Antineutrophil cytoplasmic antibodies in myelodysplasia

Antibodies to neutrophil cytoplasmic antigens (ANCA) are good serological markers for patients with mainly vasculitic conditions. Two main types of ANCAs have been detected, the first termed cytoplasmic antineutrophil cytoplasmic antibody (cANCA) are mainly associated with patients with Wegener's granulomatosis, the other termed perinuclear antineutrophil cytoplasmic antibody (pANCA) are mainly associated with patients with renal vasculitis, rheumatic and collagen disorders. These antibodies are against various constituents of neutrophil granules. In patients with myelodysplasia, defects in normal granulocyte development are seen. We report a series of twelve patients with myelodysplasia of whom at least four showed a low titre and one a high titre of pANCA. Two of these patients also had demonstrable activity against myeloperoxidase (MPO). None of these patients had any evidence of systemic or cutaneous vasculitis or of any autoimmune disorder. There was no pANCA positivity in an age matched control group.

Development and standardization of solid phase assays for the detection of anti-neutrophil cytoplasmic antibodies (ANCA). A report on the second phase of an international cooperative study on the standardization of ANCA assays

Anti-neutrophil cytoplasmic antibodies (ANCA) are diagnostic markers for systemic vasculitis. They are classically I detected by an indirect immunofluorescence test using normal donor neutrophils as substrate. This assay lacks antigenic specificity and is not quantitative. The 'EC/BCR Project for ANCA Assay Standardization' is an international collaboration study with the aim to develop and standardize solid phase assays for ANCA detection. In this part of the study the isolation and characterization of proteinase-3 and myeloperoxidase, the two main target molecules for ANCA, and the development and standardization of ELISAs with these antigens are described. Six laboratories successfully isolated purified proteinase-3 preparations that could be used. Three of these preparations, together with one myeloperoxidase preparation, were subsequently used for ANCA testing by ELISA. The ELISA technique was standardized in two rounds of testing in the 14 participating laboratories. The coefficient of variation of these new assays decreased from values of approx. 50% in the first round to approx. 20% in the second round. We conclude that purified proteinase-3 and myeloperoxidase can be used in standardized ELISAs for ANCA detection. Whether such procedures offer advantages over the IIF test will be determined in a prospective clinical study.

Caveolin-1 single nucleotide polymorphism in antineutrophil cytoplasmic antibody associated vasculitis

Immunosuppression is cornerstone treatment of antineutrophil cytoplasmic antibody associated vasculitis (AAV) but is later complicated by infection, cancer, cardiovascular and chronic kidney disease. Caveolin-1 is an essential structural protein for small cell membrane invaginations known as caveolae. Its functional role has been associated with these complications. For the first time, caveolin-1 (CAV1) gene variation is studied in AAV.

Anti-neutrophil cytoplasmic antibodies (ANCA) in the clinical forms of leprosy

Anti-neutrophil cytoplasmic antibodies (ANCA) are autoantibodies against enzymes present in primary granules of neutrophils and lysosomes of monocytes detected in systemic vasculitis and in other diseases, including infections, ANCA are markers of active Wegener granulomatosis, which presents some anatomo-pathologic and immune response features similar to those of leprosy. Thus, we raised the hypothesis that ANCA may be present in leprosy as markers specifically linked to the presence of vasculitis. The aim of this study was to determine the presence of ANCA in leprosy and its correlation with the clinical forms of the disease. Sera from 60 normal individuals and from 59 patients with different clinical forms of leprosy were studied. The patients were also allocated into reactional and nonreactional groups. By indirect immunofluorescence, ANCA were positive, an atypical pattern A-ANCA, in 28.8% of the patient sera. A-ANCA predominated, although not significantly (p >0,05), in the reactional groups (37.9% vs 20.0%), and in those at the lepromatous pole (41.6% vs 20.0%). There was no correlation between ANCA positivity and either disease duration, disease activity, or therapeutic regimen (p >0.05), An interesting finding was the correlation between ANCA and gender: 94.1% of ANCA-positive patients were males (p <0.01), a feature that so far has not been reported in ANCA-related diseases and for which there is no explanation at the moment. By ELISA, the sera of the lepromatous leprosy patients did not show activity against either PR3, MPO, HLE, the most common ANCA antigens. Because A-ANCA are nonspecific, this finding requires further investigation for the determination of the responsible antigen(s), in conclusion, A-ANCA are present in 28.8% of leprosy patients but are not related to vasculitis in the erythema nodosum leprosum reaction and are not a marker of a specific clinical form.

Absence of cross-reactivity to myeloperoxidase of anti-thyroid microsomal antibodies in patients with autoimmune thyroid diseases

Background: Thyroperoxidase is the major antigen of the thyroid microsomal antibodies (TMA) detected in autoimmune thyroid diseases. Its amino acid sequence has 44% homology with myeloperoxidase (MPO), an enzyme present in the primary granules of neutrophils and one of the major antineutrophil cytoplasmic antibodies (ANCA) antigens. The objective of the present study was to investigate the presence of cross-reactivity to MPO of TMA. Methods: We studied sera from 51 patients with autoimmune thyroid diseases, all of them TMA-positive. The presence of ANCA was investigated by indirect immunofluorescence and by capture enzyme-linked immunosorbent assay. Results: ANCA were positive in 3.9% of the TMA-positive sera and none of them reacted with MPO. In contrast, the ANCA-positive sera revealed antielastase activity. None of the ANCA-positive cases presented clinical signs of vasculitis. However, these 2 patients had been on prolonged treatment with propylthiouracil. Conclusions: We conclude that there is no cross-reactivity to MPO of TMA in patients with autoimmune thyroid diseases, possibly because of difference in the spatial configuration of the immunodominant region. The presence of ANCA in patients with autoimmune thyroid diseases without evidence of vasculitis might result from propylthiouracil-induced polyclonal activation.

Vasculitides associated with IgG antineutrophil cytoplasmic autoantibodies in childhood

Immunoglobulin (Ig)G antineutrophil cytoplasmic autoantibodies are causally associated with necrotizing vasculitides that are characterized immunopathologically by little or no deposition of immunoreactants, such as Wegener granulomatosis, microscopic polyangiitis, Churg-Strauss angiitis, "renal-limited" vasculitis and a number of drug-induced vasculitides. Clinical routine testing targets the antigens myeloperoxidase and proteinase 3. However, in all of the conditions mentioned, the renal histopathologic findings are indistinguishable. Churg-Strauss angiitis (characterized by necrotizing vasculitis, granulomatous inflammation and tissue eosinophilia), Wegener granulomatosis (characterized by necrotizing vasculitis and granulomatous inflammation) and microscopic polyangiitis (characterized by necrotizing vasculitis) often present with fever, weight loss and a multisystem involvement (ear, nose, throat, lung, eyes, peripheral nerve and heart). Fifty years ago these conditions were very often fatal within 6 months of diagnosis. The introduction of corticosteroids and cyclophosphamide has resulted in a dramatic clinical benefit. Patients who develop treatment-related morbidity can be switched from cyclophosphamide to azathioprine after achieving remission. In patients with less severe disease, methotrexate achieves remission with a success rate similar to that of cyclophosphamide. Plasma exchange, in association with immunosuppression, is likely to be a beneficial therapy for patients with severe kidney disease or pulmonary hemorrhage.

Diagnostic value of biopsies in identifying cytoplasmic antineutrophil cytoplasmic antibody-negative localized Wegener's granulomatosis presenting primarily with sinonasal disease

A substantial proportion of Wegener's disease (WG) patients present with localized disease of the upper airways, i.e., sinonasal and other ear/nose/throat (ENT) symptoms. Because of the oligosymptomatic presentation a timely diagnosis of this potentially fatal disease is challenging. This study evaluates diagnostic peculiarities between WG in its localized and generalized form of the disease.

Pneumocystis carinii pneumonia during immunosuppressive therapy for antineutrophil cytoplasmic autoantibody-positive vasculitis.

We describe two human immunodeficiency virus-negative patients who developed Pneumocystis carinii pneumonia (PCP) during immunosuppressive therapy for antineutrophil cytoplasmic autoantibody-positive vasculitis and review the literature regarding the pathogenesis and frequency of PCP. The recent application of DNA amplification techniques suggests that PCP developing in immunocompromised individuals does not necessarily result from reactivation of a dormant focus, but may arise as de novo infection after exposure to an exogenous source of P carinii. In addition, several reports about clusters of PCP cases raise concern about the risk of a nosocomial transmission of P carinii. Therefore, PCP should be added to the list of bronchopulmonary complications in patients with antineutrophil cytoplasmic autoantibody-positive vasculitis who are receiving long-term steroid therapy.

Idiopathic pulmonary hemosiderosis with cystic lesions: A rare presentation

This report describes a case of a 49-year-old man with cough, recurrent hemoptysis, and dyspnea during 18 months, presenting with radiological findings of alveolar infiltrate and cystic lesions in left upper lobe. Laboratory studies revealed normocytic hypochromic anemia and normal coagulation tests. C-reactive protein and mucoproteins were negative. Serum protein electrophoresis and complement, urinalysis, serum creatinine, creatinine clearance, and 24-hour urine protein were normal. Tests for antineutrophil cytoplasmic antibodies and anti-glomerular-basement membrane antibodies were negative. Tests for connective tissue diseases were all negative. Histological findings were consistent with those of idiopathic pulmonary hemosiderosis. Radiological findings are discussed.

HLA-DR in Brazilian patients with polyarteritis nodosa (PAN) and microscopic polyangiitis (MPA)

The aim of this study was to evaluate the frequency and clinical associations of HLA-DR alleles in Brazilian Caucasian patients with polyarteritis nodosa (PAN) or microscopic polyangiitis (MPA). We evaluated 29 Caucasian patients with vasculitis classified as PAN or MPA according to the American College of Rheumatology (ACR) 1990 Criteria, Chapel Hill Consensus Conference (CHCC) nomenclature for vasculitis and EULAR recommendations for conducting clinical studies in systemic vasculitis. HLA-DR alleles were typed using polymerase chain reaction-amplified DNA, hybridized with sequence-specific low resolution primers. DNA obtained from 59 Caucasian healthy blood donors were used as control. In order to evaluate if a specific HLA may have influence on the clinical profile of those diseases, we also divided the patients according to Birmingham vasculitis score (BVAS) and Five-Factors Score (FFS) at the time of diagnosis. Increased frequency of HLA-DRB1*16 (p = 0.023) and DRB4*01 (p = 0.048) was found in patients with higher disease activity at the time of diagnosis (BVAS >= 22). Patients with less severe disease (FFS = 0) had a higher frequency of HLA-DRB1*03 (p = 0.011). Patients with gastrointestinal tract involvement had significantly increased frequency of HLA-DRB1*11 or B1*12 (p = 0.046), B1*13 (p = 0.021) and B3 (p = 0.008). In contrast, patients with renal disease, had higher frequency of DRB1*15 or DRB1*16 (p = 0.035) and B5 (p = 0.035). In the subgroup of patients with MPA, increased frequency of HLA-DRB1*15 was found in patients with BVAS >= 22 (p = 0.038) and FFS >= 1 (p = 0.039) suggesting that this allele is associated with more aggressive disease. Antineutrophil cytoplasmic antibodies (ANCA) negative MPA patients had significantly increased frequency of HLA-DRB1*11 or DRB1*12 when compared to ANCA positive patients (p = 0.023). Our results suggest that HLA-DR alleles may influence PAN and MPA clinical expression and outcome and that in MPA they participate in the mechanisms involved in the development to ANCA.

[Which clinical symptoms suggest distinct autoantibody measurements?]

The detection of autoantibodies is an important cornerstone in the diagnosis of systemic autoimmune disorders such as autoimmune connectivitides and small vessel vasculitides. Antinuclear antibodies (ANAs ) and antineutrophil cytoplasmic antibodies (c+p-ANCAs) are appropriate diagnostic screening tools for autoimmune connectivitides and small vessel vasculitides. For economic and intellectual/didactic reasons more extensive autoantibody diagnostics should be performed only in particular situations when patients history and clinical exam lead to strong diagnostic suspicion.

Isolated Rosai-Dorfman disease of intracranial meninges

Rosai-Dorfman disease (RDD) is a non-neoplastic proliferative histiocytic disorder that primarily affects lymph nodes (sinus histiocytosis with massive lymphadenopathy). Primary RDD of the central nervous system is most uncommon. We report on a 35-year-old man with isolated RDD of the meninges overlying the left cerebral hemisphere. Presenting signs and symptoms included severe progressive ipsilateral headaches of 4 months duration, as well as laboratory evidence of mild non-specific systemic inflammatory reaction. On magnetic resonance imaging, the lesion was seen as a contrast-enhancing, plaque-like thickening of the dura mater over the left convexity,without impinging on adjacent bone or cerebral parenchyma. Meningeal biopsy revealed a mixed mononuclear infiltrate dominated by CD68(+), S100(+), CD1a(-) non-Langerhans type histiocytes on a background of fibrosis. Bacteria, in particular mycobacteria, and fungi were excluded with special stains. Extensive clinical workup, encompassing computed tomography of thoracal and abdominal organs, bone marrow biopsy, and bronchoalveolar lavage failed to reveal any extracranial involvement. Laboratory tests for autoimmunity, including C- and P-antineutrophil cytoplasmic antibodies, antinuclear antibody, and serum rheumatoid factor, were negative. Methylprednisolone therapy induced complete remission of symptoms, with the neuroradiologic status remaining unchanged on follow-up after 2 months. We discuss the complex clinicopathologic differential diagnosis and therapeutic issues of this rare condition. While the correct diagnosis of central nervous system RDD is unlikely to be established without invasive procedures (biopsy), a conservative therapeutic approach may be considered a legitimate option.

Wegener's granulomatosis presenting as pyoderma gangrenosum

Half of the patients with Wegener's granulomatosis develop skin lesions due to the systemic vasculitis. Wegener's granulomatosis should be included in the differential diagnostic considerations for necrotic ulcers, including leg ulcers. We present a case which demonstrates the importance of histological evaluation of a skin biopsy from the margin of the ulcer for establishing the diagnosis. Antineutrophil cytoplasmic antibodies with antigen specificity for proteinase 3 (PR3-ANCA) were detected supporting the diagnosis of Wegener granulomatosis. Further evaluation showed involvement of the eyes and kidneys. The ulcer rapidly healed under treatment with cyclophosphamide and corticosteroids.

Autoantibodies against bactericidal/permeability-increasing protein (BPI) in children with acute pneumonia

Antineutrophil cytoplasmic antibodies directed against bactericidal/permeability-increasing protein (BPI), an inhibitor of a lipopolysaccharide of gram-negative bacteria, are a common feature of chronic neutrophilic inflammatory processes such as cystic fibrosis. We investigated whether serum and salivary anti-BPI autoantibodies also appear in the course of acute pneumonia in 24 otherwise healthy children. Nine (38%) and four (17%) patients had detectable serum anti-BPI immunoglobulin G (IgG) (> or =4 IU mL(-1)) and IgA (ratio> or =1.2), respectively, on the day of hospital admission (day 0). There was no increase in the rate of occurrence or the concentration of these antibodies in the convalescent sera obtained on day 30. The presence of anti-BPI IgG on admission did not correlate with inflammatory markers (peripheral white blood cell count, C-reactive protein) or temperature on admission. Also, salivary anti-BPI IgA, determined on days 0, 3-5 and 30, did not appear during the course of acute pneumonia. In summary, a substantial proportion of previously healthy children have pre-existing anti-BPI IgG autoantibodies. Acute neutrophilic infection, i.e. pneumonia, however, neither triggered the appearance of new antibodies nor boosted the concentrations of pre-existing ones. Thus, in typical acute pneumonia in children, autoantibodies directed against BPI may not have clinical significance.