Neurological and neuroendocrine-cytokine inter-relationship in the antiphospholipid syndrome

CNS dysfunction in the antiphospholipid syndrome

Though many neurological deficits have been described in the antiphospholipid syndrome (APS), only stroke is well establishedand accepted as a diagnosticcriterion in this disease. We review clinical data obtainedfrom a large series of cases regardingstroke, dementia, epilepsy, chorea, migraine, white matter disease and behavioralchangesin APS or linked to laboratory criteria such as antiphospholipid antibodies (aPL). The contribution of animal models to our understanding of these manifestations of APS is stressed, especially regarding the cognitive and behavioral aspects for which we have established model systems in the mouse. These models utilize immunization of mice with b2-glycoprotein I, a central autoantigen in APS, which induces persistent high levels of aPL. These mice develop hyperactive behavior after a period of four to five months as well as deficits in learning and memory and are potentiallyvaluableas a system in which to study the pathogenesisand treatment of cognitive and behavioral aspects of APS. Another model we have developed, in which IgG from APS patients induce depolarization of brain synaptoneurosomes, may serve as a model for the pathogenesis of epilepsy in APS.

Obstetrical APS: is there a place for hydroxychloroquine to improve the pregnancy outcome?

The use of the conventional APS treatment (the combination of low-dose aspirin and LMWH) dramatically improved the obstetrical prognosis in primary obstetrical APS (OAPS). The persistence of adverse pregnancy outcome raises the need to find other drugs to improve obstetrical outcome. Hydroxychloroquine is widely used in patients with various autoimmune diseases, particularly SLE. Antimalarials have many anti-inflammatory, anti-aggregant and immune-regulatory properties: they inhibit phospholipase activity, stabilize lysosomal membranes, block the production of several pro-inflammatory cytokines and, in addition, impair complement-dependent antigen-antibody reactions. There is ample evidence of protective effects of hydroxychloroquine in OAPS similar to the situation in SLE arising from in vitro studies of pathophysiological working mechanism of hydroxychloroquine. However, the clinical data on the use of hydroxychloroquine in primary APS are lacking and prospective studies are necessary.

A patient with bipolar disorder and antiphospholipid syndrome

Antiphospholipidsyndrome (APS) is an autoimmune disorder which causes a hyper-coagulable state characterized by recurrent thrombosis. It has a diverse range of central nervous system manifestations. We describe a case of a 61 year old man with bipolar disorder and APS, and we compare this to a previously reported case. Additionally, we reviewed literature regarding APS-related markers and the relationship of APS to other psychiatric and neurologic illnesses. We discuss possible mechanisms for an association between APS and bipolar disorder. We encourage clinicians to be aware of this possible relationship and have proposed research strategies.

Cognitive impairment in antiphospholipid syndrome: evidence from animal models

Although antiphospholipid syndrome (APS) is a multisystem prothrombotic condition, its inflammatory nature has been increasingly recognized in recent years. Stroke and transitory ischemic attacks are the neurological manifestations included in APS criteria, however many other neurological involvements have been attributed to antiphospholipid antibodies (aPL), such as seizures, transverse myelitis, and cognitive impairment. In this article we will review evidence from animal model that explain the role of aPL in cognition.

Peripheral neuropathy in patients with primary antiphospholipid (Hughes') syndrome

The involvement of the peripheral nervous system in diverse autoimmune diseases is well established. However, no appropriately designed studies have been performed in primary antiphospholipid syndrome (PAPS)-related peripheral neuropathy. We aimed to investigate the occurrence of peripheral neuropathy in patients diagnosed with PAPS. Twenty-six consecutive patients with PAPS (Sapporo criteria) and 20 age- and gender-matched healthy controls were enrolled at two referral centers. Exclusion criteria were secondary causes of peripheral neuropathy. A complete clinical neurologic exam followed by nerve conduction studies (NCS) was performed. Paresthesias were reported in eight patients (31%). Objective mild distal weakness and abnormal symmetric deep tendon reflexes were observed in three patients (11.5%). With regard to the electrophysiologic evidence of peripheral neuropathy, nine patients (35.0%) had alterations: four (15.5%) had pure sensory or sensorimotor distal axonal neuropathy (in two of them a carpal tunnel syndrome was also present) and one (4%) had sensorimotor demyelinating and axonal neuropathy involving upper and lower extremities, while four patients (15.5%) showed isolated carpal tunnel syndrome. Clinical and serologic results were similar in all the patients with PAPS, regardless of the presence of electrophysiologic alterations. In conclusion, peripheral neuropathy is a common asymptomatic abnormality in patients with PAPS. The routine performance of NCS may be considered when evaluating such patients.

Neonates born from mothers with autoimmune disorders

Systemic autoimmune disorders have a higher prevalence in women, particularly during their childbearing age. A growing interest is being paid to the possible consequences of maternal disease and associated treatment on the fetus and newborn infant. If maternal disease is characterized by the presence of IgG isotype auto-antibodies, these can cross the placenta with possible antibody-mediated damage to the fetus. The risk of gestational complications, including preterm delivery, intrauterine growth retardation and low birth weight is higher in autoimmune diseases rather than in the general population and probably this finding is related to both maternal disorder and immunosuppressive therapy. Recently, results of our studies suggest that the antenatal exposure to immunosuppressive drugs given to mothers during pregnancy to treat autoimmune diseases does not impair significantly the development of immunity in exposed children. Finally, mothers disease and/or treatment could be related to neuropsychological dysfunctions reported in some of their children.

Antibodies to glutamate receptor subtype 3 (GluR3) are found in some patients suffering from epilepsy as the main disease, but not in patients whose epilepsy accompanies antiphospholipid syndrome or Sneddon's syndrome

Autoantibodies (Ab's) to the "B" peptide (amino acids 372-395) of glutamate/AMPA receptor subtype 3 (GluR3) are found in serum and cerebrospinal fluid of some patients with different types of epilepsy. Since such anti-GluR3B Ab's can activate and/or kill neurons in vitro and in vivo, they may contribute to epilepsy. To investigate whether anti-GluR3B Ab's may also be relevant to epilepsy when it accompanies some autoimmune-diseases, we tested for these Ab's in patients suffering from epilepsy that accompanies anti-phospholipid syndrome (APS) or Sneddon's syndrome (SNS), both being autoimmune-diseases with frequent neurological complications. We tested 77 pediatric patients whose epilepsy is their main disease; 31 adult patients whose epilepsy accompanies APS (primary or SLE-associated) or SNS; 45 epilepsy-free APS and SNS patients; and 90 healthy controls. Compared to the controls, significantly elevated anti-GluR3B Ab's were found in 22/77 (29%) patients whose epilepsy is their main disease, but in none of the patients whose seizures accompany APS or SNS. Yet, all the APS and SNS patients harbored the characteristic anti-phospholipid Ab's (aPL), directed against cardiolipin and beta2-glycoprotein I, and had lupus anti-coagulant. Thus, anti-GluR3B Ab's are not crossreactive with aPL, and not produced as a non-specific consequence of seizures on the one hand, or autoimmune-diseases on the other. Taken together with new findings accumulated recently in our lab, we suggest that anti-GluR3B Ab's are produced primarily in the periphery due to specific/non-specific "irritation" of the immune system, and that once they reach the brain via a leaky blood-brain barrier they may cause neuronal/glial damage and facilitate the outburst of epilepsy and additional neurological abnormalities. In contrast, the presence of anti-GluR3B Ab's does not seem to increase the probability of developing APS, SNS or the seizures that often accompany these autoimmune-diseases. These findings may have important diagnostic and therapeutic implications.

Neonatal effects of maternal antiphospholipid syndrome

Antiphospholipid antibodies (aPL) can impair the physiologic development of a fetus during pregnancy not only by causing thrombosis of the placental vessels, but also by directly binding throphoblast cells and modifying their functions. Consequently, the presence of aPL in pregnant women is linked to an increased rate of pregnancy complications. These include recurrent early miscarriages, late fetal losses, and hypertensive disorders of gestation. In this clinical setting, preeclampsia is usually early and severe and can be complicated by the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome). The close association between aPL and obstetric pathology supports the inclusion of these manifestations in the clinical classification criteria of antiphospholipid syndrome. About 30% of children born to mothers with aPL passively acquire these autoantibodies; fortunately, the occurrence of thrombosis seems extremely rare in these babies. The prospective ongoing studies of children born to antiphospholipid syndrome patients reassure us about their general good health; however, some data suggest that learning difficulties might occur, possibly related to in utero exposure to aPL.

Presence of lupus anticoagulant in an asymptomatic Nigerian

BACKGROUND

The lupus anticoagulant (LA) is one of the antiphospholipid antibodies (aPL), which prolong phospholipid- dependent coagulation tests by interfering with coagulation reactions that depend on protein - phospholipid complexes in vitro.

METHOD

A 25 year old 'healthy' male Nigerian was screened for the presence of any coagulation abnormality using the KCT, PT and platelet count; after volunteering for his plasma to be used in the preparation of normal pooled plasma in a study.

RESULTS

He was discovered to have a prolonged KCT, PT and normal platelet count. Based on the prolonged KCT his plasma was subjected to mixing studies with various concentration of normal pooled plasma; the KCT index was calculated and a curve was plotted. His KCT index was 1.6 and the curve convex in the left axis suggesting the presence of LA. His past medical history and physical examination were not remarkable. Three months after the initial study, a repeat KCT index was 1.4 and the subject asymptomatic.

CONCLUSION

From literature review this is the first report of LA in an asymptomatic adult Nigerian; the importance of this finding is discussed.

Genetic and immunological factors interact in a mouse model of CNS antiphospholipid syndrome

The antiphospholipid syndrome (APS) includes systemic and central nervous system (CNS) pathology associated with antibodies to a complex of phospholipids and beta(2)-glycoprotein I (beta(2)-GPI). We have recently reported the induction of APS associated with behavioral and cognitive deficits in BALB/c female mice that developed 4-5 months after immunization with beta(2)-GPI. In the present study, we examined the influence of genetic factors on the ability to induce experimental APS with CNS involvement by testing several mouse strains immunized with beta(2)-GPI. Female mice from five strains were immunized once with beta(2)-GPI in complete Freund's adjuvant (CFA) or with CFA alone (controls). Autoantibody levels were examined at 1 and 5 months after immunization. Neurological assessment in a staircase test was performed 4-5 months following the immunization. Induction of APS resulted in elevated levels of antibodies against negatively charged phospholipids and beta(2)-GPI in all five mouse strains. Autoantibody levels were significantly higher in Balb/c, ICR, and C57BL/6 mouse strains compared to AKR and C3H. aPL levels dropped significantly more in the C57BL/6 compared to Balb/c mice over a period of 4 months. Hyperactivity reflected by higher number of stairs climbed in 3 min, was induced by APS in the Balb/c and ICR, mouse strains. Exploratory behavior reflected by more frequent rears, was seen in the APS-Balb/c and AKR mice. Hypoactivity and less exploration were seen in the APS-C57BL/6 and C3H mice. The study supports a link between high levels of aPL and behavioral changes in a mouse APS model. Qualitative differences in behavioral patterns may be due to nervous system as well as immune genetic factors. The minimal effect of APS in C57BL/6 mice may provide a suitable background for the study of transgenes in these mice.