Phenotype Information for MRL-lpr (000485)

MRL/MpJ-Faslpr/J mice (MRL-lpr; Strain 000485) develop an autoimmune disease resembling systemic lupus erythematosus (SLE) due to a mutation (Faslpr) that promotes survival of self-reactive lymphocytes, and a strain background (MRL/MpJ; Strain 000486) predisposed to autoimmunity.  Both sexes develop disease, although it is accelerated and more severe in females.  Disease characteristics in MRL-lpr include:

  • Lymphoproliferation by 16-18 weeks in females and 18-20 weeks in males (Table 1)
  • Progressive renal failure, as indicated by urine albumin:creatinine ratios that increase with age (Table 2)
  • Lymphadenopathy and skin lesions (Table 3)

Table 1 Blood counts.  Submandibular blood was collected in EDTA-coated microtainers and analyzed using an Advia 2120 hematology analyzer in a longitudinal study of MRL-lpr and MRL/MpJ control mice. Values indicate the median white blood cell count (x103cells/μL); range and sample sizes are shown in parentheses.

Strain MRL/MpJ-FaslprJ MRL/MpJ
Age (weeks) Female Male Female Male
6 3.5 (2.5 - 4.8; N=9) 3.3 (2.0 - 3.7; N=9) 5.4 (3.9 - 6.3; N=5) 4.3 (2.5 - 5.4; N=5)
8 3.5 (2.6 - 5.0; N=9) 3.2 (2.1 - 4.2; N=10) 5.4 (4.0 - 6.6; N=5) 4.8 (4.0 - 5.7; N=5)
10 3.8 (2.2 - 4.6; N=9) 3.0 (1.8 - 4.1; N=10) 4.9 (4.6 - 6.3; N=5) 3.7 (3.3 - 6.6; N=5)
12 3.0 (2.2 - 3.9; N=8) 3.7 (2.9 - 5.0; N=10) 5.2 (3.1 - 6.9; N=5) 3.1 (2.8 - 3.9; N=5)
14 4.2 (3.1 - 6.3; N=8) 4.2 (2.8 - 7.3; N=8) 5.0 (3.4 - 6.2; N=5) 4.5 (2.8 - 6.0; N=5)
16 5.5 (3.4 - 14.5; N=8) 4.0 (2.8 - 7.4; N=9) 3.7 (2.7 - 5.4; N=5) 4.9 (3.2 - 6.5; N=5)
18 9.2 (2.2 - 29.5; N=7) 6.1 (3.6 - 9.7; N=9) 4.6 (3.6 - 6.4; N=5) 5.3 (3.2 - 6.2; N=5)
20 9.8 (9.2 - 12.1; N=3) 6.6 (4.1 - 15.8; N=8) 4.0 (2.4 - 5.1; N=5) 3.6 (2.7 - 4.6; N=5)
22 No mice remaining 5.7 (4.2 - 14.6; N=9) 3.7 (2.3 - 4.6; N=5) 3.1 (2.1 - 6.1; N=5)
24 No mice remaining 5.9 (3.4 - 17.1; N=8) 3.7 (2.4 - 4.7; N=4) 4.1 (3.6 - 5.7; N=5)

Table 2 Urinalysis.  Urine was analyzed using a Beckman Coulter AU680 chemistry analyzer in a longitudinal study of MRL-lpr and MRL/MpJ control mice.  The albumin:creatinine ratios (mg/g) were grouped by age, sex and strain into ranges (< 10, 10 -100, >100).  The median values are also provided. 

    Age (weeks)
Strain   Albumin:Creatinine ratio 5 7 9 11 13 15 17 19 21 23
MRL-lpr Females Number of mice in range < 10 3 0 1 0 3 3 0 0 - -
10 - 100 6 9 8 8 3 2 0 0 - -
> 100 1 1 1 1 3 4 8 3 - -
Total # Mice 10 10 10 9 9 9 8 3 - -
Median Ratio 14 28 17 38 57 47 535 957 - -
MRL-lpr Males Number of mice in range < 10 3 0 0 0 4 7 0 0 0 0
10 - 100 7 10 10 10 4 1 6 6 4 3
> 100 0 0 0 0 0 1 2 3 5 4
Total # Mice 10 10 10 10 8 9 8 9 9 7
Median Ratio 12 21 26 38 10 0 31 84 110 195
MRL/MpJ Females Number of mice in range < 10 0 1 2 1 3 4 0 0 0 0
10 - 100 5 4 3 4 2 0 5 3 3 2
> 100 0 0 0 0 0 0 0 1 0 1
Total # Mice 5 5 5 5 5 4 5 4 3 3
Median Ratio 26 30 13 20 6 0 24 56 24 33
MRL/MpJ Males Number of mice in range < 10 0 0 0 1 3 5 0 0 0 1
10 - 100 5 5 5 4 2 0 5 5 5 3
> 100 0 0 0 0 0 0 0 0 0 0
Total # Mice 5 5 5 5 5 5 5 5 5 4
Median Ratio 50 44 22 32 6 0 31 38 39 33

Table 3 Overt signs of disease.  Male (M) and female (F) MRL-lpr mice were assessed weekly in a longitudinal study for the presence of enlarged lymph nodes and skin lesions.  Columns indicate the percentage of mice displaying the indicated phenotype; rightmost column indicates the number of mice assessed.  

Lymphadenopathy Skin Lesions # Mice
Cervical Axillary Inguinal Interscapular Ears
Age (weeks) M F M F M F M F M F M F
Up to 10 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 39 39
11 0% 38% 0% 5% 0% 0% 0% 0% 0% 0% 39 39
12 18% 46% 0% 10% 0% 0% 0% 0% 0% 0% 39 39
13 26% 55% 0% 26% 0% 3% 0% 3% 0% 3% 39 38
14 51% 74% 10% 61% 5% 34% 0% 3% 0% 3% 39 38
15 79% 95% 56% 82% 5% 87% 3% 18% 3% 3% 39 38
16 87% 89% 69% 92% 15% 97% 3% 19% 5% 22% 39 36
17 92% 94% 89% 94% 21% 89% 8% 37% 5% 29% 38 35
18 95% 94% 92% 94% 29% 94% 8% 53% 8% 35% 38 34
19 95% 93% 92% 97% 37% 97% 8% 45% 8% 24% 38 29
20 78% 100% 72% 100% 31% 100% 0% 50% 3% 0% 32 10
21 93% 100% 89% 100% 41% 100% 0% 0% 7% 0% 27 2
22 96% 92% 88% 0% 8% 24 0
23 100% 100% 91% 0% 9% 23 0
24 100% 100% 90% 0% 10% 23 0