SEROPREVALENCE OF VARICELLA IGG ANTIBODIES IN ADULT CKD POPULATION IN INDIA AND THEIR IMMUNE RESPONSE TO VARICELLA VACCINATION

Introduction:

Infections are common among p withatients chronic kidney disease CKD; outcomes of infections are poor; seroconversion rate to vaccination is less; and antibody titres are lost more rapidly. 

Varicella zoster infection occurs commonly among children. Protective antibodies reduce with aging, permitting reactivation of virus, which manifests as Herpes zoster (HZ). It is safe in patients with CKD. However, varicella vaccine is not mandatory for CKD patients; awareness about varicella vaccine and vaccination rate among CKD patients are less. There are no guidelines for monitoring varicella IgG antibody titres. There are no studies of seroprevalence of varicella antibodies; seroconversion response to vaccine, and sustenance of antibody titres among CKD patients in India. 

Methods:

This was a prospective cohort, including consecutive adult CKD patients having e-GFR of less than 60ml/min, who attended out patient department (OPD) or were admitted in the hospital or were getting dialysed regularly in our unit. Those with other pre-existing immunosuppressed states or malignancy were excluded. They were evaluated with demographic data, medical history and lab investigations. Varicella  IgG antibody titres were checked by Enzyme-Linked Fluorescence Assay(ELFA)  once at recruitment and again during follow up. Those with equivocal and negative antibody titres at recruitment received 1 and 2 doses (4 weeks apart) of varicella vaccine respectively. All data were extracted on to excel sheet and analysed. T-test was applied for significance, p-value of <0.05 was considered significant.

Results:

A total of 175 patients, who fulfilled study criteria and consented were recruited. Their mean age was 64.67 years, 60% were males and  57.14% were on dialysis. None of them had received the varicella vaccine prior to the study. Seroprevalence of varicella antibody was 90.86% (Image 1). Though the proportion of seropositive patients decreased with advancing stages of CKD, even patients on dialysis had 89% seropositivity.  Baseline varicella antibody titres was 2.35 (range 0.01 – 5.61). Varicella IgG antibody titres among those who had HZ prior to recruitment, as compared to those without, was statistically similar (p-0.52). Those who were seropositive at baseline, dropped titres from 2.58 to 2.28 during study period (p<0.01), however none turned seronegative. Seroconversion rate was 46.15%. Increase in the titres among those who received 1 dose (0.91 ;Image 2) despite having higher baseline titres, was lower than those who received 2 doses (1.57) of vaccine. Seroconversion rate was 55.56% among dialysis patients. None of patients developed varicella zoster virus infection during study period.

Conclusions:

Seroprevalence of varicella IgG antibodies was 90.86% among patients with varying stages of CKD; titres gradually reduced with time in CKD patients. Seroconversion with vaccination is poor among CKD patients.  2 doses of the vaccine gave better results than a single dose. 

(The above study was presented in Indian Society of Nephrology congress 2023 held at Kolkata)

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.