Rewriting regulatory DNA to dissect and reprogram gene expression

Regulatory DNA sequences within enhancers and promoters bind transcription factors to encode cell type-specific patterns of gene expression. However, the regulatory effects and programmability of such DNA sequences remain difficult to map or predict because we have lacked scalable methods to precisely edit regulatory DNA and quantify the effects in an endogenous genomic context. Here we present an approach to measure the quantitative effects of hundreds of designed DNA sequence variants on gene expression, by combining pooled CRISPR prime editing with RNA fluorescence in situ hybridization and cell sorting (Variant-FlowFISH). We apply this method to mutagenize and rewrite regulatory DNA sequences in an enhancer and the promoter of PPIF in two immune cell lines. Of 672 variant-cell type pairs, we identify 497 that affect PPIF expression. These variants appear to act through a variety of mechanisms including disruption or optimization of existing transcription factor binding sites, as well as creation of de novo sites. Disrupting a single endogenous transcription factor binding site often led to large changes in expression (up to -40% in the enhancer, and -50% in the promoter). The same variant often had different effects across cell types and states, demonstrating a highly tunable regulatory landscape. We use these data to benchmark performance of sequence-based predictive models of gene regulation, and find that certain types of variants are not accurately predicted by existing models. Finally, we computationally design 185 small sequence variants (≤10 bp) and optimize them for specific effects on expression in silico. 84% of these rationally designed edits showed the intended direction of effect, and some had dramatic effects on expression (-100% to +202%). Variant-FlowFISH thus provides a powerful tool to map the effects of variants and transcription factor binding sites on gene expression, test and improve computational models of gene regulation, and reprogram regulatory DNA.

Domain adaptive neural networks improve cross-species prediction of transcription factor binding

The intrinsic DNA sequence preferences and cell type–specific cooperative partners of transcription factors (TFs) are typically highly conserved. Hence, despite the rapid evolutionary turnover of individual TF binding sites, predictive sequence models of cell type–specific genomic occupancy of a TF in one species should generalize to closely matched cell types in a related species. To assess the viability of cross-species TF binding prediction, we train neural networks to discriminate ChIP-seq peak locations from genomic background and evaluate their performance within and across species. Cross-species predictive performance is consistently worse than within-species performance, which we show is caused in part by species-specific repeats. To account for this domain shift, we use an augmented network architecture to automatically discourage learning of training species–specific sequence features. This domain adaptation approach corrects for prediction errors on species-specific repeats and improves overall cross-species model performance. Our results show that cross-species TF binding prediction is feasible when models account for domain shifts driven by species-specific repeats.

Comprehensive identification of mRNA isoforms reveals the diversity of neural cell-surface molecules with roles in retinal development and disease

Genes encoding cell-surface proteins control nervous system development and are implicated in neurological disorders. These genes produce alternative mRNA isoforms which remain poorly characterized, impeding understanding of how disease-associated mutations cause pathology. Here we introduce a strategy to define complete portfolios of full-length isoforms encoded by individual genes. Applying this approach to neural cell-surface molecules, we identify thousands of unannotated isoforms expressed in retina and brain. By mass spectrometry we confirm expression of newly-discovered proteins on the cell surface in vivo. Remarkably, we discover that the major isoform of a retinal degeneration gene, CRB1, was previously overlooked. This CRB1 isoform is the only one expressed by photoreceptors, the affected cells in CRB1 disease. Using mouse mutants, we identify a function for this isoform at photoreceptor-glial junctions and demonstrate that loss of this isoform accelerates photoreceptor death. Therefore, our isoform identification strategy enables discovery of new gene functions relevant to disease.

Ex vivo investigation of the effect of the transverse arytenoid ligament on abduction of the arytenoid cartilage when performing equine laryngoplasty

Aims: To investigate the effect of the transverse arytenoid ligament (TAL) on abduction of the arytenoid cartilage when performing laryngoplasty. Methods: Modified prosthetic laryngoplasty was performed on right and left sides of 13 cadaver larynges. Increasing force was sequentially applied to the left arytenoid cartilage at 3 N intervals from 0-24 N, when the force on the right arytenoid cartilage was either 0 or 24 N, before and after TAL transection. Digital photographs of the rostral aspect of the larynx were used to determine the left arytenoid abduction angles for these given force combinations and results compared before and after TAL transection. Longitudinal and transverse sections of the TAL from seven other equine larynges were also examined histologically. Results: Increasing force on the left arytenoid cartilage from 0-24 N produced a progressive increase in the angle of the left arytenoid cartilage (p < 0.001) and increasing force on the right arytenoid cartilage from 0-24 N reduced the angle of the left arytenoid cartilage (p < 0.001). Following transection of the TAL the mean angle of the left arytenoid increased from 36.7 (95% CI = 30.5-42.8)° to 38.4 (95% CI = 32.3-44.5)°. Histological examination showed that the TAL was not a discrete ligament between the arytenoid cartilages but was formed by the convergence of the ligament and the left and right arytenoideus transversus muscles. Conclusions: Transection of the TAL in ex vivo equine larynges enabled greater abduction of the left arytenoid cartilage for a given force. These results indicate that TAL transection in conjunction with prosthetic laryngoplasty may have value, but the efficacy and safety of TAL transection under load in vivo, and in horses clinically affected with recurrent laryngeal neuropathy must be evaluated. Abbreviations: F_max: Force needed to maximally abduct the left or right arytenoid; TAL: Transverse arytenoid ligament.

Is It Painful to Manage Chronic Pain? A Cross-Sectional Study of Physicians In-Training in a University Program

BACKGROUND

Prescribing opioids for chronic non-cancer pain (CNCP) is a challenge due to associated risks from abuse, addiction and adverse effects. We surveyed resident physicians on their knowledge, attitude and practices in opioid prescription practices in the ambulatory setting and conducted an educational module to address their knowledge gaps.

METHODS

A phase 1 survey assessed knowledge, attitudes and practices of residents in the out-patient management of CNCP with opioids. Demographics, numbers of patients seen, those with concerns for risky behaviors, adverse effects and the reasons for concern were also recorded. In Phase 2, an educational module in the form of didactics and case based discussions addressed the perceived deficiencies noted from results of phase 1 survey. Pre and post module surveys assessed the effectiveness of the educational module.

RESULTS

In the phase 1 study (45/49, 92% response rate, M:F = 30:15) 33.3% (15/45) were in Post-Graduate Year (PGY) 1, 35.6% (16/45) PGY2s and 31.1% (14/45) PGY3s; 80% (36/45) saw more than one patient with CNCP in the previous 3 months; 62.2% (28/45) had at least one patient with concerns for misuse and addiction; 77.8% (35/45) and 86.7% (39/45) reported a lack of training and consistent documentation respectively, and 82.2% (37/45) were uncomfortable to refill for other provider's patients. All (100%, 45/45) consulted the clinical pharmacist; 86.7% (39/45) believed that either focused education would be beneficial. In the phase 2 study (44/49, 89.7% response rate, M: F = 29: 15), the pre- and post-module responses showed that > 90% of the residents perceived improvement in knowledge and confidence in management of CNCP with opioids after the educational module.

CONCLUSIONS

Internal medicine residents perceived deficits in their ability to manage CNCP. Following a focused educational training, residents' knowledge and confidence in prescription of opioids improved, demonstrating the need to include management of CNCP with opioids into their curriculum.

First Report of Downy Mildew on Blackberry Caused by Peronospora sparsa in Arkansas

In March of 2014, blackberry (Rubus fruticosus) greenhouse seedlings with leaf symptoms that included yellowing on the leaf surface and reddish brown angular lesions with necrotic centers and chlorotic margins were detected in the University of Arkansas Fruit Research Station in Clarksville, AR (35°32.065' N, 93°24.3564' W). Symptoms were observed on multiple blackberries in the greenhouse, with an estimated prevalence of 25%. Three symptomatic samples of the affected plants were submitted to the Plant Health Clinic in Fayetteville, AR, for diagnosis. Sporulation was observed on the underside of the symptomatic leaf tissue. Hyaline sporangiophores were observed emerging from stomata on the undersides of leaves, 295 to 620 × 4 to 6 μm with long, straight trunks and were branched 3 to 4 times with bifurcated tips, with a length of 5 to 23 μm. Typically, one branch of each pair curved inward and one reflexed. Sporangiophores ended with sporangia that were round or slightly ovoid, colorless to yellowish-brown, and 14 to 22 × 11 to 18 μm. The causal agent was morphologically identified as Peronospora sparsa Berk (1,2). The identification was confirmed using a molecular method directly from plant tissue. DNA was extracted from two samples (~3 × 3 mm) from each of three symptomatic leaves, followed by PCR amplification using P. sparsa-specific rDNA-ITS region primers P1: 5'-CACGTGAACCGTATCAACC-3' and P2: 5'-GATAGGGCTTGCCCAGTAG-3' (GenBank Accession No. Y15816) (4). DNA amplification was successful, resulting in a product of 94 bp, confirming that P. sparsa was present in the symptomatic blackberry tissue. Sporulating leaf tissue was laid on the underside of surface sterilized blackberry leaves from three plants with a similar genetic background and incubated at 17°C with a 12-h photoperiod in a moist chamber. Sporangiophores and sporangia developed on the underside of lesions on previously uninfected leaves 16 days after inoculation. As a control, leaves from the same three plants were surface sterilized and placed in a moist chamber and incubated at 17°C with a 12-h photoperiod and examined 16 days later. No lesions or sporulation developed on the controls. Previously, P. sparsa has been reported on blackberry in California (3) and Mexico (5). To our knowledge, this is the first report of P. sparsa causing downy mildew on blackberry in Arkansas. References: (1) M. J. Berkeley. Gardeners' Chronicle 14:307, 1861. (2) M. A. Ellis. Page 15 in: Compendium of Raspberry and Blackberry Diseases and Insects. APS Press, St. Paul, MN, 1989. (3) D. Farr et al. Page 486 in: Fungi on Plants and Plant Products in the United States. APS Press, St. Paul, MN, 1989. (4) A. Hukkanen et al. Eur. J. Plant Pathol. 116:225, 2006. (5) A. Rebollar-Alviter et al. Plant Dis. 93:674, 2009.

Interpreting nurses' responses to clinical documentation alerts

OBJECTIVE

To understand how nurses respond to alerts that detect attempts to enter into electronic health records patient weights that vary significantly from previously recorded weights.

METHODS

Examination of subsequent patient weights to determine if the alerts were true positive (TP) or false positive (FP), and whether nurses overrode alerts, changed their entry or quit without storing a value.

RESULTS

Alerts occurred 2.74%, with 41.9% TP and 58.1% FP. Nurses overrode 30.3% of TP and 97.3% of FP alerts.

CONCLUSIONS

The alert has an acceptable FP rate and does not appear to cause nurses to change entries to satisfy the alert. The alert improves recording of patient weights.

Distance learning for hospital managers

Telemedicine technology enabled this class to meet. The Chapel Hill instructor could not have traveled to Scotland Neck for the classes, and the class members could not have taken time away from their jobs to travel to Chapel Hill. The technology allowed the participants to fit the classes into their schedules. For the group of managers at this small, isolated hospital, the experience of participating in a management class with an expert was a positive one. They were introduced to standard management practices, learned new skills, and formed a support group/team onsite. The students felt close to the leader, yet the physical distance made her an outsider in a way that encouraged frankness. The technology seemed to foster the best of both worlds--intimacy, yet physical distance and, thus, safety. These new managers were able to take part in a course that taught tangible skills for improving their job performance and, more important, afforded access to resources outside of Halifax County. They were able to step away from their daily routine and interact with outsiders and each other in new ways, without the stress and expense of travel. The results of this pilot study indicate that distance learning is feasible for courses of this kind. Staff burnout and turnover are chronic problems in rural facilities, with isolation contributing to job dissatisfaction. Distance learning offers exciting possibilities for addressing these problems in healthcare settings across the country.

The psychosocial aspects of osteoporosis in women

Osteoporosis has been documented to be a physiologically and psychologically debilitating disease. Health perceptions can be improved through both psychosocial support and specific intervention programs. These programs can improve independence and the quality of life of many people afflicted with this disease.

Interleukin-12 augments cytolytic activity of peripheral blood lymphocytes from patients with hematologic and solid malignancies

Interleukin-12 (IL-12) is a heterodimeric 70-kD cytokine that can enhance the activity of cytotoxic effector cells. Although IL-12 shares some functional properties with interleukin-2 (IL-2), it appears to act via a distinct mechanism. In this report, we examined the effects of IL-12 on the cytolytic activity and proliferation of peripheral blood mononuclear cells (PBMC) obtained from patients with malignant disease. PBMC from two groups of patients were evaluated. The first group consisted of 12 individuals with metastatic solid tumors. PBMC from these patients demonstrated a marked defect in their ability to lyse natural killer (NK)-sensitive targets (K562) compared with normal volunteers. Overnight incubation with IL-12 (35 pmol/L) corrected this defect. The effect of 35 pmol/L of IL-12 on cytotoxicity was similar to that of 3 nmol/L of IL-2. In contrast, this concentration of IL-12 had little effect on cytolytic activity against an NK-resistant cell line (COLO 205). When IL-12 was added to PBMC obtained from cancer patients who were being treated with low-dose IL-2 in vivo, a dramatic increase in cytolytic activity against both NK-sensitive and -resistant tumor targets was observed. Unlike IL-2, IL-12 failed to stimulate proliferation of resting PBMC from cancer patients significantly. The second group of patients we studied comprised 13 patients who had recently undergone allogeneic bone marrow transplantation (BMT) for hematologic malignancy. In resting PBMC from these transplant recipients, IL-12 was capable of enhancing cytotoxicity against both NK-sensitive and -resistant tumor targets. Our findings indicate that IL-12 can restore defective NK activity of PBMC from patients with metastatic cancer, as well as enhance cytolytic function of PBMC from patients after allogeneic BMT. The clinical use of IL-12 as an immunomodulator in patients with malignancy merits further consideration.

Prediction of graft-versus-host disease by phenotypic analysis of early immune reconstitution after CD6-depleted allogeneic bone marrow transplantation

Graft-versus-host disease (GVHD) is a major cause of morbidity and mortality following allogeneic bone marrow transplantation (BMT). Because GVHD is frequently refractory to treatment, the early identification of high-risk patients could have significant clinical value. To identify such patients, we examined early immunologic recovery in 136 patients with hematologic malignancies who received anti-T12 (CD6)-purged allogeneic bone marrow over a 9-year period. The majority of patients received marrow from HLA-matched sibling donors after ablation with cyclophosphamide and total body irradiation. No patients received any immune suppressive medications for GVHD prophylaxis. The fraction and absolute numbers of peripheral blood lymphocytes (PBL) expressing the CD3, CD4, CD8, and CD56 surface antigens were determined weekly by immunofluorescence analysis in patients beginning 8 to 14 days (week 2) after marrow infusion. Results in patients who did or did not subsequently develop GVHD post-BMT were compared. Within 2 weeks of marrow infusion, patients who developed grades 2-4 GVHD had significantly higher percentages and absolute numbers of CD8+ T cells and a lower fraction of CD56+ natural killer (NK) cells than individuals who remained free of GVHD. Thirty-five percent of patients whose PBL were greater than 25% CD8+ in the second posttransplant week developed GVHD, compared with only 3% of patients who had < or = 25% CD8+ cells (odds ratio 37.8; 95% confidence interval [CI] 4.1 to 397). A subgroup of patients at very high risk for GVHD could be identified based on the combined frequency of CD8+ T cells and NK cells in blood. Seventy-five percent of patients with greater than 25% CD8+ cells and < or = 45% CD56+ cells during week 2 post-BMT developed GVHD, compared with only 11% of the remaining patients (odds ratio 24.9; 95% CI, 5.3 to 117.0). None of the 23 patients with both less than 25% CD8+ cells and greater than 45% CD56+ cells in the second posttransplant week developed grades 2-4 GVHD. Our findings indicate that CD8+ T cells play an important role in the pathogenesis of GVHD in humans. Analysis of immune reconstitution early after BMT is useful in predicting the onset of GVHD and can help direct the implementation of treatment strategies before the appearance of clinical manifestations. Such interventions may decrease the morbidity and mortality associated with allogeneic BMT and ultimately improve overall survival.

Selective modulation of human natural killer cells in vivo after prolonged infusion of low dose recombinant interleukin 2

The immunologic consequences of prolonged infusions of rIL-2 in doses that produce physiologic serum concentrations of this cytokine were investigated. rIL-2 in doses of 0.5-6.0 x 10(6) U/m2 per d (3.3-40 micrograms/m2 per d) was administered by continuous intravenous infusion for 90 consecutive days to patients with advanced cancer. IL-2 concentrations (25 +/- 25 and 77 +/- 64 pM, respectively) that selectively saturate high-affinity IL-2 receptors (IL-2R) were achieved in the serum of patients receiving rIL-2 infusions of 10 micrograms/m2 per d and 30 micrograms/m2 per d. A gradual, progressive expansion of natural killer (NK) cells was seen in the peripheral blood of these patients with no evidence of a plateau effect during the 3 mo of therapy. A preferential expansion of CD56bright NK cells was consistently evident. NK cytotoxicity against tumor targets was only slightly enhanced at these dose levels. However, brief incubation of these expanded NK cells with IL-2 in vitro induced potent lysis of NK-sensitive, NK-resistant, and antibody-coated targets. Infusions of rIL-2 at 40 micrograms/m2 per d produced serum IL-2 levels (345 +/- 381 pM) sufficient to engage intermediate affinity IL-2R p75, which is constitutively expressed by human NK cells. This did not result in greater NK cell expansion compared to the lower dose levels, but did produce in vivo activation of NK cytotoxicity, as evidenced by lysis of NK-resistant targets. There was no consistent change in the numbers of CD56- CD3+ T cells, CD56+ CD3+ MHC-unrestricted T cells, or B cells during infusions of rIL-2 at any of the dosages used. This study demonstrates that prolonged infusions of rIL-2 in doses that saturate only high affinity IL-2R can selectively expand human NK cells for an extended period of time with only minimal toxicity. Further activation of NK cytolytic activity can also be achieved in vivo, but it requires concentrations of IL-2 that bind intermediate affinity IL-2R p75. Clinical trials are underway attempting to exploit the differing effects of various concentrations of IL-2 on human NK cells in vivo.

Clinical and immunologic effects of prolonged infusion of low-dose recombinant interleukin-2 after autologous and T-cell-depleted allogeneic bone marrow transplantation

Bone marrow transplantation (BMT) can produce prolonged clinical remission in some patients with hematologic malignancies. Unfortunately, disease relapse may occur despite BMT. Studies in animal models and clinical experience have provided evidence that immunologic factors play an important role in preventing relapse post-BMT. To stimulate immunologic activity in patients post-BMT, we administered prolonged uninterrupted continuous infusions of low-dose recombinant interleukin-2 (rIL-2). Thirteen marrow recipients (seven autologous BMT, six CD6 T-depleted allogeneic BMT) received rIL-2 at a dose of 2 x 10(5) U/m2/d for a scheduled period of 90 days. rIL-2 was administered through a Hickman catheter with a portable pump beginning a median of 85 days after BMT. Toxicity was minimal and all treatment could be undertaken in the outpatient setting. No patient developed any signs of graft-versus-host disease, hypotension, or pulmonary capillary leak syndrome. Treatment did not affect the absolute neutrophil count or hemoglobin level, but eosinophils increased substantially in most patients. Platelet counts decreased by 20% in 10 of 13 individuals within 2 weeks, but stabilized thereafter. Despite the low dose of rIL-2 administered, significant immunologic changes were noted. Specifically, all 13 patients experienced a marked increase (fivefold to 40-fold) in natural killer (NK) cell number. Phenotypic characterization showed that the majority of NK cells were CD56bright+ CD16+ CD3-. In contrast, a minor increase in T-cell number was noted in only 4 of 13 patients. Low-dose rIL-2 treatment resulted in augmentation of in vitro cytotoxicity against K562 and COLO tumor targets. This cytotoxic activity could be dramatically enhanced by incubation with additional rIL-2 in vitro. The immunologic effects of rIL-2 treatment were similar in both autologous and allogeneic marrow recipients. Our data suggest that prolonged infusion of rIL-2 at low doses is safe and can selectively increase NK cell number and activity after BMT. Further studies to assess the impact these changes may have on disease relapse post-BMT will be undertaken.

Extended continuous infusion low-dose recombinant interleukin-2 in advanced cancer: prolonged immunomodulation without significant toxicity

In previous clinical trials, recombinant interleukin-2 (rIL-2) has been infused at high doses over short periods of time to generate lymphokine-activated killer (LAK) cells in vivo. These trials have been limited by severe toxicities, and the immunologic effects of rIL-2 have been transient. The present study was designed to assess the toxicity and immunologic effects of prolonged administration of low doses of rIL-2. In this phase I study, patients with advanced cancer were scheduled to receive intravenous (IV) infusion of rIL-2 without interruption for 3 months in an outpatient setting. Twenty-one patients received rIL-2 at doses ranging from 0.5 x 10(5) to 6.0 x 10(5) U/m2/d. Treatment was extremely well tolerated, and no patient experienced grade 3 or grade 4 toxicity. The lowest dose level (0.5 x 10(5) U/m2/d) did not have demonstrable immunologic activity. At doses of 1.5 x 10(5) and 4.5 x 10(5) U/m2/d, rIL-2 infusion resulted in the specific expansion of natural-killer (NK) cells (sixfold and ninefold increases, respectively, at these two dose levels) without any changes in B cells, T cells, neutrophils, or monocytes. Grade 2 toxicity was observed at the dose of 6.0 x 10(5) U/m2/d, as three patients required interruption of therapy and two patients who completed therapy developed transient hypothyroidism. In patients with increased NK cells, enhancement of non-major histocompatibility complex (MHC)-restricted cytotoxicity and increased generation of LAK cells in vitro were also demonstrated. Therapy with low-dose rIL-2 can be given safely in an uninterrupted fashion for prolonged periods of time in an outpatient setting. This results in selective expansion of NK cells in vivo with minimal toxicity. Further investigation of this schedule for immunomodulation in vivo should be pursued in phase II studies of both malignant and immunodeficient disease states.

Reconstitution of T-cell function after CD6-depleted allogeneic bone marrow transplantation

Patients who undergo allogeneic bone marrow transplantation (BMT) are clinically immunodeficient for a prolonged period after engraftment. In the present study, we examined immune function after BMT in a series of patients who had received HLA compatible sibling marrow grafts purged of T cells with anti-CD6 monoclonal antibody and complement. None of the patients in this analysis received immunomodulating agents and none had developed graft-versus-host disease (GVHD). Initially after BMT, natural killer (NK) cells are the predominant cell type, giving way to CD3+, CD5+ T cells after 4 to 8 weeks. Despite the return of normal numbers of T lymphocytes post-BMT phenotypic analysis reveals several long-term abnormalities, including an inverted T4:T8 ratio and a significant fraction of CD3+ T cells that do not co-express CD6. In mitogenic assays, stimulation by either nonspecific lectin (phytohemagglutinin; PHA) or antibodies to the CD2 surface structure (anti-T11(2) + anti-T11(3)) results in decreased levels of T-cell proliferation compared with controls for over 18 months post-BMT. In contrast, the ability of unstimulated peripheral blood mononuclear cells (PBMC) to respond to recombinant interleukin-2 (rIL-2) is relatively intact, most likely reflecting early functional reconstitution of the NK cell population. To further characterize the prolonged abnormalities in T-cell proliferation after PHA or CD2 stimulation, we examined more proximal events in T-cell activation such as induction of IL-2 receptor expression and stimulus-induced intracellular calcium flux. We found that the induction of IL-2 receptor (p55) after in vitro activation, although initially abnormal, recovers completely by 6 months post-BMT. We also found that, after CD2 stimulation, calcium flux in T cells was normal immediately after engraftment. In contrast, after stimulation with anti-CD3 antibodies, a large population of T cells do not develop intracellular calcium flux compared with controls. We conclude that despite the recovery of normal numbers of T lymphocytes early after engraftment of CD6-depleted marrow, these T cells exhibit several physiologic and functional abnormalities that persist for varying intervals post-BMT. At present, it is unclear which of these specific defects is most closely associated with increased susceptibility to infectious agents after BMT.

Oro-facial granulomatosis--a clinical and pathological analysis

A study of 60 patients with oro-facial granulomatosis has been conducted and the clinical presentation of this disorder defined. It encompasses the previously recognised clinical entities of Melkersson-Rosenthal syndrome and cheilitis granulomatosa. The pathological features of the disease are lymphoedema and the presence of multiple non-caseating giant cell granulomata. These granulomata are histologically indistinguishable from those found in both gastrointestinal Crohn's disease and systemic sarcoidosis. Within this series of patients, nine had evidence suggestive of gastrointestinal Crohn's disease, and in six this was confirmed. A diagnosis of sarcoidosis was made in a further two patients. The relationship of oro-facial granulomatosis to these systemic granulomatous diseases is not yet clear. Patients with oro-facial granulomatosis who have gastrointestinal symptoms should be investigated for the presence of gastrointestinal Crohn's disease. Those without symptoms should be investigated for evidence of malabsorption or serological evidence of Crohn's disease. Within the present study, the erythrocyte sedimentation rate, full blood count, corrected whole blood folate, serum albumin and calcium were the most sensitive markers of gastrointestinal involvement. Sarcoidosis should be considered in all patients with oro-facial granulomatosis. The absence of clinical signs suggestive of sarcoidosis, a normal chest radiograph and normal levels of serum angiotensin-converting enzyme makes sarcoidosis unlikely.