The effect of steroids on lymphocyte profile in primary chronic glomerulonephritis. Empirical or tailored therapy?

Mycophenolate mofetil in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis: a prospective pharmacokinetics and clinical study

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) treatment strategy is based on immunosuppressive agents. Little information is available concerning mycophenolic acid (MPA) and the area under the curve (AUC) in patients treated for AAV. We evaluated the variations in pharmacokinetics for MPA in patients with AAV and the relationship between MPA-AUC and markers of the disease. MPA blood concentrations were measured through the enzyme-multiplied immunotechnique (C(0), C(30), C(1), C(2), C(3), C(4), C(6) and C(9)) to determine the AUC. Eighteen patients were included in the study. The median (range) MPA AUC(0-12) was 50·55 (30·9-105·4) mg/h/l. The highest coefficient of determination between MPA AUC and single concentrations was observed with C(3) (P < 0·0001) and C(2) (P < 0·0001) and with C(4) (P < 0·0005) or C(0) (P < 0·001). Using linear regression, the best estimation of MPA AUC was provided by a model including C(30), C(2) and C(4): AUC = 8·5 + 0·77 C(30) + 4·0 C(2) + 1·7 C(4) (P < 0·0001). Moreover, there was a significant relationship between MPA AUC(0-12) and lymphocyte count (P < 0·01), especially CD19 (P < 0·005), CD8 (P < 0·05) and CD56 (P < 0·05). Our results confirm the interindividual variability of MPA AUC in patients treated with MMF in AAV and support a personalized therapy according to blood levels of MPA.

"Surprise" in the evolution of chronic membranoproliferative glomerulonephritis associated with severe strongyloidiasis under corticotherapy: "hygienic paradox"?

A case of strongyloidiasis in a patient with membranoproliferative glomerulonephritis is reported. In our patient, strongyloidiasis evolved latently and became overt after corticotherapy, and it turned to be a very severe outcome and life-threatening complications, hyperinfection syndrome and upper digestive tract hemorrhage. Besides its well-known complications, steroid therapy may provide real surprises. The association of this therapy with strongyloidiasis may turn an undiagnosed inactive, chronic form of the disease into an active form within the framework of a hyperinfection syndrome which might lead to death. In our case, the diagnosis of strongyloidiasis was established only after duodenal biopsy was performed for upper digestive tract hemorrhage, which revealed the parasite. It should be underlined that under corticotherapy, the patient evolved favorably with regard to glomerular disease, while strongyloidiasis worsened. The outcome was positive after the patient was treated with albendazole and ivermectin. The diagnosis of strongyloidiasis is sometimes difficult to establish due to the fact that eosinophilia may be absent, while commonly utilized stool examinations may be negative. By analyzing our case, it may be assumed that the immune mechanisms involved in strongyloidiasis do not activate the glomerular nephropathy. On the contrary, these mechanisms seem to have an immunosuppressive effect. The "hygienic hypothesis" also needs to be considered. While on corticotherapy, patients with glomerulonephritis need immunologic and parasitologic monitoring. This is important for other immunodepressing diseases and for immunosuppressive drugs. If the patient has originated in a mining area, as is the case with our patient, or in endemic areas, this monitoring becomes mandatory. The case reflects the complexity of the interrelation between the immune mechanisms in glomerulonephritis and those in parasitic diseases, strongyloidiasis in our case.

Treatment of systemic lupus erythematosus in two patients with extreme B-cell lymphopenia: importance of immunomonitoring and avoidance of B-cell targeted therapy

INTRODUCTION

Because dysfunction of the B-cell compartment is thought to be important in the pathogenesis of systemic lupus erythematosus (SLE), there has been a recent focus on therapies that target humoral immunity via multiple mechanisms. The aim of this paper was to demonstrate the importance of immunomonitoring in two cases with class II lupus nephritis on steroids who presented with a flare-up of disease. After a thorough work-up for infectious triggers of disease activity, conversion to another histopathological class of lupus nephritis was suspected. Deterioration of the patients' clinical condition made kidney biopsy impossible, and as B-cell targeted therapy was considered, we decided to perform an immunophenotypic analysis and to tailor therapy to the results of the lymphocyte profile. As we incidentally found extremely low B-cell counts, any B-cell-targeted therapy was prohibited, and cyclophosphamide (Cy) was considered a viable therapeutic option.

METHODS

We performed flow-cytometric lymphocyte (Ly) phenotyping (CD19, CD3, CD3CD4, CD3CD8, CD56/16) on two patients with class II lupus nephritis before and after two intravenous (i.v.) Cy pulse administrations. During all this time, patients were on steroids.

RESULTS

 Both patients showed extreme B-cell lymphopenia, a marker of active SLE, which was not greatly impacted by the treatment over the follow-up period.

CONCLUSIONS

As current therapies are aimed at targeting the B cell, an important component of adaptive immunity, caution must be exercised before their use. In addition, monitoring of Ly subsets is essential due to the occurrence of extreme B-cell lymphopenia.

Prospective study of natural killer cell phenotype in recurrent hepatitis C virus infection following liver transplantation

BACKGROUND/AIMS

Graft re-infection invariably occurs after liver transplantation (OLT) for chronic hepatitis C and disease progression is unpredictable. We prospectively examined peripheral blood mononuclear cells (PBMC) subsets and natural killer (NK) cell receptors (NKRs) in patients with recurrent hepatitis C post-OLT.

METHODS

PBMC were obtained at baseline and at different time points after OLT. NKRs were identified using monoclonal antibodies by flow cytometry.

RESULTS

The proportions of NK, natural T (NT), total and gammadelta T cells were significantly reduced (p<0.01) 7 days post-transplant, probably as a result of graft repopulation. NKG2D+ NK cells were significantly higher compared with healthy controls (p<0.01), declined post-OLT and subsequently returned to baseline values. This, together with a progressive increase in the proportion of CD94/NKG2C+ NK cells over time (p< or = 0.01), appeared to be related to hepatitis C recurrence. There was a statistically significant correlation between expression of the natural cytotoxicity receptors (NCRs) and ALT (p<0.05), supporting the hypothesis that NK cells participate in the necroinflammatory process.

CONCLUSIONS

The data are compatible with homing of immune cells to the liver allograft after surgery, most of which return to pre-OLT levels. HCV recurrence may cause variations in selected NKRs expression akin to other viral infections.