[Positron emission tomography (PET) with [18F]-FDG in bronchopulmonary cancer and its impact on medical decision at the time of diagnosis, staging, or recurrence evaluation]

Clinical usefulness of [18F]-FDG imaging, performed by means of a dedicated or a "hybrid" PET machine, has been recognised in France since November 1998. Among the clinical indications, three major clinical settings of lung cancer have been included: characterisation, staging and detection of recurrences. After a brief presentation of the PET scintigraphic imaging modality, authors report on the experience of the nuclear medicine team of Hôspital Tenon and summarise the results in literature. For tumour characterisation, a recent meta-analysis obtained a 96% sensitivity, a 73% specificity, a 91% positive predictive value and a 90% negative predictive value, the performances being better for lesions greater than 1 cm. For staging, an increase greater than 15% both in sensitivity and specificity has been observed with dedicated or "hybrid" PET versus CT for N staging. Detection of distant metastases was also more accurate using [18F]-FDG. A similar increase was observed in the detection of recurrence, in accordance with our study; some authors described even better results. A better anatomical delineation of the lesions detected with FDG can be achieved by means of image fusion with CT; this technique is likely to develop as a routine tool in the near future. Finally, FDG imaging led to modification of patient's management in 37% of the cases according to a recent meta-analysis versus 53% of the cases in our retrospective survey concerning the first year of installation of a dedicated PET machine. This rate was equal with dedicated PET and with CDET. In 46% of the cases an inter-modality change occurred, and in 7% an intra-modality change consisting mainly in adaptation of the surgical procedure. As soon as the FDG examination became available, its clinical impact, in the French medical context, appeared to reach the highest values that were published internationally.

Spectrum of CD4 to CD8 T-cell ratios in lymphocytic alveolitis associated with methotrexate-induced pneumonitis

The present study was conducted to confirm the presence of severe lymphocytic alveolitis and to determine the factors responsible for the very different alveolar CD4 to CD8 T-cell ratios (CD4/ CD8) described in methotrexate-induced pneumonitis (MTX-pneumonitis). Clinical and radiologic findings, as well as bronchoalveolar lavage (BAL) data, including CD4 and CD8 subset analysis, were retrospectively reviewed for patients hospitalized between 1985 and 2000 for MTX-pneumonitis. BAL cell counts from patients with MTX-pneumonitis (cases) were compared with those from patients receiving MTX but who did not have evidence of MTX toxicity (MTX-exposed patients) and those from healthy subjects (control subjects). Nineteen BAL were performed in 14 consecutive cases of MTX-pneumonitis. MTX was given for various underlying diseases. All cases presented a subacute diffuse interstitial pneumonitis that recovered, with MTX discontinuation and/or initiation of adjunctive steroid therapy. At the time of diagnosis, BAL cell counts in MTX-pneumonitis indicated severe lymphocytic alveolitis when compared with MTX-exposed patients and control subjects and moderate neutrophil alveolitis compared with control subjects. The lymphocytic alveolitis resulted from an increase in both CD4 and CD8 lymphocyte cell counts. Nevertheless, alveolar CD4/ CD8 T-cell ratios ranged from 0.4 to 9.6. CD4/CD8 values correlated positively with lymphocyte counts but negatively with time elapsed between last MTX administration and BAL and with steroid cumulative dose received by the patients. Severe lymphocytic alveolitis was confirmed in our series of MTX-pneumonitis. The between-patient variation in CD4/CD8 T-cell ratios may reflect the large range of time intervals between last MTX administration and BAL evaluation and the use of adjunctive steroid therapy.

AIDS-related alveolar hemorrhage: a prospective study of 273 BAL procedures

STUDY OBJECTIVES

To evaluate the frequency and diagnostic significance of alveolar hemorrhage (AH) in HIV-infected patients.

DESIGN

A 3-year prospective cohort study.

SETTING

A university hospital in Paris, France.

PATIENTS

Two hundred forty-three HIV-infected patients undergoing 273 BAL procedures during the study period.

METHODS

AH was assessed by using the Golde score. Data on the patients treated and observed in our institution were collected, as well as on their survival rate 12 months after undergoing BAL. Risk factors for AH were sought by comparing patients with AH (cases) and those without AH (control subjects).

RESULTS

AH frequently occurred but usually was subclinical and cytologically mild. AH did not alter the 12-month survival rate. AH always was associated with at least one specific AIDS-related pulmonary disorder, and the following four independent risk factors were identified in a stepwise forward logistic regression model: pulmonary Kaposi's sarcoma (KS; odds ratio [OR], 5.3; 95% confidence interval [CI], 1.8 to 16.7; p = 0.003), cytomegalovirus (CMV) pneumonia (OR, 9.8; 95% CI, 1 to 100; p = 0.05), hydrostatic pulmonary edema (OR, 16.4; 95% CI, 1.8 to 142; p = 0.01), and platelet count < 60,000 cells/microL (OR, 5.6; 95% CI, 1.5 to 20; p = 0.009).

CONCLUSIONS

AH is frequently diagnosed during BAL in HIV-infected patients. Its presence may point to an underlying cause, such as pulmonary KS, CMV pneumonia, or hydrostatic pulmonary edema, or to triggering factors such as thrombocytopenia.

[Bronchopulmonary disease in drug abusers]

Drug abuse is a growing problem in industrialized countries, opening the way to new diseases of the respiratory tract. It has been demonstrated that regular inhalation of cannabis has the same consequences as tobacco smoking. The same cannot be said for other drugs. Cocaine, amphetamines or crack expose the patient to particular toxic effects: in addition to barotrauma related to the administration route, syndromes of acute respiratory distress have been described. These result either from bronchial reactions, asthma exacerbation or eosinophil bronchopneumonia, or alveolar involvement: intra-alveolar bleeding, pulmonary edema or organized pneumonia. Respiratory complications induced by opiates, often used in injections, are related to central alveolar hypoventilation and/or the development of injury from pulmonary edema or pneumonia. The pathophysiology of these lesions is not perfectly understood. Besides these specific conditions, infection is a major problem in drug abusers, irrespective of the drug: bacterial pneumonia, tuberculosis, HIV infection are much more frequent in this high-risk group. Finally repeated intravenous injections of various drugs designed for oral intake can lead to severe complications such as pulmonary hypertension or toxic interstitial lung disease. Summarizing, respiratory diseases in drug abuses can take on a wide range of quite complex presentations. Occasional or regular use of illicit drugs can lead, not exceptionally, to severe respiratory complications requiring rapid management. Knowledge of the principal complications and the appropriate diagnostic procedures is indispensable.

Acute respiratory failure following HAART introduction in patients treated for Pneumocystis carinii pneumonia

Cases of paradoxical worsening of opportunistic infections shortly after the beginning of highly active antiretroviral therapy (HAART) prompted questions on the optimal timing of introduction of HAART in patients with inaugural AIDS-related opportunistic infections. We describe three cases of acute respiratory failure after early introduction of HAART in patients treated for Pneumocystis carinii pneumonia (PCP). The three patients had severe PCP that initially improved with anti-PCP and adjunctive steroid therapy. HAART was introduced 1 to 16 d after diagnosis of PCP, and steroids were stopped on Day 15. Seven to 17 d after HAART introduction, the three patients developed a second episode of severe acute respiratory failure with high-grade fever and patchy alveolar opacities on the chest roentgenogram. PCP resistant to cotrimoxazole, pulmonary superinfection, and drug-related pneumonitis were suspected but subsequently ruled out. Bronchoalveolar lavage and lung pathologic findings showed severe nonspecific pulmonary inflammatory foci surrounding a few persistent P. carinii cysts. All three patients recovered after HAART interruption or steroid reintroduction. We conclude that acute respiratory failure can recur after initiation of antiretroviral therapy in patients being treated for severe PCP. This phenomenon could result from rapid pulmonary recruitment of fully competent immune and inflammatory cells responding to a few persistent P. carinii cysts. A short course of steroid therapy may suppress this reaction.

Loss of imprinted genes and paternal SUR1 mutations lead to focal form of congenital hyperinsulinism

Persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) is a heterogeneous disorder characterized by profound hypoglycaemia due to inappropriate hypersecretion of insulin. An important diagnostic goal is to distinguish patients with a focal hyperplasia of islet cells of the pancreas (FoPHHI) from those with a diffuse abnormality of islets (DiPHHI), because the management differs significantly. The intriguing similarity between islet cell hyperplasia and tumourigenesis prompted us to investigate whether the imprinted genes in the 11p15 region are involved. Results showed that diffuse forms are caused by constitutional homozygous or compound heterozygous mutations of the SUR1 gene. In contrast, focal forms are caused by loss of the maternally inherited 11p15 region, resulting in both loss of the maternally expressed tumour suppressor genes accounting for hyperplasia and somatic reduction to hemizygosity or homozygosity of the paternally inherited SUR1, limited to the lesion. Thus, this somatic disorder, which leads both to beta-cell proliferation and to hyperinsulinism, can be considered the somatic equivalent, restricted to a microscopic focal lesion, of constitutional uniparental disomy associated with unmasking of a heterozygous parental mutation.

[Lemierre's syndrome: a case report]

We report a case of Lemierre's syndrome with a pleuropulmonary complication. Lemierre's syndrome is a rare etiology of lung abscess. The diagnosis is clinical and microbiological (anaerobic organisms). This syndrome associates an acute oropharyngeal infection with septic thrombophlebitis of the internal jugular vein (sometimes many days before the lung lesion) and pulmonary abscess formation. Clinicians should be aware of this syndrome that is fatal in 10% of patients, usually after delayed or missed diagnosis. The frequency of Lemierre's syndrome would be higher if antibiotics were given only to pharyngitis patients positive for streptococcus.

[Yellow nail syndrome. Three cases]

Yellow nail syndrome is an uncommon diagnosis established on the basis of clinical presentation with slow-growing yellow discolored nails, lymphedema, and pulmonary manifestations. We report 3 new cases with their pulmonary component.

[Role of thoracic radiography in the management of community-acquired pneumonia]

In patients presenting with a lower respiratory tract infection, it is generally recommended to order a chest X-ray in two circumstances: when the clinical signs suggest the diagnosis of pneumonia or in case of rather atypical symptoms suggesting a potential risk of complications. Indeed, the presence of one or more recent opacities, and more specifically, homogeneous alveolar infiltration(s) remains the gold standard criterion for the diagnosis of pneumonia. One must not however let this rule overshadow certain limitations of the chest X-ray reported in the literature: 1. the misdiagnosis of certain cases of pneumonia or bronchopneumonia seen early; 2. the extent of the infiltration gives only a very relative assessment of severity; 3. the characteristics of the infiltration are only relatively specific for etiological diagnosis. In patients with community acquired pneumonia diagnosed on the basis of clinical signs and radiographic findings, systematically performed series of follow-up X-rays have shown that the initial extension of the infiltration and the rate of its resolution contribute quite variably to the diagnosis of complications. The best indication for ordering a follow-up X-ray before 6 weeks remains an unfavorable clinical course.

Cardiac cause of hypoxaemia in a kyphoscoliotic patient

This report presents the case of a 73 yr-old female in whom kyphoscoliosis, osteoporotic vertebra compression fractures and sternal injury resulted in severe respiratory failure and hypoxaemia. Pulmonary function testing showed moderate restrictive pattern and rare mismatches were found on lung ventilation/perfusion scanning. Transoesophageal echocardiography with contrast studies showed abnormal anatomic mediastinal interactions which led to right-to-left interatrial shunt, through patent foremen ovale. First-intention treatment, because of orthopaedic and respiratory surgical restraints, was to close the shunt using transcatheter devices. Follow-up after 6 months demonstrated that these interauricular umbrella devices corrected arterial hypoxaemia. True right-to-left interatrial shunts can be found in kyphoscoliotic patients, as a result of thoracic deformation, and can be safely treated with percutaneous trancatheter closure.

Respiratory high dependency care units (RHDCU) in France

The concept of intermediary intensive care units appeared in France with the progress of respiratory intensive care in the 1970s and an increment of the percentage of patients who were surviving an acute respiratory episode. It then became necessary to provide them with an optimal transition between the medical intensive care unit (ICU) and the home, thus explaining the emerging need for units of post-intensive care. At the present time, French health regulations recognize medical and surgical ICUs with a specific budget for equipment and nurses, and the specialized ICU which exists through a means share with the medical units (pulmonology, cardiology, etc.) inside which they are located. New regulations should make official the separation between medical and surgical intensive care units, intermediate (specialized) intensive care units and wards of reinforced follow-up, in a general perspective of improvement of the health network between the patient, home, and the different sectors of hospitalization (acute/chronic, public and private).

[Conclusion: what is the choice of antibiotics in adult respiratory tract infections?]

TREATMENT OF SINUSITIS: For both acute rhinosinusitis in patients with no past history where S. pneumoniae and H. influenzae are the main causal agents, or recurrent sinusitis in a chronic background where anaerobic bacteria are increasingly implicated, pristinamycin is one of the rare compounds which can be expected to be effective and is a treatment of choice for an empirical strategy. LOWER RESPIRATORY TRACT INFECTIONS: Besides high-risk subjects with non-microbiologically proven bronchial infection, where enterobacteriaceae could involve a pristinamycin is a useful alternative to the conventional strategy (i.e.: amoxicillin, macrolides and cotrimoxazole) in the treatment of LRT infection.

Pulmonary malignancies in the immunocompromised patient

Clinicians should be familiar with immunodeficiency-related malignancies, as their incidence is expected to increase further with the rise in the number and survival of immunocompromised patients. The most common malignancies affecting the lungs in those patients are Kaposi's sarcoma, non-Hodgkin's lymphoma and, to a far less extent, Hodgkin's disease and bronchogenic carcinoma. However, their relative frequency depends on the types of immune deficiency, including those due to congenital disorders, AIDS and drug treatments. This review will summarize epidemiological data on the frequency of immmunodeficiency-related malignancies, recent advances on their pathogenesis and current approaches to their diagnosis and treatment in the various immunosuppressed groups.

AIDS-related Pneumocystis carinii pneumonia in the era of adjunctive steroids: implication of BAL neutrophilia

Factors predictive of mortality in patients with AIDS and Pneumocystis carinii pneumonia (PCP) were identified before the introduction of adjunctive steroids, but they have not been reevaluated since. Because PCP still occurs in AIDS, remaining fatal in some cases, we conducted a multivariate analysis of factors predicting mortality in patients with HIV-positive PCP managed from 1990 to 1995, i.e., after the consensus conference on the use of adjunctive steroids. The predictive value of clinical, laboratory, and bronchoalveolar lavage (BAL) data at admission and during the course of PCP was studied retrospectively using multivariate methods, in 144 patients with AIDS. Overall mortality was 21.5%. The univariate analysis identified seven factors predictive of 90-d mortality: Pa(O(2)) on room air < 60 mm Hg, lactate dehydrogenase > 1,000 IU, albuminemia < 30 g/L, BAL neutrophilia > 10%, nosocomial infection, pneumothorax, and a need for mechanical ventilation. Four of these factors were independently associated with 90-d mortality in the multivariate analysis; among them, two were evaluable at admission, namely, Pa(O(2)) < 60 mm Hg on room air and BAL neutrophilia > 10%, and two during hospitalization, namely, the development of pneumothorax and a need for mechanical ventilation. Moreover, BAL neutrophilia was correlated to occurrence of pneumothorax and a need for mechanical ventilation. In the era of adjunctive steroid use, AIDS-related PCP remains fairly common. Two independent factors evaluable at admission, Pa(O(2)) on room air and BAL neutrophilia, are predictive of death.

Lymphoma of pulmonary mucosa-associated lymphoid tissue: CT scan findings and pathological correlations

The aim of this study was to describe the lesions of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma observed by means of computed tomography (CT) and to determine the value of CT in the management of this disease. Sixty six CT scans were performed in 13 consecutive cases of histologically proven pulmonary MALT lymphoma at the time of diagnosis (n=13) or periodically (n=53). They were reviewed separately with chest radiographs by consensus between two observers. Pulmonary abnormalities were described and compared to histopathological findings on surgical specimens from seven patients. At the time of diagnosis, elementary lesions observed by means of CT consisted of nodular areas of attenuation (12 of 13), linear areas of attenuation (eight of 13) and consolidations (six of 13). All these lesions were centred on airways that appeared dilated in seven cases and were more often bilateral and multiple on CT than on the chest radiographs. CT abnormalities correlated with gross pathological appearance and were related to a lymphomatous infiltration with a peribronchovascular distribution. Pathological examination also confirmed the presence of dilated airways within lymphomatous lesions and showed that the bronchial wall was respected. During follow-up, in patients on chemotherapy, response, relapse or progression were easily identified by means of plain radiography. In the initial evaluation, computed tomography contributed to the choice of therapeutic strategy, avoiding unnecessary surgical resection in one-third of patients. By contrast, it is unclear whether computed tomography is useful for post-treatment follow-up of mucosa-associated lymphoid tissue.

[Trismus and tetanus vaccine]

BACKGROUND

Tetanus immunization, mandatory in France before the age of 18 months, is usually well tolerated. Fever and local reaction at the site of injection are the most common side effects. We report a case of trismus associated with tetanus immunization.

CASE REPORT

A 12-year-old boy was hospitalized for a trimus which occurred 22 h after a booster dose of tetanus polio vaccine. The spasm of masticator muscles was so severe that the patient had difficulties in elocution and feeding. A moderate fever and a hypertonia of the lower limbs were associated. The trismus resolved itself within about 5 min after diazepam intravenous infusion. After examination of the buccal cavity, a local cause was discarded. The outcome was favorable and the clinical status of the boy was still normal six months later.

DISCUSSION

Although no similar cases have been published, 13 other comparable adverse events associated with four vaccines containing tetanus toxoid were reported to the manufacturer within a period of 12 years. During the same period, more than 66 millions doses of vaccines containing tetanus toxoid were distributed. Trisms appeared to be more likely reported in adults after booster doses. Onset of the symptoms was between a few hours to 15 days. Outcome was always favorable.

CONCLUSION

Although trimus associated to tetanus toxoid immunization is rare and remains unexplained, physicians should be aware of this adverse event.

Sarcoid-like pulmonary disorder in human immunodeficiency virus-infected patients receiving antiretroviral therapy

We report two cases of HIV-infected patients who presented with diffuse interstitial micronodular lesions on chest X-ray after institution of protease inhibitor-containing highly active antiretroviral therapy (HAART). Granulomatous pulmonary disorder mimicking sarcoidosis was diagnosed on histopathological studies revealing noncaseating granuloma and bronchoalveolar lavage analysis showing an intense CD4(+) lymphocyte alveolitis. Causative agents such as infectious organisms and environmental compounds were excluded. The relationship between sarcoid-like reaction and immune reconstitution under HAART is discussed.

AIDS-related primary pulmonary lymphoma

We describe 12 cases of AIDS-related primary pulmonary lymphoma occurring between 1986 and 1996 in a large French cohort of HIV-infected patients. Diagnostic criteria were: (1) histologically proven lymphomatous pulmonary involvement; (2) absence of mediastinal and/or hilar adenopathy on chest radiography; (3) absence of extrathoracic lymphoma extension. All patients were severely immunodeficient at the time of diagnosis. All but one patient presented with B and/or nonspecific respiratory symptoms. Chest radiography showed one or more marginated nodule(s) or large mass. CT scan showed a cavitary lesion in five patients. No lymph node enlargement or specific pleural effusion was detected. Transthoracic needle biopsies were performed in 10 patients and avoided open-lung biopsy for the diagnosis of lymphoma in five patients. All but one of the primary pulmonary lymphoma were high-grade B-cell non-Hodgkin's lymphomas. Using antilatent membrane protein-1 antibodies and an Epstein-Barr-Virus-encoded RNA transcript-specific probe, latent EBV infection of tumor cells was demonstrated in every case. All but one of the patients received chemotherapy. The median survival time was 4 mo, and no patient was still alive at the cut-off date for this analysis. Progessive pulmonary lymphoma was the main cause of death, but infections were also frequent.

[Pulmonary crytosporidium in a patient with AIDS]

Compared to digestive disorders, respiratory disease linked to cryptosporidium has not been very well documented in AIDS. We report a case of a patient suffering from AIDS who presented with chronic bronchial symptoms which became more and more incapacitating. Different respiratory specimens (broncho-alveolar lavage, expectoration and bronchial biopsy) revealed the presence of cryptosporidium species. The patient died in a few weeks from respiratory insufficiency without the parasite being eradicated from the bronchi. Although the autopsy confirmed the presence of cryptosporidium species, it was difficult to confirm its responsibility due to the fact that other pathogens were present in the bronchial tree.

[Acute respiratory insufficiency in patients with bronchopulmonary cancer]

Acute respiratory failure is relatively frequent in patients with bronchogenic cancer. The respiratory disorder may be related to tumor extension itself or opportunistic infection above or below the tumoral stenosis. Radiotherapy and chemotherapy can also be causal. The condition is particularly serious in patients with one lung. We discuss the different complications, their frequency and conditions of occurrence.

Role of intracellular pathogens in respiratory tract infections

Recent epidemiologic studies have shown that in patients with acute respiratory tract infection, intracellular pathogens, and particularly Mycoplasma pneumoniae and Chlamydia pneumoniae, might be involved more frequently than was previously assumed. In addition, newer investigations, such as specific culture or polymerase chain reaction (PCR), when systematically performed in patients with asthma, chronic obstructive pulmonary disease and even cystic fibrosis, frequently detect Mycoplasma pneumoniae or Chlamydia pneumoniae in those individuals. The significance of such detection (chronic bronchial infection?) and the role that these intracellular pathogens might play in the natural history of chronic respiratory diseases remain to be evaluated.

Neutrophil alveolitis in bronchioloalveolar carcinoma: induction by tumor-derived interleukin-8 and relation to clinical outcome

Tumor infiltrate, predominantly constituted by lymphocytes, may represent an important prognostic factor in bronchioloalveolar carcinoma (BAC), in addition to tumor extension and histological type. In the present study, we determined the presence, the origin, and the prognostic importance of neutrophils that also participate in leukocyte infiltrates of BAC. Neutrophil alveolitis was determined immunohistochemically in both lung biopsies and bronchoalveolar lavage (BAL) fluid samples from 29 patients with histologically proved BAC. The local expression of interleukin (IL)-8 was determined by immunohistochemical and immunoenzymatic techniques. Neutrophil counts were analyzed in relation to the clinical outcome of patients by the Kaplan-Meier method and Cox's univariate and stepwise multivariate models. Lymphocytes and neutrophils dominated the inflammatory cell population in the lower respiratory tract of patients with BAC. Neutrophils were located mainly in the alveolar lumen and seldom in alveolar wall whereas lymphocytes were exclusively present in alveolar wall. A relationship was observed between the number of neutrophils and the level of IL-8 in BAL fluid suggesting the involvement of that chemokine in neutrophil recruitment. The tumor cells were the predominant cells that appeared to express IL-8 by immunolocalization. The presence of increased numbers of neutrophils was significantly associated with a poorer outcome in patients with BAC (P = 0.02). In a multivariate analysis, the neutrophil percentage in BAL fluid was an independent predictor of clinical outcome. The risk of death was increased substantially (rate ratio, 5.2; 95% confidence interval, 1.1 to 24.7) among patients with BAL neutrophil percentage of > or = 39% (median of the distribution) as compared with the others. In BAC, neutrophils accumulate in the alveolar lumen. Elaboration of IL-8 by tumor cells may be responsible for this event, which is associated with a significantly higher risk of death.

[Multicentric Castleman's disease with mediastinal involvement in a patient with HIV infection]

Castleman's disease is most often seen by a thoracic physician as a mediastinal tumour which is discovered fortuitously and whose surgical excision leads to a cure. We report a case of a patient of 30 who was seropositive for HIV and was suffering from Castleman's disease initially localised to the mediastinum. The disease was associated with a cutaneous and bronchial Kaposi sarcoma. The mediastinal disease, associated with cutaneous and bronchial Kaposi sarcoma, was marked by evolving in a multicentric manner. We review the histological definition and recent data concerning the pathophysiology and the diagnostic and therapeutic management of this disorder and the very varied clinical expression.

Tuberculosis generates a microenvironment enhancing the productive infection of local lymphocytes by HIV

Tuberculosis (TB) contributes to the progression of HIV disease but, so far, the mechanism involved is not clear. Several cytokines accumulating in vivo at the site of mycobacterial infection up-regulate HIV expression in vitro. In this study, we assessed the role of pleural fluids recovered from seronegative patients with TB on HIV replication in acutely infected blast cells. Pleural fluids from subjects with congestive heart failure served as controls. In all cases, TB pleural fluids stimulated HIV replication in vitro. TNF-alpha, IL-6, IFN-gamma, and granulocyte/macrophage (GM)-CSF, as well as very low levels of IL-2, were detected in TB pleural fluids. An anti-IL-2 Ab preincubated with TB pleural fluids exhibited no blocking effect on HIV replication similarly to anti-IFN-gamma and anti-GM-CSF Abs. In contrast, anti-TNF-alpha and anti-IL-6 Abs decreased HIV replication by 60 and 90%, respectively. Recombinant TNF-alpha and IL-6 stimulated HIV replication, while IFN-gamma and GM-CSF had a more ambiguous role. The capacity of pleural fluids to stimulate HIV replication was specific for TB, since the capacity of control fluids was significantly lower. Finally, in contrast to PBL, which require in vitro activation for their productive infection by HIV, unstimulated tuberculous pleural lymphocytes were productively infectable by HIV. Taken together, our data suggest that the microenvironment generated by TB might increase the HIV burden in infected subjects, partly through cytokines other than IL-2, namely TNF-alpha and IL-6.

Tuberculosis generates a microenvironment enhancing the productive infection of local lymphocytes by HIV

Tuberculosis (TB) contributes to the progression of HIV disease but, so far, the mechanism involved is not clear. Several cytokines accumulating in vivo at the site of mycobacterial infection up-regulate HIV expression in vitro. In this study, we assessed the role of pleural fluids recovered from seronegative patients with TB on HIV replication in acutely infected blast cells. Pleural fluids from subjects with congestive heart failure served as controls. In all cases, TB pleural fluids stimulated HIV replication in vitro. TNF-alpha, IL-6, IFN-gamma, and granulocyte/macrophage (GM)-CSF, as well as very low levels of IL-2, were detected in TB pleural fluids. An anti-IL-2 Ab preincubated with TB pleural fluids exhibited no blocking effect on HIV replication similarly to anti-IFN-gamma and anti-GM-CSF Abs. In contrast, anti-TNF-alpha and anti-IL-6 Abs decreased HIV replication by 60 and 90%, respectively. Recombinant TNF-alpha and IL-6 stimulated HIV replication, while IFN-gamma and GM-CSF had a more ambiguous role. The capacity of pleural fluids to stimulate HIV replication was specific for TB, since the capacity of control fluids was significantly lower. Finally, in contrast to PBL, which require in vitro activation for their productive infection by HIV, unstimulated tuberculous pleural lymphocytes were productively infectable by HIV. Taken together, our data suggest that the microenvironment generated by TB might increase the HIV burden in infected subjects, partly through cytokines other than IL-2, namely TNF-alpha and IL-6.

[Epidemiology of acute lower respiratory tract infections in adults. Role of Chlamydia pneumoniae and Mycoplasma pneumoniae]

INCIDENCE

Mycoplasma pneumoniae and Chlamydia pneumoniae infections cause 15 to 40% of acute pneumonia cases treated by community physicians. This incidence is lower for cases of pneumonia treated in a hospital setting, falling to less than 3% for cases treated in intensive care units. Incidence varies with the geographical area, season, age and patient population.

BRONCHIAL INVOLVEMENT

Mycoplasma pneumoniae and Chlamydia pneumoniae cause 6 to 15% of all cases of acute bronchitis and are the causal agents in approximately 5% of acute episodes in patients with chronic bronchitis.

PATHOGENESIS

Chlamydia pneumoniae and Mycoplasma pneumoniae are general identified as the causal agents on the basis of clinical features, microbiological results and the clinical course. The question of the role of carriers or chronic infection is debated; it most likely has a real effect.

Diagnosis of smear-negative pulmonary tuberculosis using sequence capture polymerase chain reaction

Techniques based on the polymerase chain reaction (PCR) can be used to rapidly identify DNA from Mycobacterium tuberculosis in clinical samples from patients with tuberculosis, but prior studies evaluating this approach in the diagnosis of paucibacillary forms of pulmonary tuberculosis have reported poor sensitivity and/or specificity. We have developed a procedure in which mycobacterial DNA in crude samples is specifically captured prior to amplification, thereby concentrating the target sequences and removing irrelevant DNA and other inhibitors of the amplification reaction (sequence capture PCR). To evaluate the usefulness of this approach in the diagnosis of paucibacillary forms of pulmonary tuberculosis, sequence capture PCR was performed prospectively on samples of bronchoalveolar lavage fluid from consecutive patients suspected of having pulmonary tuberculosis but for whom three consecutive samples of respiratory secretions were smear negative. Of the 27 patients evaluated, active tuberculosis was diagnosed in nine; sequence capture PCR was positive for all of these patients, including the three for whom all specimens submitted for culture were negative. No positive results were obtained for lavage fluid from the 18 patients for whom the diagnosis of active tuberculosis was subsequently excluded or 25 additional patients undergoing bronchoalveolar lavage for evaluation of other pulmonary problems, even though many of these patients had a history of prior tuberculosis or radiographic evidence of prior tuberculous infection. Paucibacillary forms of pulmonary tuberculosis can be rapidly identified with high sensitivity and specificity using sequence capture PCR performed on samples obtained by bronchoalveolar lavage.

[Primary pulmonary lymphoma]

There are three distinct clinico-anatomical entities today covered by the definition of a primary clonal pulmonary lymphoid proliferation. These are pulmonary lymphomas of B cell phenotype, of low grade malignancy, B cell lymphomas of high grade malignancy and finally lymphomatoid granulomatosis whose clonal characteristic is sometimes difficult to confirm. This general review aims to specify the pathophysiological, diagnostic, prognostic and therapeutic aspects of these different types. Low grade B cell lymphoma is the most common pulmonary lymphoma. Their development depends on mucosa associated lymphoid tissue. They are most often indolent and present as a chronic alveolar opacity. Their prognosis is excellent and the modalities of treatment are discussed (no therapy, surgery or monochemotherapy). High grade B cell pulmonary lymphomas are much rarer and may result from the transformation of a low grade lymphoma or arise in a particular situation such as imunodepression. Their prognosis is poor and the therapeutic possibilities depend most often on the underlying disease. The presence of lymphomatoid granulomatosis in this group of pulmonary lymphomas is debatable. The demonstration of a clonal character of this proliferation is practically never obtained and there is often extra pulmonary disease. The prognosis of this type of illness is extremely variable because certain studies have shown a cure using corticosteroids and cyclophosphamide whilst others have found that the disease is always fatal in spite of using strong polychemotherapy.

[Asthma and Chlamydia pneumoniae. A future prospect for macrolides in general and roxithromycin in particular?]

A LOGICAL HYPOTHESIS: Recent publications raise the question of an association between Chlamydia pneumoniae and asthma. There has been no formal proof justifying routine search for C.pneumoniae in patients with uncontrolled asthma nor for systematic treatment with an antibiotic.

OPEN QUESTIONS

Can Chlamydia pneumoniae infection initiate or aggravate asthma? Are acute manifestations of asthma associated with an overly high frequency of recent C.pneumoniae infection? Is a past history of C.pneumoniae infection abnormally frequent in patients with chronic asthma?

PERSPECTIVES

Rigorously controlled clinical trials evaluating the efficacy of antibiotics such as macrolides which are active against C.pneumoniae are warranted to further elucidate these questions.

[Drug-induced pneumopathies accompanied by acute respiratory insufficiency]

Drug induced pneumonias accompanying acute respiratory failure are defined by a delay in presentation of less two months and severe hypoxaemia (PaO2 < 60 mmHg in ambient air). They are poorly indexed, often poorly understood by the clinician and pose difficult problems both of diagnosis and treatment. This general review touches successively on hypoxaemic drug induced pneumonia observed in oncology and haematology then those observed outside this very specific context. In each of the two groups five questions are posed: 1) Which patients? 2) Which clinical patterns? 3) What initial diagnostic discussion? 4) Which successful elements support the drug induced hypothesis? 5) What outcome? The replies obtained were compared to case reports from the literature (188 references) or from recent general reviews concerned more specifically with the hypoxaemic forms.

Diffuse panbronchiolitis in an Asian immigrant

Diffuse panbronchiolitis (DPB) is a disease with chronic inflammation exclusively located in the region of the respiratory bronchiole. It is largely restricted geographically to the Far East, and cases in Western countries are exceptional, even among Asian immigrants. A patient of Asian origin with DPB who had been living in France for 10 years is described. Only re-examination of the initial open lung biopsy specimen after an eight year period allowed this rare disease to be diagnosed correctly. The known efficacy of low dose erythromycin in DPB was again confirmed after failure of long term high dose corticosteroid therapy administered before an accurate diagnosis had been made.