Long-lasting Clinical Remission Research Articles

Germline SAMD9/9L MDS Predisposition Syndromes Are Characterized By Complex Clonal Architecture and Lineage-Specific Escape Mechanisms Including Somatic Genetic Rescue in T and B Lymphocytes

Inherited bone marrow failure (BMF) and MDS predisposition syndromes have an intrinsic defect resulting in loss and/or dysfunction of hematopoietic stem and progenitor cells (HSPC). HSPC clones can escape this process by acquiring gene- or genome-level genetic changes (compensatory mutations or uniparental disomies (UPD)) thereby increasing cellular fitness. This process, referred to as somatic genetic rescue (SGR) has been shown to occur in >70% of patients with gain-of-function mutations in SAMD9 and SAMD9L (SAMD9/9L) genes, which are a common cause of early onset BMF and pediatric MDS with monosomy 7. It is unknown how SGR arises and in which cells it originates. Furthermore, little is known about the epistatic interactions of various rescue events. We aimed to address these questions by utilizing a newly established single cell (sc)-proteogenomic platform that can simultaneously detect single nucleotide variants (SNVs) and copy number variation (CNVs) in addition to protein expression. We applied this technology to study clonal architecture and cellular origins of SGR lesions in a cohort of clinically annotated SAMD9/9L-mutated (SAMD9/9Lmut) patients. We also asked if monosomy 7, traditionally assessed by karyotyping, can be also detected in peripheral blood (PB) of affected patients. We first performed whole exome and panel sequencing to characterize 67 germline SAMD9/9Lmut patients. Guided by this data, we designed a sc-proteogenomic panel with 69 amplicons specific to variants in SAMD9/9L and leukemia driver genes, and 250 amplicons covering high-frequency SNVs on chromosome 7q. For validation of initial findings, we developed a second panel targeting full coding regions of SAMD9/9L genes, and additional 7p SNVs allowing for a precise delineation of uniparental isodisomy 7q (UPD7q). We included oligonucleotide-conjugated antibodies specific to major hematopoietic antigens, including CD19, CD3, CD11b, CD38 and CD34. Using this panel, we analyzed 22 samples (15 bone marrow (BM) and 7 PB) of 10 patients enrolled in local biobanking protocols. On average, 3,845 high-quality cells were genotyped per sample, and we robustly identified SNVs, monosomy 7 and UPD7q changes in single cells. Somatic rescue SAMD9/9Lmut were found only in clones with normal (diploid) chromosome 7, UPD7q (containing two wild type SAMD9/9L alleles after mitotic recombination event) was a stand-alone clone, while monosomy 7 (SAMD9/9Lmut lost) occurred alone or together with leukemia driver mutations. We also detected lesions that were previously missed using routine clinical sequencing in 3 patients (somatic SAMD9/9Lmut or UPD7q). Most patients had branching clonal architecture (i.e., independent monosomy 7, UPD7q, and somatic SAMD9/9Lmut), while linear trajectories were rare (i.e., monosomy 7 à + leukemia driver mutation). Serial assessment of 4 patients with stable hematology (3 with monosomy 7 and 1 with an additional somatic SAMD9/9Lmut) for a period of up to 4.8 years, revealed stable clonal populations without acquisition of additional driver mutations. Quantification of clones in paired BM and PB in 4 patients demonstrated equal frequencies of monosomy 7 and somatic SAMD9/9Lmut in both compartments, demonstrating the utility of this assay in surveillance. Our findings were confirmed by sorting BM cells into different lineages followed by sequencing, error-corrected sequencing, and ddPCR. Finally, analysis of protein expression data revealed that while monosomy 7 is present exclusively in cells with myeloid phenotype, the SGR events can arise in lymphocyte lineage only; 4 patients carried clones with somatic SAMD9/9Lmut in CD3+ lymphocytes, and 2 patients had UPD7q clones in either CD3+ or CD19+ lymphocytes. These findings provide clues why most of the SGR events in patients do not result in long-lasting clinical remission since the genetic rescue can be restricted only to certain hematopoietic lineages. In conclusion, single cell proteogenomic analysis is useful for the understanding the mechanisms of clonal evolution in SAMD9/9L syndromes. This method also offers the opportunity for less invasive surveillance of karyotype abnormalities from peripheral blood in patients who are at high risk for MDS progression.

Efficacy and safety of PUVA and UVB-311 nm in psoriasis: single-center retrospective study

BACKGROUND:Psoriasis is a widespread, genetically determined immunemediated dermatosis of a multifactorial nature, characterized by a recurrent course with frequent associative damage to other organs and systems, which significantly reduces the quality of patients lives. For many years, phototherapy (PUVA and UVB-311 nm) has had one of the leading places in the treatment of moderate and severe psoriasis according to the world dermatological communities. However, with the advent of genetically engineered biological drugs, the frequency of its administration has significantly decreased.
 AIM:to evaluate the efficacy and safety of PUVA and UVB-311 nm in the treatment of moderate and severe psoriasis.
 MATERIALS AND METHODS:A retrospective study was conducted on the basis of the Federal State Institution Central polyclinic with the participation of 920 patients with moderate and severe psoriasis who received phototherapy (PUVA and UVB-311 nm) in the period from 2005 to 2021. The initial radiation dose was 0.51 J/cm2at PUVA and 0.10.2 J/cm2at UVB-311 nm with a gradual increase in the dose every 12 sessions by 0.5 J/cm2and 0.1 J/cm2, respectively. The treatment was carried out according to the method of four-time irradiation per week using the UV-7001K cabin (Waldmann, Germany).
 RESULTS:Among 920 patients there were 478 (52%) men and 442 (48%) women (aged 21 to 68 years). The average age of psoriasis onset is 345.2 years. The duration of the disease averaged 10.58.2 years. Vulgar psoriasis was observed in 756 (82%) patients, teardrop-shaped ― in 36 (4%), exudative ― in 73 (8%), inverse ― in 55 (6%). 249 (27%) were diagnosed with psoriatic arthritis. On average, the first phototherapy sessions were prescribed 2.11.6 years after the onset of the disease. The choice of phototherapy method depended on the severity of the process. Thus, with moderate psoriasis, patients were prescribed UVB-311 nm (n=473). The course consisted of 2535 sessions of radiation with a cumulative dose of 35.35.9 J/cm2. Clinical remission was observed in 93% of patients, significant improvement ― in 7%. The achieved clinical remission was maintained for 361194 days. In total, during the studied period, 149 people received 27 courses of UVB-therapy, 132 ― 24 courses, 53 ― 19 courses, 69 ― 15 courses, 58 ― 11 courses, 12 ― 7 courses. Multiple infiltrated plaques and refractory course of severe psoriasis was an indication for PUVA therapy (n=447). The course consisted of 2030 irradiation sessions with a cumulative dose of 81.514.3 J/cm2. Clinical remission was observed in 98% of patients, a significant improvement in 2%. 14 people received 23 courses, 21 ― 20 courses, 12 ― 19 courses, 227 ― 15 courses, 104 ― 13 courses, 33 ― 10 courses, 27 ― 4 courses, 9 ― 2 courses of PUVA. The achieved clinical remission was maintained for 420275 days. 12 (1.3%) patients cancelled PUVA prematurely due to the inability to take a photosensitizer. In other cases, the observed side effects were minor and did not cause discontinuation of therapy.
 CONCLUSION:PUVA and UVB-311 nm have demonstrated high efficacy and safety in the treatment of moderate and severe psoriasis. At the same time, it is necessary to conduct further research to improve the methods of phototherapy for faster achievement of long-lasting clinical remission, which will allow phototherapy to regain its leading position in the treatment of psoriasis, increasing the doctors trust and patients compliance.

Rituximab and Corticosteroid Effect on Desmoglein-Specific B Cells and Desmoglein-Specific T Follicular Helper Cells in Pemphigus

Pemphigus is an autoimmune blistering disease mediated by autoantibodies directed against desmogleins (DSGs). We recently showed that first-line treatment with rituximab (RTX) enables more patients to achieve long-lasting remission off therapy than corticosteroids alone. To understand the immunological mechanisms that mediate long-lasting clinical remission after RTX treatment, we analyzed the phenotype of DSG-specific memory B cells and DSG-specific T follicular helper cells by flow cytometry and measured antibody-secreting cells by enzyme-linked immune absorbent spot in patients treated with corticosteroids alone or RTX. This post hoc analysis of the RITUX3 trial showed that RTX induced a significant decrease of IgG-switched DSG-specific memory B cells. Accordingly, anti-DSG antibody-secreting cells were no longer detected in patients in complete remission after RTX. In contrast, corticosteroids did not modify the frequency or the phenotype of DSG-specific memory B cells, and anti-DSG antibody-secreting cells were still detected after treatment, even in patients in remission. Using peptide-HLADRB1∗0402 tetramer staining, we identified DSG-3-specific T follicular helper cells, which dramatically decreased after RTX, while remaining stable after corticosteroid treatment. Our findings suggest that long-lasting response to RTX in pemphigus relies on the decrease of DSG-specific circulating T follicular helper cells, which correlates with a sustained depletion of IgG-switched memory autoreactive B cells, leading to the disappearance of anti-DSG antibody-secreting cells.

Recent advances in inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is a group of chronic, relapsing disorders of the gastrointestinal (GI) tract that significantly affect patient's quality of life. The main goals of IBD treatment are long-lasting clinical remission without serious adverse events. The lack of fully effective treatment urges researchers to seek for new therapeutic strategies and design of novel anti-inflammatory compounds.In this review, we focus on the latest advances in the IBD therapy. We characterize the clinical efficacy and mechanism of action of stem cell-, antibody- and small molecule-based methods of treatment that already reached clinic or are currently evaluated in clinical studies. The scope of this article is on agents targeting interleukin 12 and 23, integrins α4β7 and αEβ7, mucosal vascular addressin cell adhesion molecule, janus kinases, sphingosine-1-phosphate and toll-like receptor 9. We also describe recent advances in the discovery of biomarkers in IBD.

Single-centre experience with anti-tumour necrosis factor treatment in budesonide-refractory microscopic colitis patients.

Microscopic colitis is an inflammatory bowel disease that causes chronic, watery diarrhoea. Microscopic colitis is usually effectively treated with budesonide, but some patients are refractory. Data on alternative treatments are sparse. The purpose of this study was to retrospectively evaluate outcome of microscopic colitis patients receiving anti-tumour necrosis factor therapy at our centre. Treatment results, including side effects, for all microscopic colitis patients receiving anti-tumour necrosis factor therapy were registered at week 12 and at end of follow-up. Clinical remission was defined as a mean of <3 stools and <1 watery stools/day/week and clinical response as a 50% reduction of mean stool frequency/day/week. Induction and maintenance treatment was either adalimumab or infliximab. The study cohort comprised 18 patients; mean age at diagnosis was 47 years (range 19-77). Ten and eight patients, respectively, received adalimumab and infliximab as first-line anti-tumour necrosis factor; seven patients received second-line anti-tumour necrosis factor due to non-response, loss of response or side effects. At week 12, 9/18 patients had achieved remission, 6/18 were responders and 3/18 were non-responders. Of the nine remission patients, 3/18 (16%) had long-lasting clinical remission post-induction therapy alone. Five patients (28%) (one first-line, four second-line anti-tumour necrosis factor) were in remission and one patient (6%) responded to maintenance treatment; follow-up was mean 22 (range 4-60) months. Six patients (33%) had minor, reversible side effects. Over half of budesonide-refractory microscopic colitis patients can achieve clinical remission or response on anti-tumour necrosis factor agents. Prospective studies are mandatory to evaluate the efficacy and safety of anti-tumour necrosis factor treatments in budesonide-refractory microscopic colitis.

Long-term follow up after switching from original infliximab to an infliximab biosimilar: real-world data.

Background:Several studies have reported positive efficacy outcomes for patients with inflammatory bowel disease treated with CT-P13, an infliximab biosimilar. Data from follow-up periods longer than 1 year are still scarce. Here, we assessed the long-term efficacy data, loss of response and safety after switching from infliximab to CT-P13 in patients with inflammatory bowel disease.Methods:This was a prospective single-center observational study involving patients with moderate-to-severe Crohn’s disease and ulcerative colitis switched from infliximab to CT-P13 treatment and reviewed up to 24 months. Efficacy and loss of response were measured using the Harvey–Bradshaw (HB) index and partial Mayo score for patients with Crohn’s disease and ulcerative colitis respectively. C-reactive protein, infliximab drug levels, adverse events and antidrug antibodies were also monitored throughout the study.Results:A total of 64 patients with Crohn’s disease and 36 patients with ulcerative colitis were included. Most of them (72%) remained on CT-P13. Overall, 28% of patients discontinued the therapy due to loss of response, adverse events or long-lasting clinical remission. Remission at 18 and 24 months occurred in 69.9% and 68.5% of patients, respectively. Dose increase was performed in 22% of patients, with remission being reached in 60% of them. HB index, partial Mayo score, C-reactive protein and infliximab drug levels did not show significant changes. Serious adverse events were reported in 14% of patients. Overall, two patients developed low levels of antidrug antibodies.Conclusions:Most of the patients switching from original infliximab were maintained on CT-P13 at 2 years of follow up with a good profile of efficacy and safety.

Development and Validation of a Confocal Laser Endomicroscopy-Based Score for In Vivo Assessment of Mucosal Healing in Ulcerative Colitis Patients.

Endoscopic monitoring is fundamental for evaluating the therapeutic response in IBD, but a validated endomicroscopic mucosal healing (MH) score is not available to date. However, confocal laser endomicroscopy (CLE) might define MH more precisely than conventional endoscopy. The major aim was to establish and validate an MH score for ulcerative colitis (UC), based on CLE. In an initial pilot study (n = 10), various CLE changes were analyzed for identification of reproducible criteria for establishing a CLE score. Four reproducible CLE criteria were implemented in a following validation study. Subsequently, active UC patients (n = 23, Mayo score ≥6) were prospectively included and underwent colonoscopy with CLE before and after 3 anti-TNF applications. Patients were clinically followed over a period of 3 years. The endomicroscopic MH score (eMHs; range, 0-4) was compared with histopathology and endoscopy scores from the same colonic location. The eMHs showed high sensitivity, specificity, and accuracy values (100% with 95% confidence interval [CI] of 15.81%-100%; 93.75% with 95% CI of 69.77%-99.84%, and 94.44%, respectively). The eMHs showed a good correlation with the histological Gupta score (rs = 0.82, P < 0.0001) and the endoscopic Mayo subscore (rs = 0.81%, P < 0.0001). Sixty percent of therapy responders presented an eMHs <1, which translated into long-lasting clinical remission and reduced hospitalization, steroid, and surgery need. CLE can accurately assess MH based on the newly developed and statistically validated eMHs in UC, and it is superior in predicting the long-lasting clinical outcome based on both descriptive and functional barrier imaging (NCT01417728).

Long-Term Treatment of Eosinophilic Esophagitis With Swallowed Topical Corticosteroids: Development and Evaluation of a Therapeutic Concept.

Swallowed topical corticosteroids (STCs) are efficacious in inducing and presumably maintaining remission in patients with active eosinophilic esophagitis (EoE). Hitherto, it has not been evaluated whether long-lasting remission can be achieved, and whether treatment can be stopped once patients have achieved this remission. Since 2007, EoE patients included into a large database at the Swiss EoE Clinics were put on STCs as induction/maintenance therapy. Disease activity was assessed on an annual basis. In patients who achieved long-lasting (≥6 months) clinical, endoscopic, and histological (=deep) remission, treatment was stopped. Data on all patients treated using this therapeutic strategy were analyzed retrospectively. Of the 351 patients, 33 (9.4%) who were treated with STCs achieved deep remission. Median age of remitters at disease onset was 32.6 years (interquartile range (IQR) 19.1-49.3), and diagnostic delay was 5.4 years (IQR 1.2-11.4). Deep remission was achieved after 89.0 weeks (IQR 64.6-173.8). Female gender was the only independent prognostic factor for achieving deep remission (odds ratio (OR) 2.518, 95% confidence interval (CI) 1.203-5.269). Overall, STCs were stopped after 104.7 weeks (IQR 65.5-176.6). No mucosal damage was observed upon histological examination. In 27 of the 33 remitters (81.8%), a clinical relapse occurred after a median of 22.4 weeks (95% CI 5.1-39.7). Six remitters (18.2%) did not experience a clinical relapse during a follow-up of 35.1 weeks (IQR 18.3-44.9). Hence, a total of 1.7% (6/351) patients were able to discontinue STCs in the long term. Long-term EoE treatment with STCs was well tolerated, but only a minority achieved deep remission. Female gender is the only prognostic factor for attainment of such remission. After treatment cessation, the majority experienced a clinical relapse.

Acute intermittent porphyria: Long-term follow up of 35 patients

Background and objectivesAcute intermittent porphyria (AIP) is a rare disease that results from a deficiency of porphobilinogen deaminase, the third enzyme of the heme biosynthetic pathway. AIP carriers are at risk of presenting acute neurovisceral attacks associated with overproduction of heme-precursors in the liver. Patients and methodWe report the characteristics of all AIP patients attended in the Hospital Clinic of Barcelona during the years 1993–2013 and their long-term follow-up. ResultsThirty-five AIP patients (33 women, 2 men) experienced acute attacks. Treatment with hemin resolved the acute neurovisceral crisis in all cases. Nine patients presented peripheral neuropathy and persistent sequelae. Long-term follow-up allowed classifying the patients into groups: A, patients with acute symptoms during 1–2 years and subsequent long-lasting clinical remission (n=24) or a few sporadic crises (n=3), and B, patients with recurrent attacks requiring chronic administration of hemin (n=8). In a majority of the patients of group A, the urinary excretion of heme-precursors decreased gradually over time. However, the chronic hemin regime did not induce a decline of urinary heme-precursors in the patients of group B. Additionally, we identified 44 asymptomatic AIP carriers, most (70.5%) with normal values of heme-precursors in urine. ConclusionsA majority of the AIP patients of our series achieved a long-lasting clinical remission. A minority (23%) presented recurrent attacks that required chronic hemin infusions without feasible interruption and without long-term biochemical remission. The type of mutation within the porphobilinogen deaminase gene and also life-style related factors may determine remission time-course.

Current and emerging treatment options for hairy cell leukemia

Hairy cell leukemia (HCL) is a lymphoproliferative B-cell disorder characterized by pancytopenia, splenomegaly, and characteristic cytoplasmic hairy projections. Precise diagnosis is essential in order to differentiate classic forms from HCL variants, such as the HCL-variant and VH4-34 molecular variant, which are more resistant to available treatments. The current standard of care is treatment with purine analogs (PAs), such as cladribine or pentostatin, which provide a high rate of long-lasting clinical remissions. Nevertheless, ~30%–40% of the patients relapse, and moreover, some of these are difficult-to-treat refractory cases. The use of the monoclonal antibody rituximab in combination with PA appears to produce even higher responses, and it is often employed to minimize or eliminate residual disease. Currently, research in the field of HCL is focused on identifying novel therapeutic targets and potential agents that are safe and can universally cure the disease. The discovery of the BRAF mutation and progress in understanding the biology of the disease has enabled the scientific community to explore new therapeutic targets. Ongoing clinical trials are assessing various treatment strategies such as the combination of PA and anti-CD20 monoclonal antibodies, recombinant immunotoxins targeting CD22, BRAF inhibitors, and B-cell receptor signal inhibitors.

Porfiria aguda intermitente: seguimiento a largo término de 35 pacientes

Background and objectivesAcute intermittent porphyria (AIP) is a rare disease that results from a deficiency of porphobilinogen deaminase, the third enzyme of the heme biosynthetic pathway. AIP carriers are at risk of presenting acute neurovisceral attacks associated with overproduction of heme-precursors in the liver. Patients and methodWe report the characteristics of all AIP patients attended in the Hospital Clinic of Barcelona during the years 1993-2013 and their long-term follow-up. ResultsThirty-five AIP patients (33 women, 2 men) experienced acute attacks. Treatment with hemin resolved the acute neurovisceral crisis in all cases. Nine patients presented peripheral neuropathy and persistent sequelae. Long-term follow-up allowed classifying the patients into groups: A, patients with acute symptoms during 1-2 years and subsequent long-lasting clinical remission (n=24) or a few sporadic crises (n=3), and B, patients with recurrent attacks requiring chronic administration of hemin (n=8). In a majority of the patients of group A, the urinary excretion of heme-precursors decreased gradually over time. However, the chronic hemin regime did not induce a decline of urinary heme-precursors in the patients of group B. Additionally, we identified 44 asymptomatic AIP carriers, most (70.5%) with normal values of heme-precursors in urine. ConclusionsA majority of the AIP patients of our series achieved a long-lasting clinical remission. A minority (23%) presented recurrent attacks that required chronic hemin infusions without feasible interruption and without long-term biochemical remission. The type of mutation within the porphobilinogen deaminase gene and also life-style related factors may determine remission time-course.

Is it really possible to cure hairy cell leukemia patients only with frontline therapy?

Hairy cell leukemia (HCL) patients could have an excellent prognosis with adequate treatment. Treatments are not generally curative but are extremely effective in inducing long-lasting clinical remissions. An observational retrospective study was conducted on a single-center registry of 144 patients with a median follow-up of 11.5years, focusing on long-lasting continuous first complete remissions (CR) wondering if patients can be cured only with front-line approach. CR for more than 5years after first-line therapy were found in 22.2% cases. The median duration of response was 9.8years, while for relapsed patients, the first response had a median duration of 2.4years. Three different subsets of long-lasting first CR were identified: 15 patients are between 5 and 10years with a median duration of CR of 6.5years; 7 patients are between 10 and 15years with a median duration of CR of 12.3years; and 10 patients present a follow-up superior to 15years with a median duration of CR of 20.0years. There is a need for continuous study in this field to better define the optimal therapeutic regimen and, in particular, the biological issues since at least 20-25% of HCL patients can be cured with only one treatment.

Detecting T-cell reactivity to whole cell vaccines

BCR-ABL+ K562 cells hold clinical promise as a component of cancer vaccines, either as bystander cells genetically modified to express immunostimulatory molecules, or as a source of leukemia antigens. To develop a method for detecting T-cell reactivity against K562 cell-derived antigens in patients, we exploited the dendritic cell (DC)-mediated cross-presentation of proteins generated from apoptotic cells. We used UVB irradiation to consistently induce apoptosis of K562 cells, which were then fed to autologous DCs. These DCs were used to both stimulate and detect antigen-specific CD8+ T-cell reactivity. As proof-of-concept, we used cross-presented apoptotic influenza matrix protein-expressing K562 cells to elicit reactivity from matrix protein-reactive T cells. Likewise, we used this assay to detect increased anti-CML antigen T-cell reactivity in CML patients that attained long-lasting clinical remissions following immunotherapy (donor lymphocyte infusion), as well as in 2 of 3 CML patients vaccinated with lethally irradiated K562 cells that were modified to secrete high levels of granulocyte macrophage colony-stimulating factor (GM-CSF). This methodology can be readily adapted to examine the effects of other whole tumor cell-based vaccines, a scenario in which the precise tumor antigens that stimulate immune responses are unknown.

High-dose cyclophosphamide and autologous hematopoieitic cell transplantation for inflammatory bowel disease – a single center experience

Background: Despite recent advances in immunosuppressive therapy, up to 10% of patients with severe inflammatory bowel disease remain refractory to conventional treatment. Recent studies show that immune ablation by high-dose immunsuppression and autologous peripheral blood hematopoietic cell transplantation (aPBHCT) may efficiently induce long-lasting clinical remission in autoimmune disease.

Argon plasma coagulation treatment of hemorrhagic radiation proctopathy: the optimal settings for application and long-term outcome

No standard treatment exists for hemorrhagic radiation proctopathy (HRP). Recently it was reported that argon plasma coagulation (APC) is effective for HRP. However, previous studies documented complications such as ulcers, strictures, and perforations in as many as 20% of APC-treated patients. The aim of this study was to determine the optimal parameters for APC by using swine rectum and to assess the safety and effectiveness of APC in HRP patients. Prospective case series. University teaching hospital. Sixty-five patients with HRP were prospectively enrolled between 2000 and 2010. APC for HRP. Optimal APC parameters, number of treatments, success rate, complications, clinical remissions. APC in swine rectal wall ex vivo was optimal with a 40-W current, 1.2-L/min gas flow rate, and 2-second application, which was sufficient to treat the submucosal telangiectasia but did not adversely affect the muscle layer. Sixty-five patients (46 men, 19 women; median age 72 years) with HRP occurring at a mean of 20 months after radiotherapy were studied. Proctopathy was classified as grade A (mild) in 7 patients (10.8%), grade B (moderate) in 41 (63.1%), and grade C (severe) in 17 (26.2%). The treatment success rate was 98.5% after a median of 2 (range 1-5) APC sessions. The median clinical score for rectal bleeding was significantly decreased after APC (P < .0001), and the hemoglobin level was significantly increased (P < .0001). APC was well tolerated, and no significant side effects or complications occurred. During a mean follow-up of 34.6 months (range 3.6 -121.1 months), 4 patients (6.3%) had minor recurrent rectal bleeding and 60 (93.8%) remained in remission. Nonrandomized study. HRP treatment with optimal APC settings yields a high success rate and long-lasting clinical remission with no significant complications.

Review article: stem cell therapies for inflammatory bowel disease – efficacy and safety

Drugs available for the treatment of inflammatory bowel disease fail to induce and maintain remission in a significant number of patients. To assess the value of stem cell therapies for treatment of inflammatory bowel disease based on published studies. Publications were identified through a MEDLINE search using the Medical Subject Heading terms: inflammatory bowel diseases, or Crohn's disease, or ulcerative colitis, and stem cell, or stromal cell or transplant. Haematopoietic stem cell therapy as a primary treatment for inflammatory bowel disease was originally supported by animal experiments, and by remissions in patients undergoing transplant for haematological disorders. Later, transplantation specifically performed for patients with refractory Crohn's disease showed long-lasting clinical remission and healing of inflammatory intestinal lesions. Use of autologous nonmyeloablative regimens and concentration of the procedures in centres with large experience are key in reducing treatment-related mortality. Initial trials of mesenchymal stem cell therapy with local injection in Crohn's perianal fistulas had positive results. Autologous haematopoietic stem cell transplant changes the natural course of Crohn's disease, and may be a therapeutic option in patients with refractory disease if surgery is not feasible due to disease location or extension.

Oropharyngeal Pemphigus Vulgaris and Clinical Remission

The pattern of clinical remission in pemphigus vulgaris patients still remains a controversial issue because of the limited data reported in the literature. To evaluate the time to clinical remission in patients with exclusive oropharyngeal pemphigus vulgaris. We conducted a long-term, longitudinal study in a university hospital. We treated 37 patients with oropharyngeal pemphigus vulgaris, who underwent a periodic follow-up for an average of 5.3 years, and evaluated their outcome in terms of clinical remission. The main outcome measure was the clinical outcome (assessed by objective measures of severity, extent of disease, intensity of therapy, and remission) before and after conventional immunosuppressive therapy. Complete and long-lasting clinical remission was achieved in 35 patients (94.6%) with oropharyngeal lesions, of whom 13 (35.1%) were off therapy and 21 (56.8%) were on therapy at the last evaluation. One patient (2.7%) died following a stroke 3 years after complete remission on therapy. Partial remission was achieved in two patients (5.4%). The mean time to achieve complete clinical remission was 4.7 +/- 2.57 months after commencement of therapy. In all patients the mean disease severity score decreased from 7.81 +/- 1.35 at time of diagnosis to 1.0 +/- 0.9 at time of clinical remission (p < 0.0001 vs baseline), while the extent of the disease decreased from 2.9 +/- 1.0 to 0.27 +/- 0.45 (p < 0.0019 vs baseline) and the intensity of therapy from 4.91 +/- 0.64 to 0.70 +/- 0.57 (p < 0.0001 vs baseline). The mean duration of complete remission was 63.53 +/- 44.9 months. In almost all patients with oropharyngeal pemphigus vulgaris it was possible to schedule a safe tapering of the conventional immunosuppressive therapy very shortly after the disease was controlled. Thus, we may conclude that: (i) the percentage of patients with oropharyngeal pemphigus vulgaris who achieved complete long-lasting clinical remission was very high; (ii) transient lesions that healed within a week were very frequent and had to be actively controlled; (iii) if treated early, most patients had a good clinical response and could achieve a disease- and drug-free clinical remission; (iv) early treatment may prevent extension or progression of disease; (v) there is a possible role for immunosuppressive agents; and (vi) a more favorable course of the disease, in terms of attainment and duration of clinical remission and a better prognosis, seemed to be related to a rapid response to therapy rather than to the initial severity and extent of the disease.

Graft-Versus-Leukemia Antigen CML66 Elicits Coordinated B and T Cell Immunity After Donor Lymphocyte Infusion.

Abstract 2449Poster Board II-426Donor lymphocyte infusion (DLI) is a highly effective treatment for relapsed chronic myeloid leukemia (CML) after allogeneic hematopoietic stem cell transplantation (HSCT), in which 70-80% patients achieve curative responses. Despite its efficacy and established clinical use, the mechanism by which DLI achieves anti-tumor immunity remains incompletely understood. CML66 was discovered as an overexpressed nonpolymorphic CML-associated antigen that elicited a high-titer (>1:50,000) antibody response in a patient who received CD4+ DLI for relapsed CML. CML66 is preferentially expressed on myeloid leukemia progenitor cells and the development of CML66 antibodies temporally correlated with attainment of molecular remission. Since CD4+ T cell responses are involved in generating both antigen-specific B cell and CD8+T cell responses, we queried whether development of potent B cell immunity was also associated with the development of cytolytic T cell immunity against CML66. To detect specific T cell responses, post-DLI PBMC from this patient were screened for reactivity against pools of overlapping 15- to 18-mer peptides encoding the entire protein sequence of CML66. Patient CD8+ T cells were found to be reactive against a single CML66-derived peptide pool, and specifically an 8 amino acid peptide (HDVDALLW), beginning at residue 459. This T cell epitope is positioned in a different region of the protein compared to the B cell epitope (at residues 198-217: GFYVSLEWVTISKKNQDNK). A peptide-specific T cell clone was isolated, whose MHC class I molecule binding was restricted to HLA B*4403. The CML66-reactive T cell clone recognized the HLA-B4403-expressing CD34+ AML cell line MUTZ-3, providing evidence that this epitope is naturally processed and presented by myeloid leukemia cells. Functional cytotoxic T cell responses to CML66 appeared to precede the appearance of antigen-specific antibody responses. While CML66-specific plasma antibody was only detectable starting 2-3 months after DLI, reactivity to the HLA-B4403-restricted epitope by peripheral blood-derived CD8+ T cells was detected by IFNγ ELISpot as early as one month following DLI. To sensitively detect CD8+ CML66-specific T cells in vivo, we sequenced the CDR3 region specific to the CML66-specific clone, and designed clone-specific quantitative PCR primers. Nested PCR of RNA directly extracted from patient PBMC revealed only minimal detection of the CML66-specific T cell clone prior to DLI, but then expansion between 1 to 6 months after DLI. Similar analysis of marrow-derived RNA also revealed the presence of CML66-specific T cell clone in patient marrow following DLI. Moreover, this clone was already detected in patient marrow prior to DLI, suggesting that marrow is a reservoir of leukemia-specific T cells following hematopoietic stem cell transplantation. Our studies provide the first description of coordinated adaptive immunity developing against a nonpolymorphic leukemia-associated antigen, in close temporal correlation with the attainment of long-lasting immune-mediated clinical remission after allogeneic HSCT. The detected cytolytic T cell response was associated with the secretion of high-titer IgG antibody specific for a distinct epitope in the same target protein. In this setting, our results indicate that infusion of CD4+ donor cells resulted in the rapid activation and expansion of pre-existing marrow-resident leukemia-specific CD8+ T cells, followed by a cascade of antigen-specific immune responses detectable in the periphery. Disclosures:No relevant conflicts of interest to declare.

Argon plasma coagulation has a long-lasting therapeutic effect in patients with chronic radiation proctitis

The optimal treatment of bleeding due to radiation proctitis is still controversial. Although argon plasma coagulation (APC) has been recently reported as an effective treatment, its efficacy in relation to disease severity is unknown. The study aims were to prospectively evaluate (i) the efficacy of APC in endoscopically mild and severe radiation proctitis, and (ii) the recurrence rate following successful treatment. 56 patients (mean age 68.4 years) with radiation proctitis after radiotherapy for prostate cancer were studied. All presented with rectal bleeding, occurring a median 21.5 months after radiotherapy. Using an established scoring system, patients were classified into two groups, with mild or severe disease. We also examined the correlation between endoscopic severity and hemoglobin level as a more objective measure of bleeding activity. Success was defined either as cessation of bleeding or a significant reduction so that further treatment was not required. Proctitis was classified as mild in 27 patients (48%) and severe in 29 (52%). Endoscopically judged severity and hemoglobin level showed good correlation (R = 0.58). All patients with mild proctitis and 23/29 (79%) with severe disease were successfully treated (P < 0.05). During a follow-up of a mean of 17.9 months (range 6-33), 34/38 patients (89.5%) remained in clinical remission. Recurrence was higher in those using anticoagulant or aspirin (P = 0.02). APC is highly effective in all patients with mild radiation proctitis and in the majority of those with severe disease, providing long-lasting clinical remission.

Maintenance treatment with infliximab for the management of Crohn's disease in adults.

Crohn's disease (CD) is a chronic, relapsing disease, the continuous cycle of which deeply affects the long-term course which, eventually, leads to fibrosis and development of transmural complications. It is well known that CD is an immune-mediated clinical condition and that tumor necrosis factor-alpha (TNF-alpha) plays a fundamental role in the pathogenesis of the disease. Current clinical guidelines recommend that patients with mild to moderate active CD should be treated initially with corticosteroids. Although this approach is effective in inducing remission, some patients may become dependent on, or refractory to, these drugs in the long term, thus increasing the risk of developing steroid-related adverse effects. A recent Cochrane systematic review established that infliximab (IFX) is effective in inducing remission in patients with CD. Although only a few published studies have assessed IFX for the maintenance of remission in the long term, there is evidence that IFX is superior to placebo in sustaining clinical remission and fistula healing; moreover, corticosteroid-sparing effects have been demonstrated. IFX is associated with the formation of antibodies to IFX which can lead to infusion reactions and shorter duration of response, but when comparing episodic vs scheduled maintenance treatment, the latter appears to sensibly reduce immunogenicity, thus offering improved efficacy and tolerance. The final point to consider is the best time to introduce IFX in the therapeutic algorithm of CD. Early use of IFX has been suggested to be more effective than late, and may potentially change the natural history of the disease. Effective induction and maintenance therapy with IFX is the only means with which to maintain long-lasting clinical and mucosal remission which, in turn, may modify the long-term course of the disease. Furthermore, when treating inflammatory bowel disease patients with IFX, an appropriate risk-benefit balance has to be taken into consideration, because the precise risk of serious adverse events associated with anti-TNF treatment in CD remains to be fully elucidated.