Serum C-reactive protein measurement in the detection of intercurrent infection in Oriental patients with systemic lupus erythematosus

The aberrant expression of CD45 isoforms and levels of sex hormones in systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a common autoimmune disease with significant gender bias in women, and sex hormones are considered to play an important role in the regulation of immune activity. The CD45 isoforms generated through alternative splicing of mRNA identify different functional status of lymphocytes and also are suggested as a biomarker for assessing the progression of SLE, while the modulation of CD45 expression in SLE patients is not clear.

METHODS

In this study, the peripheral blood sera of 46 SLE patients and 15 health individuals were collected for detecting the levels of sex hormones and immune associated factors. The expression of CD45 isoforms and the status of CD45 DNA methylation of the peripheral mononuclear blood cells were detected by flow cytometry and bisulfite sequencing PCR, respectively.

RESULTS

The levels of complement C3 and IgA decreased, especially decline of the serum IgA to the level of selective immunoglobulin A deficiency, and the C-reactive protein increased in SLE patients when compared with healthy controls, which manifested the abnormal immune activity of the SLE patients. Sex hormones detection showed a decreased testosterone and increased prolactin in SLE. An accelerated expression of CD45RO, reduced CD45RA and CD45RB, and a relative hypermethylation of CD45 DNA in SLE were also identified that provided a clue to explain the possible regulatory mechanism for the immune function in SLE.

CONCLUSION

The results indicated that the aberrant CD45 isoforms, DNA methylation and hormone levels might be correlated with the imbalanced immune activity of SLE patients. Key Points • Selective immunoglobulin A deficiency was significantly higher in SLE than in healthy individuals. • SLE patients had decreased testosterone and increased prolactin in the sera. • An aberrant expression of CD45 isoforms and CD45 DNA methylation were identified in SLE.

Tissue Dependent Role of PTX3 During Ischemia-Reperfusion Injury

Reperfusion of an ischemic tissue is the treatment of choice for several diseases, including myocardial infarction and stroke. However, reperfusion of an ischemic tissue causes injury, known as Ischemia and Reperfusion Injury (IRI), that limits the benefit of blood flow restoration. IRI also occurs during solid organ transplantation. During IRI, there is activation of the innate immune system, especially neutrophils, which contributes to the degree of injury. It has been shown that PTX3 can regulate multiple aspects of innate immunity and tissue inflammation during sterile injury, as observed during IRI. In humans, levels of PTX3 increase in blood and elevated levels associate with extent of IRI. In mice, there is also enhanced expression of PTX3 in tissues and plasma after IRI. In general, absence of PTX3, as seen in PTX3-deficient mice, results in worse outcome after IRI. On the contrary, increased expression of PTX3, as seen in PTX3 transgenic mice and after PTX3 administration, is associated with better outcome after IRI. The exception is the gut where PTX3 seems to have a clear deleterious role. Here, we discuss mechanisms by which PTX3 contributes to IRI and the potential of taming this system for the treatment of injuries associated with reperfusion of solid organs.

Peripheral neutrophil CD64 index combined with complement, CRP, WBC count and B cells improves the ability of diagnosing bacterial infection in SLE

OBJECTIVE

To investigate the diagnostic role of complement C3, complement C4, C-reactive protein (CRP), procalcitonin (PCT), white blood cell count (WBC), neutrophil CD64 (nCD64) index, lymphocyte subsets and their combination in differentiating bacterial infection from disease relapse in systemic lupus erythematosus (SLE).

METHODS

The above biomarkers in 36 hospitalized SLE patients with bacterial infection and 45 with lupus flare without infection were retrospectively studied. Bacterial infection was proven by positive cultures or typical clinical symptoms and signs combined with positive response to antibiotics. Lupus flare was defined as three points greater than their previous SLE disease activity index score. The diagnostic value for bacterial infection was evaluated by the areas under the receiver operating characteristic curves (AUC) and a novel bioscore system combining multiple biomarkers.

RESULTS

Increased CRP ( p = 0.049), WBC ( p = 0.028) and nCD64 index ( p = 0.034) were observed in the infected group and C3 ( p = 0.001), C4 ( p = 0.016) and B cells levels ( p = 0.010) were significantly reduced. The AUC for the above six biomarkers had no significant difference. Interestingly, the combination of nCD64 index, CRP, WBC, C3 and C4 improved significantly the diagnostic potential of SLE infection (AUC 0.783 (interquartile range 0.672, 0.871), p < 0.001; sensitivity 85.29% specificity 62.50%). In the bioscore system including the above six biomarkers, the bacterial infection rate in patients with bioscore ≤2, 3, 4, 5 and 6 were 0.00, 39.29, 59.10, 61.54 and 100.00%, respectively.

CONCLUSION

The combination of nCD64 index, C3, C4, CRP, WBC and B cells in a bioscore is useful to diagnose bacterial infection in SLE.

High-sensitivity C-reactive protein, disease activity, and cardiovascular risk factors in systemic lupus erythematosus

OBJECTIVE

To study the level of high-sensitivity C-reactive protein (hsCRP) and its relationship with disease activity, damage, and cardiovascular risk factors in patients with systemic lupus erythematosus (SLE).

METHODS

Consecutive patients who fulfilled ≥4 American College of Rheumatology criteria for SLE who did not have a concurrent infection were recruited. Blood was assayed for hsCRP level, and disease activity, organ damage of SLE, and cardiovascular risk factors were assessed. Linear regression analyses were performed for the relationship between hsCRP levels, SLE activity, damage, and cardiovascular risk factors.

RESULTS

In total, 289 patients were studied (94% women, mean ± SD age 39.0 ± 13.1 years, and mean ± SD SLE duration 7.8 ± 6.7 years). The mean ± SD Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score was 4.9 ± 5.6 and clinically active SLE was present in 122 patients (42%). The mean ± SD hsCRP level was 4.87 ± 12.7 mg/liter, and 28 patients with active SLE (23%) had an undetectable hsCRP level (<0.3 mg/liter). The linear regression analyses revealed a significant correlation between hsCRP level and musculoskeletal disease (β = 0.21), hematologic disease (β = 0.19), active serositis (β = 0.46), and clinical SLEDAI score (β = 0.24) after adjusting for age, sex, body mass index, serum creatinine, and the use of various medications (P < 0.005 for all). hsCRP levels correlated significantly with anti-double-stranded DNA titer (β = 0.33, P < 0.001) but did not correlate with complement C3 (β = -0.07, P = 0.26). An hsCRP level >3 mg/liter was significantly associated with male sex, long-term smoking, diabetes mellitus, a higher atherogenic index, and a history of arterial thrombosis. hsCRP levels correlated significantly with pulmonary and endocrine damage scores.

CONCLUSION

hsCRP was detectable in 77% of SLE patients with clinically active disease and correlated with SLEDAI scores, particularly in serositis and in the musculoskeletal and hematologic systems. Elevated hsCRP levels in SLE were associated with certain cardiovascular risk factors and a history of arterial thromboembolism.

High-sensitivity C-reactive protein and erythrocyte sedimentation rate in systemic lupus erythematosus

Levels of C-reactive protein (CRP) have been shown to rise in acute illnesses such as infections and some autoimmune diseases, but not in flares of systemic lupus erythematosus (SLE). Our goal was to investigate the high-sensitivity CRP (hsCRP) response to infection versus disease flare in patients with SLE, and to compare this with the erythrocyte sedimentation rate (ESR) response in these patients. We aimed to determine the hsCRP level that distinguishes between infection and flare in SLE, and investigated the correlation between hsCRP and organ involvement in SLE. We reviewed electronic medical records of all patients with SLE admitted to Cedars Sinai Medical Center between 28 August 2001 and 27 April 2008. Patients were divided into three groups based on the reason for hospitalization: 1) lupus flare; 2) active infection; and 3) both lupus flare and active infection. Data were collected on patient demographics, medication use, microbial culture results, organ involvement in lupus flare, ESR and CRP levels. Data were collected on 85 eligible patients, of whom 54 had a lupus flare, 22 had active infection and eight had both. While the ESR levels did not differ significantly between patients with disease flare and active infection, the hsCRP level was significantly lower in the lupus flare group than in the infection group. Most patients in the lupus flare group who had a significantly high hsCRP level had serositis. We found that at a cut-off of above 5 mg/dl, hsCRP level was correlated with infection with a specificity of 80%. At a cut-off of above 6 mg/dl, hsCRP correlated with infection with a specificity of 84%. hsCRP level was found to be significantly higher in patients with pulmonary involvement than without. hsCRP levels are significantly lower in SLE patients with disease flare than in those with active infection. Elevated hsCRP levels can be used as a predictor of active infection in SLE patients with a high specificity. We review the relationship between IL-6 and hsCRP production in lupus patients.

Serum procalcitonin does not differentiate between infection and disease flare in patients with systemic lupus erythematosus

Systemic erythematosus lupus (SLE) is a common autoimmune disease. Disease flares may mimic infection with fever, inflammatory syndrome and chills, sometimes resulting in a difficult differential diagnosis. Elevated serum procalcitonin (PCT) levels have been reported to be predictive of bacterial infections, but with conflicting results. The value of serum procalcitonin has not been assessed in large series of SLE. We aimed to describe the distribution of PCT levels in SLE patients with and without flares, to assess the factors associated with increased PCT levels, and to determine the positive and negative predictive values of increased PCT for bacterial infection in SLE patients. Hospitalized SLE patients were included in a retrospective study. Serum PCT had been assayed, or a serum sample had been frozen on admission, before treatment modification. Serum PCT, measured by an automated immunofluorometric assay, and SLEDAI were assessed at the same time. Some 53 women (median age: 33.7 years, range 16–76) and seven men (median age: 52.5 years ± 19) were included. The median SLEDAI for patients with flare ( n = 16, 28%) was 2 (range: 0–29). Five patients (8%) had systemic infection. Only one patient had increased PCT levels. Men had significantly higher PCT levels than women (0.196 ± 0.23 versus 0.066 ± 0.03, p < 0.01) and a significant correlation was observed between PCT, age, erythrocyte sedimentation rate, and C-reactive protein. We conclude that PCT levels were within the normal range in infected and non-infected SLE patients and there was no ability to differentiate SLE patients with or without bacterial infection.

Variability and correlates of high sensitivity C-reactive protein in systemic lupus erythematosus

In the general population, high-sensitivity C-reactive protein (hsCRP), a marker of inflammation, is relatively stable over time and independently predicts cardiovascular events. Systemic lupus erythematosus (SLE), a chronic inflammatory disease, is strongly associated with coronary artery disease (CAD). The objective of this study was to determine the variability and correlates of hsCRP in patients with SLE. Two cohorts from the University of Toronto Lupus Clinic, one with newly diagnosed and the other with prevalent SLE for 4 or more years, were selected. HsCRP was measured on serially collected samples, and hsCRP levels were ranked according to quartiles of cardiovascular risk. Correlates of hsCRP were determined using multivariate regression modelling with analysis of repeated measures. Among 58 patients in the inception cohort, over time, 36 (62%) moved from one hsCRP risk quartile to another. Among 414 patients in the prevalent cohort, 294 (71.0%) moved from one risk quartile to another. In both cohorts, within-patient variance comprised the majority of total variance in hsCRP levels. In multivariate regression analysis, hsCRP increased with age ( P = 0.002), postmenopausal status ( P = 0.03), smoking ( P = 0.007) and presence of infection ( P = 0.0001) and decreased with use of immunosuppressives ( P = 0.02). There is marked variability of hsCRP level over time in SLE, regardless of disease duration. This variability is due to age and SLE treatment, menopausal status, smoking and the occurrence of infection. The variability of hsCRP in SLE casts doubt over its usefulness as an independent predictor of CAD risk in this disease and potentially in other chronic inflammatory diseases.

Urinary endothelin-1 in chronic kidney disease and as a marker of disease activity in lupus nephritis

Chronic inflammation contributes to the development and progression of chronic kidney disease (CKD). Identifying renal inflammation early is important. There are currently no specific markers of renal inflammation. Endothelin-1 (ET-1) is implicated in the pathogenesis of CKD. Thus, we investigated the impact of progressive renal dysfunction and renal inflammation on plasma and urinary ET-1 concentrations. In a prospective study, plasma and urinary ET-1 were measured in 132 subjects with CKD stages 1 to 5, and fractional excretion of ET-1 (FeET-1) was calculated. FeET-1, serum C-reactive protein (CRP), urinary ET-1:creatinine ratio, and urinary albumin:creatinine ratio were also measured in 29 healthy volunteers, 85 subjects with different degrees of inflammatory renal disease but normal renal function, and in 10 subjects with rheumatoid arthritis without renal involvement (RA). In subjects with nephritis associated with systemic lupus erythematosus (SLE), measurements were done before and after 6 mo of treatment. In subjects with CKD, plasma ET-1 increased linearly as renal function declined, whereas FeET-1 rose exponentially. In subjects with normal renal function, FeET-1 and urinary ET-1:creatinine ratio were higher in SLE subjects than in other groups (7.7 +/- 2.7%, 10.0 +/- 3.0 pg/mumol, both P < 0.001), and correlated with CRP, and significantly higher than in RA subjects (both P < 0.01) with similar CRP concentrations. In SLE patients, following treatment, FeET-1 fell to 3.6 +/- 1.4% (P < 0.01). Renal ET-1 production increases as renal function declines. In subjects with SLE, urinary ET-1 may be a useful measure of renal inflammatory disease activity while measured renal function is still normal.

Pathogenic implications for autoantibodies against C-reactive protein and other acute phase proteins

Systemic lupus erythematosus (SLE) is a systemic rheumatic disease characterized clinically by multiorgan involvement and serologically by the occurrence of antinuclear antibodies. SLE patients may present with multiple autoantibodies to cytoplasmic and cell surface antigens as well as to circulating plasma proteins. Another feature of SLE is that serum levels of C-reactive protein (CRP) often remain low despite high disease activity and despite high levels of other acute phase proteins and interleukin-6, i.e. the main CRP inducing cytokine. Apart from its important role as a laboratory marker of inflammation, CRP attracts increasing interest due to its many intriguing biological functions, one of which is a role as an opsonin contributing to the elimination of apoptotic cell debris, e.g. nucleosomes, thereby preventing immunization against autoantigens. Recently, autoantibodies against CRP and other acute phase proteins have been reported in certain rheumatic conditions, including SLE. Although the presence of anti-CRP autoantibodies does not explain the failed CRP response in SLE, antibodies directed against acute phase proteins have several implications of pathogenetic interest. This paper thus highlights the biological and clinical aspects of native and monomeric CRP and anti-CRP, as well as autoantibodies against mannose-binding lectin, serum amyloid A and serum amyloid P component.

Lymphoma in a patient with systemic lupus erythematosus

BACKGROUND

A 40-year-old woman with a 10-year history of systemic lupus erythematosus (SLE) presented with fever, lymphadenopathy and fatigue. Before that time, her SLE symptoms had been controlled with hydroxychloroquine, NSAIDs, and an occasional short course of moderate-dose prednisone. Two months before presentation, she experienced fevers ranging from 38.3 to 39.7 degrees C, but she had no specific symptoms that suggested local infection.

INVESTIGATIONS

Physical examination, multiple blood cultures, and laboratory investigations that included the following tests: hemoglobin concentration; erythrocyte sedimentation rate; C-reactive protein level; serum lactate dehydrogenase level; aspartate aminotransferase level; alanine aminotransferase level; serum complement C3 and C4 levels; white-blood-cell count; platelet count; urinalysis; serum creatinine level; CT of the chest and abdomen; bone-marrow biopsy; serum electrophoresis; and tests for Epstein-Barr virus, cytomegalovirus, hepatitis B virus, hepatitis C virus, HIV-1, antinuclear antibodies, antibodies to Smith antigen, antibodies to double-stranded DNA, and antibodies to Ro and La.

DIAGNOSIS

Stage IVB diffuse large B-cell lymphoma with marrow and liver involvement concurrent with SLE.

MANAGEMENT

The patient promptly underwent chemotherapy, receiving three courses of 3 mg/m(2) vindesine on day 1, 1,500 mg/m(2) cyclophosphamide and 80 mg/m(2) doxorubicin on day 2, and 50 mg/m(2) prednisolone on days 1-5.

Autoantibody Determination in the Diagnosis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that usually develops in young women aged 18-50 years and is characterized by the presence of autoantibodies. Diagnosis is difficult as SLE is a great imitator of other diseases. When SLE is suspected clinically in a patient (involvement of two or more organ systems), an initial laboratory evaluation would be antinuclear antibody (ANA) testing. If ANA is negative, SLE is unlikely and results positive at less than 1:40 strongly argue against SLE. Other explanations for organ system involvement should be pursued. Results positive at greater than 1:40 may merit further evaluation for SLE and at times referral to a rheumatologist for a full SLE evaluation. While the American College of Rheumatology classification criteria for SLE are primarily a tool for research, they may be useful clinically, in that those patients fulfilling four or more criteria are highly likely to have SLE.

Autoantibodies to C-reactive protein is a common finding in SLE, but not in primary Sjögren's syndrome, rheumatoid arthritis or inflammatory bowel disease

The occurrence of antibodies to human C-reactive protein (CRP) was analysed by enzyme-linked immunosorbent assay (ELISA) in 56 patient sera known to contain antibodies to double-stranded DNA (dsDNA) and in 16 sera from patients with primary Sjögren's syndrome (SS), 15 rheumatoid arthritis, 31 Crohn's disease, and 37 ulcerative colitis. Eighty-seven per cent of the patients with anti-dsDNA antibodies had systemic lupus erythematosus (SLE) and the remaining had autoimmune hepatitis. The cut-off for positive anti-CRP test was set at the 95th percentile of 100 healthy blood donors. Twenty of 56 anti-dsDNA sera (36%) and two of 16 SS sera (13%) had antibodies reactive with human CRP, whereas all other samples were negative. Thirteen of 27 SLE patients (48%) were positive on at least one occasion. The sera containing anti-CRP antibodies only reacted with surface-bound antigen, but not with native CRP in solution. In conclusion, we found that autoantibodies to CRP are common in sera from patients with anti-dsDNA antibodies. It is not likely that this explains the relative failure of CRP response in patients with active SLE. However, it cannot be excluded that anti-CRP autoantibodies have other biological potentials of pathophysiological interest in SLE, for instance by binding to CRP deposited on cell and tissue surfaces.

Infections in the immunocompromised rheumatologic patient

Immunocompromised patients with rheumatic diseases have an increased risk of infections. A major risk factor for infection seems to be the immunosuppressive therapy used. Newer therapies for RA may lead to increased rates of infection by opportunistic pathogens such as Mycobacteria tuberculosis. Because disease manifestation may mimic signs and symptoms of infection, prompt diagnosis may be difficult. Familiarity with the likely infections and their causes should aid in obtaining the appropriate culture specimens.

High sensitivity C-reactive protein: biological variations and reference limits

Serum C-reactive protein (CRP) concentration was determined for 3605 subjects using an immunonephelometric assay improved to provide greater sensitivity. Subjects were from 5 to 75 years old and belonging to 1003 nuclear families recruited from the Stanislas Cohort Study between January 1994 and August 1995. Sample values for CRP ranged from 0.17 mg/l to 100 mg/l. Geometric means (mean - SD; mean +/- SD) were in the 5-14 years old group 0.37 (0.17-1.07) mg/l, in the 15-28 years old group 0.47 (0.17-1.38) mg/l and in the 29-75 years old group 0.98 (0.34-2.85) mg/l. For women, the geometric means were 0.38 (0.17-1.10) mg/l, 0.62 (0.20-1.90) mg/l and 0.98 mg/l (0.31-3.13) mg/l respectively. The interindividual variability ranged from 138% to 759% among different age classes. Biological factors associated with CRP concentration variations were examined and accounted for 25% of the CRP variability in men and 40% in women. The main biological factors statistically associated with CRP concentration variations in men were: drugs, leukocyte count, body mass index, tobacco consumption, age, and in women: drugs, leukocyte count, age, body mass index and hemoglobin concentration. These factors were used to define the exclusion and partition criteria when obtaining the reference samples. Medians for reference values ranged from 0.20 to 0.68 mg/l in males and from 0.20 to 0.78 mg/l in women.

The use of laboratory tests in the diagnosis of SLE

ANA IIF is an effective screening assay in patients with clinical features of SLE and will detect most anti-ssDNA, anti-dsDNA, ENAs, and other autoantibodies. False positives are common. The clinical importance cannot be extrapolated from the ANA titre or pattern, although higher titres (> 1/160) are more likely to be important. HEp-2 cells are the most sensitive substrate for ANA detection, but this must be balanced against an increased incidence of insignificant positivity. ANA positive samples should be subjected to more specific assays for the diagnosis of SLE. A combination of ENA (Ro/La/Sm/RNP) and dsDNA assays will detect most patients with SLE as long as the characteristics of the assays used are well understood. ESR and CRP measurements provide useful additional information. Sjogren's syndrome and MCTD will produce overlapping serology with SLE, and anti-dsDNA titres are sometimes seen in autoimmune hepatitis and rheumatoid arthritis. All results should be reported in the light of the clinical details, by an experienced immunologist. A suggested diagnostic protocol is outlined in fig 1. The type of assay used crucially influences the predictive value of the tests. ELISA technology dominates routine laboratory practice, but tends to produce more false positive and true weak positive results, which may reduce the PPV of the test. This can be minimised by using IgG specific conjugates and careful assay validation. The NPV for SLE [figure: see text] is high for most assays but the PPV varies. Where necessary, laboratories should use crithidia or Farr dsDNA assays to confirm dubious ELISA dsDNA results, and ID/IB to confirm dubious ENA results. For monitoring, a precise, quantitative assay is required. It is unclear whether the detection of IgM or low affinity antibodies has a role here. A combination of anti-dsDNA, C3, C4, CRP, and ESR assays provides the most useful clinical information. Anti-ssDNA assays are likely to be useful, and are potentially more robust than anti-dsDNA assays, but require more validation. Local validation of individual assays and EQA participation is essential. Not all assays that apparently measure the same antibody specificities have equal clinical relevance, even within a single technology. Insufficient international or national reference preparations are currently available for many antibody specificities to enable effective standardisation. Quality assurance schemes reveal large differences in units reported by different assays for some analytes, even when calibrated against an IRP or equivalent reference preparation. Serial results can therefore only be compared from the same laboratory at present. Most autoantibodies increase during active disease, but few prospective data are currently available to justify treatment on the basis of rising titres. Further randomised prospective studies are required to examine the importance of antibody isotype and affinity in the monitoring of SLE by individual assay methods. The most important aspect of the appropriate use of laboratory assays is to become familiar with the limitations of the technology currently in use in your local laboratory, and to consult with your clinical immunologist in cases of doubt, preferably before commencing serological screening.

Infection in systemic lupus erythematosus

The improved survival of SLE patients since the 1950s is the result of not only better treatment, but also supportive treatment of renal failure and the wealth of antibiotics now available. Ironically, the wider use of immunosuppressives, especially the alkylating drugs, and the longer survival of patients with renal insufficiency and renal failure have made the identification and appropriate treatment of infection in SLE an ongoing challenge.

Reliability and feasibility of a near patient test for C-reactive protein in primary care

BACKGROUND

The applications of new diagnostic technologies such as near patient tests are relevant to the further development and potential of primary care. Through their use, doctors in the community may increase the accuracy of their diagnoses and improve their ability to monitor disease. A reliable indicator of disease activity in various clinical conditions is C-reactive protein (CRP) and a near patient test for this is now available, although there is little information on its use outside hospitals.

AIM

A study was set up to evaluate the feasibility of using a novel near patient test for CRP in primary care to validate the results against the laboratory "gold standard' for CRP (Beckman Array) and to compare results with the usual inflammation test used in general practice.

METHOD

Prospective recording of CRP as a near patient test on an "intention to investigate' basis, with validation of results against the Beckman Array system for CRP and hospital laboratory erythrocyte sedimentation rate results, in six general medical practices in Birmingham. Main outcome measures were change in local laboratory usage, characteristics of patients chosen for testing, use of quality control, and comparison of readings with results from the same sample sent to an independent laboratory.

RESULTS

Tests of CRP levels were rarely requested before the study was undertaken. During the 3-month study period, 181 near patient tests were carried out, 146 (81%) to establish a diagnosis and the remainder for disease monitoring. Out of the tests, 67% were performed by general practitioners, mostly during the consultation itself. Using a cut-off level of 10 mg I-1, the near patient test and the Beckman Array gave results which agreed in 84% of cases. The sensitivity and specificity of the near patient test results were 97 and 79%, respectively. The predictive value of a positive result was 59% and that of a negative result was 99%. Cohen's Kappa was 62% and the overall mean bias for results in the range of the test was 6.11 mg I-1 (SE = 3.07 mg I-1). Each test took 6 min on average to perform, including all preparations, blood letting, performing the test and averaging the time for quality control estimations. The cost per test averaged pounds 1.72, rising to pounds 4.17 including labour, capital costs, quality controls and consumables (general practitioner performing the assay at average frequency found in this study).

CONCLUSIONS

Measurement of CRP is rarely used in primary care and awareness of its value could be raised. This near patient test proved feasible for use by general practitioners and practice nurses. Its reliability compared with a laboratory result was satisfactory overall, and excellent with adequate operator technique.

Systemic lupus erythematosus for general practitioners: a literature review

Systemic lupus erythematosus (SLE) is a multisystem disease of unknown etiology or etiologies.The disease may be acute or chronic. A wide clinicopathological spectrum is expressed in each organ involved which is induced through multiple antibodies that result in. imnunologically mediated tissue injury.In this literature review, the clinical and pathological features as well as laboratory abnormalities, measures /or diagnosis, outlines of management, and prognosis are discussed.

Serum C-reactive protein concentrations in patients with pulmonary sarcoidosis

In a prospective study serum C-reactive protein concentrations were measured in nine patients with "active" pulmonary sarcoidosis (as assessed by bronchoalveolar lavage lymphocyte counts, gallium-67 lung scanning, and serial pulmonary function testing), and in five patients with "inactive" disease. Active pulmonary sarcoidosis was associated either with no rise or with only a modest rise in serum C-reactive protein concentrations. In contrast, serum C-reactive protein concentrations in 12 patients with sputum positive pulmonary tuberculosis were considerably raised. Serum C-reactive protein may thus provide a valuable test in the differentiation of sarcoidosis from conditions which it may mimic and which are known to induce an acute phase response.

Microheterogeneity of alpha 1-acid glycoprotein in the detection of intercurrent infection in systemic lupus erythematosus

We evaluated the clinical usefulness of determinations of alpha 1-acid glycoprotein microheterogeneity patterns in distinguishing patients who have active systemic lupus erythematosus (SLE) from those who have SLE with intercurrent infection. We used agarose affinity electrophoresis with concanavalin A (Con A) as a ligand. Results were expressed as reactivity coefficients (RC), which are the ratios of variants reactive with Con A to the variants not reactive with Con A. No significant differences were found between the mean RC (+/- SD) in healthy individuals (1.35 +/- 0.26) and that in patients with various degrees of SLE activity. In contrast, a significantly higher mean RC was found in sera from patients with intercurrent infection (2.70 +/- 0.76) compared with each of the other groups studied (P less than 0.001). An RC greater than 2.25 was found in none of 42 sera from patients without infection and in 15 of 18 sera from patients with infection (sensitivity 83%, specificity 100%). C-reactive protein (CRP) levels were also significantly higher in SLE patients with intercurrent infection than in patients with very active disease (P less than 0.05). Levels of CRP greater than 60 mg/liter were found in 3 of 42 SLE patients without infection and in 8 of 18 patients with infection (sensitivity 39%, specificity 93%). The results show that in SLE patients, the finding of a relative increase in Con A-bound serum alpha 1-acid glycoprotein is a more sensitive indicator of intercurrent infection than is the finding of increased levels of CRP.