Diagnosing Lupus

This site is intended for healthcare professionals as a useful source of information on the diagnosis, treatment and support of patients with lupus and related connective tissue diseases.
Early diagnosis is essential to reduce the risks of long term organ damage. For a diagnosis of lupus, a patient needs to meet four out of the following eleven criteria that have been established in agreement with the American College of Rheumatology:-
Malar rash

Discoid rash

Photosensitivity

Mucosal ulcers

Serositis

Arthritis

Renal disorder


Neurological disorder

Haematological disorder

Immunological disorder


Antinuclear Antibody (ANA)
Fixed malar erythema, flat or raised

Red patches of skin associated with keratotic scaling and follicular plugging, some atrophy in older lesions

Skin rash after exposure to sunlight

Oral or nasopharyngeal ulcers

Serosal surface inflammation – pleura, pericardium, peritoneum

Non-erosive flitting arthralgias, also tenosynovitis of flexor tendons

Persistent Protein/haematuria and nephrotic syndrome, renal biopsy to confirm classification of focal, diffuse or membranous glomerulonephritis

Seizures or neurocognitive dysfunction or psychosis

Haemolytic anaemia, leucopenia, lymphopenia or thrombocytopenia

Anti-ds DNA, Sm, antiphospholipid antibodies (abnormal IgM or IgG, lupus anticoagulant) or false positive syphilis serology

Positive ANA
Active lupus is indicated by the presence of a variety of antibodies which react against some of the chemicals in the cell nuclei. The condition can normally be diagnosed through a thorough history, patient examination and blood tests including ANA and in most cases, a more specific test, the anti-dsDNA test. Other antibodies that can be found in lupus include the following table:
Antibody

Anti-Smith (anti-Sm)
Anti-Ribosomal RNP
Anti-U1 snRNP
Anti-Ro (anti-SS-A) and Anti-La (anti-SS-B)

Anti-histone
Frequency in lupus

20-30%
A & C 30%
Sensitivity poor, seen in overlap syndromes
Ro – up to 50%
La – 10-15%
50-80%
Also associated with:

MCTD
Raynaud’s, mild renal disease
MCTD
Sjögren’s syndrome

Drug induced lupus
Full Blood Count can reveal a normochromic and normocytic anaemia (known as anaemia of chronic disease), lymphopenia and thrombocytopenia, which can lead to internal bleeding and purpura. In active lupus the erythrocyte sedimentation rate (ESR) and plasma viscosity (PV) may be elevated. Interestingly, other tests for acute phase inflammation such as C-reactive protein may remain normal providing helpful diagnostic data for the clinician. If the CRP is elevated infection should be considered as a possible cause.

Urine analysis is very important as proteinuria can indicate kidney involvement, especially in a patient with raised urea and creatinine levels. The estimated glomerular filtration rate (e-GFR) and a renal biopsy may be required to confirm this. Complement deficiency (C3 and C4 proteins) is also present in lupus during times of disease flare. Cholesterol levels should be checked regularly as lupus can lead to accelerated atherosclerosis. Thyroid function can also be affected.
Blood monitoring is essential to the complete diagnosis of lupus, although due to the multi-system nature of the disease, monitoring of other aspects of disease activity and systemic review in clinic is essential to prevent major flares of lupus.

One of the most important roles of the nurse specialist is to support and advise patients especially in times of flare of the disease. Patients can learn to recognise ‘red flags’ when medical help is required urgently and can also learn ways of managing their unpredictable symptoms in different ways. By mastering self-management techniques, patients can manage difficult times and plan realistic achievable goals to remain in control of their lupus wherever possible.