Is Erythrocyte Sedimentation Rate Necessary for the Initial Diagnosis of Giant Cell Arteritis?

Giant cell arteritis (GCA) is an ophthalmological emergency that can be difficult to diagnose and prompt treatment is vital. We investigated the sequential diagnostic value for patients with suspected GCA using three biochemical measures as they arrive to the clinician: first, platelet count, then C-reactive protein (CRP), and lastly, erythrocyte sedimentation rate (ESR). This retrospective cross-sectional study of consecutive patients with suspected GCA investigated platelet count, CRP, and ESR using diagnostic test accuracy statistics and odds ratios (ORs) in a sequential fashion. The diagnosis was established by experts at follow-up, considering clinical findings and tests including temporal artery biopsy. A total of 94 patients were included, of which 37 (40%) were diagnosed with GCA. Compared with those without GCA, patients with GCA had a higher platelet count (p < 0.001), CRP (p < 0.001), and ESR (p < 0.001). Platelet count demonstrated a low sensitivity (38%) and high specificity (88%); CRP, a high sensitivity (86%) and low specificity (56%); routine ESR, a high sensitivity (89%) and low specificity (47%); and age-adjusted ESR, a moderate sensitivity (65%) and moderate specificity (65%). Sequential analysis revealed that ESR did not provide additional value in evaluating risk of GCA. Initial biochemical evaluation can be based on platelet count and CRP, without waiting for ESR, which allows faster initial decision-making in GCA.

Optical Coherence Tomography of Peripapillary Vessels in Giant Cell Arteritis and Ischaemic Ocular Disease.

With normal retinal blood flow, cross-sectional optical coherence tomography (OCT) of retinal vessels shows a structured intravascular reflectivity profile, resembling a 'figure-of-8'. Altered profiles have been reported in vascular occlusive and haematological diseases. Giant cell arteritis (GCA) can cause visual loss, usually due to anterior ischaemic optic neuropathy (AION) or retinal artery occlusion. Our aim was to extend the assessment of OCT vascular profiles to patients with suspected GCA and to determine if any abnormalities were related to GCA per se or to ischaemic ocular conditions. This nested retrospective study included 61 eyes of 31 patients (13 with GCA). Six eyes had arteritic and seven eyes non-arteritic AION, three eyes had non-arteritic retinal artery occlusion, 11 eyes had other ocular conditions and 34 were unaffected control eyes. For each eye the appearance of structured intravascular profiles on peripapillary OCT was graded as present, partial, absent or uncertain. Non-presence of structured intravascular profiles was more frequent in AION and retinal artery occlusion than in other ocular conditions or unaffected eyes (Fisher's test, p = .0047). Based on follow-up of 25 eyes, reflectivity profiles normalised in three out of four eyes after 85 (35-245) days. Vessel profiles were not associated with GCA (p = .32) and were similar in arteritic and non-arteritic AION (p = .66). In conclusion, absence of structured intravascular reflectivity profiles may be a marker of acute ischaemia in the anterior optic nerve or inner retina. However, it did not seem specific for GCA. The prognostic value warrants further studies.

Validity and interobserver agreement of lower extremity local tissue water measurements in healthy women using tissue dielectric constant.

BACKGROUND: Tissue dielectric constant (TDC) measurement may become an important tool in the clinical evaluation of chronic lower extremity swelling in women; however, several factors are known to influence TDC measurements, and comparative data on healthy lower extremities are few. METHODS: Thirty-four healthy women volunteered. Age, BMI, moisturizer use and hair removal were registered. Three blinded investigators performed TDC measurements in a randomized sequence on clearly marked locations on the foot, the ankle and the lower leg. The effective measuring depth was 2.5 mm. RESULTS: The mean TDC was 37.8 ± 5.5 (mean ± SD) on the foot, 29.0 ± 3.1 on the ankle and 30.5 ± 3.9 on the lower leg. TDC was highly dependent on measuring site (P<0.001) but did not vary significantly between investigators (P=0.127). Neither age, BMI, hair removal nor moisturizer use had any significant effect on the lower leg TDC. Intraclass correlation coefficients were 0.77 for the foot, 0.94 for the ankle and 0.94 for the lower leg. CONCLUSION: The TDC on the foot was significantly higher compared with ankle and lower leg values. Foot measurements should be interpreted cautiously because of questionable interobserver agreement. The interobserver agreement was high on lower leg and ankle measurements. Neither age, BMI, hair removal nor moisturizer use had any significant on effect on the lower leg TDC. TDC values of 35.2 for the ankle and 38.3 for the lower leg are suggested as upper normal reference limits in women.

The washout rate of a subcutaneous 99mTc-HSA depot in lower extremity lymphoedema.

PURPOSE: Lymphoscintigraphy is currently the leading diagnostic modality of lower extremity lymphoedema but has been criticized for being unreliable. Washout rate constants have been investigated and proven to be of diagnostic value in several studies of breast-cancer-related lymphoedema; however, the applicability in lower extremity lymphoedema needs further evaluation. The aim of the study was to verify if washout of (99m) Tc-human serum albumin ((99m) Tc-HSA) is a reliable diagnostic tool in lower extremity lymphoedema. METHODS: Twenty healthy volunteers and eight patients (11 legs) with lymphoscintigraphy verified lower extremity lymphoedema participated in the study. A depot consisting of 0.1 ml 10 MBq/ml (99m) Tc-HSA was injected subcutaneously into the dorsum of each foot. The depot washout rate was measured using a portable scintillation detector system and time-activity curves were generated. After 30 min of supine rest and 10 min of standardized ergometric exercise, measurements were recorded for 20 min. Following correction for physical decay of (99m) Tc, the depot washout rate constant was calculated using linear regression analysis. Finally depot half-life was calculated from the washout rate constant. RESULTS: Median half-life for healthy volunteers was 9.4 h (range 2.5-28.3 h). Median half-life for lymphoedema patients was 10.7 h (range 1.5-35.1 h). No statistical significant difference could be detected between healthy volunteers and lymphoedema patients (P = 0.78). CONCLUSIONS: The washout rate of a subcutaneous (99m) Tc-HSA depot is not a reliable diagnostic tool in examination of lower extremity lymphoedema. Additional examinations revealed in vivo instability of the utilized (99m) Tc-HSA as the likely reason.

Lymphoedema of the lower extremities--background, pathophysiology and diagnostic considerations.

Lymphoedema of the lower extremities is a chronic debilitating disease that is often underdiagnosed. Early diagnosis and treatment is paramount in reducing the risk of progression and complications. Lymphoedema has traditionally been defined as interstitial oedema and protein accumulation because of a defect in the lymphatic drainage; however, some findings suggest that the interstitial protein concentration may be low in some types of lymphoedema. Primary lymphoedema is caused by an inherent defect in the lymphatic vessels or lymph nodes. Secondary lymphoedema is caused by damages to the lymphatic system most often caused by cancer or its treatment. Many of the underlying pathophysiological mechanisms have yet to be elucidated. Many methods have been developed for examination of the lymphatic system. Lymphoscintigraphy is presently the preferred diagnostic modality. Lack of consensus regarding protocol and qualitative interpretation criteria results in a too observer dependent outcome. Methods for objectifying the scintigraphy through quantification have been criticized. Depot clearance rates are an alternative method of quantification of lymphatic drainage capacity. This method however has mostly been applied on upper extremity lymphoedema. The aim of this review is to provide a literature-based overview of the aetiology and pathophysiology of lower extremity lymphoedema and to summarize the current knowledge about lymphoscintigraphy and depot clearance techniques. The abundance of factors influencing the outcome of the examination stresses the need for consensus regarding examination protocols and interpretation. Further studies are needed to improve diagnostic performance and understanding of pathophysiological mechanisms.