Capillary leak syndrome
Capillary leak syndrome | |
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Other names | SCLS, Clarkson's Disease, Capillary hyperpermeability syndrome |
montelukast |
Capillary leak syndrome, or vascular leak syndrome, is characterized by the escape of
These conditions and factors are sources of secondary capillary leak syndrome.Systemic capillary leak syndrome (SCLS), also called Clarkson's disease, or primary capillary leak syndrome, is a rare, grave and episodic medical condition observed largely in otherwise healthy individuals mostly in middle age.
Symptoms
Most SCLS patients succumb to viral infections manifesting themselves by way of flu-like symptoms (like a runny nose), gastro-intestinal disorders (diarrhea or vomiting), or general weakness or pain in the limbs, but others get no particular or consistent warning signs ahead of their episodes. They subsequently develop thirst and lightheadedness and the following conditions measurable in a hospital emergency-room setting: [3][4][5]
- hemoconcentration (elevated hematocrit and hemoglobinreadings, with hematocrit levels >49% in men and >43% in women, not because of an absolute increase in them but because of the leak of plasma);
- very low blood pressure (profound arterial hypotension, with systolic blood pressure levels <90 mm Hg);
- albumin deficiency (hypoalbuminemia measuring <3.0 g/dL);
- partial or generalized edema, and cold extremities;
- a MGUSin approximately 80% of cases).
Cause
Although the precise molecular cause of SCLS remains undetermined, scientific research in recent years, conducted mainly at a unit (
Studies suggest that the presence of various inflammatory factors during episodes of SCLS may explain the temporarily abnormal permeability of the endothelial cells lining the inner surface of the capillaries. These include transient spikes in
There is no evidence that SCLS is hereditary, and the role of specific gene defects in patients with SCLS, which might program their endothelial cells for an overreaction to external stimuli such as viral infections, has not been established.[4] The significance, if any, of the paraprotein (MGUS) present in most patients with SCLS is unknown, other than it has been a precursor to multiple myeloma in a minority (7% in the largest reported cohort) of SCLS patients.[4][8]
Diagnosis
SCLS is often difficult to recognize and diagnose on initial presentation, and thus misdiagnoses are frequent. The characteristic triad of profound arterial hypotension, hemoconcentration (elevated hematocrit,
Treatment
The natural history of SCLS episodes indicates they usually resolve spontaneously within 2-to-4 days, and that they consist of two distinct phases:[3][4][5]
The capillary leak phase
The initial stage is the capillary leak phase, lasting from 1 to 3 days, during which up to 70% of total plasma volume invades body cavities, especially in the extremities.
Urgent medical attention in this phase often features fluid resuscitation efforts, mainly the intravenous administration of
Consequently, fluid resuscitation should be minimized as much as possible in patients experiencing episodes of SCLS, and they should be closely monitored in a hospital intensive-care setting including for orthopedic complications requiring surgical decompression.
The recruitment phase
The second stage features the reabsorption of the initially extravasated fluid and albumin from the tissues, and it usually lasts 1 to 2 days. Intravascular fluid overload leads to
The prevention of episodes of SCLS has involved two approaches. The earliest was advocated by the Mayo Clinic, and it recommended treatment with high doses of
The rationale for use of these drugs was their ability to increase intracellular cyclic AMP (adenosine monophosphate) levels, which might counteract inflammatory signaling pathways that induce endothelial permeability.[4] It was the standard of care until the early 2000s, but was sidelined afterwards because patients frequently experienced renewed episodes of SCLS, and because these drugs were poorly tolerated due to their unpleasant side effects.[4][11][12]
The second, more recent approach pioneered in France during the early 2000s involves monthly intravenous infusions of immunoglobulins (IVIG), with an initial dose of 1-2 gr/kg/month of body weight, which has proven very successful as per abundant case-report evidence from around the world.[4][11][12][13]
IVIG has long been used for the treatment of autoimmune and MGUS-associated syndromes, because of its potential
A review of clinical experience with 69 mostly European SCLS patients found that preventive treatment with IVIG was the strongest factor associated with their survival, such that an IVIG therapy should be the first-line preventive agent for SCLS patients.[12] According to an NIH survey of patient experience, IVIG prophylaxis is associated with a dramatic reduction in the occurrence of SCLS episodes in most patients, with minimal side effects, so it may be considered as frontline therapy for those with a clear-cut diagnosis of SCLS and a history of recurrent episodes.[11]
A recent study involving 59 patients to evaluate the safety of IVIG tapering and withdrawal in French and Italian patients with SCLS concluded that the incidence of severe flares was not statistically different across the different dosages of IVIG, but that withdrawal was associated with increased mortality and higher rates of recurrence, such that lifelong treatment with IVIG is recommended for patients with SCLS.[14]
Prognosis
In mostly European experience with 69 patients during 1996–2016, the 5- and 10-year
History
The syndrome was first described by a team of New York City physicians led by Dr. Bayard D. Clarkson in 1960,[15] after whom it was later informally named. Beyond numerous case reports published since then, three comprehensive reviews of clinical and research experience were published in 2017.[4][5][12]
References
External links
Additional links:
- RareShare Systemic Capillary Leak Syndrome Community
- Cleveland Clinic
- Clinical trial number NCT00936325 for "Studies in the Pathogenesis of Systemic Capillary Leak Syndrome" at ClinicalTrials.gov