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:
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 (x103 cells/μL); range and sample sizes are shown in parentheses.
| MRL/MpJ-Faslpr/J | 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. Female (F) and male (M) 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 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cervical | Axillary | Inguinal | Interscapular | Ears | # Mice | |||||||
| Age (weeks) | F | M | F | M | F | M | F | M | F | M | F | M |
| Up to 10 | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 39 | 39 |
| 11 | 38% | 0% | 5% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 39 | 39 |
| 12 | 46% | 18% | 10% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 39 | 39 |
| 13 | 55% | 26% | 26% | 0% | 3% | 0% | 3% | 0% | 3% | 0% | 38 | 39 |
| 14 | 74% | 51% | 61% | 10% | 34% | 5% | 3% | 0% | 3% | 0% | 38 | 39 |
| 15 | 95% | 79% | 82% | 56% | 87% | 5% | 18% | 3% | 3% | 3% | 38 | 39 |
| 16 | 89% | 87% | 92% | 69% | 97% | 15% | 19% | 3% | 22% | 5% | 36 | 39 |
| 17 | 94% | 92% | 94% | 89% | 89% | 21% | 37% | 8% | 29% | 5% | 35 | 38 |
| 18 | 94% | 95% | 94% | 92% | 94% | 29% | 53% | 8% | 35% | 8% | 34 | 38 |
| 19 | 93% | 95% | 97% | 92% | 97% | 37% | 45% | 8% | 24% | 8% | 29 | 38 |
| 20 | 100% | 78% | 100% | 72% | 100% | 31% | 50% | 0% | 0% | 3% | 10 | 32 |
| 21 | 100% | 93% | 100% | 89% | 100% | 41% | 0% | 0% | 0% | 7% | 2 | 27 |
| 22 | - | 96% | - | 92% | - | 88% | - | 0% | - | 8% | 0 | 24 |
| 23 | - | 100% | - | 100% | - | 91% | - | 0% | - | 9% | 0 | 23 |
| 24 | - | 100% | - | 100% | - | 90% | - | 0% | - | 10% | 0 | 23 |