Post-Transplant Parvovirus B19-Associated Anemia Management

In a case study published in Pediatric Nephrology, Mehmet Sabanci and others described a 13-year-old female kidney transplant recipient who presented 4 weeks after the surgery with a 10-day history of fatigue, headache, and paleness. Lab testing found that the patient had severe anemia and was positive for parvovirus B19 (PVB19).

The patient had a leukocyte count of 3.88 K/uL, polymorphonuclear leukocyte count 2.82 K/uL, hemoglobin 6.7 g/dL, and platelet count 123.00 K/uL. Her blood urea nitrogen was 11.00 mg/dL, serum creatinine 1.11 mg/dL, albumin 4.1 g/dL, sodium 139.0 mmol/L, potassium 4.1 mmol/L, serum tacrolimus 10.0 ng/mL, and CRP 0.10 mg/dL. Urinalysis found absence of protein, leukocytes, erythrocytes, or glucose.

The patient reported headache and fatigue at 6 weeks of follow-up. She was receiving prednisolone 5 mg, tacrolimus 2 mg, and mycophenolate mofetil (MMF) 1500 mg; the latter was dropped to 600 mg/m²/day due to the patient’s leukopenia and severe anemia. She received two units of red blood cells, but the anemia persisted for the next 2 weeks. She again tested positive for PVB19, with more than 50 million IU/mL copies. Parvovirus immunoglobulin M was positive (1.40), while parvovirus immunoglobulin G was negative. Her MMF dosages were gradually tapered.

Two months later she received a course of intravenous immunoglobulin (IVIG; 0.5 g/kg four times over a month) due to persistent severe anemia (hemoglobin 5.3 g/dL) and high viral load (PVB19, >50 million IU/mL). Despite low-dose immunosuppression and IVIG treatment, during 11 months of subsequent follow-up the patient required another 10 units of red blood cells.

At 12 to 16 months post-transplantation, the patient received IVIG four times at a dose of 0.5 g/kg. Her viral load declined to 140.800 IU/mL copy number, but she still experienced severe anemia and required red blood cell transfusions five times in 4 months. At 16 months post-transplant, MMF was replaced with the mammalian target of rapamycin (mTOR) inhibitor everolimus, after which her hemoglobin level improved significantly, from 5.0 g/dL to 11.9 g/dL within 2 months; no further red blood cell transfusion was needed.

Kidney transplant recipients may be at a higher risk of developing PVB19-related complications, particularly if they received kidneys from donors after circulatory death or are using immunosuppressant agents such as antithymocyte globulin, tacrolimus, or MMF. Unfortunately, there is no universal consensus on how to treat PVB19 infection, although guidelines usually suggest a reduction of immunosuppressants and IVIG administration. Furthermore, there is no consensus on whether to administer a high (2.00 g/kg) versus low (0.25 g/kg) dosage of IVIG. In the reported case, IVIG was given at a high dose but at longer intervals.

A secondary treatment approach is modifying the immunosuppressive regimen. IVIG treatment combined with a reduction of immunosuppressive medication has been reported to be effective in cases of relapsing severe anemia due to PVB19 infection within the first 6 months after kidney transplant. Introducing mTOR inhibitors, everolimus in particular, has also shown promise.

“Guidelines on reducing immunosuppression and potential medication changes in such cases should be developed,” the authors concluded.

Source: Pediatric Nephrology