24 year-old African-American woman comes to clinic with dyspnea on exertion and nonproductive cough. CXR shows diffuse interstitial infiltration with bilateral ill-defined hazy airspace opacities. CT scan of the lungs show bilateral patchy and ground-glass opacities and tree-in-bud nodular opacities. Laboratory results show normal levels of circulating B cells, very low serum levels of IgG and IgA and elevated levels of serum IgM levels. You diagnosed her pneumonia is due to pneumocystic jirovecii and started her on antibiotics. Her laboratory report should make you think of
