We present a series of 52 patients with chronic kidney disease (CKD) on haemodialysis who presented SARS-CoV-2 infection diagnosed by nasopharyngeal swab polymerase chain reaction (PCR). The inclusion period was from 8 March 2020 until 21 February 2021, in which antibody testing for SARS-CoV-2 was performed during follow-up.

Mean age was 74.7 (±13.7) years, 80.7% were over 65; male sex predominated (73%), 7.6% were active smokers and 28.8% were former smokers. Of the main comorbidities, arterial hypertension (HTN) accounted for 96.1%, diabetes (DM) 69.2%, previous pulmonary disease 32.6%, coronary disease 25%, heart failure 23% and active cancer 3.8%. The most common chronic kidney disease (CKD) aetiologies were diabetic and vascular, followed by undetermined aetiology. A 15.8% had received a kidney transplant and 3.8% were on the transplat waiting list.

The most frequent clinical symptom was fever (75%), followed by cough (42.3%), dyspnoea (40.3%) and GI symptoms (diarrhoea 9.6%, nausea 5.7%). Mean lymphocyte count at admission was 1.23 (±2.0) × 10E9/L and C-reactive protein was 9.3 (±9.2) mg/dL.

The treatment received was lopinavir/ritonavir (57.6%), azythromycin (34.6%), hydroxychloroquine (30.7%), tocilizumab (9.6%), with neither remdesivir nor high steroid doses (Fig. 1).

Figure 1.

Kaplan-Meier survival curve.

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One of the 52 patients was managed as an outpatient. One patient was admitted to the Intensive Care Unit. Mortality was 31.3% (16 patients) due to SARS-CoV-2 pneumonia (31.3%), associated with being male and a smoker. There were no statistically significant differences in relation to the clinical and analytical variables (Table 1).

Of the survivors (36 patients, 68.6%), 19 patients (54.2%) were discharged home and 16 patients (45.6%) were transferred to a community health centre to continue their recovery. SARS-CoV-2 antibodies were determined in 33 patients using the (IgG Ab, Roche Cobas), 31 patients developed SARS-CoV-2 (91.6%) antibodies 39 days (21-104) after infection.

Chronic kidney disease patients on haemodialysis are known to present frequent infections plus a suboptimal response to vaccines, partly due to alterations in both innate and adaptive immunity1,2.

CKD is one of the risk factors that have been associated with greater mortality from SARS-CoV-2 infection3,4, since not only do these patients present immune system alterations, but further exposure to hospital centres renders them more vulnerable to contracting the infection.

Not a great deal is known about humoral response to SARS-CoV-2 infection in patients on haemodialysis. Sakhi et al. reported that seroconversion presented in 89% of the cases at a median 67 days post-diagnosis5, and while these data are similar to our population in terms of seroconversion, the development of antibodies in our cohort occurred earlier, at a median 39 days.

In conclusion, immunological response to SARS-CoV-2 infection in our patients on a haemodialysis programme was good, with seroconversion occurring in the majority of the patients. Nevertheless, this population’s future response to the SARS-CoV-2 vaccine is unknown.