Can Kidney Biopsies Predict Outcomes for Lupus Patients with Kidney Disease?
Arthritis & Rheumatism, Volume 54, Issue 11, October 30, 2006, Pages 3633-3639
Hepatocyte growth factor and transforming growth factor 1 ratio at baseline can predict early response to cyclophosphamide in systemic lupus erythematosus nephritis
Lupus researchers continue to search for ways to anticipate the course of the disease, whether it will progress or improve, what organs may become involved, how patients will respond to treatment. Taking cues from studies about diabetic kidney disease, a team of investigators in Rome focused on two molecules that can be measured in kidney biopsies as possible clues to predict outcomes for lupus patients with kidney disease (lupus nephritis).
The two molecules studied were "hepatocyte growth factor" (HPG), a protein that is involved in stimulating different kinds of cells and tissue repair, and "transforming growth factor beta 1" (TGF1), which is involved in regulating the production of HPG as well as other functions that might keep a tissue in balance. In people with diabetes who have kidney disease, the balance between these two has been shown to influence the outcome of the disease. The researchers suspected that the same could be true of lupus-related kidney disease.
Thirty-six lupus patients with new, active kidney flares were studied. A kidney biopsy was performed on each of the patients at their baseline visit. Each patient had a kidney biopsy before they were treated with anything other than low to moderate doses of steroids or antimalarials. After the biopsy and determination of the level of kidney disease, 25 of the patients were treated for six months with cyclophosphamide (brand name Cytotoxan®) and steroids. These 25 patients were divided on the basis of those who got better after the treatment (responders) and those who did not (non-responders).
The responders had more HGF, while non-responders had higher TGF1. The ratio of HGF to TGF1 at the time of the first biopsy was higher in the responders: in 17 of 18 responders, this ratio was ≥1, whereas only one of seven non-responders had this ratio. Nothing else that was measured in this study (other than age) produced distinctions between the responder and non-responder groups.
These findings indicate that baseline measurement of these two factors might help to predict which patients will be more responsive to treatment with cyclophosphamide. It is possible that with further study these measurements might be used to help guide the dosing of this treatment, and/or select patients who might be better off with alternative treatments. This would be a marked advance in the treatment of lupus, since patients and their doctors currently may have to wait a number of months to determine if a certain treatment (or amount of treatment) is going to work to halt the kidney disease, and some of the tests that are relied on to help determine how a patient is doing can be misleading.
Connect with Us: