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1st
International Workshop of Anti-Phospholipid Syndrome (APS) October 12-13,
2001, Pleven, Bulgaria Reported by Yehuda Shoenfeld, M.D. published 21. November 2001 Bulgaria attracted
worldwide attention when the king, who left Bulgaria when he was 9 years old,
returned to his country. He was recently nominated Prime Minister, which gave
great hope to Bulgaria, which has a population of 8.5 million. The hope and the
enthusiasm also engulf the field of medicine.
The international meeting
on APS is the first to put Bulgarian medicine and science on the map. Five years
ago, people in Bulgaria hardly related to APS. However, due to the efforts of
Dr. Emiliana Konova and the groups around her, insight into the syndrome grew to
entail diagnoses of many patients with many rare manifestations as well as
developing novel therapies.
The meeting took place in Pleven, a city
with a millennial history. Throughout the centuries, different cultures have
thrived in the region – Prehistoric, Thracian and Roman, Byzantine, Slavonic,
and Bulgarian. The battle on Pleven on December 10, 1878, was decisive for the
outcome of the Russo-Turkish war.
Behind the meeting was the Highest
Medical Institute (HMI) in Pleven which was founded in 1974, at first as a
faculty of the Sofia Medical University. Today, HMI-Pleven is a separate medical
school with its own curriculum developed under the requirements of the Ministry
of Education and Science (MES). By 2001, 3738 Bulgarian and 307 foreign students
from different countries have graduated from HMI-Pleven. In 1997, HMI-Pleven
introduced a medical curriculum that was taught in English in compliance with
state requirements. Now almost 150 students are enrolled in this curriculum.
Because the aim of the APS meeting was to solve unanswered questions in
APS, the summary of the conference will be by questions and answers.
WHAT PRECIPITATES CATASTROPHIC APS (CAPS)?
Ron Asherson
(South Africa), who published the first description of cAPS in 50 patients
delineated the diagnostic parameters as well as detailed clinical findings in 80
patients (the article will be published in Medicine). In this meta-analysis,
Asherson et al found that in 35% of patients the precipitating factor was
infection, which ranged from upper respiratory infections to leg ulcers and
other septic conditions, such as urinary tract infections, and rare conditions,
such as typhoid fever.
The second most frequent precipitating factor was
trauma and invasive procedures (13%), ranging from needle-stick injury to
angioplasty and other various major operations. An association with tumors was
recorded in 8% of cases. Withdrawal of anticoagulant or low INR led to 8% of the
cases of cAPS. An instructive association was noted with obstetric complications
(6%) such as post-fetal loss or the HELPP syndrome. Others were associated with
SLE "flares" (5%) or exposure to estrogen (3%).
Precipitating factors
in 80 patients with catastrophic APS
|
No. |
(%) |
|
|
|
Infections |
12 |
(5) |
Respiratory tract
|
6 |
(8) |
Cutanous |
5 |
(6) |
Urinary tract
|
2 |
(3) |
Spesis |
1 |
(1) |
Gastrointestinal
|
7 |
(9) |
Other |
10 |
(13) |
Surgery, trauma, and
invasive procedures |
6 |
(8) |
Neoplasia |
6 |
(8) |
Anticoagulation
withdrawal/low INR |
5 |
(6) |
Obstetric complications
|
4 |
(5) |
SLE flares |
2 |
(3) |
Oral contraceptives
|
28 |
(35) |
No factor
identified |
|
|
Infectious Etiology of
APS
Yehuda Shoenfeld (Israel) expanded on the infectious etiology of
APS, also acting as a specific trigger mechanism for cAPS. Originally,
antiphospholipid antibodies (aPL) were reported in infectious conditions such as
syphilis (for example, false-positive serologic test for syphilis), since then,
aPL have been reported in a variety of infections from human imunno-deficiency
virus (HIV) and to bacterial and even parasitic infestation (for example,
malaria, leishmaniasis, and trypanosomiasis). Most of the infection related-aPL
seems to be a non-pathogenic type, in that their binding to cardiolipin is not
B2GPI dependent. Yet this classification is not necessarily clear-cut.
Furthermore, it is not inconceivable that in susceptible subjects having the
necessary HLA DR4 or DR7 or other genetic tendency the "non-pathogenic"
infections induced anticardiolipin antibodies (aCL) will mutate and rearrange
the amino acid at the CDR3 domain of the binding site determining the B2GPI
dependency and the pathogenic nature of antibody.
Recent research from
two groups supports the infectious origin of pathogenic aPL by immunization with
foreign B2GPI or synthetic peptides representing the phospholipid-binding site
of the B2GPI. These autoantibodies caused intrauterine fetal death and
transverse myelopathy (due to spinal cord infraction in mice), and activated
endothelial cells in vitro. This group (Gharavi et al) also demonstrated the
induction of aPL in mice by immunization with phospholipid-binding viral
peptides and observed their pathogenic effects. Recently, the same authors
proved the pathogenic effects of aPL induced by immunization with human
CMV-derived phospholipid-binding synthetic peptides. These research findings are
compatible with CMV- and HIV-induced APS in patients.
Shoenfeld et al
complemented the relationship between infections and APS by adding a series of
additional studies. Employing a peptide phage display library, they identified
three hexapeptides that reacted specifically with anti- B2GPI monoclonal
antibodies. All three peptides inhibited the biologic function of the
corresponding anti- B2GPI monoclonal antibodies and the in vitro endothelial
cell activation and induction of experimental APS in vivo. Using the Swiss
protein database, they revealed a high degree of homology between the
hexapeptides with different bacteria and viruses.
Naive mice were
immunized with a panel of pathogenic particles, sharing the appropriate homology
with peptides. All the immunized mice developed aPL. Mouse IgG, specific to
relevant peptide (equivalent to B2GPI), was affinity purified from the immunized
mice. These specific immunoglobulins were infused into BALB/c mice to study the
development of associated clinical manifestations. Only the mice infused with
mouse antibodies derived from mice immunized with Haemophilus influenzae or
Neisseria gonorrhoeae, directed to the peptide TRLVYK, had the potential to
induce clinical manifestations that resembled experimental APS. Shoenfeld
hypothesized that the mechanism of pathogenic anti-B2GPI generation is induced
by epitope mimicry, and APS should be included in the group of infection-induced
autoimmunity.
Several presenters stressed the infectious etiology of
APS. M. Nikolova et al (Sofia, Bulgaria) found aCL in 11% and 5% of patients
with infectious with chlamydia and mycoplasma, respectively. Some of the
patients had APS clinical manifestations. Lieva P. et al (Pleven, Bulgaria)
reported an associated aCL with hepatitis A and B, while M. Daskolova (Pleven,
Bulgaria) detailed a case of echinococcosis with aCL. WHAT ADDITIONAL FINDINGS
CHARACTERIZE APS?
Bone Marrow Necrosis
Ron Asherson (South
Africa) reported the surprising frequency of cases of APS with associated
bone-marrow necrosis. As opposed to osteonecrosis – no fewer than 6 patients
from his present series developed these complications. Bone-marrow necrosis is a
relatively uncommon condition and is most frequently encountered in patients
with lymphoma, neoplastic diseases (metastatic carcinoma, acute leukemia
following radiotherapy or chemotherapy), sickle-cells disease, and severe
bacterial infections (particularly septic shock). To this list Asherson has
added catastrophic APS.
Bulvik et al in 1995 first report the
association between APS and bone-marrow necrosis in young pregnant patients who
developed this complication on the third day post-cesarean section. The
postpartum occurrence of these complications (2 days postpartum) had been noted
some years before by Knickerbockers et al. Their patients had had a previous
history of recurrent thrombophlebitis and three spontaneous abortions. Its
assurance in pregnancy was reported by Paydas et al in 1997 in a 27-year-old
pregnant woman with a history of 9 miscarriages, a cerebrovascular accident, and
high titers of aPL.
Murphy et al in 1998 documented this complications
associated with lymphoma and aPL. In the literature associated with APS, 9
patients have been reported tohave this complication, of whom 6 suffered
catastrophic APS. It is, therefore, among the less well-known manifestations of
the aPL-associated complications occurring mainly in catastrophic APS patients
for reasons unknown at the present time.
WHAT KIND OF PHOSPHOLIPID
AND IG ISOTYPES ARE MEASURED FOR THE DIAGNOSIS OF APS?
Sozos Loizou
(U.K) in 1980 with G. Hughes and other colleagues published the first paper on a
quantitative Elisa for measurements of aCL antibodies. Based on this extensive
experience, they recommended a series of 6 phospholipids (CL, PS, PEA, PC,
prothrombin, B2GPI) to detect autoantibodies. Loizou reported cases with a
single unique anti-phospholipid and emphasized the importance of all 3 isotypes,
i.e. IgM, anti-CL, and anti-PEA may specifically characterize patients with APS
associated with autoimmune hemolytic anemia. He also referred to the many cases
with only IgA aCL.
WHAT IS THE EURO-PHOSPHOLIPID PROJECT?
Richard Cervera (Spain) explained that the aim of this
"Euro-phospholipid project" is to evaluate prospectively the clinical and
serologic manifestations and the evaluation of the APS by means of a long-term
follow-up study of a large cohort of European patients. The specific objectives
of the project are: 1. To determine the incidence and characteristics of the
different APS clinical manifestations at the onset of disease and during
follow-up. 2. To analyze the biologic and immunologic features of these
patients and the relationship with their clinical manifestation in order to
clearly define different subsets of the disease. 3. To determine the
natural history, severity, and response to treatment of these APS subsets.
4. To evaluate to morbidity of the different APS subsets (including
complications induced by the different treatment regimens of this condition).
5. To establish the mortality rate and the main causes of death in the
European APS population.
The final cohort includes 1,000 unselected
patients with APS attending 20 tertiary referral university centers from 13
countries (Spain, France, United Kingdom, Israel, Denmark, Hungary, Italy,
Greece, The Netherlands, Germany, Bulgaria, Belgium, and Portugal). All fulfill
the Consensus Criteria for the APS [1]. Patients with both primary APS and APS
associated with systemic lupus erythematosus (SLE) or other autoimmune diseases
have been enrolled and they will be followed for 10 years.
Information
on the progress of the study can be obtain at the website of the "European Forum
of Antiphospholipid Antibodies" (www.med.ub.es/MIMMUN/FORUM/INDEX.HTM).
Dr. Cervera detailed the findings in the first 1,000 patients with APS (to be
published in Arthritis & Rheumatism).
ARE THERE AGE DIFFERENCES
IN THE APPEARANCE OF APS?
The answer by Cervera analysis is YES. For
instance, chorea is seen almost only in children.
CAN WE PREDICT
CASES OF APS THAT WILL EVOLVE TO SLE?
No definite criteria are
currently available to predict such an evolvement (short follow-up of the
disease). Yet, analyses of the 1,000 cases seems to indicate that high ANA,
lymphopenia, anti-Sm, and arthritis can be used as predictive markers for such
progression.
HOW DO ANTI-PHOSPHOLIPID ANTIBODIES AFFECT PLACENTAL
FUNCTION?
Siohan Donohoe (UK) summarized the growing evidence that
aPL affect pregnancy viability through a variety of mechanisms. However, the
currently available laboratory parameters defining APS give little indication of
the obstetric risk of PET, intrauterine growth retardation (IUGR), or recurrent
miscarriages. To date the best clinical indicator of obstetric outcome is the
outcome of previous pregnancies, both with and without prophlyxis.
aPL
may mediate placental dysfunction by disrupting endometrial and/or trophoblast
function and promote procoagulant conditions [157]. Histologic and cell culture
studies support a pathogenic role of aPL on the processes of implantation and
invasion occurring in early pregnancy. Thrombosis is a relatively common feature
of the placenta in women with aPS and is likely to contribute to the observed
pathology, either as a cause or a consequence of placental dysfunction. A
primary causative role for aPL-related thrombosis mediating miscarriage,
pre-eclampsia, IUGR, fetal loss, and preterm delivery is in question. However,
the unifying features of placental histology are fetal death, preterm birth,
pre-eclampsia, and intrauterine growth restrictions. The latter include
thrombosis, defective placentation, abnormal uteroplacental vascular conversion,
and chronic inflammation, which provide insight into the etiology of the
complications and suggest abnormal trophoblast invasion as a pathologic
mechanism. In APS as are for PET and IUGR, events occurring during early
pregnancy are thought to determine pregnancy outcome. The level of disruption to
these processes is likely to determine pregnancy outcome.
More recent
placental research suggests that aPL restrict trophoblast invasion. As a result,
the conversion of the spiral arteries to placid vessels, which allow increasing
blood flow, is reduced. Furthermore, aPL have been associated with
atherosclerosis, apoptosis, and endothelial activation, which combined with the
procoagulant activity of these antibodies present the feto-maternal junction
with a multiple hit. It is her hypothesis that the placenta has an inherent
excess capacity and that the obstetric presentation in APS reflects the degree
of underlying physiologic feto-maternal functional compromise associated with
heterogeneous aPL. This balance may be tipped sufficiently in favor of a
successful pregnancy as a response to therapy.
WHAT IS THE PREVALENCE
OF FACTOR LEIDEN AND 20210 6-A MUTATION OF PROTHROMBIN IN APS?
Baleva Metal (Sofia, Bulgaria) analyzed the frequencies of factor
Leiden and 20210 6-A mutation of prothrombin in 80 patients with APS and healthy
controls and could not find an increased prevalence compared with controls.
IS APS A PURE ANTIBODY-MEDIATED DISEASE OR IS T CELL IMMUNITY ALSO
INVOLVED?
D. Kyurkchiev et al (Sofia, Bulgaria) found in patients
with high anti-CL titers T-cell reaction in vitro against 200 ug/mL B2GPI/CL
complex, but no reaction against B2GPI alone. Their study confirms the
immunogenic role of B2GPI in APS and is supported by previous studies showing
the transfer of experimental APS by bone marrow T cells.
ARE
PLATELETS ACTIVATED IN APS OR ARE THEY AN INNOCENT BYSTANDER?
According to the new Sapporo Criteria for APS diagnosis, the 40%
occurrence of thrombocytopenia were not included. Tz Lukanov et al (Pleven,
Bulgaria) employing flow cylometry revealed expression of CD3 and CD62 on
platelets from 29 patients with APS. These data point to the existence of
circulating activated platelets in APS. Many discussants raised the question
whether thrombocytopenia should be incorporated again in the diagnostic criteria
for APS.
CAN HEROIN ABUSE INDUCE aPL?
M. Nikolova et al
(Sofia, Bulgaria) reported 4 heroin addicts (22 to 30 years old) with a mean
duration of heroin abuse of 46 months (range, 6 to 96 months). All had aPL in
addition to other antibodies (ANA). Yet one of them developed clinical findings
of APS. The question of heroin being the inciting factor or the co-association
with HCV or HIV was raised. The report draws attention to addicts with APS
manifestations.
ARE KIDNEYS INVOLVED IN APS?
Previously
kidney involvement in APS was limited to cases with APS secondary to SLE. More
and more papers appearing recently indicate kidney involvement in APS. M.
Nikolova (Sofia, Bulgaria) reported 48% prevalence of aCL in lupus nephritis.
One third had clinical manifestations of APS. The presence of aCL with lupus
nephritis did correlate with a specific histologic type.
IS APS A
GENETIC DISEASE?
K. Ongelova et al (Pleven, Bulgaria) described
three generations of one family with multiple cases of APS. Other members were
found to harbor only aCL. The asymptotic cases raised the question of therapy:
should we follow these subjects with aCL or should we at least give them low
dose aspirin? The discussant raised the legal issue of both options. The
question of treating an asymptotic aCL-positive subject remains unanswered.
THE MOSAIC OF APS
Additional interesting aspects of APS
raised by presenters included:
1. High titers of aCL in advanced
coronary atherosclerosis (I. Stankulov). 2. The appearance of aCL often with
myocardial infarction. 3. The 5% to 10% incidence of epilepsy in APS,
related to the effect of aCL on the central nervous system. 4. The 29% of
aCL positivity in sera of patients (I. Kokareshkov) with multiple
sclerosis.
All the above indicates that indeed APS is a
multi-disciplinary disease.
CAN IVIG IMPROVE APS PATIENTS?
There is a local institute in Sofia, Bulgaria, producing IVIG. This safe
IVIG was given to a series of SLE patients whose disease was resistant to a
conventional therapy. The condition of most patients improved. Another study
included 19 women with a history of two or more consecutive recurrent pregnancy
failures and presistantly positive tests for aCL. In two patients, IVIG (250
mg/kg in two infusions) was started within 2 weeks after attempted conception.
Once conception was achieved, IVIG was continued in all patients on a monthly
basis at the same dose through 23 to 36 weeks of gestation.
1) aCL were
significantly suppressed after each IVIG infusion (p<0.01) for about 3 weeks;
2) platelets, autoantibodies, and activity index were decreased after
each infusion (p<0.05) for 2 to 3 weeks;
3) platelet count rapidly
increased at the 24 hours to normal levels for a period of 2 to 3 weeks
(p<0.01).
Reproductive outcome: 19 pregnancies were reported; 17
delivered maturely, the infants were normal for gestational age. One woman had a
missed abortion at 8 weeks of gestation and one at 13 weeks of gestation. The
rate of successful deliveries was 89.5% (17 out of 19).
Conclusion: it
seems that IVIG therapy is a therapeutic benefit for the feto-placental unit for
women with a history of antiphospholipid-associated miscarriages. aPL lead to an
early organ failure, defective placentation, and hypercoagulation. IVIG down
regulates the levels of these autoantibodies. This therapy is immunomodulating,
safe, and well tolerated.
R. Roussey et al (Chicago, USA) reported
similar results in patients with recurrent pregnancy failure.
The unique
observation in the Bulgarian experience with IVIG was that the IVIG was given in
one-tenth of the dosage regularly reported to help in the literature. If
approved in extended studies, this low dose of IVIG (150 to 250 mg/kg.B.W) may
lower substantially the expenses associated with this therapy. Yehuda
Shoenfeld, M.D. Department of Medicine ‘B’ and Center
of Autoimmune Diseases, Sheba Medical Center, Tel-Hashomer, and Sackler Faculty
of Medicine, Tel-Aviv University, Israel
Correspondence to: Y. Shoenfeld,
M.D., Department of Medicine ‘B’, Sheba Medical Center, Tel-Hashomer, 52621,
Israel. Tel: 972-3-5302652. Fax: 972-3-5352855. E-mail: shoenfel@post.tau.ac.il
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