid stromal cell progenitors (CFU-RF) in murine bone marrow

The hemopoietic inductive microenvironment (HIM) of the bone marrow is responsible for secretion of growth factors that regulate hemopoiesis. It is composed of an extracellular matrix and a complex variety of cell types with a range of functions related to blood cell development. In order to understand how such a complex system operates, it will first be necessary to determine the role(s) of the integral parts. Several of the stromal cell types have been identified morphologically in various culture systems, and some of their functions have been elucidated. We have identified a new stromal cell type in mouse bone marrow that appears similar if not identical to its human counterpart. When bone marrow cells are placed in methylcellulose/plasma clot culture with phytohemagglutinin-stimulated human leukocyte-conditioned medium in the presence of bovine calf serum (BCS), mercaptoethanol, and hydrocortisone, extensive branching colonies develop within 14 days. These "reticulo-fibroblastoid" (RF) colonies arise from a putative reticulo-fibroblastoid colony-forming unit (CFU-RF) stem cell, and many become adipocytic by day 14; the addition of fresh medium, methylcellulose, and BCS on day 7 inhibits this change. The batch of human citrated plasma used in the culture system and the type and source of stimulating factor all influence the number of RF colonies that develop as well as the percent of colonies that become adipocytic. Whether this adipogenesis represents functional maturity or terminal differentiation is not yet known. Information gained on the role of these RF cells in normal and impaired hemopoiesis should contribute to the elucidation of the complicated interactive role of the microenvironment in the support and modulation of hemopoiesis.