Immunogenicity of repeat COVID-19 mRNA vaccinations in a patient with myasthenia gravis receiving mycophenolate, prednisone, and eculizumab

Vaccination can prevent infection and disease due to SARS-CoV-2. Early reports indicate that immune suppressed or immune compromised populations have reduced immune responses to US emergency use authorized (EUA) vaccines. Patients with autoimmune disorders are at risk for severe COVID-19, and are frequently immune suppressed related to therapy, the underlying disease, or both. Myasthenia gravis (MG) is an autoimmune disorder characterized by antibodies that interrupt neuromuscular transmission. Chronic immune suppressive therapy is typically required. We report the case of a 74 year old woman with MG receiving mycophenolate, prednisone, and eculizumab in whom mRNA vaccination failed to elicit detectable circulating vaccine-specific IgG or IFN-γ T cell responses. Eculizumab was discontinued, and repeat vaccination with two doses of an alternative EUA mRNA vaccine led to circulating IgG specific for the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein, and to detectable S-specific T cell responses. While it is not known if these responses will protect against SARS-CoV-2 infection or disease, a repeat course of mRNA vaccination appears to be safe and was broadly immunogenic in this individual.

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T and B cell immune responses to SARS-CoV-2 mRNA vaccine reduced in an immune suppressed patient.

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Repeat vaccination course with an alternative mRNA vaccine led to detectable, specific T and B cell responses.

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Persons with autoimmune disease receiving immune suppression may benefit from additional doses of vaccine.

The role of mycophenolate in the treatment of antineutrophil cytoplasmic antibody-associated vasculitis

Mycophenolic acid, the active metabolite for mycophenolate mofetil and mycophenolic sodium, is a strong, noncompetitive, reversible inhibitor of inosine monophosphate dehydrogenase, the key enzyme in de novo synthesis of guanosine nucleotides leading to selective inhibition of lymphocyte proliferation. Mycophenolic acid has been evaluated as induction and remission maintenance agent in the treatment of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Since the course of disease of AAV usually requires long term immunosuppression, mycophenolate has been explored as a less toxic agent compared to cyclophosphamide and azathioprine. Mycophenolate is a potent immunosuppressive agent in the therapy of AAV, non-inferior to other available drugs with comparable side effect profile. Therefore, it could be a valuable alternative in cases of toxicity with life threatening side effects or intolerance to cyclophosphamide or azathioprine, in cases with high cumulative dose of cyclophosphamide, but also in cases with insufficient response. Several studies have shown a higher relapse rate following discontinuation of mycophenolate or in mycophenolate treated subjects that raises concerns about its usefulness in the treatment of AAV. This review describes the efficacy of mycophenolate in AAV as remission induction agent, as remission maintenance agent, and as therapeutic option in relapsing AAV disease, the relapse rate following discontinuation of mycophenolate, and the adverse events related to mycophenolate treatment.

Nonlinear relationship between enteric-coated mycophenolate sodium dose and mycophenolic acid exposure in Han kidney transplantation recipients

The aim of the research was to investigate the pharmacokinetics (PK) of enteric-coated mycophenolate sodium (EC-MPS) by quantification of the active metabolite of mycophenolic acid (MPA) after multiple escalating oral doses in Han kidney transplant recipients. A total of 28 Han postoperative kidney transplant recipients were given a multiple-dose of 540, 720 or 900 mg of EC-MPS two times a day in combination with tacrolimus for 6 days. Blood specimens were collected at each time point from 0 to 12 h after EC-MPS administration. MPA plasma concentrations were measured by UPLC—UV. The relationship between the EC-MPS dose and its PK parameters was assessed. In the range from 540 to 900 mg, C_max and AUC_0—12h did not increase with dose escalation. The AUC_0—12h, C_max, C₀ and T_max for the 540 720 and 900 mg doses were not significantly different, respectively (P >0.05). AUC_0—12 h and C_max were increased less than proportionally with increasing EC-MPS dose levels. Inter-individual variability in AUC_0—12h, C_max and C₀ were considerable. Nonlinear PK relationships were found from the doses of 540–900 mg of EC-MPS.

Unusual Case of Acute Lung Injury in a Renal Allograft Recipient

A renal allograft recipient developed cough with hemoptysis on the 1^st postoperative day. A chest X-ray was performed which was suggestive of fluid overload. His fluid was restricted and diuretics were added. On the same day, his pulmonary infiltrates worsened and a computed tomography (CT) of the chest was carried out, which was suggestive of the right lower lobe consolidation and left pleural effusion. He underwent a bronchoscopy and the lavage was sent for cultures, which did not grow any infective organism. Besides routine antibiotics, treatment for possible cytomegalovirus, fungal infections, and pneumocystis infection was instituted. Noninvasive ventilation was started on day 8. A repeat CT of the chest on the postoperative day 8 showed further worsening of the pulmonary infiltrates. As all the initial cultures and serology were negative, a possibility of interstitial pneumonitis was considered. Mycophenolate sodium was considered as a possible cause of the lung infiltrates and was withdrawn. The patient showed progressive improvement. His antibiotics were withdrawn. He was discharged on day 14. A repeat CT 4 weeks post transplant showed significant improvement in his pulmonary pathology. The acute lung injury was considered to be a drug reaction secondary to mycophenolate sodium. In a renal allograft recipient with persistent pulmonary infiltrates, interstitial involvement secondary to drugs should be considered if the patient does not improve with the standard treatment measures.