Manasseh Miclea v. HHS - MMR, hemophagocytic lymphohistiocystosis (HLH) (2004)

On June 14, 2001, Manasseh Miclea's mother, Emma Hart, filed a petition under the National Childhood Vaccine Injury Act of 1986, alleging that the measles-mumps-rubella (MMR) vaccination Manasseh received on April 10, 1999, caused his death from hemophagocytic lymphohistiocytosis (HLH). Manasseh, born January 1, 1998, was described as a normal, healthy child for his first 15 months.

Following the April 10, 1999, vaccinations, he developed a rash and fever over the next several days. He was seen by his pediatrician on April 22, 1999, with symptoms that the pediatrician noted were likely either a viral exanthem or an MMR reaction.

Over the following two weeks, his condition worsened, with symptoms including crying, fever, vomiting, a red throat, rash, and swollen gums. He was hospitalized on May 9, 1999, and remained hospitalized until his death on June 20, 1999.

The cause of death, hemophagocytic lymphohistiocytosis (HLH), was undisputed. HLH is a rare, often fatal disease of infancy involving an overreactive immune system, believed to be triggered by stimuli such as active infections producing cytokines.

The Special Master denied compensation, finding that while the timing of Manasseh's symptoms was consistent with an MMR reaction and that vaccines could trigger HLH (citing prior cases Ackley and Gall), the evidence indicated that Manasseh's HLH was likely triggered by an Epstein-Barr virus (EBV) infection. The Special Master relied on statistical evidence that EBV is the most common cause of HLH and credited the testimony of the respondent's expert, Dr.

Berger, over the petitioner's expert, Dr. Byers, and Manasseh's personal physician, Dr.

Stanton. Dr.

Berger's conclusion was based on a bone marrow biopsy showing occasional EBER-positive cells (suggesting prior exposure) and a positive PCR test for EBV genetic material. However, two contemporaneous antibody tests indicated Manasseh was not producing antibodies to EBV, suggesting no active infection.

The Special Master acknowledged these negative antibody tests gave him "pause" but credited Dr. Berger's testimony that some EBV-related HLH cases do not show an antibody response.

The Special Master also gave weight to the reports of hospital physicians who concluded EBV was the likely trigger, although one physician, Dr. Lindquist, later clarified in a letter that it remained unclear what triggered Manasseh's HLH and that his treatment would not have changed regardless of the trigger.

The Court of Federal Claims, on May 3, 2004, vacated the Special Master's decision and remanded the case. The court held that the Special Master's reliance on probabilistic statistics—using population-level frequency of EBV as an HLH trigger to conclude it was the trigger in this individual case—was contrary to law, citing Knudsen v.

Secretary of Health & Human Services. The court instructed the Special Master to reweigh the remaining evidence, excluding the statistical reasoning, to determine if the MMR vaccine was a substantial factor in causing Manasseh's HLH.

The court noted that the record, even without the statistics, remained mixed but weighted more in the petitioner's favor. The final disposition on remand is not included in this opinion.