Background
Inflammatory markers like interleukin-1, 6, and 8, transforming growth factor-β (TGF-β)1, and tumor necrosis factor-α have been found to be associated with diabetic nephropathy (DN), indicating that its pathogenesis may be inflammatory. These inflammatory markers are not routinely used, so, creating the need for easily and routinely done markers aim to enhance the prognostic process of diabetic microvascular complications. Lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) can be routinely assessed, in addition to being considered as predictors for the survival of patients in renal diseases and malignancies.
Aim
The aim was to evaluate the prognostic value of LMR in DN of type 2 diabetes mellitus, and to compare it with other ratios: NLR and PLR.
Patients and methods
A case–control study including 100 type 2 diabetes mellitus patients and 25 apparently healthy controls. It was carried out at the inpatient and outpatient clinics, Internal Medicine Department, Al-Azhar University Hospital, New Damietta. Three groups were formed according to urinary albumin-to-creatinine ratio; group I, type 2 diabetics with normoalbuminuria, group II, type 2 diabetics with increased albuminuria, with further division into group IIA: with microalbuminuria/group IIB: macroalbuminuria or overt DN, and group III: controls. Full history, clinical examination, and laboratory tests: urinary albumin-to-creatinine ratio and complete urine analysis, complete blood count with assessment of LMR, NLR, and PLR, beside, blood sugar, HbA1c, renal function with assessment of estimated glomerular filtration rate, liver function, abdominal ultrasonography, fundus examination, and ECG were done for all the participants.
Results
The LMR mean was 2.4/2.8/3.2/2.1 in group I/IIA/IIB/III, respectively, showing the increasing ratios in parallel with the progression of DN severity and albuminuria through the groups, with the highest ratios in group IIB of overt DN. The NLR mean was 1.8/2.9/3.7/1.2 and the PLR mean was 175, 8/249, 2/277, 3/108, 3 in the corresponding group. Receiver operating characteristic curve analysis for ratios between groups I and IIA demonstrated that with a best cutoff point of 2.66 for the LMR, the sensitivity was 44%, the specificity: 92% (the ability of the LMR to predict DN risk); 2.2 for the NLR, the sensitivity: 84%, the specificity: 98%; 207 for the PLR, the sensitivity: 72%, and the specificity: 80%. So, in predicting the DN risk, NLR came first as regards the specificity followed by LMR and then PLR, but followed by PLR and then LMR as regards the sensitivity.
Conclusion
LMR may be considered as a surrogate inflammatory marker for DN in early stages and in between stages, but it is not better than NLR as a screening tool for DN diagnosis.