Goodpasture syndrome: molecular and clinical advances

Goodpasture syndrome: a rare case presenting with recurrent haemoptysis

Goodpasture syndrome is a rare autoimmune disease which affects young adults with a male preponderance and can be triggered at any point in life with a classical clinical triad of rapidly progressive glomerulonephritis, diffuse pulmonary haemorrhage and circulating anti-glomerular basement membrane antibody (anti-GBM antibody). Here we are presenting a case of a young man with hypertension in his early 20s who presented with fatigue, recurrent haemoptysis, breathlessness and decreased urine output without features of infection. He was diagnosed at an early stage of the disease with the help of clinical, serological and radiological findings. An early diagnosis with effective treatment using plasma exchange, intravenous high-dose methylprednisolone, and cyclophosphamide showed a rapid improvement in the patient's condition with an immediate decrease in anti-GBM titres and proteinuria.

A Review of Clinical and Imaging Features of Diffuse Pulmonary Hemorrhage

OBJECTIVE. The purpose of this article is to review the clinical and imaging features of diffuse pulmonary hemorrhage. CONCLUSION. Diffuse pulmonary hemorrhage is a life-threatening syndrome associated with a wide variety of underlying pathologic categories. Nonspecific clinical and imaging features pose challenges to promptly diagnosing this condition. Chest radiography commonly shows alveolar opacification, and CT reveals the extent of disease. Integration of clinical, radiologic, laboratory, and pathologic findings facilitates timely diagnosis and etiologic identification.

Alveolar Hemorrhage

Alveolar hemorrhage (AH) is a clinical syndrome with diverse etiologies both immune and nonimmune. The defining pathological feature of AH is the presence or absence of pulmonary capillaritis. The antineutrophil cytoplasmic antibody (ANCA) related vasculitis and systemic lupus erythematosus are the commonest causes of immune AH with pulmonary capillaritis, whereas Goodpasture's syndrome and idiopathic pulmonary hemosiderosis are common causes of immune AH without pulmonary capillaritis. The major nonimmune causes of AH are primarily drug induced, or due to hematological malignancy and disorders of coagulation. Clinical features of AH include: dyspnea, fever, hemotypsis, bilateral crackles and pallor. Hypoxemia and bilateral diffuse airspace disease on the chest radiograph with relative sparing of the bases and apices which most often clears within 48 hours after its onset further characterize this syndrome. The major clinical implications of this syndrome are its potential to cause respiratory failure in severe cases and its sequelae of pulmonary fibrosis with associated morbidity and disability. In addition, AH may be the initial manifestation of a systemic immune disorder which can be managed optimally if recognized early. The diagnosis of AH is confirmed by bronchoalveolar lavage by demonstrating a progressively bloody return on successive aliquots of instilled saline or hemosiderin laden macrophages in the bronchoalveolar lavage fluid. The open lung biopsy remains the gold standard for the diagnosis of AH but is reserved for inapparent cases in whom corticosteroids and immunosuppressive therapy may be life saving. Serologic testing and examination of the urine sediment are useful adjuncts to the diagnosis. The treatment of AH is primarily supportive while an attempt is made to determine its etiology and initiate specific therapy. Glucocorticoids and cyclophosphamide are the cornerstones of therapy in immune AH with adjunctive plasmapheresis in life-threatening cases.

Basement membranes and autoimmune diseases

Basement membrane components are targets of autoimmune attack in diverse diseases that destroy kidneys, lungs, skin, mucous membranes, joints, and other organs in man. Epitopes on collagen and laminin, in particular, are targeted by autoantibodies and T cells in anti-glomerular basement membrane glomerulonephritis, Goodpasture's disease, rheumatoid arthritis, post-lung transplant bronchiolitis obliterans syndrome, and multiple autoimmune dermatoses. This review examines major diseases linked to basement membrane autoreactivity, with a focus on investigations in patients and animal models that advance our understanding of disease pathogenesis. Autoimmunity to glomerular basement membrane type IV is discussed in depth as a prototypic organ-specific autoimmune disease yielding novel insights into the complexity of anti-basement membrane immunity and the roles of genetic and environmental susceptibility.

A Patient with Abnormal Kidney Function and a Monoclonal Light Chain in the Urine

Monoclonal gammopathy is increasingly recognized as a cause of kidney injury. These renal conditions behave differently than ones without monoclonal gammopathy and require specific treatment. To avoid misdiagnosis, testing for paraprotein should be performed in addition to vasculitis and autoimmune diseases serologies in adults with unexplained AKI or proteinuria. Because the prevalence of monoclonal gammopathy is much more common than glomerular diseases, the nephrotoxicity of the monoclonal protein must be confirmed before cytotoxic therapy is initiated. This can only be done by a kidney biopsy. After a monoclonal gammopathy of renal significant is verified, the evaluation should then focus on the identification of the pathologic clone, because therapy is clone specific. We present this patient to illustrate the clinical presentation of a patient with renal dysfunction and a monoclonal gammopathy. This patient is also used to discuss the diagnostic process in detail when monoclonal gammopathy-associated renal disease is suspected.

Respiratory Diseases

▪

Pulmonary arteriovenous fistulas have congenital and hereditary etiology, and patients are at risk for life-threatening rupture requiring surgery.

▪

Wegener's granulomatosis can affect any organ system, although renal and pulmonary involvement is most common; men ages 40 to 50 are at increased risk.

▪

Lymphomatoid granulomatosis affects cardiopulmonary, neurologic, and myeloproliferative systems; may result from opportunistic infection, and frequently progresses to lymphoma; men age 50 to 60 are at increased risk. Spontaneous remission occurs in some cases; mortality is 60% to 90% at 5 years.

▪

Churg-Strauss syndrome is usually associated with long-standing asthma, with men and women affected equally, and can affect any organ system; major cause of death is cardiac related.

▪

Primary pulmonary hypertension is a diagnosis of exclusion; women are affected twice as likely as men; right-to-left shunt may occur in 30%, secondary to patent foramen ovale; hypoxia with resultant heart failure is typical cause of death.

▪

Cystic fibrosis is an autosomal recessive disease, eventually fatal, with increased risk for airway obstruction, fluctuating pulmonary function, and chronic hypoxia; risk for spontaneous pneumothorax is 20%.

▪

Bronchiolitis obliterans organizing pneumonia is a pulmonary obstructive disease that may be reversible and usually resolves spontaneously.

▪

Idiopathic pulmonary hemosiderosis is associated with autoimmune disorders; patients have recurrent hemorrhage, pulmonary fibrosis, restrictive lung disease, and pulmonary hypertension, with some cases of spontaneous remission.

▪

Chronic eosinophilic pneumonia may be preceded by adult-onset asthma; women are at increased risk; prognosis is good.

▪

Goodpasture's syndrome is a genetic autoimmune disorder involving the pulmonary and renal systems.

▪

Pulmonary alveolar proteinosis, a lipoprotein-rich accumulation in alveoli, has three forms: congenital, decreased alveolar macrophage activity, and idiopathic; some cases of spontaneous remission occur.

▪

Sarcoidosis may affect any organ system; African American, northern European, and females are at greater risk; many patients are asymptomatic.

▪

Systemic lupus erythematosus may affect any organ system; women of childbearing age are at increased risk.

▪

Idiopathic pulmonary fibrosis is a rare interstitial lung disease, with smokers at increased risk for pulmonary malignancy; survival is usually 2 to 3 years from diagnosis; no effective treatment exists, with lung transplant the only therapeutic option.

▪

Acute respiratory distress syndrome (ARDS) is associated with underlying critical illness or injury, developing acutely in 1 to 2 days; mortality is 25% to 35%.

▪

Pulmonary histiocytosis X is an interstitial lung disease associated with cigarette smoking and an unpredictable course; some spontaneous remission occurs.

▪

Lymphangioleiomyomatosis involves progressive deterioration of lung function, associated with tuberous sclerosis and exacerbated by pregnancy, with women at increased risk; possible spontaneous pneumothorax and chylothorax; death usually results from respiratory failure.

▪

Ankylosing spondylitis is a genetic inflammatory process resulting in fusion of axial skeleton and spinal deformities, with men at increased risk; radiologic bamboo spine, sacral to cervical progression, and restrictive lung disease with high reliance on diaphragm; extraskeletal manifestations may occur.

▪

Kyphosis (exaggerated anterior flexion) and scoliosis (lateral rotational deformity) are spinal/rib cage deformities with idiopathic, congenital, or neuromuscular etiology; corrective surgery done if Cobb thoracic angle >50% lumbar angle >40%.

▪

Bleomycin is an antineoplastic antibiotic used in combination chemotherapy, with no myelosuppressive effect; toxicity can cause life-threatening pulmonary fibrosis.

▪

Influenza A is highly infectious, presenting with flulike symptoms and possible progression to ARDS; human-to-human exposure is through droplets or contaminated surfaces, with high risk for infants, children, pregnancy, chronically ill, or renal replacement therapy patients. No prophylactic treatment exists; treat patients with high index of suspicion without definitive testing; rRT-PCR and viral cultures are sensitive for pandemic H1N1 strain.

▪

Severe acute respiratory syndrome (SARS) is highly infectious, transmitted by coronavirus with human-to-human exposure via droplets or surfaces, and may progress to ARDS.

▪

Echinococcal disease of lung is from canine tapeworm, transmitted by eggs from feces; rupture of cyst may result in anaphylactic reaction or spread of disease to other organs; children are at increased risk. No transthoracic needle aspiration is done; surgery is only option.

Anti-glomerular basement membrane disease: outcomes of different therapeutic regimens in a large single-center Chinese cohort study

Anti-glomerular basement membrane (GBM) disease usually presents with rapidly progressive glomerulonephritis accompanied by pulmonary hemorrhage. The low incidence and fulminant course of disease preclude a large randomized controlled study to define the benefits of any given therapy. We conducted a retrospective survey of 221 consecutive patients seen from 1998 to 2008 in our hospital, and report here the patient and renal survival and the risk factors affecting the outcomes. Considering the similar clinical features of the patients, we could compare the effects of 3 different treatment regimens: 1) combination therapy of plasmapheresis and immunosuppression, 2) steroids and cytotoxic agents, and 3) steroids alone.The patient and renal survival rates were 72.7% and 25.0%, respectively, at 1 year after disease presentation. The serum level of anti-GBM antibodies (increased by 20 U/mL; hazard ratio [HR], 1.16; p = 0.009) and the presentation of positive antineutrophil cytoplasmic antibodies (ANCA) (HR, 2.18; p = 0.028) were independent predictors for patient death. The serum creatinine at presentation (doubling from 1.5 mg/dL; HR, 2.07; p < 0.001) was an independent predictor for renal failure.The combination therapy of plasmapheresis plus corticosteroids and cyclophosphamide had an overall beneficial effect on both patient survival (HR for patient mortality, 0.31; p = 0.001) and renal survival (HR for renal failure, 0.60; p = 0.032), particularly patient survival for those with Goodpasture syndrome (HR for patient mortality, 0.29; p = 0.004) and renal survival for those with anti-GBM nephritis with initial serum creatinine over 6.8 mg/dL (HR for renal failure, 0.52; p = 0.014). The treatment with corticosteroids plus cyclophosphamide was found not to improve the renal outcome of disease (p = 0.73). In conclusion, the combination therapy was preferred for patients with anti-GBM disease, especially those with pulmonary hemorrhage or severe renal damage. Early diagnosis was crucial to improving outcomes.

Bronchoalveolar carcinoma (adenocarcinoma) mimicking recurrent bacterial community-acquired pneumonia (CAP)

Depending on the community-acquired pneumonia (CAP) pathogen, host factors, and immune status, CAPs resolve on chest x-rays at different rates. CAPs that resolve more slowly than expected, or not at all, are termed "slowly or non-resolving CAPs." In contrast, recurrent CAPs may be due to host defense defects (eg, multiple myelomas) or post-obstructive bronchogenic carcinomas. There are a variety of noninfectious disorders that may mimic CAPs on chest x-ray: alveolar hemorrhage, pulmonary drug reactions, radiation pneumonitis, Wegener's granulomatosis, bronchiolitis obliterans organizing pneumonia, bronchogenic carcinomas, and lymphomas. Noninfectious mimics of recurrent CAPs include congestive heart failure, pulmonary emboli, infarctions, sarcoidosis, and systemic lupus erythematosus pneumonitis. We present the case of a middle-aged man who presented with recurrent right middle lobe and right lower lobe CAPs. Diagnostic bronchoscopy showed no bronchial obstruction, but open lung biopsy showed bronchoalveolar carcinoma (well-differentiated adenocarcinoma). Bronchoalveolar carcinomas presenting as post-obstructive or recurrent CAPs are rare because the spread is along tissue planes and not endobronchially. The case described demonstrates a rare cause of bronchogenic carcinoma mimicking recurrent CAP.

Dr Goodpasture: "I was not aware of such a connection between lung and kidney disease"

This article describes how Dr Ernest Goodpasture's 1919 study of influenza became the basis for his name being attached to pulmonary-renal syndromes by Stanton and Tange in 1958. Dr Goodpasture was an unwilling participant in this naming, and in retrospect, the patient he described who served as the prototypic case probably had a vasculitic syndrome. Finally, Dr Goodpasture's major contributions to virology are summarized.

Anemia, cough, and acute renal failure in a teenager: case presentation and review

Anemia and cough are common problems with adolescent females. We present a case where these common symptoms led to the discovery of an uncommon entity, Goodpasture's Syndrome. The purpose of this report is to review the clinical manifestations, treatment and pathology of Goodpasture's Syndrome.

Pulmonary-renal syndromes

Pulmonary-renal syndromes or lung-kidney syndromes are clinical syndromes defined by a combination of diffuse alveolar haemorrhage (DAH) and glomerulonephritis. Pulmonary-renal syndromes are not a single entity, but are caused by a wide variety of diseases, including various forms of primary systemic vasculitis (especially Wegener's granulomatosis and microscopic polyangiitis), Goodpasture's syndrome (associated with autoantibodies to the alveolar and glomerular basement membrane) and systemic lupus erythematosus. The diagnosis rests on the identification of particular patterns of clinical, radiologic, pathologic and laboratory features. Serologic testing is important in the diagnostic work-up of patients presenting with a pulmonary-renal syndrome. The majority of cases of pulmonary-renal syndrome are associated with ANCAs, either c-ANCA or p-ANCA, due to autoantibodies against the target antigens proteinase-3 and myeloperoxidase respectively. The antigen target in Goodpasture's syndrome is type IV collagen, the major component of basement membranes. Diffuse alveolar haemorrhage is characterized by the presence of a haemorrhagic bronchoalveolar lavage (BAL) in serial BAL samples. In the clinical setting of an acute nephritis syndrome, percutaneous renal biopsy is commonly performed for histopathology and immunofluorescence studies. Treatment of generalized ANCA-associated vasculitis consists of corticosteroids and immunosuppressive agents such as cyclophosphamide (as induction therapy) or azathioprine (as maintenance therapy once remission has been achieved). The combination of plasmapheresis with these cytotoxic agents and steroids is effective in patients with Goodpasture's syndrome, especially if instituted early in the course of the disease. Recent evidence suggests that patients with severe ANCA-associated vasculitis, defined by the presence of diffuse alveolar haemorrhage and/or severe renal involvement (creatinine concentration > 5.7 mg/dl), might benefit from plasma exchange in combination with cyclophosphamide and corticosteroids.

T Cell Epitope Mimicry in Antiglomerular Basement Membrane Disease

Antiglomerular basement membrane (GBM) disease or Goodpasture's syndrome is among the earliest recognized human autoimmune diseases. Although collagen 4alpha3 NC1 (Col4alpha3NC1) has been identified as the responsible autoantigen, it remains unknown how autoimmunity to this autoantigen is provoked. We have demonstrated in our rat model that a single nephritogenic T cell epitope pCol28-40 of Col4alpha3NC1 induces glomerulonephritis. We hypothesized that microbial peptides that mimic this T cell epitope could induce the disease. Based on the critical residue motif (xxtTxNPsxx) of pCol28-40, seven peptides derived from human infection-related microbes were chosen through GenBank search and synthesized. All peptides showed cross-reactivity with pCol28-40-specific T cells at various levels. Only four peptides induced transient proteinuria and minor glomerular injury. However, the other three peptides induced severe proteinuria and modest to severe glomerulonephritis in 16-25% of the immunized rats. Unexpectedly, the most nephritogenic peptide, pCB, derived from Clostridium botulinum, also induced modest (25%) to severe (25%) pulmonary hemorrhage, another important feature of anti-GBM disease; this was not correlated with the severity of glomerulonephritis. This finding suggests that subtle variations in T cell epitope specificity may lead to different clinical manifestations of anti-GBM disease. In summary, our study raises the possibility that a single T cell epitope mimicry by microbial Ag may be sufficient to induce the anti-GBM disease.

Pulmonary-renal syndromes in the intensive care unit

Renal disease associated with pulmonary hemorrhage is seen in a variety of clinical disorders and is a common cause of admission to intensive care units. Recent advances in the understanding of the pathogenesis of these disorders have improved the therapeutic options significantly and have favorably influenced the course of many of these disorders. This article discusses rheumatologic diseases that involve both the kidney and lungs, with emphasis on pathogenesis and therapeutic options. Common pulmonary-renal syndromes including anti-glomerular basement membrane disease and anti-neutrophil cytoplasmic autoantibodies-associated vasculitis.

Outcomes in patients with Goodpasture's syndrome and hydrocarbon exposure

Goodpasture's Syndrome has been associated with hydrocarbon exposure. No study has examined outcomes in these patients. All reported cases of Goodpasture's Syndrome and hydrocarbon exposure were identified using MEDLINE and was analyzed for factors related to outcomes. A total of 43 cases were identified since 1969. The mean age of patients was 28 years old. There was a slight predilection for males (60%) when analyzing gender. Various types of hydrocarbons were identified and the duration of exposure varied from minutes to years. A majority of patients (86%) had pulmonary hemorrhage and antiglomerular basement membrane antibodies (AGBM) (92%). Patients were treated with immunosuppressive agents. The only significant statistical correlation was female patients with hydrocarbon exposure were younger. There was no correlation between age, gender, duration of exposure, presence of pulmonary hemorrhage or AGBM, or other risk factors and outcome. The relationship between hydrocarbon exposure and Goodpasture's Syndrome remains unclear since only 6% of cases in the literature had exposure. Even though most patients survived, no factor studied affected outcome making it difficult to predict prognosis in these patients.

Hemoptysis in patients with renal insufficiency : the role of flexible bronchoscopy

STUDY OBJECTIVES

To assess the indications, yield, and therapeutic impact of flexible bronchoscopy (FB) in patients with hemoptysis and renal insufficiency.

DESIGN

Retrospective cohort analysis.

SETTING

Tertiary-care university hospital.

PATIENTS

Thirty-four patients over a 7.5-year period who underwent FB to evaluate hemoptysis in the setting of renal insufficiency (ie, serum creatinine level, > 1.5 mg/dL).

MEASUREMENTS AND RESULTS

The etiology of hemoptysis was undetermined in 41% of cases. Defined causes of bleeding included infections (29%), pulmonary renal syndromes (15%), airway injury (9%), and pulmonary embolism (6%). No specific bleeding site was identified, but FB lateralized hemorrhaging to one lung in 24% of patients. FB results influenced therapy in 29% of patients overall and in 8% of patients without respiratory tract infection. The hospital survival rate was 47% and did not differ based on the presence or absence (presence vs absence) of the following variables: a defined etiology for hemoptysis (45% vs 50%); lateralized bleeding (38% vs 50%); or management alterations prompted by other FB findings (50% vs 46%). Factors associated with survival included the onset of bleeding prior to hospital admission (80% vs 33%; p = 0.02), the absence of respiratory failure requiring mechanical ventilation at the time of FB (90% vs 29%; p = 0.002), and lack of prohemorrhagic factors (other than uremia) such as disseminated intravascular coagulation, recent treatment with warfarin, heparin, or antiplatelet agents (78% vs 33%; p = 0.05). During the 6 months following hospital discharge, hemoptysis recurred in 14% of patients, and 5 patients died, for an overall mortality rate of 62%.

CONCLUSIONS

These data suggest that FB in hospitalized patients with hemoptysis and renal insufficiency, and without radiographic findings suggesting neoplastic disease, has a low yield and limited impact. Whether FB influences outcome in selected patients in this setting requires prospective investigation.

High affinity of anti-GBM antibodies from Goodpasture and transplanted Alport patients to alpha3(IV)NC1 collagen

BACKGROUND

Anti-glomerular basement membrane (anti-GBM) antibody-mediated diseases are characterized by rapidly progressive glomerulonephritis (RPGN) that often results in irreversible loss of renal function and renal failure. Although many factors contribute to the fulminant nature and treatment resistance of this disease, we questioned whether high affinity autoantibody-alpha3(IV) collagen interactions lead to persistent antibody deposition, thereby perpetuating inflammation. To address this hypothesis, the binding kinetics of human anti-GBM antibodies (Ab) to alpha3(IV)NC1 were evaluated using an optical biosensor interaction analysis.

METHODS

Polyclonal anti-GBM Abs were purified by alpha3(IV)NC1 affinity chromatography from the sera of patients with anti-GBM AB-mediated diseases, including individuals with Goodpasture syndrome (GS), idiopathic RPGN (N = 7), and Alport syndrome (AL) following kidney transplantation (N = 4). The affinity-binding characteristics of the autoantibodies were determined using a biosensor analysis system, with immobilized bovine alpha3(IV)NC1 dimers.

RESULTS

All of the autoantibody preparations bound to alpha3(IV)NC1, whereas none bound to alpha1(IV)NC1 (control). Purified, normal serum IgG did not bind to either antigen. Estimated dissociation constants (Kd) for the purified autoantibodies were 1.39E-04 +/- 7.30E-05 s-l (GS) and 8. 90E-05 +/- 2.80E-05 s-l (AL). Their estimated association constants (Ka) were 2.67E+04 +/- 1.8E+04 (M-ls-l) and 2.76E+04 +/- 1. 70E+04(M-ls-l) for GS and AL patients, respectively. By comparison with other Ab interactions, these Abs demonstrated high affinity, with relatively high on (binding) rates and slow off (dissociation) rates.

CONCLUSIONS

The results suggest that anti-GBM Abs bind rapidly and remain tightly bound to the GBM in vivo. This property likely contributes to both the fulminant nature of this disease and its resistance to therapy, because persistent glomerular Ab deposition has the potential to produce continuous inflammation, despite removal of circulating Abs and adequate immunosuppression.

Sequential development of pulmonary hemorrhage with MPO-ANCA complicating anti-glomerular basement membrane antibody-mediated glomerulonephritis

We report a case of rapidly progressive glomerulonephritis caused by anti-glomerular basement membrane (anti-GBM) antibodies that progressed to end-stage renal disease in a 67-year-old woman with diabetes. Intensive combined immunosuppressive therapy with methylprednisolone bolus, oral prednisone, and cyclophosphamide led to negativity of anti-GBM antibodies but was not able to restore renal function. After 28 months of hemodialysis, the patient suddenly presented with pulmonary hemorrhage. In this setting, high levels of myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) and negative anti-GBM antibodies were found. Therapy with oral prednisone and cyclophosphamide led to resolution of pulmonary hemorrhage and negativity of MPO-ANCA.

Fcgamma receptor IIB-deficient mice develop Goodpasture's syndrome upon immunization with type IV collagen: a novel murine model for autoimmune glomerular basement membrane disease

The combination of hemorrhagic pneumonitis and rapidly progressive glomerulonephritis is a characteristic feature of Goodpasture's syndrome (GPS), an autoimmune disease resulting from the interaction of pathogenic anti-collagen type IV (C-IV) antibodies with alveolar and glomerular basement membranes. Lack of a suitable animal model for this fatal disease has hampered both a basic understanding of its etiology and the development of therapeutic strategies. We now report a novel model for GPS using mice deficient in a central regulatory receptor for immunoglobulin (Ig)G antibody expression and function, the type IIB Fc receptor for IgG (FcgammaRIIB). Mutant mice immunized with bovine C-IV reproducibly develop massive pulmonary hemorrhage with neutrophil and macrophage infiltration and crescentic glomerulonephritis. The distinctive linear, ribbon-like deposition of IgG immune complex seen in GPS was observed along the glomerular and tubulointerstitial membranes of diseased animals. These results highlight the role of FcgammaRIIB in maintaining tolerance and suggest that it may play a role in the pathogenesis of human GPS.

Other smoking-affected pulmonary diseases

Cigarette smoking is the leading cause of preventable death in the United States. Smoking adversely affects many organ systems, but especially the lung. Carcinoma of the lung and chronic obstructive pulmonary disease account for most smoking-associated respiratory morbidity and mortality, and their association with smoking is both well established and widely recognized. Cigarette smoking also is associated with differences in the incidence, severity, or natural history of a broad array of other respiratory illnesses, ranging from the common cold to pneumothorax, pulmonary hemorrhage, and various interstitial lung diseases. Interestingly, while the general effect of smoking on respiratory diseases is adverse, in the cases of sarcoidosis and hypersensitivity pneumonitis smoking may actually be associated with a decrease in the incidence of disease. In this article, the author briefly discusses some of the pulmonary and systemic effects of smoking that might mediate its effects on an array of lung diseases, then comprehensively reviews less common or less well-recognized smoking-affected lung diseases such as pulmonary infections, spontaneous pneumothorax, Goodpasture's syndrome, eosinophilic granuloma and other interstitial lung diseases, and pulmonary metastatic disease.

Nonresolving or slowly resolving pneumonia

Given the variability in rate of radiographic resolution, it remains controversial to decide when to initiate an invasive diagnostic work-up for nonresolving or slowly resolving pulmonary infiltrates. In immunocompetent patients who present with classical features of CAP (i.e., fever, chills, productive cough, new pulmonary infiltrate), clinical response to therapy is the most important determinant for further diagnostic studies. Within the first few days, persistence or even progression of infiltrates on chest radiographs is not unusual. Defervescence, diminished symptoms, and resolution of leukocytosis strongly support a response to antibiotic therapy, even when chest radiographic abnormalities persist. In this context, observation alone is reasonable, and invasive procedures can be deferred. Serial radiographs and clinical examinations dictate subsequent evaluation. In contrast, when clinical improvement has not occurred and chest radiographs are unchanged or worse, a more aggressive approach is warranted. In this setting, we advise fiberoptic bronchoscopy with BAL and appropriate cultures for bacteria, legionella, fungi, and mycobacteria. When endobronchial anatomy is normal and there is no purulence to suggest infection, TBBs should be done to exclude noninfectious causes (discussed earlier) or infections attributable to mycobacteria or fungi. An aggressive approach is also warranted in patients who are clinically stable or improving when the rate of radiographic resolution is delayed. As discussed earlier, what constitutes excessive delay is controversial, and depends upon the acuity of illness, specific pathogen, extent of involvement (i.e., lobar versus multilobar), comorbidities, and diverse host factors. Stable infiltrates even 2 to 4 weeks after institution of antibiotic therapy does not mandate intervention provided patients are improving clinically. Invasive techniques can also be deferred when unequivocal, albeit incomplete, radiographic resolution can be demonstrated. Lack of at least partial radiographic resolution by 6 weeks, even in asymptomatic patients, however, deserves consideration of alternative causes (e.g., endobronchial obstructing lesions, or noninfectious causes). Fiberoptic bronchoscopy with BAL and TBBs has minimal morbidity and is the preferred initial invasive procedure for detecting endobronchial lesions or substantiating noninfectious causes. The yield of bronchoscopy depends on demographics, radiographic features, and pre-test likelihood. In the absence of specific risk factors, the incidence of obstructing lesions (e.g., bronchogenic carcinomas, bronchial adenomas, obstructive foreign body) is low. Bronchogenic carcinoma is rare in nonsmoking, young (< 50 years) patients but is a legitimate consideration in older patients with a history of tobacco abuse. Non-neoplastic causes (e.g., pulmonary vasculitis, hypersensitivity pneumonia, etc.) should be considered when specific features are present (e.g., hematuria, appropriate epidemiologic exposures). Ancillary serologic tests or biopsies of extrapulmonary sites are invaluable in some cases. In rare instances, surgical (open or VATS) biopsy is necessary to diagnose refractory or non-resolving "pneumonias."

Glomerulonephritis

The differential diagnosis of glomerulonephritis without systemic disease includes poststreptococcal glomerulonephritis, IgA nephropathy, rapidly progressive glomerulonephritis (RPGN), and membranoproliferative glomerulonephritis (MPGN). Glomerular inflammation is probably induced directly by a nephritogenic streptococcal protein in poststreptococcal glomerulonephritis, and by mesangial deposition of abnormally glycosylated IgA1-containing immune aggregates in IgA nephropathy. In crescentic RPGN the role of cellular rather than humoral immune mechanisms is now becoming clear. Many patients with MPGN have chronic hepatitis C infection. There is no effective disease-specific therapy for poststreptococcal glomerulonephritis or IgA nephropathy. RPGN benefits from high-dose steroids and cytotoxic drug therapy with the addition of plasma exchange in disease induced by antibody to glomerular basement membrane. Antiviral therapies reduce the severity of MPGN due to hepatitis C virus. However, various new therapies directed at specific cytokines, growth factors, fibrin deposition, and other mediators of injury are being developed, as well as more specific and less toxic forms of immunotherapy.

Pulmonary manifestations of Goodpasture's syndrome. Antiglomerular basement membrane disease and related disorders

Goodpasture's syndrome, or antiglomerular basement membrane disease, is a disorder in which lungs and kidneys are affected by the binding of anti-GBM antibodies, leading to pulmonary hemorrhage and glomerulonephritis with rapidly progressive renal insufficiency. Recent advances in the understanding of disease pathogenesis and diagnosis and treatment have significantly improved our ability to recognize the syndrome, distinguish it from other similar disorders, and offer successful treatment. This article focuses on the pathogenetic features, clinical manifestations, diagnostic strategies, and therapeutic principles of anti-GBM disease.

Pulmonary manifestations of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that primarily affects young women. The respiratory system is more commonly involved in SLE than in any other collagen vascular disease. SLE may affect virtually all components of the respiratory system, including the upper airway, lung parenchyma, pulmonary vasculature, pleura, and respiratory muscles. Respiratory system involvement ranges from symptomatic to fulminant and life threatening. This article reviews the pulmonary manifestations of SLE, including drug-induced SLE.

Therapeutic apheresis for renal diseases

Plasma exchange is used frequently in renal diseases for the removal of the humoral components of immune responses. Various pathological circulating factors are recognized in primary and secondary renal diseases. Recent advances in medical technology have allowed a wider clinical application of plasmapheresis in the clinical management of a variety of conditions. However, the clinical efficacy of plasmapheresis in renal diseases is still controversial. In this article, we review the therapeutic use of apheresis in different renal diseases.

A novel marker of Schwann cells and myelin of the peripheral nervous system

Cellular markers are useful in the immunohistochemical studies of normal and pathological tissues. Herein, the development of a monoclonal antibody, Schwann/2E, which reacts with Schwann cells and myelin of the peripheral nervous system (PNS) is described. The Schwann/2E antibody was secreted by a hybridoma of mouse myeloma cells and mouse spleen cells that were immunized in vivo with a cytoskeletal fraction of the human spinal nerve. This antibody immunostained formalin-fixed, paraffin-embedded human, rat, and mouse tissue by the indirect immunoperoxidase method. Schwann cells and myelin of the PNS were intensely labeled by the Schwann/2E antibody. Both the nuclei and cytoplasm of the Schwann cells were labeled. As shown by a comparative light and an electron microscopic study, the Schwann/2E antibody immunoreacted with the Schwann cells that had myelinated axons, but not with those that had unmyelinated axons. The endoneurial fibroblast was not immunolabeled. This antibody slightly stained the endothelial cells of the lung and kidney. Myelin and oligodendroglia of the central nervous system did not react with the Schwann/2E antibody. The Schwann/2E antigen was stable in several histological fixatives. These results indicate that, under normal and pathological conditions, the Schwann/2E antibody could be a useful immunohistochemical marker of Schwann cells and myelin of the PNS.

Self-reactive B cells are not eliminated or inactivated by autoantigen expressed on thyroid epithelial cells

Graves' Disease results from the production of autoantibodies against receptors for thyroid stimulating hormone (TSH) on thyroid epithelial cells, and represents the prototype for numerous autoimmune diseases caused by autoantibodies that bind to organ-specific cell membrane antigens. To study how humoral tolerance is normally maintained to organ-specific membrane antigens, transgenic mice were generated selectively expressing membrane-bound hen egg lysozyme (mHEL) on the thyroid epithelium. In contrast to the deletion of autoreactive B cells triggered by systemic mHEL (Hartley, S.B., J. Crosbie, R. Brink, A.B. Kantor, A. Basten, and C.C. Goodnow. 1991. Nature. 353:765-769), selective expression of mHEL autoantigen on thyroid cells did not trigger elimination or inactivation of circulating HEL-reactive B cells. These results provide evidence that tolerance is not actively acquired to organ-specific antigens in the preimmune B cell repertoire, underscoring the importance of maintaining tolerance to such antigens by other mechanisms. The role of an intact endothelial barrier in sequestering organ-specific antigens from circulating preimmune B cells is discussed.

Diffuse alveolar hemorrhage and systemic lupus erythematosus. Clinical presentation, histology, survival, and outcome

Diffuse alveolar hemorrhage (DAH) complicating systemic lupus erythematosus (SLE) remains a devastating pulmonary complication of this systemic disease. We conducted this study to review the clinicopathologic presentation and the effects of prior treatment, presence of infection, and current treatment on the survival and outcome of patients with DAH and SLE. We reviewed the records of 15 SLE patients who experienced 19 episodes of DAH over a 10-year period in a single tertiary care hospital. These patients were compared with 57 previously reported cases. The 19 episodes of DAH represented 3.7% of the 510 admissions occasioned by various complications of SLE. As previously reported, the majority (66%) were women with a median age of 27 years. The onset was often abrupt: < 3 days in 12 of the episodes. In 3 patients (20%), DAH was the initial manifestation of SLE, compared with 11% in the literature series. In the other patients in the present series, DAH appeared a median of 31 months following the diagnosis of SLE, versus 35 months in the literature series. In only 42% of the episodes in the present series, compared with 66% in the literature series, was hemoptysis present at the time of admission. However, hemoptysis eventually appeared in all 19 episodes. Temperature elevation (> 38 degrees C) was another inconsistent finding, found in only 5 episodes (26%) in the present series. The most constant concurrent systemic finding was lupus nephritis (14/15 patients). This represents a significant increase when compared with the literature series (29/48 patients). In 8 of 10 patients in whom lung tissue was available, pulmonary capillaritis accompanied the DAH. This represents a marked difference in the underlying histologic pattern when compared with the literature series. In those patients, 72% (31/43 patients) had bland pulmonary hemorrhage, and capillaritis was described in only 6 patients. The overall patient mortality rate was 53% in the current series and 50% in the literature series. Factors associated with an increased mortality in the present series include the following: mechanical ventilation (62%) versus no mechanical ventilation (0%); infection (78%) versus no infection (20%); and cyclophosphamide therapy for the acute DAH episode (70%) versus no cyclophosphamide therapy (20%). The incidence of infection in DAH and SLE (9/19 episodes) is far greater than previously reported (7/ 57 episodes). One possible explanation for this difference is the increased use of outpatient immunosuppressive therapy with monthly intravenous cyclophosphamide therapy for lupus nephritis. Eighteen DAH episodes in the present series were treated with intravenous methylprednisolone. When one combines both the current and literature series experience (16 episodes), the use of plasmapheresis does not improve survival. Of the 7 patients in the present series who survived all episodes of DAH, 6 remain alive a median of 50 months post episode and without recurrence of DAH. Diffuse alveolar hemorrhage is an uncommon but lethal complication of SLE. The survival rate remains unchanged from previous reports. The absence of hemoptysis should not exclude this diagnosis, particularly in those patients who experience an acute pulmonary syndrome with new radiographic infiltrates accompanied by falling hematocrit and the presence of a hemorrhagic bronchoalveolar lavage. Evidence for lupus nephritis is present in the great majority of cases. Most cases demonstrate the histologic pattern of pulmonary capillaritis. The mortality is adversely affected by the need for mechanical ventilation, either the presence of infection at the time of admission or the development of infection in the hospital, and the use of cyclophosphamide for treatment of the acute event.

[Intrapulmonary hemorrhages associated with Basedow disease]

We report the second case of intraalveolar haemorrhage associated with an autoimmune thyrotoxicosis. While intraalveolar haemorrhage was not recurrent since 7 years with corticosteroid therapy, a relapse occurred when we began the treatment for an autoimmune thyrotoxicosis. We discuss the link between intraalveolar haemorrhage and autoimmune thyrotoxicosis or its treatment.

Vasculitis in children

Common vasculitic disorders in children include those associated with infections (e.g., Rickettsiae, subacute bacterial endocarditis), Schonlein-Henoch purpura, and Kawasaki disease. Recent advances have occurred in understanding the pathogenesis of vasculitides. In this review, the reader will be exposed to some of the developments in adhesion molecules, antineutrophil cytoplasmic antibodies, antiendothelial antibodies, and antiphospholipid antibodies. Classification criteria and diagnostic strategies are also summarized.