Antibodies against linear epitopes on Goodpasture autoantigen in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis

Establishment of a scoring model for the differential diagnosis of white coat hypertension and sustained hypertension

OBJECTIVES

This study aimed to establish a scoring model for the differential diagnosis of white coat hypertension (WCH) and sustained hypertension (SHT).

METHODS

This study comprised 553 adults with elevated office blood pressure, normal renal function, and no antihypertensive medications. Through questionnaire investigation and biochemical detection, 17 parameters, such as gender and age, were acquired. WCH and SHT were distinguished by 24 h ambulatory blood pressure monitoring. The participants were randomly divided into a training set (445 cases) and a validation set (108 cases). The above parameters were screened using least absolute shrinkage and selection operator regression and univariate logistic regression analysis in the training set. Afterward, a scoring model was constructed through multivariate logistic regression analysis.

RESULTS

Finally, six parameters were selected, including isolated systolic hypertension, office systolic blood pressure, office diastolic blood pressure, triglyceride, serum creatinine, and cardiovascular and cerebrovascular diseases. Multivariate logistic regression was used to establish a scoring model. The R2 and area under the ROC curve (AUC) of the scoring model in the training set were 0.163 and 0.705, respectively. In the validation set, the R2 of the scoring model was 0.206, and AUC was 0.718. The calibration test results revealed that the scoring model had good stability in both the training and validation sets (mean square error = 0.001, mean absolute error = 0.014; mean square error = 0.001, mean absolute error = 0.025).

CONCLUSION

A stable scoring model for distinguishing WCH was established, which can assist clinicians in identifying WCH at the first diagnosis.

Acute renal failure in systemic sclerosis revealing Goodpasture syndrome: "All that glitters is not scleroderma renal crisis"

The most common cause of acute renal failure in systemic sclerosis patients is scleroderma renal crisis but other etiologies have to be considered such as another autoimmune disease. We report the case of a 60-year-old male admitted to our hospital with a renal failure. His medical history included a diagnosis of systemic sclerosis 6 months ago. Antinuclear antibodies were positive at a titer of 1:1280 with positive anti-Scl-70 and anti-myeloperoxidase (34 U/mL) antibodies. Scleroderma renal crisis was suspected. However, antineutrophil cytoplasmic antibody-associated vasculitis could not be excluded and a renal biopsy was performed. Histopathology revealed crescentic glomerulonephritis and rupture of Bowman's capsule. Anti-glomerular basement membrane antibodies were detected in serum and the diagnosis of Goodpasture syndrome was confirmed by kidney's immunofluorescence analysis showing typical deposits. Only three other cases of systemic sclerosis associated with Goodpasture syndrome have been reported in the literature. Also, rapidly progressive glomerulonephritis with positivity of both antineutrophil cytoplasmic antibody and anti-glomerular basement membrane antibodies has been described. Several studies have suggested that antineutrophil cytoplasmic antibody positivity occurs first leading to damages of the glomerular basement membrane, to the release of alpha-3 NC1 antigen, and ultimately to anti-glomerular basement membrane antibody production. Although rare, antineutrophil cytoplasmic antibody-associated vasculitis and Goodpasture syndrome should be searched for in systemic sclerosis patients with acute renal failure.

H1N1 influenza virus epitopes classified by monoclonal antibodies

Epitopes serve an important role in influenza infection. It may be useful to screen universal influenza virus vaccines, analyzing the epitopes of multiple subtypes of the hemagglutinin (HA) protein. A total of 40 monoclonal antibodies (mAbs) previously obtained from flu virus HA antigens (development and characterization of 40 mAbs generated using H1N1 influenza virus split vaccines were previously published) were used to detect and classify mAbs into distinct flu virus sub-categories using the ELISA method. Following this, the common continuous amino acid sequences were identified by multiple sequence alignment analysis with the GenBank database and DNAMAN software, for use in predicting the epitopes of the HA protein. Synthesized peptides of these common sequences were prepared, and used to verify and determine the predicted linear epitopes through localization and distribution analyses. With these methods, nine HA linear epitopes distributed among different strains of influenza virus were identified, which included three from influenza A, four from 2009 H1N1 and seasonal influenza, and two from H1. The present study showed that considering a combination of the antigen-antibody reaction specificity, variation in the influenza virus HA protein and linear epitopes may present a useful approach for designing effective multi-epitope vaccines. Furthermore, the study aimed to clarify the cause and pathogenic mechanism of influenza virus HA-induced flu, and presents a novel idea for identifying the epitopes of other pathogenic microorganisms.