CONNECTIVE
TISSUE DISEASES (CTDs) OTHER THAN SCLERODERMA
The
connective tissue diseases (CTDs) comprise a group of syndromes
of unknown aetiology affecting as many as one person in 40, often
with a predilection for women. CTDs include
scleroderma, systemic lupus erythematosus (SLE), overlap syndromes
(or mixed CTDs), polymyositis and dermatomyositis, Sjögren’s syndrome,
and the vasculitides (e.g. polyarteritis nodosa, Wegener’s, giant
cell arteritis). The following information will focus on the two
most common CTDs after scleroderma: SLE and mixed CTD.
SYSTEMIC
LUPUS ERYTHEMATOSUS (SLE)
Systemic lupus erythematosus (SLE) is an autoimmune, connective
tissue disease with frequent internal organ involvement. It is associated
with a wide variety of symptoms, including:
-
A
butterfly-shaped rash over the cheeks
-
A
skin rash appearing in areas exposed to the sun
-
Sores
in the mouth and nose
-
Arthritis
involving one or more joints.
The
prevalence of SLE is 40-50 per 100,000 but is higher among certain
ethnic groups. Women with SLE outnumber men by more than three to
one.
The
prevalence of pulmonary arterial hypertension (PAH) among patients
with SLE is five to 10 percent higher than that in the general population.
This raised prevalence is thought to be related to connective tissue
changes in the pulmonary vasculature.
Despite
its increased prevalence in SLE, PAH is seldom diagnosed in its
early stages.
Screening
for pulmonary arterial hypertension in SLE
A transthoracic echocardiogram is recommended to be performed if
patients have symptoms suggestive of pulmonary hypertension.
MIXED
CONNECTIVE TISSUE DISEASES
Mixed CTD is an umbrella term and not all specialists agree that
mixed disease is a true entity, as first suggested by Dr Sharp and
colleagues in 1972. Sharp used the term to describe patients with
some of the features of polymyositis, SLE and scleroderma who ran
a benign course with no pulmonary, cerebral, or renal involvement,
and no vasculitis. The patients responded well to low-dose steroids,
and were identified by the presence of an anti-nuclear antibody,
the U1 ribonucleoprotein (RNP). However, it is now clear that many
of these patients will develop organ involvement which are not responsive
to low dose steroids. For some patients, MCTD is not a benign disease,
because pulmonary hypertension has come to be one of its marked
features, as have neurological disease and other forms of pulmonary
involvement. Pulmonary arterial hypertension (PAH) is found in seven
to 15 percent of patients with undifferentiated or mixed CTD.
Screening
for pulmonary arterial hypertension in MCTDs
A transthoracic echocardiogram is recommended to be performed only
if patients have symptoms suggestive of pulmonary hypertension.
References
-
Black
CM, Presented at The role of endothelin receptor antagonism
in cardiopulmonary disease, Venice, Italy, 26-28 April, 2002
-
Asherson
RA, Pulmonary hypertension in systemic lupus erythematosus.
J Rheumatol. 1990 Mar;17(3):414-5
-
Rich
S (Ed). Primary pulmonary hypertension: Executive summary from
the WHO symposium, Evian, France 6-10 Sept 1998
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