By Majid Philippe Abi Saab, Rheumatology consultant.
To Explain the BILAG-2004 index updated 2010 scoring scheme for renal system.
The BILAG 2004 developed by the British Isles Lupus Assessment Group (BILAG) 2004 index and based on classical BILAG update that was 1st developed in 1995.
it is a composite index of Systemic Lupus Erythematosus (SLE) referring to organ manifestations assessment during the past 4 weeks compared to the previous 4 weeks as disease activity consistent with manifestation attributed to SLE and not to the pre-existing SLE irreversible damage.
However damage due to SLE should be considered as a cause of features that are fixed/persistent (SLICC/ACR damage index uses persistence ?6 months to define damage). The evaluation is based on 9 systems, each contains related items and some items needs Physicians judgment only as no tests can define it. Ophthalmic assessment needs also a record from ophthalmologist.
Only record manifestations/items due to SLE Disease Activity. These components or systems involved are listed as System 1 Constitutional, System 2 Mucocutaneous, System 3 Neuropsychiatric, System 4 Musculoskeletal, System 5 Cardiorespiratory, System 6 Gastrointestinal, System 7 Ophthalmic, System 8 Renal and System 9 Haematological.
The BILAG 2004 classification of categories and scoring is used to assess the disease activity in patients with systemic lupus erythematosus (SLE), however The renal component of the BILAG score assesses the activity of lupus nephritis, which is a complication of SLE, and the BILAG 2004 index updated 2010 version scoring scheme has experienced difficulties in understanding and therefore limited feasibility in practice.
THE BILAG-2004 INDEX.
Each system in BILAG-2004 is categorised for its specific disease activity, severity and/or damage. there is no summation of the 9 systems together as each one has separated scoring, however, summations are used within the system, but the renal one is subject to confusion, using objectivity of progression within 6 domains and 12 parameters in total.
As the results of each domain is classified on 5 categories A, B, C, D, E. A is the worst and E as no previous involvement, the updated BILAG 2010 scoring system for the renal component of the BILAG 2004 scoring scheme remains a comprehensive tool for assessing the activity of lupus nephritis in patients with SLE. The updated scoring system includes some modifications to the original scoring scheme that are aimed at improving the reliability and validity of the score. The renal component domains are further classified into grade A (null) to E (severe) and each grade is converted to numerical to summate the total score and define the Category of the System: A (severe) to E/D (null).
The updated BILAG 2010 scoring system includes three main changes from the original 2004 scheme:
1. The definition of the A grade has been revised to require no proteinuria or hematuria rather than just no active urinary sediment. This change was made to improve the specificity of the A grade, which is intended to indicate no evidence of disease activity.
2. The scoring criteria for the renal function domain have been modified to be more objective and quantitative. The 2004 scheme used a subjective rating system based on clinical judgement, while the 2010 scheme uses a formula based on the estimated glomerular filtration rate (eGFR).
3. The scoring criteria for the hypertension domain have been updated to reflect current clinical practice guidelines for the management of hypertension.
Despite these changes, the basic structure of the BILAG 2010 scoring system for the renal component remains the same as the 2004 scheme. There are still six domains assessed, and each domain is scored on a scale of A to E based on specific criteria. The overall renal score is calculated by summing the scores for each renal domain assessed that has evidence of disease activity (i.e., a total score of B, C, D, or E) as A is null.
the Scale for renal domains are A:0, B:1. C:2, D:3, E:4 and its total score define its category as disease activity (for renal system) as in BILAG 2004 index categories.
As these categories apply to the total score of each system for BILAG 2010 index categories, and including the renal component, the categories for the renal component alone are not different from the overall BILAG score categories.
It’s important to note that the category cut-offs for each organ system may differ slightly, and that the categories should be interpreted in the context of the individual patient’s clinical presentation and disease activity.
The renal component of the BILAG score assesses the activity of lupus nephritis.
To calculate the BILAG 2004 score for the renal component, it is needed to assess six different renal domains, including:
3. Renal function
5. Renal biopsy
6. Other renal features
Each domain is scored on a scale of A to E, with A indicating no evidence of disease activity and E indicating severe disease activity. The scores are assigned based on specific criteria for each renal domain, which are outlined in the BILAG 2004 scoring guide and divided into 12 parameters or Questions.
To calculate the overall BILAG score for the renal component, a score should be assigned for each of the 6 renal domains that have evidence of disease activity (i.e., a score for A=0, B=1, C=2, D=3, E=4). For example, if a patient has a score of B for proteinuria, a score of C for hematuria, and a score of D for renal function, their overall renal BILAG score would be 6.
As with the original scheme, it is important to use the BILAG 2010 score It’s important to note that the BILAG 2004 index updated 2010 scoring scheme should be used in conjunction with other clinical and laboratory measures to assess disease activity and guide treatment decisions. It is also recommended to seek the assistance of a qualified healthcare professional in interpreting and applying the BILAG score. The updated categories were introduced in the BILAG 2010 index and represent the most recent version of the scoring scheme.
Example of how to score the six domains of the renal component using the updated 2010 BILAG index:
• A: No proteinuria
• B: Proteinuria below 0.5 g/24 hours or protein-creatinine ratio below 50 mg/mmol
• C: Proteinuria 0.5-1.0 g/24 hours or protein-creatinine ratio 50-100 mg/mmol
• D: Proteinuria 1.0-2.0 g/24 hours or protein-creatinine ratio 100-200 mg/mmol
• E: Proteinuria above 2.0 g/24 hours or protein-creatinine ratio above 200 mg/mmol
Example score: B (proteinuria less than 0.5 g/24 hours)
• A: No hematuria
• B: Microscopic hematuria only
• C: Gross hematuria or red blood cell casts
• D: Microscopic hematuria with dysmorphic red blood cells or moderate number of red blood cells
• E: Microscopic hematuria with above 50% dysmorphic red blood cells or numerous red blood cells
Example score: C (gross hematuria or red blood cell casts)
3. Renal function:
• A: eGFR ? 90 ml/min/1.73 m2
• B: eGFR 60-89 ml/min/1.73 m2 or serum creatinine ? 1.2 mg/dL
• C: eGFR 30-59 ml/min/1.73 m2 or serum creatinine 1.3-1.9 mg/dL
• D: eGFR 15-29 ml/min/1.73 m2 or serum creatinine 2.0-3.0 mg/dL
• E: eGFR below 15 ml/min/1.73 m2 or serum creatinine above 3.0 mg/dL or requiring dialysis
Example score: C (eGFR 30-59 ml/min/1.73 m2)
• A: No hypertension
• B: Controlled hypertension on ? 1 antihypertensive medication
• C: Uncontrolled hypertension on ? 2 antihypertensive medications or controlled hypertension on more than 1 medication
• D: Uncontrolled hypertension on more than 2 antihypertensive medications
• E: Hypertensive crisis or malignant hypertension
Example score: B (controlled hypertension on ? 1 antihypertensive medication)
5. Renal biopsy:
• A: No recent biopsy or inactive lupus nephritis
• B: Active lupus nephritis with mild to moderate changes on recent biopsy
• C: Active lupus nephritis with severe changes on recent biopsy
• D: Proliferative lupus nephritis on recent biopsy or biopsy not performed due to contraindications
• E: Advanced sclerotic changes on recent biopsy or biopsy showing advanced glomerular or tubulointerstitial changes
Example score: A (no recent biopsy or inactive lupus nephritis)
6. Other renal features:
• A: No other renal features
• B: Renal thrombotic microangiopathy or drug-induced interstitial nephritis
• C: Severe acute kidney injury requiring hospitalization or renal vein thrombosis
• D: Chronic kidney disease stage 4 or 5 or renal artery stenosis or renal transplant dysfunction
• E: Renal infarction or renal artery aneurysm or vasculitis or malignant hypertension
Example score: A (no other renal features)
To calculate the total score for the renal component of the BILAG updated scoring 2010, you need to assign a numerical value to each of the five possible scores (A-E) for each of the six domains (proteinuria, hematuria, renal function, hypertension, renal biopsy, and other renal features). The numerical values are as follows specific for each renal domain:
• A: 0
• B: 1
• C: 2
• D: 3
• E: 4
Once the numerical value is assigned to each of the scores, the sum of the domain scores is obtained as final value of the total renal score.
We have not to be confused by the letter A to E increasing is severity assigned on each renal domain , with the sum of all the domains categorised inversely A to E decreasing in severity.
The categories for the total BILAG 2010 index are as follows:
• A: Total score of 12, indicating severe disease activity
• B: Total score of 8-11, indicating moderate disease activity
• C: Total score of 1-7, indicating mild disease activity
• D/E: Total score of 0, indicating no disease activity, in other term D and E do not need to escalate the treatment to decide for “intention to treat”, see below for comprehensive approach)
Here’s an example of how to do this based on the scores from the previous example:
Proteinuria: B (score = 1) Hematuria: C (score = 2) Renal function: C (score = 2) Hypertension: B (score = 1) Renal biopsy: A (score = 0) Other renal features: A (score = 0)
Total renal score = 1 + 2 + 2 + 1 + 0 + 0 = 6
So the total score for the renal component in this example is 6, which falls into the category of “mild renal involvement (mild disease activity)” which is categorised as C.
This indicates that there is renal involvement of mild significance but it is not as severe as the higher or highest categories. This brings to attention to the physician to treat accordingly, a score that aims to the intention to treat. It is important to note that the interpretation of the scores should be done in the context of the individual patient’s clinical presentation and overall disease activity.
Intention To Treatment
Based on treatment options:
Scoring is based on the principle of the physician’s intention to treat, in which
– category A (for activity) implies severe disease activity requiring systemic high-dose oral glucocorticoids (equivalent to prednisolone at > 20 mg/dl), systemic immunomodulators, or high-dose anticoagulation;
– category B (for beware) implies moderate disease activity requiring systemic low-dose oral glucocorticoids (equivalent to prednisolone at ? 20 mg/dl), intramuscular/intraarticular or soft tissue glucocorticoid injection, or topical glucocorticoids, topical immunomodulators, or antimalarials; and
– category C (for contentment) implies mild disease,
– category D (for discount) implies for inactive disease but previously affected, and
– category E (for never, ever active) implies system never involved.
For the target of remission and intention to treat we retain the most important of above categories:
A- Severe disease activity requiring any of the following treatment
1. systemic high dose oral glucocorticoids (equivalent to prednisolone > 20
2. intravenous pulse glucocorticoids (equivalent to pulse methylprednisolone ? 500 mg)”,
3. systemic immunomodulators (include biologicals, immunoglobulins and plasmapheresis)”,
4. therapeutic high dose anticoagulation in the presence of high dose steroids or immunomodulators. eg: warfarin with target INR 3 – 4″
B- Moderate disease activity requiring any of the following treatment
1. systemic low dose oral glucocorticoids (equivalent to prednisolone ? 20 mg/day)”,
2. intramuscular or intra-articular or soft tissue glucocorticoids injection (equivalent to methylprednisolone < 500mg)”,
3. topical glucocorticoids
4. topical immunomodulators
5. antimalarials or thalidomide or prasterone or acitretin
6. symptomatic therapy. eg: NSAIDs for inflammatory arthritis
C- Mild disease activity is manageable according to organ involvement and intention to treat.
References BILAG 2004
1. Chee-Seng Yee , Lynne Cresswell , Vernon Farewell, Anisur Rahman, Lee-Suan Teh, Bridget Griffiths, Ian N. Bruce, Yasmeen Ahmad, Athiveeraramapandian Prabu, Mohammed Akil, Neil McHugh, David D’Cruz, Munther A. Khamashta, David A. Isenberg and Caroline Gordon.
2. D. A. Isenberg, A. Rahman, E. Allen, V. Farewell et al. BILAG 2004. Development and initial validation of an updated version of the British Isles Lupus Assessment Group’s disease activity index for patients with systemic lupus erythematosus. Rheumatology 2005;44:902–906
3. Yee CS, Farewell V, Isenberg DA et al. The BILAG- 2004 index is sensitive to change for assessment
of SLE disease activity. Rheumatology 2009;48:691–5
4. Cresswell L, Yee CS, Farewell V et al. Numerical scoring for the Classic BILAG index. Rheumatology 2009;48:1548–52.
5.Michelle Petri, Nuntana Kasitanon, Shin-Seok Lee, Kimberly Link, Systemic lupus international collaborating clinics renal activity/response exercise: development of a renal activity score and renal response index. Arthritis Rheum 2008 Jun;58(6):1784-8
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