Preliminary Assessment of a Newly Designated Predictive Index for Relapse in a Treated Cohort of IgG4 -RD Egyptian Patients
Background: IgG4 related disease (IgG4-RD) is systemic fibroinflammatory condition characterized by remissions and relapses. Glucocorticoids and rituximab are used for inducing remission. The duration of remission variable and the current predictors of relapse are insufficient and depend mainly on laboratory measures ignoring the clinical picture of the patient.
Objectives: At our center, we adopt 6 measures in a newly designated index to predict any relapse of the disease after treatment of IgG4-patient. The Objective of this prospective study is a preliminary assessment of this index in predicting the disease relapse.
Methods: In a prospective cohort study, during the period of June 2015 till June 2017. 25 Egyptian patients full filing the clinicopathological criteria for diagnosis of IgG4-RD in Kobri El-Kobba medical military complex, are included in the study. Of them, 21 patients are treated by glucocorticoids and 4 by rituximab 2 doses of 1gm with 15 days in between. At our center, we adopt using 6 measures in a newly designated prediction index for relapse extending the benefits of the current predictors of relapse which are mainly laboratory. The new index, which is named for simplicity (Saadany index) after the surname of the author, consists of a very trusted measure based on a clinical bases which is IgG4 responder index (IgG4- RI) and a questionnaire of the patient assessing the well-being and the daily activity in addition to the laboratory predictor parameters of elevated IgE titer, circulating eosinophils, circulating plasma blasts by flow cytometry gated to CD138, CD38, CD20, IgG4 titer. Estimation of the score is as follows,4 points to IgG4-RI, and 1 point to any other elevated element of the other parameters than the baseline before treatment to make the sum at its maximum 9 points. Measurements are done after 1 month of the end of glucocorticoid treatment and 6 months of the end of rituximab treatment respectively and then once quarterly for the rest of 2 years.
Results: 17 patients of the 21 (80.9%) treated with glucocorticoids that had a score less than 3/9 didn’t relapse. 4 patients (19%) who had a score more than 3/9 developed a relapse. 2 of them (50%) which had a score 6,7 respectively developed multisystem relapse. 4 patients of 25 included in the study are treated with rituximab, 3 of them which had a score less than 3/9 didn’t relapse and the other (25%) who had a score 5/9 relapsed.
Conclusion: Up to our experience at our center, the use of this simple, easy applicable, mixed clinical and investigative measurement index, predicts well the possibility of relapse after treatment of a cohort of IgG4-RD patients either by glucocorticoids or rituximab and the higher scores are associated with a multisystem relapse. Further research probably a large multicenter prospective study is recommended for more accurate evaluation.