Limited forms of Wegener's granulomatosis presenting as polymyalgia rheumatica

Early skeletal muscle manifestations in polyarteritis nodosa and ANCA-associated vasculitis

Skeletal muscle involvement is common in patients with small- and medium-sized vasculitis, particularly polyarteritis nodosa (PAN) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Despite being not included in the standard classification criteria for PAN and AAV, skeletal muscle involvement is an important clinical indicator, particularly when vasculitic myopathy is the only pathological evidence in the absence of other organ involvement. Herein, we comprehensively reviewed and compared the clinical features of 71 and 135 patients with PAN and AAV, respectively, with skeletal muscle involvement at the time of disease onset. Most patients with PAN and AAV exhibited skeletal muscle involvement, often characterized by myalgia and occasional muscular weakness, predominantly in the lower extremities. Myalgia and weakness were observed more frequently in the distal lower extremities in patients with PAN than in those with AAV. In contrast, skeletal muscle involvement tended to exhibit a more dispersed distribution across all four extremities in those with AAV. Muscle magnetic resonance imaging T2-weighted and short-tau inversion recovery sequences can effectively identify hyperintense areas attributed to hypervascularity of affected muscle tissues and serve as a sensitive and useful modality for visually determining the suitable biopsy site. >90% of patients with PAN and AAV demonstrated perivascular inflammation in their affected muscle tissues, whereas fibrinoid necrosis of the vessel walls was reported in two-thirds of patients. Serum creatine kinase (CK) levels were within the normal range in approximately 80% of patients presenting with skeletal muscle involvement in PAN and AAV. Furthermore, muscle fiber damage was milder in patients with skeletal muscle involvement in PAN and AAV than those with idiopathic inflammatory myositis. Meanwhile, serum CK levels were elevated in 65-85% of patients with PAN and AAV who had myofiber necrosis and degeneration in the affected muscles. Most patients with PAN and AAV showed improvement in skeletal muscle involvement following glucocorticoids (GCs) administration; however, relapse was observed in some patients during the tapering of GCs. In summary, skeletal muscle involvement is a potential indicator for establishing PAN and AAV diagnoses during the early phases of the disease.

Ophthalmic presentation of Wegener's granulomatosis on a background of polymyalgia rheumatica

We present a case of Wegener's granulomatosis (WG) in a 79-year-old man with limbitis and granulomatous conjunctivitis, on a background of polymyalgia rheumatica (PMR). The undifferentiated nature of ocular presentations of WG can be diagnostically challenging, especially in cases, such as this, where findings are initially inconclusive and evolve with time. This case highlights the significance of a history of PMR in patients with ocular inflammation. The systemic inflammatory systems of WG, including arthralgias, may mimic other conditions such as PMR. Patients with undifferentiated ocular inflammatory syndromes should be questioned regarding arthralgias, myalgias and stiffness. Such symptoms, or a background of PMR, should raise suspicion of WG.

Calcium pyrophosphate deposition disease mimicking polymyalgia rheumatica: A prospective followup study of predictive factors for this condition in patients presenting with polymyalgia symptoms

OBJECTIVE

To assess the characteristics of calcium pyrophosphate deposition disease (CPDD) with proximal involvement mimicking polymyalgia rheumatica (PMR), and to identify the best predictive factors for the presence of a clinical pattern of CPDD in patients presenting with polymyalgia symptoms.

METHODS

Patients diagnosed with either PMR or CPDD at the Rheumatology Division of Hospital Meixoeiro (Vigo, Spain) over a 7-year period (1997-2003) were prospectively followed for at least 12 months.

RESULTS

The study group comprised 118 patients with PMR features and 112 patients with CPDD. Eighty-two of the 118 patients with PMR manifestations were diagnosed as having pure PMR, and 36 met the diagnostic criteria for both PMR and CPDD. Patients with CPDD mimicking PMR were older (P = 0.02) and had peripheral arthritis more frequently (P = 0.004) than those with pure PMR. Radiologic osteoarthritic changes in the hands and knees, including more advanced radiologic grade of knee osteoarthritis, and tendinous calcifications were more frequent in patients with PMR/CPDD (P < 0.001). The best predictive factors for the occurrence of this atypical pattern of CPDD in a patient presenting with PMR features were the age at diagnosis and the presence of tibiofemoral osteoarthritis, tendinous calcifications, and ankle arthritis.

CONCLUSION

Involvement of proximal joints may be the clinical presentation of CPDD. CPDD should be included in the spectrum of diseases mimicking PMR. The presence of tibiofemoral osteoarthritis, tendinous calcifications, and ankle arthritis are clues that may alert the clinician to the presence of CPDD in an elderly patient presenting with PMR manifestations.

A prospective study of antineutrophil cytoplasmic antibody (c-ANCA) and clinical criteria in diagnosing Wegener's granulomatosis

Antineutrophil cytoplasmic antibody (c-ANCA) has a reported sensitivity and specificity greater than 90% for active Wegener's granulomatosis in selected patients with previously-defined disease. Because of these reports, some clinicians believe that a positive c-ANCA result provides strong circumstantial evidence for the diagnosis of Wegener's granulomatosis in patients with compatible clinical symptoms. However, this approach has not been examined prospectively. We prospectively studied 346 consecutive patients suspected of having vasculitis; those with previously established Wegener's granulomatosis (n = 29) or receiving immunosuppressives other than corticosteroids (n = 65) at baseline were excluded. Measures included a baseline c-ANCA, blinded chart reviews to record symptoms, physical findings, and corticosteroid use at baseline, and 2 to 8 months later to record final diagnoses and biopsy results. Wegener's granulomatosis was defined using the 1990 American College of Rheumatology (ACR) criteria, which does not require a biopsy. Follow-up information was available for 212 (84%) of the 252 patients eligible for this study (no corticosteroids: n = 174; corticosteroids: n = 78). 25 patients with compatible symptoms were classified with Wegener's granulomatosis by ACR criteria; only 6 of the 25 had biopsy-proven disease. 14 of these 212 patients had positive c-ANCA results. The overall sensitivity and specificity of c-ANCA for ACR-defined Wegener's granulomatosis were 28% (95% CI, 10%-46%) and 96% (93%-99%) respectively. The positive and negative predictive values were 0.50 and 0.91. The specificity remained greater than 90% regardless of baseline corticosteroid use or disease activity; however, the sensitivity and positive predictive value remained poor. For Wegener's granulomatosis defined by biopsy criteria and compatible clinical symptoms, the sensitivity was 83% (53%-100%); however, the positive predictive value was 36%. These results raise serious questions about the use of positive c-ANCA tests in diagnosing Wegener's granulomatosis in patients with clinical symptoms alone.