Transition of lymphocyte subsets in peritoneal dialysis effluent and its relationship to peritoneal damage.

Objective: Peritoneal function during peritoneal dialysis (PD) declines over time due to peritoneal inflammation; however, the immunological mechanism has not been fully clarified. Here, we examined changes in each cellular fraction in the peritoneal dialysis effluent by flow cytometry and their relationship to peritoneal damage. Patients and Methods: We enrolled 23 patients who began PD between 2006 and 2017 and had available datasets of the peritoneal equilibration test and flow cytometric analysis for at least three consecutive visits, with an interval of six months from six months after introducing PD. The levels and changes in each cellular fraction, dialysate/plasma (D/P) creatinine ratio, and the forward scatter (FSC) ratio of mesothelial cells to lymphocytes were compared using a simple linear regression analysis. Results: Among the examined variables, only the fraction of CD8+ TCM cells during the first observation was significantly correlated with the change rate in the D/P creatinine ratio (ß=1.47, P=0.001, adjusted R2=0.379). The CD8+ naïve T and CD8+ TCM cell fractions were negatively correlated with the change rate of the D/P creatinine ratio (naïve T cells: ß=-0.058, P=0.022, adjusted R2=0.188; TCM cells: ß=-0.096, P=0.046, adjusted R2=0.137). In addition, the change rates of the D/P creatinine ratio tended to be higher, though not significantly (one way ANOVA; P=0.080), in accordance with the increase in the change rate of the CD8+ effector memory T cells (TEM). Conclusion: The CD8+ naïve T and TCM cells may transition into TEM cells by repeated exposure to the dialysate over time. The TEM cells residing in the peritoneum may play a significant role in the progression of peritoneal damage.

Predominant tubulointerstitial lupus nephritis with preceding pernicious anemia.

Predominant tubulointerstitial nephritis with negligible glomerular lesions is a rare form of lupus nephritis. Although tubulointerstitial changes occur in two-thirds of patients with lupus nephritis, these lesions were mostly accompanied by glomerulonephritis. Predominant tubulointerstitial lupus nephritis has been reported to be only 13 cases in the literature as far as we surveyed. Here, we present a case of a 72-year-old male who had pancytopenia associated with pernicious anemia and later developed a mild proteinuria and renal insufficiency. Although urinary tubulointerstitial markers increased, serological screening tests for tubulointerstitial nephritis were all negative. Three months later, the patient was diagnosed as systemic lupus erythematosus, based on polyarthritis, positive antinuclear antibody, immunological disorder and hematological disorder. Renal biopsy revealed severe infiltration of mononuclear cells in the interstitium with minimal abnormalities in glomeruli. Positive IgG and C1q staining with immunofluorescence antibody method in the tubular basement membrane and dense deposits in the same region with electron microscopy confirmed a diagnosis of predominant tubulointerstitial lupus nephritis. Since the patient's renal function declined rapidly, treatment with intravenous 500 mg methyl prednisolone followed by 40 mg/day of oral prednisolone was initiated. The patient's renal function improved and became stable even after tapering of prednisolone. Although lupus nephritis is generally accompanied by multiple symptoms such as fever, malaise, arthralgia, rashes, this case showed only pernicious anemia and tubulointerstitial nephritis initially.