Undifferentiated systemic connective tissue disease-"overlap' in Zimbabwe

Area of Science:

• Rheumatology
• Immunology
• Internal Medicine

Background:

• Systemic connective tissue diseases (CTDs) encompass a range of autoimmune disorders.
• Undifferentiated and overlapping CTDs present diagnostic challenges, particularly in resource-limited settings.
• Understanding the clinical spectrum of these diseases in diverse populations is crucial for accurate diagnosis and management.

Purpose of the Study:

• To define the clinical characteristics of overlapping, undifferentiated systemic connective tissue diseases.
• To investigate the prevalence and specific patterns of overlap among CTDs in a tropical African population.

Main Methods:

• A descriptive retrospective study was conducted.
• Patient records from a rheumatology clinic in Harare, Zimbabwe, between 1989 and 1994 were analyzed.
• Data collected included patient demographics and clinical and laboratory features of CTDs.

Main Results:

• Rheumatoid arthritis (RA) was the most common diagnosis (52.8%), followed by systemic lupus erythematosus (SLE) (18.7%), juvenile chronic arthritis (JCA) (11%), polymyositis/dermatomyositis (PMD) (4.4%), and overlapping CTDs (12.1%).
• Among overlapping CTDs, SLE-RA was the most frequent pattern (five patients), followed by SLE-progressive systemic sclerosis (PSS) (three patients).
• Patients with overlapping CTDs often met criteria for individual diseases, indicating complex presentations.

Conclusions:

• Overlapping and undifferentiated connective tissue diseases occur in tropical Africa.
• Systemic lupus erythematosus-rheumatoid arthritis overlap is the predominant pattern observed.
• These overlapping conditions represent moderately severe diseases requiring further investigation.