The ever-expanding association between rheumatologic diseases and tuberculosis

Rheumatoid arthritis autoantibodies benefit from inflammation temperatures

BACKGROUND

Symptoms of rheumatoid arthritis are associated with local inflammation and may include low-grade fever.

OBJECTIVE

To establish the role of fever/inflammation temperatures (38℃-39℃) on the activity of autoantibodies and therapeutic antibodies relevant for rheumatoid arthritis.

METHODS

Through the use of molecular dynamics and free energy calculations, we investigated the role of temperature on the formation of pertinent immune complexes.

RESULTS

Rheumatoid arthritis autoantibodies bind with higher affinity at febrile/inflammation temperatures.

CONCLUSIONS

Fever may modulate binding affinity of autoantibodies relevant for rheumatoid arthritis.

Tuberculous extensor tenosynovitis of the wrist in a patient with systemic lupus erythematosus mimicking a giant cell tumour: A case report and review of literature

INTRODUCTION & IMPORTANCE

Extrapulmonary tuberculous involvement of the musculoskeletal system is not common and seen in less than 10 % of all cases. The bidirectional association between tuberculous infection of the musculoskeletal system and rheumatological diseases has been widely recognized and arises both as a result their underlying immunosuppressive state and of drug induced immunosuppression.

CASE PRESENTATION

A 45-year-old female on treatment for SLE, in remission, presented with a slow growing mass over the dorsum of the right wrist with functional impairment which was clinically and radiologically compatible with a giant cell tumour. Pathological examination after surgical excision revealed pathognomonic features of tuberculous tenosynovitis. Multidrug antituberculous therapy was commenced.

CLINICAL DISCUSSION

Clinical diagnosis of tuberculous tenosynovitis is difficult due to the non-specific clinical symptoms and signs. Laboratory investigations are usually normal except for ESR which may be elevated. Delay in establishing therapy may lead to dissemination of mycobacteria to the surrounding bursae, muscles and soft tissue leading to joint and tendon damage. Detection of mycobacteria through TB culture and microscopy of the specimen has a low sensitivity and therefore treatment should be promptly initiated when typical pathological findings are seen.

CONCLUSION

Tuberculous tenosynovitis of the extensor tendons is a rare clinical presentation and must be suspected in cases of chronic and recurrent tendon sheath infection especially in an immunocompromised patient in a TB endemic country. The lack of clinical suspicion, nonspecific findings and mimicry of other conditions can lead to delayed diagnosis and complications.

Tuberculosis and Autoimmunity

Tuberculosis remains a common and dangerous chronic bacterial infection worldwide. It is long-established that pathogenesis of many autoimmune diseases is mainly promoted by inadequate immune responses to bacterial agents, among them Mycobacterium tuberculosis. Tuberculosis is a multifaceted process having many different outcomes and complications. Autoimmunity is one of the processes characteristic of tuberculosis; the presence of autoantibodies was documented by a large amount of evidence. The role of autoantibodies in pathogenesis of tuberculosis is not quite clear and widely disputed. They are regarded as: (1) a result of imbalanced immune response being reactive in nature, (2) a critical part of TB pathogenicity, (3) a beginning of autoimmune disease, (4) a protective mechanism helping to eliminate microbes and infected cells, and (5) playing dual role, pathogenic and protective. There is no single autoimmunity-mechanism development in tuberculosis; different pathways may be suggested. It may be excessive cell death and insufficient clearance of dead cells, impaired autophagy, enhanced activation of macrophages and dendritic cells, environmental influences such as vitamin D insufficiency, and genetic polymorphism, both of Mycobacterium tuberculosis and host.

Neglected tropical rheumatic diseases

The complexities of dealing with rheumatic diseases in tropical countries are diverse and likely due to limited health care infrastructure, lack of diagnostic and therapeutic facilities, impact of dominant prevailing diseases, and the challenges of differentiating from infectious and non-infectious disease mimics. Several tropical diseases present with musculoskeletal and rheumatic manifestations and often pose a diagnostic dilemma to rheumatologists. The diagnosis is often delayed or the disease is misdiagnosed, leading to poor patient outcomes. Endemic tropical diseases like tuberculosis and leprosy have myriad rheumatic presentations and remain important differentials to consider in patients with rheumatic manifestations. Infection with human immunodeficiency virus is a great masquerade and can mimic manifestations of multiple diseases. The role of viral infections in triggering and perpetuating autoimmunity is well known and chikungunya arthritis is a classic example of the same. This review highlights the rheumatic manifestations of tropical diseases and aims to create awareness among the caregivers. Key Points • It is crucial to be aware and identify infectious diseases presenting with rheumatic manifestations in the tropics. • Presentations akin to classic rheumatic syndromes such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus and vasculitis are common.

First Case of Erythema Nodosum Associated With Pfizer Vaccine

Vaccine-related erythema nodosum is uncommon, especially after the coronavirus disease 2019 (COVID-19) vaccine. This study presents the first case of the Pfizer vaccine associated with erythema nodosum. A 22-year-old healthy woman presented with a five-day history of several red painful areas with swelling in the lower extremities that started one day after receiving the first dose of Pfizer vaccine. Past medical history, laboratory investigation, and chest radiograph revealed normal results. Erythema nodosum is an immune reaction that manifests as multiple, painful nodules commonly seen on the shin that resolved spontaneously two to eight weeks after the onset. In the absence of laboratory and chest radiograph abnormalities and shortly after receiving the Pfizer vaccine, vaccine-related erythema nodosum is the only possible explanation.

Tuberculosis in patients with systemic lupus erythematosus-a 37-year longitudinal survey-based study

BACKGROUND

Infections are one of the most common causes of morbidity and mortality in patients with systemic lupus erythematosus (SLE). SLE patients have a higher risk of tuberculosis (TB) infection due to impaired immune defence.

OBJECTIVES

To investigate the demographics, clinical characteristics and outcomes of patients with SLE and concomitant TB.

METHODS

Medical records of SLE patients with TB who were admitted to Peking Union Medical College (PUMC) Hospital in 1983-2019 were retrospectively reviewed. Age- and sex-matched SLE inpatients without TB were randomly selected as controls. Clinical and laboratory features and treatment were analysed and compared, and subjects were followed up to assess their outcome.

RESULTS

Of the 10 469 SLE inpatients, 249 (2.4%) were diagnosed with TB. Compared with controls, SLE/TB + patients exhibited higher frequency of prior haematologic, mucocutaneous and musculoskeletal system involvement, and prior treatment with potent glucocorticoid/immunosuppressive agents (GC/ISA). Arthritis and alopecia, positive T-SPOT.TB test and lymphocytopenia were more common in SLE/TB + patients. SLE/TB + patients with lupus before TB (SLE → TB) had higher risk of miliary TB (22.8%) and intracranial TB (16.5%) than SLE/TB + patients with lupus after TB (TB → SLE). SLE/TB + patients exhibited shorter long-term survival than SLE/TB- patients; those with poorer in-hospital outcomes had more severe lymphocytopenia and had received less treatment with ISAs.

CONCLUSION

Systemic lupus erythematosus patients treated vigorously with GC/ISA should be alerted of increased risk of TB infection, especially miliary and intracranial TB. Positive T-SPOT.TB and lymphocytopenia served as discriminatory variables between SLE/TB + and SLE/TB- patients. Lymphocytopenia was associated with poorer outcomes in SLE/TB + patients.

Case of Crohn's Disease Initially Misdiagnosed as Intestinal Tuberculosis Due to Active Pulmonary Tuberculosis

Differentiating Crohn's disease (CD) from intestinal tuberculosis (TB) is a challenge. In patients suspected of having CD or intestinal TB compounded with active pulmonary TB in its early stages, clinicians often lean towards a diagnosis of intestinal TB. A 14-year-old female patient was admitted with symptoms of abdominal pain and diarrhea with hematochezia. Colonoscopy revealed a stricture of the ileocecal valve and scattered longitudinal ulcers. Initial chest radiography showed consolidation in the left lower lobe of the lung. Chest CT revealed branching nodular opacities and consolidation. The TB PCR of the bronchial washing fluid was positive. The patient was diagnosed with pulmonary and intestinal TB. The colonoscopy findings favored CD. Despite this, anti-tubercular therapy was initiated based on the radiology findings and PCR test. After treatment with anti-tubercular therapy, the patient's diarrhea and abdominal pain worsened despite the improvement observed on her chest radiography. Follow-up colonoscopy revealed aggravation of her ulcers. The patient was diagnosed with CD and treated with prednisolone and mesalazine. Her clinical condition improved, and follow-up colonoscopy showed significant improvement of the ulcers. This case highlights the need for caution in diagnosis and suggests that clinicians consider reevaluation in similar cases.

Multifocal osteoarticular tuberculosis in a systemic lupus erythematosus (SLE) patient: a rarity or an underdiagnosed condition?

Tuberculosis (TB) and its association with rheumatic diseases have been widely recognised. Occurrence of multifocal skeletal involvement constitutes <5% of all skeletal TB cases. We present a Malay patient with multifocal osteoarticular TB (OATB). A 35 year-old SLE woman with background usage of corticosteroid therapy and Azathioprine presented with lupus nephritis flare. Renal biopsy revealed diffuse proliferative lupus nephritis and intravenous (IV) Cyclophosphamide 0.5 g/m² (850 mg) was initiated. One week later, patient complained dorsum of left hand and right knee swelling. On physical examination, patient was afebrile and the left hand swelling was cystic in consistency while right knee was warm and tender. Erythrocyte Sedimentation Rate (ESR) was 50 mm/hr and C-Reactive Protein (CRP) was 9.4 mg/L. Her Mantoux test was positive with 20 mm induration. Wrist radiograph and chest radiograph was normal. Musculoskeletal ultrasound showed 4th extensor compartment tenosynovitis with Doppler signal and right knee effusion with synovial proliferation. Extensor tenosynovectomy and right knee aspiration was performed. Left hand excised tissue and right knee synovial fluid for acid-fast bacilli (AFB) stain, TB PCR, bacterial and fungal cultures were negative. Urgent histopathological examination of the excised tissue showed necrotising granulomatous inflammation. Patient was empirically started on TB treatment and subsequent mycobacterial culture confirmed the diagnosis of TB. The joints swelling resolved after one month of TB treatment. Multifocal OATB is an infrequent form of extrapulmonary TB and diagnosing OATB requires high index of suspicion particularly in SLE patient on immunosuppression. Prompt investigations are essential to the diagnosis of this rare condition for early initiation of anti-tuberculous therapy.

Poncet's disease in an adolescent with abdominal tuberculosis

Poncet disease is a rare, acute-onset polyarthritis associated with active extra-articular tuberculosis (TB) without evidence of active infection in the affected joint and resolves without residual joint damage or long-term complications. Most cases are reported at the commencement of anti-tuberculous therapy (ATT). A 13-year-old girl with Poncet disease is reported which, despite almost 6 months of treatment for abdominal TB, manifested with bilateral knee joint involvement which resolved only with continuation of ATT. A synovial biopsy was sterile.

Intestinal tuberculosis and Crohn's disease: the importance and difficulty of a differential diagnosis

Tuberculosis (TB) is the most prevalent infection worldwide and affects one third of the population, predominantly in developing countries. Intestinal TB (ITB) is the sixth most frequent extra-pulmonary TB infection. Crohn's disease (CD) is a chronic inflammatory bowel disease that arises from the interaction of immunological, environmental and genetic factors. Due to changes in the epidemiology of both diseases, distinguishing CD from ITB is a challenge, particularly in immunocompromised patients and those from areas where TB is endemic. Furthermore, both TB and CD have a predilection for the ileocecal area. In addition, they share very similar clinical, radiological and endoscopic findings. An incorrect diagnosis and treatment may increase morbidity and mortality. Thus, a great degree of caution is required as well as a familiarity with certain characteristics of the diseases, which will aid the differentiation between the two diseases.

Tuberculous sacroiliitis in a patient with systemic lupus erythematosus: a case report and literature review

Systemic lupus erythematosus (SLE) patients are at higher risk of developing opportunistic infections such as tuberculosis (TB), especially extrapulmonary forms like osteoarticular TB, compared to the general population. However, tuberculous sacroiliitis has been scarcely reported in these patients. We present a 34-year-old woman with SLE who developed articular tuberculosis simultaneously affecting the right sacroiliac joint and the left knee. The patient was successfully treated with antituberculosis therapy for nine months. In this case, in addition to the immunological abnormalities of lupus, the long-term glucocorticoid therapy at high dosages was the main risk factor for the development of osteoarticular tuberculosis.

Extrapulmonary Tuberculosis in Federation of Bosnia and Herzegovina

Introduction:

Health Introduction: The two types of tuberculosis (TB) are: pulmonary TB (PTB) and extrapulmonary TB (EPTB).

Objective:

to represent the frequency of ETPB of all localization , ratio between EPTB and PTB and demographic characteristics of EPTB in FBiH in the period of four years : from 2014 to 2017.

Material and methods:

This is the retrospective analysis of all the reported cases of TB in FBiH with the special insight in EPTB from 2014 to 2017. A standard set of data for TB patients is used which is included in the standardized form–“Minimum information for reporting tuberculosis” which has been used according to the recommendation of the WHO and IUATLD all over the Europe and elsewhere in the world.

Results:

we registered 2588 patients with TB and among them there were 316 patients or 12.21% with EPTB. In the 2014 there were 795 cases of TB and of that 103 (13.0%) were EPTB ;in 2015 of 728 cases of TB 91 (12.5%) were EPTB ; in 2016 of 573 cases of TB 69 (12%) were ETPB ;2017 of 492 cases of TB 53 (11%) were ETPB. ETPB is more frequent in males but with no statistical significance. The most cases of EPTB were in the group of patients aged from 21 to 30 years because of frequency of tuberculous pleurisy. The tuberculous pleuritis is the most frequent form of ETPB (p<0.01).

Conclusion:

The frequency of TB and ETPB in FBiH decreases over the years. This indicates good control and therapeutic regimen of TB in FBiH. The ratio of PTB and EPTB remains approximately the same–about 12% of all TB cases are EPTB. Thus we are getting close to the situation in developed countries.

Case: Bacillus Calmette-Guerin (BCG)-induced Reiter syndrome with an attempt at repeat BCG induction

We present a case of BCG-induced Reiter syndrome with 19-year followup, and the first instance of BCG re-induction in this cohort of patients. This was attempted given the substantial duration of disease control following the initial treatment.

An undiagnosed pleural effusion with surprising consequences

We present the case of a 43-year-old Italian woman with a left undiagnosed pleural effusion, which in subsequent months presented a clinically unexpected evolution with the appearance at first of a right wrist tenosynovitis and subsequently a bilateral lung involvement caused by M. Tuberculosis. With this case report, we would like to underline the importance of making a correct diagnosis of any pleural effusion as soon as possible by at least a thoracocentesis. If untreated, tuberculosis may easily disseminate to other organs. Some considerations and suggestions for antibiotic treatment of pleural effusion will also be given, since many antibiotics have some anti-tuberculosis effect and may delay the diagnosis of this infectious disease.

Musculoskeletal Tuberculosis

Musculoskeletal tuberculosis (TB) accounts for approximately 10% of all extrapulmonary TB cases in the United States and is the third most common site of extrapulmonary TB after pleural and lymphatic disease. Vertebral involvement (tuberculous spondylitis, or Pott's disease) is the most common type of skeletal TB, accounting for about half of all cases of musculoskeletal TB. The presentation of musculoskeletal TB may be insidious over a long period and the diagnosis may be elusive and delayed, as TB may not be the initial consideration in the differential diagnosis. Concomitant pulmonary involvement may not be present, thus confusing the diagnosis even further. Early diagnosis of bone and joint disease is important to minimize the risk of deformity and enhance outcome. The introduction of newer imaging modalities, including MRI (imaging procedure of choice) and CT, has enhanced the diagnostic evaluation of patients with musculoskeletal TB and for directed biopsies of affected areas of the musculoskeletal system. Obtaining appropriate specimens for culture and other diagnostic tests is essential to establish a definitive diagnosis and recover M. tuberculosis for susceptibility testing. A total of 6 to 9 months of a rifampin-based regimen, like treatment of pulmonary TB, is recommended for the treatment of drug susceptible musculoskeletal disease. Randomized trials of tuberculous spondylitis have demonstrated that such regimens are efficacious. These data and those from the treatment of pulmonary TB have been extrapolated to form the basis of treatment regimen recommendations for other forms of musculoskeletal TB.

Differential diagnosis of Crohn's disease versus ileal tuberculosis

Both intestinal tuberculosis and Crohn's disease are chronic granulomatous inflammatory diseases of the bowel having overlap of clinical, endoscopic, radiological, and histological features. Differentiating between the two disorders is relevant not only in Asian countries but also in the West. In spite of diagnostic criteria for both diseases being available, still the dilemma of segregating the two diseases remains. Nearly one third of the patients with Crohn's disease may receive anti-tuberculosis treatment also. Diagnosis should be based on the combination of all disease-specific and corroborative evidences.

Combined reduced-antigen content tetanus, diphtheria, and acellular pertussis (tdap) vaccine-related erythema nodosum: case report and review of vaccine-associated erythema nodosum

Background

Vaccination programs reduce the morbidity and mortality of diphtheria, pertussis, and tetanus. Erythema nodosum is a reactive erythema that can be associated with infections, drugs, and many conditions. The new onset of erythema nodosum after receiving vaccination is uncommon.

Purpose

Combined reduced-antigen content tetanus, diphtheria, and acellular pertussis (Tdap) vaccine-associated erythema nodosum is described and the reports of vaccine-related erythema nodosum are summarized.

Methods

The clinical features of a 39-year-old woman who developed erythema nodosum after receiving Tdap vaccine are reported. Using the PubMed database, an extensive literature search was performed on erythema nodosum, vaccine, and vaccination.

Results

Tdap, the most commonly used booster vaccine against tetanus, diphtheria, and pertussis, is well tolerated in all age groups. Local injection-site reactions are the most common adverse events, whereas headache, fatigue, gastrointestinal symptoms, and fever are the most frequent systemic events. Erythema nodosum has not previously been reported in patients who have received Tdap vaccine. The patient developed erythema nodosum within 48 h after receiving Tdap vaccine; her symptoms cleared and nearly all skin lesions resolved within 2 weeks after initiating oral treatment with ibuprofen, fexofenadine, and prednisone. Vaccine-associated erythema nodosum has previously been reported following vaccination for cholera, hepatitis B, human papillomavirus, malaria, rabies, small pox, tuberculosis, and typhoid.

Conclusion

Vaccine-associated erythema nodosum is uncommon. Erythema nodosum occurring after Tdap vaccination is a rare, yet potential, adverse effect.

A proposed comprehensive classification of tuberculosis disease severity in children

BACKGROUND

Tuberculosis (TB) in children has conventionally been classified as pulmonary TB (PTB) and extrapulmonary TB (EPTB) disease, including disseminated TB (TB meningitis and miliary disease). There is no existing approach that comprehensively characterizes the spectrum and severity of pediatric TB. This limits accurate classification of patients and comparison across cohorts.

AIMS

To develop a classification of pediatric TB that reflects the spectrum and severity of clinical disease better than currently available approaches.

METHODS

We propose a framework for the standard classification of TB disease severity in children. From a literature search, the following sources of information were used: clinical data, bacteriologic, histopathologic, and imaging data (including information from chest radiography, computerized tomography, and bronchoscopy). Each individual disease entity was systematically considered. Based on the extent and the presence of complications, each entity was then classified as "severe" or "nonsevere." As an initial application, we compared the proposed classification with the convention (PTB, EPTB) in a cohort of HIV-infected and -uninfected infants with culture-confirmed TB. Agreement between the 2 systems was poor.

CONCLUSIONS

The proposed comprehensive disease classification system may more accurately reflect the clinical TB disease spectrum in children, is relevant to clinical management, and may be valuable to inform research on diagnostic tools and TB treatment strategies in children. Prospective studies are required to evaluate this approach in representative pediatric populations, correlating TB disease severity with diagnostic yield, treatment response, and application in existing and novel treatment strategies.

Fatal tuberculous myositis in an immunocompromised adult with primary Sjögren's syndrome

Tuberculous myositis, which mimics rheumatic symptoms, is an extremely rare disease. Clinical ambiguity easily leads to misdiagnosis and delayed initial treatment. We present the case of a 55-year-old man who had primary Sjögren's syndrome and active cutaneous vasculitis treated with steroid and immunosuppressive drugs. He presented with a swollen, painful, hot left thigh. Although anti-tuberculosis medications were administered soon after a positive acid-fast stain of incisional muscular tissue, he died of rapidly progressive tuberculous myositis and multiorgan failure following 18 days of hospitalization. This case is presented to increase the awareness of this rare entity in clinical practice.

Mycobacterium tuberculosis, autoimmunity, and vitamin D

Mycobacterium tuberculosis (TB) is a major cause of morbidity and mortality worldwide. Current anti-TB chemotherapies, although effective, are associated with side effects and are limited in treating drug-resistant strands. Autoimmune diseases are a leading cause of morbidity and mortality, with a growing mass of evidence implicating infections (e.g., TB) as their triggers. The burden of TB might further increase by reactivation threats hovering over millions harboring latent infection, thus, calling for novel approaches for this dire ailment. In recent years, the non-calcemic physiological actions of vitamin D have drawn a great deal of attention. In this review, we will focus on the role of vitamin D in the innate immune defense against TB on the one hand and conversely on the immunomodulatory effects of vitamin D on autoimmunity. Taken together, the suggested dual role of vitamin D in treating TB infection and possibly preventing associated autoimmunity will constitute the basis of the current review.

Trends in tuberculosis mortality in the United States, 1990-2006: a population-based case-control study

OBJECTIVE

We assessed demographic and temporal trends of tuberculosis (TB)-related deaths in the United States and examined associated comorbidities listed on death certificates.

METHODS

We analyzed TB-related mortality from 1990 through 2006 by examining multiple-cause-of-death data from the National Center for Health Statistics. We assessed age-adjusted mortality rates, secular trends, associations with demographic variables, and comorbid conditions.

RESULTS

From 1990 through 2006, TB was reported as a cause of death among 53,505 people in the U.S. with a combined overall mean age-adjusted mortality rate of 1.16 per 100,000 person-years. The age-adjusted TB mortality rate declined from 2.22 per 100,000 person-years in 1990 to 0.47 per 100,000 person-years in 2006, demonstrating mean annual decline of about 10%. People aged 75 years and older; males; foreign-born people; and those of Hispanic, Asian, black, and Native American race/ethnicity had comparatively elevated TB-related mortality rates. The mortality rate in foreign-born people was more than two times higher than in U.S.-born people. About 89% of deaths among people of Asian race/ethnicity and nearly 50% among black people were foreign-born individuals. Human immunodeficiency virus and selected autoimmune diseases were more common in TB-related deaths.

CONCLUSIONS

TB mortality decreased substantially from 1990 through 2006, but remains an important cause of preventable mortality. The observed decrease was more pronounced among U.S.-born people than among foreign-born people. Disparities in TB-related mortality and the identification of important comorbid conditions can inform strategies targeting subpopulations at increased risk for fatal TB infection.

Osteoarticular tuberculosis in patients with systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) patients are at increased risk of developing tuberculosis (TB), particularly extrapulmonary TB (ExP-TB).

AIM

The present study was undertaken to investigate whether SLE patients showed increased susceptibility to develop osteoarticular TB (OA-TB).

DESIGN AND METHODS

We retrospectively reviewed and compared the frequency of ExP-TB, in particular OA-TB, in patients with SLE at a tertiary hospital in South Africa, to a non-SLE control TB group seen at the same hospital.

RESULTS

TB was diagnosed 111 times in 97 (17%) of the 568 SLE patients. The relative frequency of ExP-TB in the SLE group (25.2%) was significantly lower than in the control group (38.5%) (OR = 1.9, P = 0.006). In contrast, OA-TB was diagnosed in the SLE group in nine (8.1%) patients (seven with peripheral arthritis and two with TB spine) compared to 54 (0.4%) in the overall control group (OR = 20.8, P < 0.001) and 13 (0.2%) in the subgroup of known HIV positive patients in the control group (OR = 44.4, P < 0.001). Within the SLE group, Black ethnicity (P = 0.003), lymphopaenia (P = 0.001), C3/C4 hypocomplementaemia (P = 0.05), corticosteroids [maximum dose (P = 0.002) and duration of treatment (P = 0.02)] and immunosuppressive agents (P = 0.02) were risk factors for TB. Duration of corticosteroid therapy was the only risk factor for OA-TB (P = 0.04).

CONCLUSION

While the relative frequency of ExP-TB was lower in the SLE group compared to the control group, our findings suggest that SLE patients are at particular risk of developing OA-TB. Further prospective studies are needed to better understand the mechanisms that predispose SLE patients to OA-TB.

Differentiating intestinal tuberculosis from Crohn's disease: a diagnostic challenge

With the changing epidemiology of Crohn's disease (CD) and intestinal tuberculosis (ITB), we are in an era where the difficulty facing physicians in discriminating between the two diseases has increased, and the morbidity and mortality resulting from a delayed diagnosis or misdiagnosis is considerably high. In this article, we examine the changing trends in the epidemiology of CD and ITB, in addition to clinical features that aid in the differentiation of both diseases. The value of various laboratory, serological, and the tuberculin skin tests are reviewed as well. The use of an interferon-gamma-release assay, QuantiFERON-TB Gold, in the workup of these patients and its value in populations where the bacillus Calmette-Guérin vaccine is still administered is discussed. Different radiological, endoscopic, and pathological similarities and features that can aid the clinician in reaching a rapid diagnosis are reviewed as well. The association between mycobacteria and CD, the concerns with the practice of antituberculosis medication trials in areas where tuberculosis (TB) is endemic, as well as extrapulmonary TB induced by the use of antitumor necrosis factor-alpha agents are delineated in this article. Furthermore, we propose an algorithm for the investigation of patients in whom the differential diagnosis encompasses CD and ITB.

A case of Poncet's disease (tuberculous rheumatism)

We describe a 37-year-old woman with recurrent polyarthritis, and recurrent erythema nodosum on the flexible side of her left forearm. On an X-ray of the chest, infiltration of the right upper lobe was observed. Transcription-reverse transcription concerted reaction in sputum samples revealed Mycobacterium tuberculosis (M. tuberculosis). Resolution of the polyarthritis with anti-tuberculosis (TB) drugs occurred in 3 days. We diagnosed her with Poncet's disease (PD). PD is considered to be a reactive arthritis, which is a different entity from tuberculous arthritis. Although PD is a rare disease, we should be aware of it as one of the differential diagnoses, even in patients without typical symptoms of TB.

Patients with pulmonary tuberculosis are frequently positive for anti-cyclic citrullinated peptide antibodies, but their sera also react with unmodified arginine-containing peptide

OBJECTIVE

The anti-cyclic citrullinated peptide (anti-CCP) enzyme-linked immunosorbent assay (ELISA) has high sensitivity and specificity for rheumatoid arthritis (RA). However, detection of anti-CCP in patients with active pulmonary tuberculosis (TB) has recently been reported. To determine whether this activity was specific for the citrullinated residue, the specificity of anti-CCP-positive sera for CCP versus that for unmodified arginine-containing peptide (CAP) was examined in patients with TB and compared with that in patients with RA.

METHODS

Anti-CCP and anti-CAP in sera from patients with pulmonary TB (n = 49), RA patients (n = 36), and controls (n = 18) were tested by ELISA. Sera were available at diagnosis from most TB patients. All TB patients were treated with a combination of 2-4 antibiotics for at least 6 months, and sera were collected over time.

RESULTS

Anti-CCP was found in 37% of TB patients and in 43% of RA patients. CAP reactivity was more common in TB than in RA. High anti-CCP:anti-CAP ratios (>2.0) were seen far more commonly in anti-CCP-positive RA patients than in anti-CCP-positive TB patients (94% versus 22%). Anti-CCP was inhibited by CCP peptide in sera from RA patients, but not in sera from TB patients. A slight increase in anti-CCP was common after initiating treatment for TB, although the anti-CCP level decreased after 1-2 months.

CONCLUSION

Anti-CCP is frequently present in patients with active TB. However, many anti-CCP-positive TB sera also reacted with CAP, and anti-CCP:anti-CAP ratios in TB sera were low. Anti-CCP:anti-CAP ratios should be useful clinically for distinguishing CCP-specific reactivity seen in RA from reactivity with both CCP and CAP frequently seen in pulmonary TB.

Review article: the diagnosis and management of Crohn's disease in populations with high-risk rates for tuberculosis

BACKGROUND

Distinguishing Crohn's disease from intestinal tuberculosis in endemic areas is challenging as both conditions have overlapping clinical, radiological, endoscopic and histological characteristics. Furthermore, high rates of latent tuberculosis confer a considerable risk of reactivation once therapy for established Crohn's disease is started.

AIM

To review current strategies in differentiating these two conditions, and in managing Crohn's disease, in populations with high rates of tuberculosis.

METHODS

Literature review and clinical experience.

RESULTS

While various clinical, radiological, endoscopic and histological parameters may aid in differentiating Crohn's disease from intestinal tuberculosis, these remain imperfect and as treatment options differ misdiagnosis has grave consequences. We propose a diagnostic algorithm, based on currently available evidence and experience, to aid in this dilemma. We also discuss approaches to the management of Crohn's disease, including agents targeting tumour necrosis factor-alpha, in patients at risk of developing tuberculosis.

CONCLUSIONS

A diagnosis of Crohn's disease in individuals at risk for tuberculosis should only be made after careful interpretation of clinical signs, abdominal imaging and systematic endoscopic and histological assessment. Newer techniques for the diagnosis of latent tuberculosis still need to be validated in this environment, and guidelines on the treatment of latent tuberculosis in this setting require clarification.

Elderly-Onset Systemic Lupus Erythematosus

Systemic lupus erythematosus is an autoimmune multi-system disease of uncertain aetiology with highly variable clinical manifestations. Women of child-bearing age are most often affected; however, approximately 10-20% of cases occur in older patients. Elderly-onset lupus has been defined in various studies as onset of lupus after age 50-65 years. Menopause and changes in cellular immunity with aging may contribute to development of lupus in older adults. Many studies suggest that the clinical and serological features of elderly-onset lupus differ from those of lupus in younger patients. Arthritis, fever, serositis, sicca symptoms, Raynaud's syndrome, lung disease and neuropsychiatric symptoms are more common in patients with elderly-onset lupus, while malar rash, discoid lupus and glomerulonephritis are less common in elderly-onset patients compared with younger lupus patients. Most elderly-onset lupus patients have a positive anti-nuclear antibody test, but the prevalence of anti-double-stranded DNA and hypocomplementaemia is lower in elderly-onset patients than in younger patients. Rheumatoid factor, anti-Ro/Sjögren's syndrome (SS) A and anti-La/SSB are more often positive in elderly-onset patients. The diagnosis of elderly-onset lupus may be delayed for many months: insidious onset, low prevalence and similarity to other more common disorders make the diagnosis of lupus challenging in this population. Treatment of lupus in the elderly may be complicated by co-morbidities and increased risk of toxicities from usual treatments. Optimal management of elderly-onset lupus is empiric because of a lack of randomised controlled studies. However, the approach to treatment is similar regardless of the age of the patient. This article discusses the prevalence, clinical course, serological features, prognosis and treatment of elderly-onset systemic lupus erythematosus.

Clinical Applications of the Polymerase Chain Reaction: An Update

The development, in the past decade, of nucleic acid amplification and detection methods is useful in the study of the etiopathogenesis, diagnosis, and management of a variety of clinical (including rheumatologic) disorders. An association between infectious agents and rheumatic disorders has been established through such methods as polymerase chain reaction. This article describes the principles behind polymerase chain reaction-based diagnosis and updates its clinical applications. It is beyond the scope of this article, however, to describe other nucleic acid amplification methods or to include a complete list of all polymerase chain reaction assays that have been developed. Other recent reviews offer additional details.