A novel variant in the GNE gene in a Malian patient presenting with distal myopathy

Background

GNE myopathy (GM) is a rare autosomal recessive disorder caused by variants in the GNE gene and characterized by progressive distal muscle weakness and atrophy. We report a novel variant in theGNE gene causing GM in a consanguineous Malian family.

Case presentation

A 19-year-old male patient from a consanguineous family of Bambara ethnicity was seen for progressive walking difficulty and frequent falls. Neurological examination found distalmuscle weakness and atrophy and reduced tendon reflexes in four limbs. Electroneuromyography (ENMG) showed an axonal neuropathy pattern with reduced distal motor amplitudes. Charcot-Marie-Tooth (CMT) gene panel testing (Medical Neurogenetics LLC, Atlanta, GA) was negative. However, whole exome sequencing (WES) revealed a novel biallelic variant in GNE (c.1838G>A:p.Gly613Glu), segregating with the phenotype in the family. This variant is predicted to be pathogenic by several in silicoprediction tools including CADD= 29. Moreover, protein folding model showed major structural disruptions in the mutant protein.

Conclusion

This study reports a novel variant in the GNE gene causing GM, the first molecularly diagnosed in sub-Saharan Africa (SSA). It highlights the diagnosis challenges in this region and broadens the genetic spectrum of this rare disease.

A novel de novo variant in the RUNX2 gene causes cleidocranial dysplasia in a Malian girl

Key Clinical Message

Cleidocranial dysplasia (CCD) is a rare genetic skeletal disorder with only few cases reported in Africa, mostly based on clinical and radiological findings. We report the first case in Mali, caused by a novel de novo variant in the RUNX2 gene.

Abstract

Cleidocranial dysplasia (CCD) is a rare autosomal dominant skeletal dysplasia characterized by an aplastic/hypoplastic clavicles, patent sutures and fontanels, dental abnormalities and a variety of other skeletal changes. We report a novel de novo variant in the RUNX2 gene causing a severe phenotype of CCD in a Malian girl.

Pentanucleotide Repeat Insertions in RAI1 Cause Benign Adult Familial Myoclonic Epilepsy Type 8

BACKGROUND

Benign adult familial myoclonic epilepsy (BAFME) is an autosomal dominant disorder characterized by cortical tremors and seizures. Six types of BAFME, all caused by pentanucleotide repeat expansions in different genes, have been reported. However, several other BAFME cases remain with no molecular diagnosis.

OBJECTIVES

We aim to characterize clinical features and identify the mutation causing BAFME in a large Malian family with 10 affected members.

METHODS

Long-read whole genome sequencing, repeat-primed polymerase chain reaction and RNA studies were performed.

RESULTS

We identified TTTTA repeat expansions and TTTCA repeat insertions in intron 4 of the RAI1 gene that co-segregated with disease status in this family. TTTCA repeats were absent in 200 Malian controls. In the affected individuals, we found a read with only nine TTTCA repeat units and somatic instability. The RAI1 repeat expansions cause the only BAFME type in which the disease-causing repeats are in a gene associated with a monogenic disorder in the haploinsufficiency state (ie, Smith-Magenis syndrome [SMS]). Nevertheless, none of the Malian patients exhibited symptoms related to SMS. Moreover, leukocyte RNA levels of RAI1 in six Malian BAFME patients were no different from controls.

CONCLUSIONS

These findings establish a new type of BAFME, BAFME8, in an African family and suggest that haploinsufficiency is unlikely to be the main pathomechanism of BAFME. © 2023 International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Novel variant in CADM3 causes Charcot-Marie-Tooth disease

CADM3 has been recently reported causing a rare axonal Charcot-Marie-Tooth disease in three independent Caucasian families carrying a recurrent change. We describe the first alternative causative mutation in CADM3 in a family from black African and also observed de novo in a patient of Caucasian ancestry. The disease inheritance was consistent with autosomal dominant and sporadic patterns, respectively. Eight patients and their relatives were enroled from both families. The mean age at diagnosis was 33.9 years, and walking difficulty was commonly the first symptom. Neurological examination showed distal muscle weakness and atrophy, sensory loss and foot and hand deformities. A high clinical variability was noted, but as seen in CADM3-associated neuropathy, symptoms were more pronounced in the arms in some patients. Nerve conduction studies showed no response in most of the examined nerves, and an axonal type of neuropathy, where recorded. Whole exome sequencing revealed a novel missense variant (c.1102G>T; Gly368Cys) in CADM3, segregating with the disease. Functional analyses showed a significant decrease in CADM3-Gly368Cys protein levels in the membrane and major structural changes in its predicted secondary structure. Therefore, we extend the genotype spectrum of CADM3, underlining the need for genetic studies in underrepresented populations like in Africa.

[Community acute bacterial pneumonitis of the subject age in pulmonology at the Point-g hospital and university center, Bamako-Mali]

INTRODUCTION

Community-acquired acute bacterial pneumonia (ABP) is an acute, non-suppurative, non-tuberculosis lower respiratory infection of the lung parenchyma acquired within the community. They have an atypical clinical presentation and a poor prognosis in the elderly.

MATERIALS AND METHODS

This was a prospective cross-sectional study conducted in the Pneumology department of the University Hospital Center (CHU) of Point-G, from October 30, 2018 to September 30, 2019. The objective was to determine the clinical, etiological, therapeutic and progression of BAP in the elderly. Were included any age ≥ 65 years, presenting clinical and radiological signs of a PAB.

RESULTS

During the study period, 85 patients met the inclusion criteria out of 178 hospitalized. The sex ratio was 3/1. About 2/3 were smokers and 11% were HIV positive. Fever was not constant recorded in 51.76% of cases. Respiratory signs were dominated by cough (96.47%), dyspnea (94.11%) and extra respiratory by impaired consciousness. Klebsiella pneumoniae was the most found germ. The most commonly used antibiotic was amoxicillin-clavulanic acid. The average length of hospitalization was 9 days. Mortality was 19%.

CONCLUSION

The PAB in the elderly is of a frustrating clinical symptomatology. It is serious with excess mortality.

Study of charged particle activation analysis (II): Determination of boron concentration in human blood samples

Boron Neutron Capture Therapy (BNCT) is a radiotherapy for the treatment of intractable cancer. In BNCT precise determination of ¹⁰B concentration in whole blood sample before neutron irradiation of the patient, as well as accurate neutron dosimetry, is crucial for control of the neutron irradiation time. For this purpose ICP-AES and neutron induced prompt γ-ray analysis are generally used. In Ibaraki Neutron Medical Research Center (iNMRC), an intense proton beam will be accelerated up to 8 MeV, which can also be used for Charged Particle Activation Analysis (CPAA). Thus, in this study, we apply the CPAA utilizing the proton beam to non-destructive and accurate determination of ¹⁰B concentration in whole blood sample. A CPAA experiment is performed by utilizing an 8 MeV proton beam from the tandem accelerator of Nuclear Science Research Institute in Japan Atomic Energy Agency. The 478 keV γ-ray of ⁷Be produced by the ¹⁰B(p, α)⁷Be reaction is used to quantify the ¹⁰B in human blood. The 478 keV γ-ray intensity is normalized by the intensities of the 847 keV and 1238 keV γ-rays of ⁵⁶Co originating from Fe in blood. The normalization methods were found to be linear in the range of 3.27 μg ¹⁰B/g to 322 μg ¹⁰B/g with correlation coefficients of better than 0.9999.

[Onchocerciasis in Burkina Faso: a Re-Emerging Vector-Borne Endemic Disease]

Burkina Faso, like other countries, reported a focal interruption of onchocerciasis transmission and was thus placed under post-therapeutic surveillance. However, the country seems to be experiencing a resurgence of the disease according to recent surveys at certain sentinel sites and data from various surveys. The aim of our study is to take stock of the evolution of the current epidemiological situation of onchocerciasis in Burkina Faso. For data collection, in addition to the scientific articles, we have used data from different epidemiological and entomological surveys conducted by the National Program for the Control of Neglected Tropical Diseases (PNLMTN) through its onchocerciasis elimination unit in Burkina Faso. Prior to implementation of the Onchocerciasis Control Program in West Africa (OCP), Burkina Faso had onchocerciasis prevalence between 60% and 80%. In 2002, the maximum prevalence dropped to 15%. However, in 2010 and 2011, epidemiological surveys indicated that some villages in the Comoé River basin had prevalence rate ranging from 0.7% to 71%. Thirteen (13) villages had prevalence rates above the tolerable threshold of 5%. Despite the implementation of the community-directed treatment with ivermectin (CDTI) since 2011, recent surveys show a tendency for a recrudescence of the disease in some sites, yet covered by the TIDC. This suggests that the elimination of onchocerciasis requires the integration of new control strategies. Thus, an essential condition for the elimination of onchocerciasis is the analysis of the situation in each focus in order to define the most cost-effective strategy for permanently interrupting the transmission of the parasite. National onchocerciasis elimination committees put in place will play a key role in determining the best strategy.

Expression of human cathelicidin peptide LL-37 in inflammatory bowel disease

Cathelicidin peptide LL-37 plays an important role in the early host response against invading pathogens via its broad-spectrum anti-microbial activity. In this study, we investigated LL-37 expression in the inflamed mucosa of inflammatory bowel disease (IBD) patients. Furthermore, the regulatory mechanism of LL-37 induction was investigated in human colonic subepithelial myofibroblasts (SEMFs). LL-37 mRNA expression and protein secretion were analysed using real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Intracellular signalling pathways were analysed using immunoblotting and specific small interference RNA (siRNA). The expression of LL-37 mRNA was increased significantly in the inflamed mucosa of ulcerative colitis and Crohn's disease. The Toll-like receptor (TLR)-3 ligand, polyinosinic-polycytidylic acid (poly(I:C), induced LL-37 mRNA expression and stimulated LL-37 secretion in colonic SEMFs. The transfection of siRNAs specific for intracellular signalling proteins [Toll/IL-1R domain-containing adaptor-inducing interferon (IFN) (TRIF), tumour necrosis factor receptor-associated factor (TRAF)6, transforming growth factor β-activated kinase (TAK)1] suppressed the poly(I:C)-induced LL-37 mRNA expression significantly. Poly(I:C)-induced phosphorylation of mitogen-activated protein kinases (MAPKs) and activated nuclear factor kappa B (NF-κB) and activating factor protein (AP)-1. siRNAs specific for NF-κB and c-Jun inhibited poly(I:C)-induced LL-37 mRNA expression. LL-37 suppressed lipopolysaccharide (LPS)-induced interleukin (IL)-6 and IL-8 expression significantly in colonic SEMFs. The expression of LL-37 was up-regulated in the inflamed mucosa of IBD patients. LL-37 was induced by TLR-3 stimulation and exhibited an anti-microbial effect via interaction with lipopolysaccharide (LPS).

Prevalence of vulvovaginal candidiasis in pregnancy at three health centers in Burkina Faso

INTRODUCTION

Pregnant women are more susceptible to vaginal colonization and infection by yeast. The role of Candida colonization in the occurrence of preterm birth is well established. The knowledge of local epidemiology and identification of risk factors for preterm birth is important for the prevention and management strategies. The purpose of the study was to determine the prevalence of Candida sp. in vaginal swabs of pregnant women.

METHODS

Pregnant women attending routine antenatal visits in three primary health centres in Bobo-Dioulasso (Burkina Faso) were enrolled into a cross-sectional study carried out from February to April 2015. Vaginal swabs samples were taken from participants after obtaining oral consent. The swabs were inoculated into Sabouraud's glucose agar supplemented with chloramphenicol and incubated at 37°C for 24 to 48hours under aerobic conditions in order to perform fungal culture. The identification of the Candida species was done by culture on HiCrome Candida Differential Agar at 35°C for 48h for production of species-specific colors.

RESULTS

A total of 229 pregnant women were included. The prevalence of vulvovaginal candidiasis (VVC) was 22.71%, (95% CI [17.45-28.69]). Candida albicans accounted for 40.39% and non-Candida albicans species for 59.61% of the isolates, with mainly C. glabrata (32.69%), C. tropicalis (15.38%) and C. krusei (11.54%).

CONCLUSIONS

This study revealed a high prevalence of non-C. albicans species. The syndromic management guidelines for VVC in Burkina Faso will be revised to include a specific protocol for pregnant women.

[A case of rhinofacial entomophthoromycosis in Soudano-Sahelian tropical climate in Burkina Faso]

We describe a rhinofacial entomophthoramycosis case in a sexagenarian (65 years old) housewife. She was immunocompetent and resident of Burkina Faso. She consulted both the service of dermatology and the service of stomatology of the Teaching Hospital of Bobo-Dioulasso in February 2016 for a diffuse facial tumefaction evolving over six months. This tumefaction was associated with headaches and a left nasal obstruction. Histological examination of the lesion showed an important and polymorphic inflammatory reaction. Also, a filamentous fungus with wide non-septated hyphae and right-angled fungal branching, consistent with mucormycosis was isolated. Mycological diagnosis based on fungal culture with Sabouraud medium without any antibiotic and cyclohexemide after incubation at 27°C and at 30°C was negative. Furthermore, it was not possible to amplify the DNA extracted from biopsy. Antifungal therapy based on the administration of fluconazole per os at 800mg/day was started allowing clinical improvement. This is the first case of a rhinofacial entomophtharomycosis documented in Bobo-Dioulasso. Rhinofacial entomophthoromycosis is largely unknown, even in tropical regions such as Burkina Faso. This lack of knowledge results in a delay in the diagnosis, and subsequently a bad prognosis. It is therefore urgent to improve knowledge on this disease to guide diagnostic steps, prognosis of outcome, and antifungal therapy.

[Cryptococcosis: a potential aetiology of facial ulceration]

Cutaneous cryptococcosis is an uncommon aetiology of chronic facial ulceration but which may be associated to a potentially lethal focus of cryptococcosis.

OBSERVATION

A 35-year-old AIDS patient under antiretroviral therapy, presented with a chronic facial ulceration. Histopathological examination of a biopsy of the facial ulceration showed an inflammatory granuloma and masses of yeasts. Mycological culture of the cerebrospinal fluid revealed Cryptococcus neoformans. The diagnosis of AIDS-related cutaneous cryptococcosis of the face and cryptococcal meningitis was concluded.

DISCUSSION

Cryptococcosis should be thought as a potential aetiology of a chronic facial ulceration in an AIDS patient. Screening of other foci of the cryptococcosis such as that of the central nervous system is mandatory. Mycological examinations are of great interest for the diagnosis in rare resources setting.

[Multiple sites extrapodal actinomycetoma: Favorable outcome to treatment with a combination of cotrimoxazole and NSAI]

Mycetoma is a bacteriological or fungal infectious disease affecting the skin and/or soft tissues, which can be complicated by bone involvement. The most common feature is a tumor of the foot, but extrapodal localizations have been described. We report one case of a 47-year-old man who presented with tumefaction of a leg with multiple skin fistulae. Histopathological examination permitted to confirm the diagnosis of actinomycetoma and TDM showed the degree of bone and soft tissues involvement. Our case was characterized by the very inflammatory aspect of the tumor, its localization to the leg without foot involvement, the modest functional signs compared to the importance of radiological bone involvements, the deep destruction of the fibula while the tibia was apparently intact and the good response to treatment. In spite of its characteristic features, diagnosis of mycetoma is still late in our country, often with bone and/or articular spread. Priority may be given to measures for reduction of mycetoma diagnosis lateness.

Seroprevalence of latent Toxoplasma gondii infection among HIV-infected pregnant women in Bobo-Dioulasso, Burkina Faso

The deficit of cellular immunity, as found in HIV infected individuals, may lead to the reactivation of latent Toxoplasma gondii cysts, with as consequence, the occurrence of toxoplasmosis and an eventual vertical transmission of the disease during pregnancy. The present study was designed for determining the occurrence of latent Toxoplasma gondii among HIV-infected pregnant women during the first trimester in Bobo-Dioulasso. Thus, 348 pregnant women aged from 17 to 47 years (average age of 6.64 ± 4.75 yaers) were enrolled. The specific anti-Toxoplasma gondii IgG and IgM antibodies were quantified from whole blood specimens using the high-sensitivity direct agglutination and the enzyme linked fluorescent assays, respectively, the IgG avidity test being used for the dating of the primary infection. The results revealed that the seroprevalence of Toxoplasma gondii latent infection was 34.7%. It was significantly higher in HIV-infected women compared with uninfected ones (68,7%; CI 95%: 43,6%-88,9%) versus (33,1%; CI 95%: 28, 2%-38,3%). In addition, all the occurrences of the high IgG avidity were closely linked with the presence of IgM. These results underlined the need for the clinical follow-up of the maternal HIV diseases including the toxoplasmosis during the pregnancy since; the newborns are still exposed to vertical transmission of Toxoplasma infection in endemic areas like Burkina Faso.

[Screening and management of the maternal and congenital toxoplasmosis in Bobo-Dioulasso, Burkina Faso]

The objectives of this prospective study, conducted from November 2011 to July 2013, in Bobo-Dioulasso were to evaluate seroprevalence of toxoplasma infection and to screen for maternal and congenital toxoplasmosis during pergravidic monitoring.

MATERIAL AND METHODS

Techniques of High Sensitivity Direct Agglutination (HSDA) and Enzyme Linked Fluorescent Assay (ELFA) were used for the detection of IgG and IgM toxoplasma respectively. The IgG avidity assay was used for the dating of seroconversion. Screening and monitoring for fetal lesions were echographic. In case of seroconversion, a prenatal treatment with pyrimethamine and sulphonamide was introduced. Systematically and regularly immunoassay surveillance of newborn from cases of recent pergravidic toxoplasmosis was performed until complete and final negativity of serology.

RESULTS

In total 301 pregnant women were included. The overall seroprevalence was 31.9%. Three cases of seroconversion (0.9%) including two cases at the 22^nd and one at the 41^th week of amenorrhea were noted. Series of obstetrical echography have detected no case of fetal Toxoplasma gondii infection and no congenital toxoplasmosis was detected.

CONCLUSION

This study underlines the importance of implementation of a legal disposition for screening and routine monitoring of toxoplasmosis during pregnancy. This is due to the low rate (31.9%) of toxoplasma immunity among gestante in Burkina Faso that may lead to pergravidic acute toxoplasmosis or congenital toxoplasmosis whose outcome is often fatal.

Regulation of eotaxin-3/CC chemokine ligand 26 expression by T helper type 2 cytokines in human colonic myofibroblasts

Eotaxins induce the trafficking of eosinophils to the sites of inflammation via CC chemokine receptor 3 (CCR3). In this study, we investigated eotaxin-3/CC chemokine ligand 26 (CCL26) expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD), and characterized the molecular mechanisms responsible for eotaxin-3 expression in human colonic myofibroblasts. Eotaxin-3 mRNA and protein expression was evaluated by real time-polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Eotaxin-3 mRNA expression was elevated significantly in the active lesions of ulcerative colitis (UC) patients. Significant elevations were also observed in the active lesions of Crohn's disease (CD) patients, but this was significantly lower than that detected in the active UC lesions. There were no significant increases in the inactive lesions of UC or CD patients. Colonic myofibroblasts were identified as a major source of eotaxin-3 in the colonic mucosa, and interleukin (IL)-4 and IL-13 enhanced eotaxin-3 mRNA and protein expression significantly in these cells. There was a significant positive correlation between mucosal eotaxin-3 and IL-4 mRNA expression in the active lesions of IBD patients. The IL-4- and IL-13-induced eotaxin-3 mRNA expression was regulated by the signal transducer and activator of transcription-6 (STAT-6) and suppressor of cytokine signalling (SOCS)1-mediated pathways. Interferon (IFN)-γ acts as a negative regulator on the IL-4- and IL-13-induced eotaxin-3 expression via STAT-1 activation. Eotaxin-3 expression was elevated specifically in the active lesions of IBD, in particular UC. Eotaxin-3 derived from colonic myofibroblasts may play an important role in the pathophysiology of UC.

[Epidemiological profile, clinical and therapeutic cutaneous leishmaniasis in the Department of Dermatology at University Hospital in Ouagadougou, Burkina Faso]

It is a retrospective study in the Service of Dermatology at the University Hospital Center Yalgado Ouédraogo of Ouagadougou (C.H.U.-YO). This study aimed to list the leishmaniasis clinical cases reported in the registers of this department from January 1999 to December 2007. In total, 251 leishmaniasis clinical cases have been reported. The hospital prevalence was 1,1%. Women represented 53% versus 47% men. The average age of patients was 22,78 ans +/- 121. The most frequent clinical forms were those often crusted (40.2%), papulo ulcerative (16.7%) and papulonodular (13.9%). Lesions most often sat on the lower limbs (33%) and thoracic limbs (45%). On the therapeutic level, the first line treatment meglumine antimonite (Glucantime) accounted for only 25.9% of prescriptions.

Epithelial expression of interleukin-37b in inflammatory bowel disease

Interleukin (IL)-37 is a member of the IL-1 cytokine family. We investigated IL-37b expression in the inflamed mucosa of inflammatory bowel disease (IBD) patients. Furthermore, we analysed IL-37b expression in human colonic epithelial cells. The human colonic epithelial cell line T84 and human colonic subepithelial myofibroblasts (SEMFs) were used. IL-37b expression in the IBD mucosa was evaluated by immunohistochemistry. IL-37b mRNA and protein expression were determined by real time-polymerase chain reaction (PCR) and Western blotting, respectively. IL-37b was not detected in the normal colonic mucosa. In the inflamed mucosa of IBD patients, epithelial IL-37b expression was increased markedly. In ulcerative colitis (UC) and Crohn's disease (CD) patients, IL-37b expression was enhanced in the affected mucosa. In the intestinal epithelial cell line T84, the expression of IL-37b mRNA and protein was enhanced by tumour necrosis factor (TNF)-α. This IL-37b induction by TNF-α was mediated by nuclear factor (NF)-κB and activator protein (AP)-1 activation. Furthermore, IL-37b inhibited TNF-α-induced interferon-γ-inducible protein (IP)-10 expression significantly in human colonic SEMFs. Epithelial IL-37b expression was increased in IBD patients, especially UC patients. IL-37b may be involved in the pathophysiology of IBD as an anti-inflammatory cytokine and an inhibitor of both innate and acquired immune responses.

[Retrospective study of cases of neuromeningeal cryptococcosis at the University Hospital of Bobo Dioulasso since accessibility to antiretroviral in Burkina Faso]

AIMS OF THE STUDY

To study the prevalence of neuromeningeal cryptococcosis since the availability of antiretroviral drugs and to determine the epidemiological profiles, clinical and biological treatment of neuromeningeal cryptococcosis cases diagnosed in the service of parasitology and mycology of university hospital center of Bobo-Dioulasso from 2002 to 2010.

PATIENTS, MATERIAL AND METHODS

We included all patients diagnosed with neuromeningeal cryptococcosis for which the presence of the fungi was observed on microscopic examination of cerebrospinal fluid after staining with Indian ink. Data were collected from the registers of the clinical service and from the laboratory of the university hospital center of Bobo Dioulasso.

RESULTS

The prevalence of neuromeningeal cryptococcosis was 1.8% (61/5129). A decrease in the prevalence was observed from 2002 to 2010 (3.1%, to 0.2%). This decrease occurred even though the number of patients treated with antiretroviral drugs increase. Headaches were the predominant clinical signs (81.9%). The CD4 median count was 56/mm(3). All patients were successfully treated with fluconazole in relay to amphotericin B intravenous. Lethality rate is 27.8%.

CONCLUSION

The overall prevalence of 1.8% of neuromeningeal cryptococcosis observed in this study was lower than that in previous studies in the same laboratory in 2001. The arrival of antiretroviral drugs could have contributed to the decline in the prevalence of neuromeningeal cryptococcosis in this study.

[Trends in incidence of cutaneous leishmaniasis from 1999 to 2005 in Ouagadougou, Burkina]

The purpose of this study is to describe trends in the annual incidence of cutaneous leishmaniasis in Ouagadougou, Burkina from 1999 to 2005. Data recorded at city health care centers were reviewed. A total of 7,444 cases of cutaneous leishmaniasis were observed, with an annual mean incidence of 1,063.3 +/- 270.8 cases. The M/F sex ratio was 0.9. Mean patient age was 22.8 +/- 13.5 years. Patients older than 15 years accounted for 72.5% of the population. The predominant age bracket was 16-30 years (51.80%).A decrease in incidence was observed from March to June and in December. Peak incidence occurred in September and October. Over the 7-year study period, the average incidence rate was 0.1% +/- 0.04. Since this rate does not reflect the real prevalence of the disease, a prospective study is needed.

Bone marrow transplantation ameliorates pathology in interleukin-10 knockout colitic mice

The authors have previously reported the derivation of colonic subepithelial myofibroblasts (SEMFs) in both humans and mice from bone marrow (BM). In the pathogenesis of inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis, colonic SEMFs mediate several types of inflammatory response. In the present study, interleukin (IL)-10-/- mice were used as a model of IBD to investigate the involvement of BM-derived cells in the inflamed mucosa. Male whole BM [either C57/BL10 (wild type: WT) or IL-10-/- donor mice] was used to perform bone marrow transplantation (BMT) into both WT and IL-10-/- female mice. Tissue samples were evaluated by immunohistochemistry for alpha-smooth muscle actin expression and by in situ hybridization using a Y-chromosome-specific probe to track the donor-derived colonic SEMFs. The mucosal expression of mRNA for pro-inflammatory cytokines was analysed by reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, mRNA expression of matrix metalloproteinase (MMP)-7 and osteopontin in the inflamed mucosa was assessed using in situ hybridization. Body weights and histological scores showed that IL-10-/- mice that received WT BM had an improved course of colitis, decreased mucosal pro-inflammatory mRNA expression, and up to 30% of their SEMFs were of BM origin. Conversely, IL-10-/- mice receiving IL-10-/- BM progressed to extensive colitis, and Y probe analysis revealed that up to 45% of colonic SEMFs were of BM origin. WT mice receiving IL-10-/- or WT BM had no signs of colonic inflammation. The expression of MMP-7 and osteopontin was up-regulated in the inflamed mucosa. In conclusion, IL-10-/- mice displayed ameliorated disease activity after WT BMT, whilst colitis was not induced in WT mice by IL-10-/- BMT. The contribution of BM-derived cells to colonic SEMFs was significantly increased in the inflamed mucosa compared with non-inflamed mucosa.

Increased expression of interleukin 17 in inflammatory bowel disease

BACKGROUND AND AIM

Interleukin (IL) 17 is a cytokine which exerts strong proinflammatory activities. In this study we evaluated changes in IL-17 expression in the inflamed mucosa and in the serum of patients with inflammatory bowel disease (IBD).

METHODS

Tissue samples were obtained endoscopically or surgically from patients with ulcerative colitis (UC) (n=20), Crohn's disease (CD) (n=20), infectious colitis (n=5), ischaemic colitis (n=8), and normal colorectal tissues (n=15). IL-17 expression was evaluated by a standard immunohistochemical procedure. Serum IL-17 levels were determined by ELISA. IL-17 mRNA expression was analysed by reverse transcriptase-polymerase chain reaction.

RESULTS

IL-17 expression was not detected in samples from normal colonic mucosa, infectious colitis, or ischaemic colitis. In the inflamed mucosa of active UC and CD patients, IL-17 expression was clearly detectable in CD3(+) T cells or CD68(+) monocytes/macrophages. The average number of IL-17(+) cells was significantly increased in active UC and CD patients compared with inactive patients. IL-17 mRNA expression was not detected in normal mucosa but was detectable in the mucosa from active UC and CD patients. IL-17 was not detected in the sera from normal individuals, infectious colitis, or ischaemic colitis patients but IL-17 levels were significantly elevated in IBD patients.

CONCLUSIONS

IL-17 expression in the mucosa and serum was increased in IBD patients. It is likely that IL-17 expression in IBD may be associated with altered immune and inflammatory responses in the intestinal mucosa.

Interleukin-1beta and tumor necrosis factor-alpha induce chemokine and matrix metalloproteinase gene expression in human colonic subepithelial myofibroblasts

BACKGROUND

Colonic subepithelial myofibroblasts may play a role in the inflammatory responses and in extracellular matrix (ECM) metabolism. In this study, we investigated the effects of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha on chemokine (IL-8 and monocyte chemoattractant protein (MCP)-1) and ECM turnover (proliferation of subepithelial myofibroblasts, and secretion of ECM and matrix metalloproteinases (MMPs)) in colonic subepithelial myofibroblasts.

METHODS

Human colonic subepithelial myofibroblasts were isolated using the method described by Mahida et al. Chemokine and MMP expressions were determined by ELISA and Northern blotting. Nuclear factor (NF)-kappaB and NF-IL6 DNA binding activities were evaluated by electrophoretic gel mobility shift assays (EMSA).

RESULTS

IL-1beta and TNF-alpha did not affect the proliferation of subepithelial myofibroblasts, but stimulated the secretion of types I and IV collagens weakly. Unstimulated subepithelial myofibroblasts secreted a large amount of MMP-2, but a small amount of IL-8, MCP-1 and MMP-1. IL-1beta and TNF-alpha both induced a dose- and time-dependent increase in IL-8, MCP-1 and MMP-1 secretion, and weakly stimulated MMP-2 secretion. IL-1beta and TNF-alpha both rapidly evoked NF-kappaB DNA-binding activity. The inhibition of NF-kappaB activation markedly blocked both IL-1beta- and TNF-alpha-induced IL-8 and MCP-1 mRNA expression, but did not affect MMP-1 mRNA expression.

CONCLUSIONS

These observations indicate that chemokine secretion and ECM metabolism are collectively regulated by the proinflammatory cytokines, IL-1beta and TNF-alpha, in colonic subepithelial myofibroblasts. Thus, colonic subepithelial myofibroblasts may play an important role in the pathophysiology of inflammation in the colon.

Interleukin-17 stimulates chemokine (interleukin-8 and monocyte chemoattractant protein-1) secretion in human pancreatic periacinar myofibroblasts

BACKGROUND

Interleukin (IL)-17 is a newly identified T-cell-derived cytokine that can regulate the functions of a variety of cell types. In this study, we investigated the effects of CD4+ T-cell-derived cytokines on chemokine secretion in human pancreatic periacinar myofibroblasts.

METHODS

The secretion of IL-8 and monocyte chemoattractant protein (MCP)-1 was evaluated by ELISA and Northern blot. The expression of IL-17 receptor (R) was analyzed by Northern blot and a binding assay using 125I-labeled IL-17. The activation of nuclear factor-kappaB (NF-kappaB) was assessed by an electrophoretic gel mobility shift assay (EMSA).

RESULTS

IL-17 induced a dose-dependent increase in IL-8 and MCP-1 secretion. The effects of IL-17 on IL-8 and MCP-1 mRNA abundance reached a maximum as early as 3 h. and then gradually decreased. IL-17 and IFN-gamma synergistically increased IL-8 secretion and additively enhanced MCP-1 secretion. IFN-gamma induced a weak increase in IL-17R mRNA abundance, but incubation with IFN-gamma for 24 h had no effects on 125I-labeled IL-17-binding, indicating that the co-stimulatory effects of IL-17 and IFN-gamma were not regulated by the modulation of IL-17R expression. Furthermore, IL-17 induced a rapid increase in NF-kappaB DNA-binding activity, and the combination of IL-17 and IFN-gamma further enhanced NF-kappaB DNA-binding activity.

CONCLUSIONS

In conclusion, it becomes clear that IL-17 is an inducer of IL-8 and MCP-1 secretion in human pancreatic periacinar myofibroblasts. The combination of IL-17 with IFN-gamma further enhances chemokine secretion. These findings indicate a linkage between T-cell-mediated immunity and inflammatory responses in the pancreas.

High mortality and severe immunosuppression in hospitalized patients with pulmonary tuberculosis and HIV-2 infection in Guinea-Bissau

The aim of this study was to prospectively compare the clinical outcomes in HIV-2-infected and HIV-negative patients with culture-confirmed pulmonary tuberculosis, evaluate immunological changes and investigate risk factors for decreased survival in HIV-2-positive subjects. From 1994 to 1997, 127 consecutive patients with pulmonary tuberculosis were included at the Raoul Follereau Hospital in Bissau, the capital of Guinea-Bissau. All subjects were initially hospitalized, and then followed to the end of the 8-month treatment period. CD4 T-lymphocyte counts were determined by flow cytometry before, during and at the end of the treatment period. The prevalences of HIV-1, HIV-2 and HIV-1/HIV-2 dual reactivity were 8.7%, 23.6% and 9.4%, respectively (95% confidence intervals 3.8-13.6, 16.2-31.0 and 4.4-14.5, respectively). The mortality rate during the study period was significantly higher in HIV-2-positive (p < 0.01) and HIV-1/HIV-2 dually reactive (p < 0.01) patients than in HIV-negative individuals (52.9, 83.3 and 8.7 per 100 person-years, respectively). In HIV-1-positive patients the mortality rate was 30.8/100 person-years (p = NS). Baseline total CD4 cell counts were 213, 104, 235 and 624 x 10(6)/l (% CD4 = 17, 15, 20 and 40) among HIV-1-, HIV-2- and HIV-1/HIV-2-positive and HIV-negative subjects, respectively. The median rates of change per year of total CD4 cell counts in HIV-2-positive and HIV-negative subjects were 66 and 340 x 10(6)/l, respectively (interquartile ranges -78-249 and 21-624). In conclusion, we found a significantly higher mortality rate in HIV-2-positive compared to HIV-negative individuals. Baseline CD4 cell counts were markedly suppressed and similar in all 3 HIV-positive groups, and in a multivariate logistic regression analysis a value of CD4 percentage of < 10 was shown to be an independent predictor of decreased survival in HIV-2-infected subjects.

Cooperation of interleukin-17 and interferon-gamma on chemokine secretion in human fetal intestinal epithelial cells

Interleukin (IL)-17 is a newly identified T cell-derived cytokine that can regulate the functions of a variety of cell types. In this study, we investigated the effects of IL-17 and interferon (IFN)-gamma on chemokine secretion in human fetal intestinal epithelial cells. IL-8 and monocyte chemoattractant protein (MCP)-1 secretion by the human fetal intestinal epithelial cell line, intestine-407, was evaluated by ELISA and Northern blot. The expression of IL-17 receptor (R) was analysed by a binding assay using [(125)I]-labelled IL-17. The activation of nuclear factor-kappa B (NF-kappa B), NF-IL6 and AP-1 was assessed by an electrophoretic gel mobility shift assay (EMSA). IL-17 induced a dose-dependent increase in IL-8 and MCP-1 secretion. The inducing effects of IL-17 on IL-8 and MCP-1 mRNA abundance reached a maximum as early as 3 h, and then gradually decreased. IL-17 and IFN-gamma synergistically increased IL-8 and MCP-1 secretion and mRNA abundance. IFN-gamma induced a weak increase in IL-17 R mRNA abundance, and incubation with IFN-gamma for 24 h enhanced [(125)I]-labelled IL-17-binding by 2.4-fold. IL-17 rapidly induced the phosphorylation and degradation of I kappa B alpha molecules, and the combination of IL-17 and IFN-gamma induced a marked increase in NF-kappa B DNA-binding activity as early as 1.5 h after the stimulation. Furthermore, this combination induced an increase in NF-IL-6 and AP-1 DNA-binding activity. In conclusion, it becomes clear that IL-17 is an inducer of IL-8 and MCP-1 secretion by human fetal intestinal epithelial cells. The combination of IL-17 with IFN-gamma synergistically enhanced chemokine secretion. These effects of IL-17 and IFN-gamma might play an important role in the inflammatory responses in the intestinal mucosa.

Plasma viral load in HIV-1 and HIV-2 singly and dually infected individuals in Guinea-Bissau, West Africa: significantly lower plasma virus set point in HIV-2 infection than in HIV-1 infection

BACKGROUND

The intriguing differences in the natural course, transmissibility, and epidemiological characteristics of human immunodeficiency virus type 1 (HIV-1) and HIV-2 are still insufficiently explained. Differences in plasma viral load are an obvious possibility, but this has been difficult to investigate because of the lack of tests for HIV-2 RNA.

OBJECTIVE

To compare plasma HIV RNA load between individuals infected with HIV-1 and HIV-2 in Guinea-Bissau, a West African country with high prevalence and incidence of HIV-1 and HIV-2 infection.

METHODS

A total of 102 participants were recruited from ongoing prospective cohort studies. These included 19 HIV-1 and 29 HIV-2 seroincident cases tested at a median of less than 2 years after seroconversion as well as seroprevalent cases with single (9 HIV-1 cases and 31 HIV-2 cases) or dual (n = 14) infections. Plasma HIV RNA levels were determined by a commercial HIV-1 assay and an experimental HIV-2 assay based on the same principles.

RESULTS

The viral set point, ie, the semi-equilibrium reached after seronconversion, was 28-fold lower in recent HIV-2 seroconverters than in recent HIV-1 seroconverters (median, 2500 and 70,000 RNA copies per milliliter, respectively; P<. 001). This difference appeared to persist to symptomatic stages of the diseases. Dually infected individuals had lower plasma HIV-1 RNA levels than singly infected individuals.

CONCLUSIONS

The differences between HIV-1 and HIV-2 infection are likely to be caused by differences in plasma viral set point and load, but the mechanisms through which HIV-2 infection is contained to a higher degree than HIV-1 remain to be identified. Arch Intern Med. 2000;160:3286-3293.