New perspective on Behçet's disease

Surgical management of aortic regurgitation secondary to Behcet's disease

Background

Aortic regurgitation (AR) related to Behcet's disease (BD) is rare, but usually fatal. Perivalvular leakage (PVL) is high if AR related to BD treated with regular AVR. In this study, we report the surgical management of AR secondary to BD.

Methods

Between September 2017 and April 2022, 38 patients with AR secondary to Behcet's disease had surgery in our center. 17 patients did not have a BD diagnosis before surgery, 2 of them were diagnosed during surgery and received Bentall procedure. The remaining 15 patients received conventional AVR. 21 patients were diagnosed as BD before surgery, all of them received modified Bentall procedures. All patients were followed up by regular outpatient visits, transthoracic echocardiogram and CT angiography were performed to evaluate the aorta and aortic valve.

Results

Seventeen patients did not have a BD diagnosis at the time of surgery. Out of them, 15 patients received conventional AVR, and a total of 13 patients suffered PVL after surgery. Twenty-one patients had a BD diagnosis before surgery. They received modified Bentall procedures and IST and steroids were given both pre- and post-surgery. In this group treated with Bentall procedure no patient suffered PVL during follow up.

Conclusions

PVL is a complex scenario after conventional AVR for AR in BD. Modified Bentall procedure seems superior to isolated AVR in these cases. The use of IST and steroids before and after surgery in combination with modified Bentall procedure could have a role in effectively reducing PVL.

Behçet's Disease: Different Systemic Manifestations at Different Ages

Behçet's disease, an inflammatory condition, can involve various systems. The disease usually manifests with dermatologic and ocular signs but can also cause serious symptoms due to pulmonary or neurologic involvement. Although the onset may occur at any age, it typically emerges in the second to fourth decades of life. As in the case presented here, Behçet's disease can manifest with the central nervous system involvement early in life and pulmonary involvement in adulthood.

Behçet's disease‬ and familial Mediterranean fever: Two sides of the same coin or just an association? A cross-sectional study‬

BACKGROUND

Familial Mediterranean fever (FMF) is a genetic disease, characterized by attacks of fever, arthritis, serositis and pain. Behçet's disease (BD) is an inflammatory disorder with a genetic basis, characterized by oral and genital ulcers, uveitis, pustular erythematous cutaneous lesions, arthritis, central nervous system involvement and possible vascular manifestations such as venous thrombosis, arteritis and aneurysms.

OBJECTIVES

To investigate the association and actual differentiation between these two entities in a large-scale population-based study.

METHODS

Data for this study was collected from the databases of "Clalit Health Services", the largest state-mandated health service organization in Israel. All adult members diagnosed with BD were included (n=892) and as well as their age- and sex-matched controls (n=4444), creating a cross-sectional population-based study. Medical records of all subjects were analyzed for documented FMF. A logistic regression model was done to estimate how BD, age, gender, BMI, ethnicity and socioeconomic status contributed as risk factors for FMF.

RESULTS

The proportion of FMF in patients with BD increased compared with those reported in controls (5.83% and 0.23%, respectively, P<0.001). This coexistence was prominent among both sex groups but was much stronger among female BD patients (females with OR of 177 and of 8.4 in males, P<0.001). In a multivariate analysis, BD was identified as an independent risk factor for FMF (OR 25.16, 95% CI 13-53.3).

CONCLUSION

BD diagnosis was found to be independently associated with higher incidence of FMF, especially in females, people of Arab descent and BMI>30. Our data imply that understating the differentiation between FMF and BD is not evident and clear in a real-life population of patients with BD.

Evaluation of KIR3DL1/KIR3DS1 polymorphism in Behçet's disease

The Behçet's disease (BD)-associated human leukocyte antigen (HLA) allele, HLA-B*51 (B*51), encodes a ligand for a pair of allelic killer immunoglobulin-like receptors (KIR) present on cytotoxic cells-KIR3DL1, which inhibits their cytotoxicity, and KIR3DS1, which activates their cytotoxic activity. We tested whether KIR-regulated mechanisms contribute to BD by testing for association of KIR3DL1/KIR3DS1 genotypes with disease in 1799 BD patients and 1710 healthy controls from Turkey, as well as in different subsets of individuals with HLA-type-defined ligands for the KIR3D receptors. HLA types were imputed from single nucleotide polymorphism genotypes determined with the Immunochip. The presence of inhibitory KIR3DL1 or activating KIR3DS1 alleles did not differ significantly between cases and controls (KIR3DL1: 92.9% vs 93.4%, P_dominant=0.55; KIR3DS1: 42.7% vs 41.0%, P_dominant=0.29). The KIR3DL1/KIR3DS1 alleles were also present at similar frequencies among cases and controls bearing HLA-B with a Bw4 motif; HLA-B with a Bw4 motif with isoleucine at position 80; and HLA-B*51. Our results suggest that pathogenic mechanisms associated with HLA-B*51 do not primarily involve differential interactions with KIR3DL1 and KIR3DS1 receptors. However, due to the complexity of this locus (that is, sequence variation and copy number variation), we cannot exclude a role for other types of KIR variation in the pathogenesis of BD.

Behçet's disease physiopathology: a contemporary review

Behçet’s disease, also known as the Silk Road Disease, is a rare systemic vasculitis disorder of unknown etiology. Recurrent attacks of acute inflammation characterize Behçet’s disease. Frequent oral aphthous ulcers, genital ulcers, skin lesions and ocular lesions are the most common manifestations. Inflammation is typically self-limiting in time and relapsing episodes of clinical manifestations represent a hallmark of Behçet’s disease. Other less frequent yet severe manifestations that have a major prognostic impact involve the eyes, the central nervous system, the main large vessels and the gastrointestinal tract. Behçet’s disease has a heterogeneous onset and is associated with significant morbidity and premature mortality. This study presents a current immunological review of the disease and provides a synopsis of clinical aspects and treatment options.

Elevated serum levels of calprotectin (MRP8/MRP14) in patients with Behçet's disease and its association with disease activity and quality of life

BACKGROUND

Behçet's disease (BD) is an inflammatory disease with multisystem chronic vasculitis. The disease is characterized by attacks of oral and genital ulcerations, skin lesions, arthritis, uveitis and deep vein thrombosis. The main histopathological feature is known to be vascular inflammatory change. Calprotectin (MRP8/MRP14) has been identified as an important alarmin that is expressed by activated phagocytes, granulocytes, monocytes and vascular endothelial cells, recognized by toll-like receptors, and induces a thrombogenic and inflammatory response in human microvascular endothelial cells.

AIM

We aimed to investigate the serum levels of calprotectin in patients with BD and its association with disease activity and quality of life.

MATERIALS AND METHODS

Forty-eight patients (25 males and 23 females) and 47 healthy controls (29 males and 18 females) were included to study. BD Current Activity Form (BDCAF) was used to assess the disease activity of patients with BD. Quality of life was assessed by using the Nottingham Health Profile (NHP). Depression and anxiety symptoms were assessed by using the Hospital Anxiety and Depression Scale (HADS). Serum level of calprotectin was determined using an ELISA kit. Results. Serum levels of calprotectin was significantly higher in patients with BD compared to healthy controls (p = 0.001). Serum levels of calprotectin did not correlate with the sores of BDCAF, NHP and HADS.

CONCLUSION

Calprotectin may play a significant role in the pathogenetic mechanisms of BD. Further insight into this area of research might provide opportunities to develop novel treatment strategies.

Behçet's disease associated with myelodysplastic syndrome with elevated levels of inflammatory cytokines

Abstract We report the case of a 56-year-old Japanese woman with Behçet's disease and myelodysplastic syndrome (MDS), who had a history of episodic high-grade fever, recurrent oral and genital ulcers, and erythema nodosum, during a 13-year period from 1989 to 2002. Bone marrow aspirates obtained in January 1995 showed refractory anemia with trisomy 8, a subtype of MDS. Her serum levels of soluble interleukin-2 receptor (IL-2R), interferon-γ, IL-1β, IL-6, IL-8, and granulocyte-macrophage colony stimulating factor in the active state were higher than those in the inactive state, whereas those of tumor necrosis factor-α and IL-10 did not increase even in the active state. In this case, it was speculated that a T-cell immune response might have been involved in the disease pathogenesis, and that the repeated febrile episodes might have been a manifestation of neutrophil hyperfunction induced by increased serum levels of inflammatory cytokines.

Animal Models in Behçet's Disease

Behçet's disease is a chronic, recurrent, multisystemic, inflammatory disorder affecting mainly the oral and urogenital mucosa and the uveal tract. Although the etiology and pathogenesis of Behçet's disease are unknown, numerous etiologies have been proposed, including environmental, infectious, and immunological factors; an autoimmune basis, characterized by circulating immune complexes and complement activation, has gained increasing acceptance. To test and understand immunopathogenesis of Behçet's disease, animal models were developed based on enviromental pollutants, bacterial and human heat shock protein derived peptides, and virus injections. Using these animal models separately and/or concurrently allows for a more effective investigation into Behçet's disease. Animal models developed in the last 10 years aim at the development of efficient and safe treatment options.

Expression of Pro-inflammatory Protein S100A12 (EN-RAGE) in Behçet's Disease and Its Association with Disease Activity: A Pilot Study

Background

S100A12 is a member of the S100 family of calcium-binding proteins and is secreted either in inflamed tissues or in the bloodstream by activated neutrophils. Expression of S100A12 has been reported in various diseases, especially non-infectious inflammatory diseases, such as Kawasaki disease, giant cell arteritis and inflammatory bowel disease.

Objective

This study was conducted to determine both the tissue expression and the serum levels of S100A12 in Behçet's disease (BD) patients and the correlation of the S100A12 serum level with disease activity of BD.

Methods

We included in this study ten BD patients who fulfilled the criteria for diagnosis, according to the International Study Group for BD. The activity of BD was calculated using the BD Current Activity Form. The serum concentrations of both S100A12 and interleukin-8 were measured by the enzyme-linked immunosorbent assay, before and after treatment. Immunohistochemical studies were also performed to detect S100A12 expression in the skin.

Results

The serum S100A12 level was significantly increased in the active BD period (p<0.001), in the inactive BD period (p=0.041) and in patients with active Kawasaki disease (p=0.028), compared with the serum level in the healthy controls. The serum S100A12 level decreased significantly from baseline, compared to post-treatment (p=0.017). The activity score of BD was significantly correlated with the serum level of S100A12 (Spearman's coefficient=0.464, p=0.039). Immunohistochemical studies showed that S100A12 was strongly expressed in the erythema nodosum-like skin lesions of patients.

Conclusion

S100A12 contributes to the pathogenesis of BD related to neutrophil hyperactivity and reflects the disease activity in BD patients.

The demonstration of serum interleukin 6–8, tumor necrosis factor-alpha, complement, and immunoglobulin levels in Behçet’s disease with ocular involvement

PURPOSE

To investigate whether there are alterations in the humoral immune system in patients with Behçet's disease (BD) with ocular involvement.

METHODS

Twenty-four BD patients with active uveitis and without any other manifestations of the disease were included in Group I-a. The same patients were reassessed during the convalescence period and assigned to Group I-c. Moreover, 24 age- and sex-matched healthy controls (Group II) were included in the study. Serum levels of immunoglobulin (Ig) A, IgM, complement (C) 3, C4, interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) in Groups I-a, I-c, and II were measured and compared.

RESULTS

IgA, C3, C4, IL-6, IL-8, and TNF-alpha levels were higher in Group I-a than in Groups I-c and II.

CONCLUSIONS

IgA-, C3-, C4-, IL6-, IL8-, and TNF-alpha-mediated mechanisms might be responsible for ocular lesions in BD.

Investigation of the association between Toll-like receptor 2 gene polymorphisms and Behçet's disease in Japanese patients

Behçet's disease (BD) is a chronic systemic inflammatory disorder characterized by recurrent ocular symptoms, oral and genital ulcers, and skin lesions. The etiology of BD is still uncertain, but genetic and environmental factors likely both play an important role in BD development. In the present study, we investigated whether polymorphisms of Toll-like receptor 2 (TLR2), previously reported to recognize BD candidate antigens, are associated with BD. Two hundred Japanese patients with BD and 128 Japanese healthy controls were recruited. We genotyped five single-nucleotide polymorphisms (SNPs) in the TLR2 gene and assessed the allele/genotype diversity between cases and controls for all SNPs. No significant differences in the frequency of TLR2 alleles, genotypes, and haplotypes in the BD cases were detected compared with the controls. These data indicate that TLR2 polymorphisms do not play an important role in the development of BD.

Role of Txk, a member of the Tec family of tyrosine kinases, in immune-inflammatory diseases

Txk/Rlk, a member of the Tec family of tyrosine kinases, is an important signaling mediator. We previously reported that human Txk is expressed in Th1/Th0 cells, and Txk translocates from cytoplasm into nuclei upon activation. Txk regulates specifically interferon-gamma gene transcription. Txk, poly(ADP-ribose) polymerase 1, and elongation factor 1alpha make a complex to bind to interferon-gamma gene promoter region-53/-39 (Txk responsive element) to exert positive effects on transcription as a Th1 cell-associated transcription factor. Txk expression is enhanced in rheumatoid arthritis and Behçet's disease, where Th1 dominant immunity occurs. In bronchial asthma and atopic dermatitis, typical Th2 diseases, Txk expression is reduced. Modulation of Txk expression by gene transfer or similar modality may lead to the correction of aberrant immunity and, consequently, disease treatment.

Tissue Doppler velocities of the right and left ventricles and their association with C-reactive protein and homocysteine levels in Behcet's disease

In the present study, we aimed to investigate whether tissue Doppler imaging could provide more information than standard echocardiography about left and right ventricular functions and their relations to homocysteine and C-reactive protein (CRP) levels in the course of Behcet's disease (BD). In the right ventricle, patients with BD had lower early diastolic tricuspid annular velocity and early diastolic/late diastolic tricuspid annular velocity ratios than the control group. Mitral and tricuspid annular systolic velocities did not significantly differ; however, diastolic velocities were correlated with duration of the disease. In addition, early/late diastolic mitral annular velocity ratio and early/late diastolic tricuspid annular velocity ratios showed an inverse relation with ocular involvement, serum homocysteine, and CRP levels in patients with BD.

Vascular endothelial function and plasma homocysteine levels in Behcet's disease

The purpose of the present study was to test endothelial function and to determine if plasma homocysteine levels are associated with endothelial injury in patients with Behcet's disease (BD). Flow-mediated dilation in patients with BD was smaller than that of control subjects (p = 0.001), and mean plasma homocysteine levels in patients with BD were significantly higher (p = 0.0001). On regression analysis, only mean plasma homocysteine concentration was independently related to flow-mediated dilation (F = 5.7, p = 0.001).

Treatment of recurrent perforating intestinal ulcers with thalidomide in Behçet's disease

OBJECTIVE

To report the beneficial effects of thalidomide on recurrent perforating intestinal ulcers in a patient with Behçet's disease (BD).

CASE SUMMARY

A 24-year-old Turkish woman with BD was admitted to our hospital because of severe abdominal pain and vomiting. She had been receiving colchicine 1.5 mg/day and azathioprine 150 mg/day for treatment of BD for 2 years. During emergency laparatomy, 2 perforating ulcers were detected in the anterior cecum, which were treated with debridement and primary repair. She experienced 2 more episodes of intestinal perforations during the second and fifth weeks despite intense immunosuppressive treatment with methylprednisolone and cyclophosphamide. New intestinal perforations were found in the posterolateral cecum and transverse colon during the second operation and in the terminal ileum during the third one. Thalidomide 100 mg/day was then started, and the symptoms disappeared within 2 weeks. The woman experienced no other intestinal perforation during the follow-up period of 4 months.

DISCUSSION

The mode of action of thalidomide in BD is still unclear. In BD, various cytokines have been shown to be abnormally expressed and neutrophils are overactive. This is a possible mechanism of action with thalidomide reducing both tumor necrosis factor and the neutrophil migration.

CONCLUSIONS

Thalidomide may be an effective alternative treatment for BD patients with recurrent and perforating intestinal ulcers despite intense immunosuppressive therapy.

Pathogenesis of Adamantiades-Behçet's disease

The aetiology of Adamantiades-Behçet's disease remains unknown and its pathogenesis is not fully understood. Linked intrinsic and extrinsic factors are thought to contribute to the development of the disease, which probably occurs by environmental triggering of a genetically determined disorder. Transmission is solely vertical, indicating that the disease is not contagious. Genetic factors have been investigated and a significant link of HLA-B51, especially of HLA-B5101, has been identified. However, none of the functional correlates of the disease appear to be restricted by HLA-B51. Recently, the role of the genes encoding TNF, Tap proteins and MICA has been emphasised. Extrinsic pathogenetic candidates have been identified, including bacterial ( Streptococcus sanguis, Mycoplasma fermentas) and viral (human herpes virus) antigens and environmental pollution, which may cross-react with oral mucosal antigens and induce immunological mechanisms. A common factor linking some of the possible pathogenetic agents is extrinsically induced tissue stress or heat shock proteins, which react with host tissues and elicit significant Th1 cell responses. Neutrophils may also play a role in the pathogenesis of the disease, as they are attracted by macrophages and activated endothelial cells, which release cytokines and chemokines (especially IL-8) at the site of the lesions, and thus contribute to tissue damage and self maintenance of inflammation. Endothelial activation leading to a chronic local inflammation process together with platelet and serum factors enhance coagulation and thrombosis.

Conjunctival ulcers in Behçet's disease

PURPOSE

To describe the occurrence of conjunctival ulcers as a manifestation of Behçet's disease.

DESIGN

Retrospective, noncomparative, interventional case series with histopathologic correlation.

METHODS

Six patients who fulfilled the diagnostic criteria for Behçet's disease and presented with painful conjunctival ulcers were included in the study. Three of these ulcers were biopsied and studied histologically and immunohistochemically. The lesions were treated with topical or subconjunctival injection of corticosteroids and, in one case, with oral indomethacin.

RESULTS

Although all six patients fulfilled the diagnostic criteria for Behçet's disease, two developed uveitis and other signs of Behçet's disease only months to years after the appearance of the conjunctival ulcers. The 3- to 5-mm, round to oval ulcers were located in the limbal and/or bulbar conjunctiva. Histopathology revealed disrupted epithelium, infiltration of both acute and chronic inflammatory cells, and high endothelial venules. Immunohistochemical analysis of the infiltrating lymphocytes revealed primarily T-cell populations admixed with several B cells and CD68-positive histiocytes. After treatment, the conjunctival lesions invariably healed without scarring.

CONCLUSIONS

In addition to the oral and genital ulceration, ulcers can also be found in the conjunctiva of patients with Behçet's disease. Although this is a rare clinical sign, when accompanied by uveitis or orogenital ulcers, it may suggest a diagnosis of Behçet's disease.

Pulmonary complications of Behçet's disease

Our knowledge about pulmonary complications of Behçet's disease continues to evolve, but we need controlled trials for the management of the disease. The main goal should be to elucidate the pathogenesis and standardize the management according to the underlying pathologic process.

Identification of alpha-tropomyosin as a target self-antigen in Behçet's syndrome

Behçet's syndrome is a multi-system inflammatory disease affecting mainly the oral and urogenital mucosa and the uveal tract. The etiology and pathogenesis of Behçet's syndrome are unknown, but autoimmune mechanisms are implicated. We initiated this work to identify self-antigens targeted by patients with Behçet's syndrome. We used patient sera to immuno-blot tissue lysates, and we found that some patients manifest antibodies to a 37-kDa band. The 37-kDa band was detected in extracts of skin, tongue, vagina, muscle and heart but not in brain, kidney, lung, liver, intestine and thymus. In-gel digestion and mass spectrometry revealed the band to be alpha-tropomyosin. Autoimmunity to alpha-tropomyosin can be pathogenic; immunized Lewis rats developed lesions in the uveal tract and skin, with features of Behçet's disease.

Novel approaches to Behçet's disease

Behçet's disease is a systemic inflammatory disorder. The patients have repeated exacerbations and remissions of the symptoms. This disease may produce a wide variety of symptoms. In mild cases, mucocutaneous lesions are only the symptoms during the whole clinical course, whereas ocular lesions, which occur in about 70% of the patients, can cause blindness. Involvement of the gastrointestinal tract, CNS and large vessels is less frequent, but sometimes life-threatening. Colchicine, NSAIDs, corticosteroids and immunosuppressants are employed for the treatment of Behçet's disease with therapies tailored to individual patients depending on clinical manifestations. Cyclosporin A is the most effective drug for ocular lesions at the present, but its neurotoxicity, which occurs in 20-30% of patients receiving cyclosporin A, restricts usage of the agent. Many patients are still suffering from a severe form of uveitis and serious neurological symptoms, which are resistant to any conventional therapies. New drugs have been investigated for Behçet's disease. IFN-alpha therapy has shown significant efficacy for common symptoms including ocular lesions without any serious adverse effects. Thalidomide and its analogues also appear to be applicable to this disease. Monoclonal antibody to TNF-alpha is now in clinical trials. These novel therapeutic approaches may provide much needed treatment options for patients with Behçet's disease.

Association of cytomegalovirus interstitial pneumonitis with HLA-type following allogeneic bone marrow transplantation

Certain human leukocyte antigens may increase the risk of cytomegalovirus interstitial pneumonitis, an important complication of bone marrow transplantation. The prevalence of this pneumonitis was compared between patients possessing either HLA-B51 or HLA-B52 and patients without either antigen. The role of tumor necrosis factor-alpha in cytomegalovirus interstitial pneumonitis was also studied. Among 72 patients undergoing allogeneic bone marrow transplantation at our institution during the past 5 years, HLA-B51 or -B52 was detected in 29. Among these 29 patients, 13 (45%) developed cytomegalovirus interstitial pneumonitis, a significantly higher rate (P < 0.001) than among patients without these HLA types (4/43, 9%). In the pre-conditioning and stable phases, tumor necrosis factor-alpha levels were higher in patients with HLA-B51 or HLA-B52 than in patients without (P < 0.05; t-test). Throughout the period from pre-conditioning to around day 40, except on day 0, tumor necrosis factor-alpha levels were also significantly higher (P < 0.05 to P < 0.001) in patients developing cytomegalovirus infection than in those without it. These results suggest that HLA-B51 and HLA-B52 may be risk factors for cytomegalovirus interstitial pneumonitis after bone marrow transplantation, with an increase of tumor necrosis factor-alpha also being involved.

Clinical patterns of neurological involvement in Behçet's disease: evaluation of 200 patients. The Neuro-Behçet Study Group

In order to define the patterns of neurological involvement in Behçet's disease and to assess prognostic factors, 558 files of the neuro-Behçet out-patient clinic were reviewed. Those patients without any evidence of objective neurological involvement as well as the patients with other possible explanations for the neurological picture, and cases not fulfilling the criteria for Behçet's disease were excluded. The remaining 200 cases (155 male, 45 female) were evaluated: 162 had parenchymal CNS involvement (brainstem or 'brainstem +' involvement in 51%, spinal cord involvement in 14%, hemispheric involvement in 15% and isolated pyramidal signs in 19%) while 38 had secondary or non-parenchymal CNS involvement. In the first group the most common findings were pyramidal signs, hemiparesis, behavioural changes and sphincter disturbance, whereas in the second group the syndrome of raised intracranial pressure due to dural sinus thrombosis was the main clinical manifestation. In 60% of the cases with parenchymal involvement, CSF was hypercellular and/or had an elevated protein level, whereas in cases with non-parenchymal involvement the CSF was usually normal except for the elevated pressure. In more than half of the patients with parenchymal involvement, MRI showed brainstem and/or basal ganglion lesions. Forty-one per cent of the cases had a course with at least one attack and remission, another 28% also had attack(s) but showed secondary progression, 10% had primary progression and 21% had silent neurological involvement. Survival analysis was performed in patients who had at least a 3-year duration of neurological disease. Parenchymal involvement, elevated protein and/or pleocytosis in the CSF, 'brainstem +' type involvement, primary or secondary progressive course and relapse during steroid tapering were all associated with a poorer prognosis.

Behçet's disease: an update

No diagnostic laboratory test or curative treatment yet exists for Behçet's disease. However, genetic studies have identified those most at risk, and newer molecular biologic investigations further elucidate the etiology and shed light on potential triggers. This article reviews current therapies.

Differential posttranslational processing confers intraspecies variation of a major surface lipoprotein and a macrophage-activating lipopeptide of Mycoplasma fermentans

The malp gene of Mycoplasma fermentans is shown to occur in single copy but to encode two discrete translated forms of lipid-modified surface protein that can be differentially expressed on isolates within this species: MALP-2, a 14-amino-acid (2-kDa) lipopeptide with potent macrophage-stimulatory activity (P. F. Mühlradt, M. Kiess, H. Meyer, R. Süssmuth, and G. Jung, J. Exp. Med. 185:1951-1958, 1997), and MALP-404, an abundant, full-length (404-amino-acid) surface lipoprotein of 41 kDa, previously designated P41 (K. S. Wise, M. F. Kim, P. M. Theiss, and S.-C. Lo, Infect. Immun. 61:3327-3333, 1993). The sequences, transcripts, and translation products of malp were compared between clonal isolates of strains PG18 (known to express P41) and II-29/1 (known to express high levels of MALP-2). Despite conserved malp DNA sequences containing full-length open reading frames and expression of full-length monocistronic transcripts in both isolates, Western blotting using a monoclonal antibody (MAb) to the N-terminal MALP-2 peptide revealed marked differences in the protein products expressed. Whereas PG18 expressed abundant MALP-404 with detectable MALP-2, II-29/1 revealed no MALP-404 even in samples containing a large comparative excess of MALP-2. Colony immunoblots with the MAb showed uniform surface expression of MALP-2 in II-29/1 populations. A second MAb to an epitope of MALP-404 outside the MALP-2 sequence predictably failed to stain II-29/1 colonies but uniformly stained PG18 populations. Collectively, these results provide evidence for novel posttranscriptional (probably posttranslational) processing pathways leading to differential intraspecies expression of a major lipoprotein, and a potent macrophage-activating lipopeptide, on the surface of M. fermentans. In the course of this study, a striking conserved motif (consensus, TD-G--DDKSFNQSAWE--), designated SLA, was identified in MALP-404; this motif is also distributed among selected lipoproteins and species from diverse bacterial genera, including Bacillus, Borrelia, Listeria, Mycoplasma, and Treponema. In addition, malp was shown to flank a chromosomal polymorphism. In eight isolates of M. fermentans examined, malp occurred upstream of an operon encoding the phase-variable P78 ABC transporter; but, in three of these isolates, a newly discovered insertion sequence, IS1630 (of the IS30 class), was located between these genes.

An uncommon cause of oral ulcers

A 25-year-old Hispanic woman presented with painful oral ulcers, a sore throat, and dysphagia of two weeks' duration. She was treated empirically with acyclovir for presumed herpes simplex stomatitis and esophagitis and sent home. A week later, she returned with complaints of worsening sore throat, fever (as high as 38.9 degrees C), and cough producing yellow-green sputum. She had not had chills, shortness of breath, burning on urination, or a change in bowel habits.