Table 3.
Association between renal parameters and BK viruria, APOL1, and additive effect of (BK viruria + APOL1 [recessive])
| Outcome | Adjustment | Association with BKV | Association with APOL1 (rec) | Association with (BKV+APOL1)1 | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Estimate | SE | P-value | Estimate | SE | P-value | Estimate | SE | P-value | ||
| Log(UACR+1) | None | 0.04 | 0.07 | 0.5433 | −0.15 | 0.04 | 0.0009 | - | - | - |
| Log(UACR+1) | Full | 0.06 | 0.07 | 0.3856 | −0.16 | 0.04 | 0.0004 | - | - | - |
| Log(Cystatin-C) | None | 0.02 | 0.37 | 0.9504 | −0.55 | 0.23 | 0.019 | −0.39 | 0.19 | 0.048 |
| Log(Cystatin-C) | Full | 0.16 | 0.36 | 0.6528 | −0.86 | 0.22 | 0.0002 | - | - | - |
| MDRD GFR | None | −2.92 | 5.2 | 0.5768 | 7.44 | 3.25 | 0.0261 | 4.43 | 2.72 | 0.1094 |
| MDRD GFR | Full | −4.33 | 5.35 | 0.4217 | 7.76 | 3.31 | 0.0231 | 4.26 | 2.76 | 0.1289 |
| CKD-EPI GFR | None | −2.47 | 5.19 | 0.6365 | 8.75 | 3.28 | 0.0099 | 5.44 | 2.74 | 0.0516 |
| CKD-EPI GFR | Full | −3.73 | 5.37 | 0.4908 | 8.68 | 3.34 | 0.0124 | 5.04 | 2.78 | 0.0758 |
| Kidney disease | None | 0.35 | 0.43 | 0.4111 | −0.72 | 0.26 | 0.0068 | - | - | - |
| Kidney disease | Full | 1.05 | 0.54 | 0.0554 | −1.74 | 0.37 | 1.3E-06 | - | - | - |
| UACR > 30 mg/g | None | 0.49 | 0.43 | 0.2568 | −0.58 | 0.27 | 0.0337 | - | - | - |
| UACR > 30 mg/g | Full | 1.09 | 0.53 | 0.0414 | −1.33 | 0.34 | 0.0001 | - | - | - |
Test was performed only when equality of the independent APOL1 and JCV effects were demonstrated (- denotes inequality);
p-values reflect the additive (BKV + APOL1) variable for association with each outcome, based on the Estimate [beta coefficient]
BKV – BK polyoma virus; SE – Standard Error; rec – recessive genetic model; MDRD Modification of Diet in Renal Disease; GFR glomerular filtration rate (units are ml/min/1.73m2); UACR urine albumin:creatinine ratio
Kidney disease defined as MDRD GFR <60 ml/min/1.73m2 and/or urine albumin:creatinine >30 mg/g
Full model adjusted for ancestry, gender and age difference between subject and the ESRD proband in their family
Linear and generalized linear mixed models were fitted to adjust for familial relationships using the expected kinship matrix. The ‘burden’ test (BKV+APOL1) was conducted when we could not reject the null hypothesis that BKV and APOL1 had the same effect on the outcome.