Clinical significance of the humoral immune response to modified LDL

Oxidized LDL immune complexes and coronary artery calcification in type 1 diabetes

OBJECTIVE

Oxidized LDL (oxLDL) and oxLDL antibodies form immune complexes (IC) that reflect essential components in the development of atherosclerosis: dyslipidemia, oxidative stress and induction of a pro-inflammatory humoral immune response. We measured oxLDL in IC (oxLDL-IC) isolated from patients with type 1 diabetes to assess the relationship between oxLDL-IC and coronary artery calcification (CAC).

METHODS

OxLDL was measured in IC isolated from baseline samples from a subgroup of 476 patients of the Diabetes Control and Complications Trial (DCCT). CAC was determined by computed tomography (CT) 11-20 years later. Multivariable log-binomial regression models were used to estimate the risk ratios associated with having a high CAC score with an increase of 1 standard deviation (SD) of the natural logarithm of oxLDL-IC.

RESULTS

Multivariable regression models indicate that a 1 SD increase in the levels of oxLDL-IC was associated with a 37% increase in the risk of having high CAC score (RR=1.36; 95% CI: 1.12-1.67) at follow-up after adjustment for DCCT treatment group, retinopathy/AER groups, gender and CT scanning site as well as baseline age, diabetes duration and HbA1C %. Further adjustment for smoking status, blood pressure and LDL resulted in a risk ratio of 1.23 (95% CI: 1.01-1.50) which remained statistically significant indicating that baseline oxLDL-IC is independently associated with the development of CAC.

DISCUSSION

Increased levels of oxLDL-IC are associated with the development of coronary calcification. This observation reinforces previously published clinical and experimental data demonstrating that oxLD-IC has pro-inflammatory and proatherogenic properties.

The association between serum levels of oxLDL-lgG and oxLDL-lgM autoantibody with adult acute myeloblastic leukaemia

AIM

To evaluate the relationship between serum antibodies against ox-LDL levels and adult acute myeloblastic leukemia (AML).

METHODS

Forty three patients with AML and 52 normal controls were enrolled in this study in the Department of Hematology, Tumor Center of Qilu Hospital of Shandong University from Feb. 2008 to Mar.2009. Serum lgG and lgM antibodies versus the oxLDL levels were evaluated by ELISA method. Data was analyzed by covariance and binary Logistic regression.

RESULTS

Serum mean levels of oxLDL-lgG in patients (38.92 +/- 21.1259 ug/ml) were significantly lower than in control subjects (78.88 +/- 9.3705 ug/ml); Meanwhile, Serum mean levels of oxLDL-lgM in patients (20.53 +/- 10.2990 IU/L) were significantly higher than in control subjects (10.29 +/- 10.5771 IU/L). Binary logistic regression showed the odds ratios of association of oxLD-lgG and oxLD-lgM with adult AML were 0.72(95%CI: 0.55-0.94) and 1.11(95%CI: 1.01-1.21) respectively after adjusted for potential confounders.

CONCLUSION

In the preliminary investigation we found a descensive oxLDL- lgG and an elevated oxLDL-lgM serum levels for the adult AML. Future studies need to confirm the hypothesis whether they related to the development and progression of adult AML.