Infective endocarditis, rheumatoid factor, and anticardiolipin antibodies

Diagnostic Work-Up in Patients with Nonbacterial Thrombotic Endocarditis

Nonbacterial thrombotic endocarditis (NBTE) is a form of endocarditis that occurs in patients with predisposing conditions, including malignancies, autoimmune diseases (particularly antiphospholipid antibody syndrome, which accounts for the majority of lupus-associated cases), and coagulation disturbances for which the correlation with classical determinants is unclear. The condition is commonly referred to as "marantic", "verrucous", or Libman-Sacks endocarditis, although these are not synonymous, representing clinical-pathological nuances. The clinical presentation of NBTE involves embolic events, while local valvular complications, generally regurgitation, are typically less frequent and milder compared to infective forms of endocarditis. In the past, the diagnosis of NBTE relied on post mortem examinations, while at present, the diagnosis is primarily based on echocardiography, with the priority of excluding infective endocarditis through comprehensive microbiological and serological tests. As in other forms of endocarditis, besides pathology, transesophageal echocardiography remains the diagnostic standard, while other imaging techniques hold promise as adjunctive tools for early diagnosis and differentiation from infective vegetations. These include cardiac MRI and 18FDG-PET/CT, which already represents a major diagnostic criterion of infective endocarditis in specific settings. We will herein provide a comprehensive review of the current knowledge on the clinics and therapeutics of NBTE, with a specific focus on the diagnostic tools.

Possible relationship between antiphospholipid antibodies and embolic events in infective endocarditis

OBJECTIVE

Antiphospholipid (aPL) antibodies may activate platelets and contribute to vegetation growth and embolisation in infective endocarditis (IE). We aimed to determine the value of aPL as predictors of embolic events (EE) in IE.

METHODS

We studied 186 patients with definite IE (Duke-Li criteria, all types of IE) from the Nanc-IE prospective registry (2007-2012) who all had a frozen blood sample and at least one imaging procedure to detect asymptomatic or confirm symptomatic EE. Anticardiolipin (aCL) and anti-β₂-glycoprotein I (β₂GPI) antibodies (IgG and IgM) were assessed after the end of patients' inclusion. The relationship between antibodies and the detection of EE after IE diagnosis were studied with Kaplan-Meier and Cox multivariate analyses.

RESULTS

At least one EE was detected in 118 (63%) patients (52 cerebral, 95 other locations) after IE diagnosis in 80 (time interval between IE and EE diagnosis: 5.9±11.3 days). At least one aPL antibody was found in 31 patients (17%).Detection of EE over time after IE diagnosis was more frequent among patients with anti-β₂GPI IgM (log-rank P=0.0036) and that of cerebral embolisms, among patients with aCL IgM and anti-β₂GPI IgM (log-rank P=0.002 and P<0.0001, respectively).Factors predictive of EE were anti-β₂GPI IgM (HR=3.45 (1.47-8.08), P=0.0045), creatinine (2.74 (1.55-4.84), P=0.0005) and vegetation size (2.41 (1.41-4.12), P=0.0014). Those of cerebral embolism were aCL IgM (2.84 (1.22-6.62), P=0.016) and anti-β₂GPI IgM (4.77 (1.79-12.74), P=0.0018).

CONCLUSION

The presence of aCL and anti-β₂GPI IgM was associated with EE, particularly cerebral ones, and could contribute to assess the embolic risk of IE.

Anticardiolipin Antibodies in Hemophiliac and Nonhemophiliac Patients with Chronic Hepatitis C

Anticardiolipin antibodies (ACA) have been de tected in a variety of infectious diseases, especially viral infec tions. ACA also have been described in human immunodefi ciency virus (HIV)-infected hemophiliacs. Recently the pres ence of ACA in hemophiliac and nonhemophiliac patients with chronic hepatitis C virus has been reported. We performed a case-controlled study to establish if ACA are present in hemo philia and if they are due to the hepatitis C infection; and to confirm the association between ACA and hepatitis C infec tions in nonhemophiliac patients. Anticardiolipin antibodies have been studied in the serum of 62 hemophiliacs with chronic hepatitis C virus and in the control group (70 hepatitis C- negative patients with hemophilia or other clotting disorders). ACA were positive in only three hepatitis C-positive hemo philiac patients and in three hepatitis C-negative patients with hemophilia or other coagulation defects (first control group). No significant statistical differences were found in the groups (OR = 1.1; 95% CI 0.2-7.4, p = .6). Sixteen of 111 nonhe mophiliacs with chronic hepatitis C were positive for ACA while in 100 matched hepatitis C-negative subjects (second control group) anticardiolipin antibodies were positive in 9 pa tients. ACA tended to be higher in hepatitis C-positive nonhe mophiliac patients than in the control group, but the difference between the two groups was not statistically significant (OR = 1.7, 95% CI 0.7-4.4, p = .3). ACA do not seem to be associ ated with the chronic hepatitis C virus.

Stroke-complicated endocarditis with positive lupus anticoagulant--a case report

Twenty to 40% of patients with infective endocarditis (IE) suffer from neurologic complications. Also many and various markers of immunologic activation have been reported in patients with IE and no history of autoimmune or other rheumatologic diseases. The authors present a case of a patient suffering from IE complicated with major cerebrovascular event with concomitant appearance of lupus anticoagulant (LAC). After successful antibiotic treatment there was major clinical improvement with disappearance of LAC. LAC could be added to the list of immunologic markers appearing in the course of infective endocarditis.

Anticardiolipin antibody levels predict flares and relapses in patients with giant-cell (temporal) arteritis. A longitudinal study of 58 biopsy-proven cases

OBJECTIVE

To evaluate the usefulness of anticardiolipin antibodies (aCL) in identifying flares and relapses in giant-cell arteritis.

METHODS

We studied 58 consecutive patients with biopsy-proven temporal giant-cell arteritis. C-reactive protein and aCL serum levels were measured simultaneously at the time of diagnosis and at each out-patient visit until recovery. All observed episodes of a rise in C-reactive protein attributable to a precise cause, for which the simultaneous measurement of aCL was available, were analysed.

RESULTS

The mean duration of clinical observation and serum aCL assessment was 34+/-18 and 24+/-11 months, respectively. Anticardiolipin antibody positivity (IgG or total antibodies > or =20 U) before treatment was found before treatment in 27 cases (46.6%) (mean 45.6+/-26 U/l, range 20-110 U). Levels of aCL decreased below 10 U with appropriate treatment in all patients except one, after a variable delay. No rise in aCL levels was recorded subsequently in any patient whose disease was controlled permanently. A significant rise in aCL was recorded in 20 of 27 (74%) of the flares or relapses of giant-cell arteritis, including seven of 12 flares in seven patients whose initial aCL level was <20 U vs none of the 28 inflammatory episodes unrelated to giant-cell arteritis (P<0.0000001). IgM aCL, infrequently found at diagnosis, was not associated with signs of disease activity.

CONCLUSION

Serum aCL levels are useful in the detection of flares and relapses in giant-cell arteritis, with fairly good sensitivity (74%) and a specificity of 100%, and can be of value in distinguishing subclinical flares from infection.

[Immunologic studies in the differential diagnosis of infectious endocarditis and septicemia without endocardiac lesion]

Differential diagnosis between infective endocarditis and septicemia without endocarditis remains a crucial clinical difficulty. Value of immunological data during those pathologies has been evaluated in a 2 year prospective study. Sixty-one patients, admitted in an internal medicine and infectious diseases unit for a documented infectious disease, were included. They were separated in three groups: group I (n = 21): demonstrated infective endocarditis; group II (n = 19): septicemia without endocarditis and group III (n = 21): non septicemic well-defined infectious disease. Following parameters were studied: immune circulating complexes, C reactive protein, erythrocyte sedimentation rate, fibrinogen, rheumatoid factor, antinuclear antibodies, Treponema pallidum serodiagnostic and cryoglobulinemia. There were no differences between the three studied groups. In particular, immune circulating complexes were present in respectively 67%, 58% and 62% of the patients of the three groups. So, presence or absence of immunologic abnormalities does not provide help for diagnosis of endocarditis in a febrile patient.

Multiple subungual splinter hemorrhages in the antiphospholipid syndrome: a report of five cases and review of the literature

Multiple subungual splinter hemorrhages have been initially described as an important sign of subacute endocarditis. Secondly, they were reported in various other conditions, especially in isolated cases of primary antiphospholipid syndrome. We report five patients with multiple fingernail subungual splinter hemorrhages occurring in the course of antiphospholipid syndrome. Antiphospholipid syndrome was secondary to systemic lupus erythematosus in two, to Fasciola hepatica infection in one and was considered as primary in two. In all patients multiple subungual splinter hemorrhages occurred concomitantly with thrombotic events of diverse arterial sites. The mechanism of subungual splinter hemorrhages is most probably thrombotic.