Pathophysiology of Vesicoureteral Reflux

Vesicoureteral reflux is the abnormal backflow of urine from the bladder to the ureter and/or kidney. When the affected individual voids, the urinary bladder contracts. The urine is supposed to leave through the urethra, but if the vesicoureteral junction is abnormal some urine will be forced back up into the ureter. How bad is the junction? How much urine goes up rather than down? These are the questions that determine the grading of reflux, established by the International Reflux Grading system.

Pathophysiology of Polycystic Kidney Disease

In my continuing quest to understand the actual "why" and "how" behind all pediatric conditions, today I will be working on one of the cystic dysplasias of the kidney - autosomal recessive polycystic kidney disease (ARPKD). This condition results from a mutation in the PKHD1 gene at chromosomal locus 6p12.2. This gene's product, fibrocystin, is found in kidney, liver, and pancreas (this helps you remember the organs involved in ARPKD)

As a reminder, autosomal dominant polycystic kidney disease (ADPKD) is the ADULT type (see what I did there?)

Pediatric Infectious Disease Questions

A 1-year-old boy presents with recurrent otitis media, pneumonitis, and sinusitis. The physical examination reveales bilateral otitis media, but no cervical lymph nodes are palpable and the tonsils are not visible. This picture is most compatible with a picture of:
a. Selective IgA deficiency
b. Chronic granulomatous disease
c. DiGeorge syndrome
d. X-linked agammaglobulinemia
e. C2 complement definciency


The triad of eczema, thrombocytopenia, and recurrent infections is characteristic of:
a. Chediak-Higashi syndrome
b. Wiskott-Aldrich syndrome
c. Common variable hypogammaglobulinemia
d. Hyper-IgE syndrome
e. Adenosine deaminase deficiency

A 2-year-old boy presents with a history of protracted lymphadenitis, cavitary pneumonitis, and organomegaly. The single best test to diagnose his immunodeficiency is:
a. CH50
b. Quantitative immunoglobulin measurement
c. Isohemagglutinin titers
d. Delayed hypersensitivity skin testing
e. Nitroblue tetrazolium dye reduction test

Infusions of interferon-gamma are especially helpful for patients with:
a. Hyper-IgM syndrome
b. Ataxia-telangiectasia
c. Chronic granulomatous disease
d. Severe combined immunodeficiency
e. Leukocyte adherence deficiency

The best screening test for immunodeficiency in a patient after her second episode of meningococcal meningitis is:
a. Quantitative immunoglobulin measurement
b. CH50
c. Determination of T-cell subsets
d. Determination of IgG subclasses
e. Nitroblue tetrazolium dye reduction test

Your patient requires a blood transfusion. In which condition must the blood be irradiated?
a. Chronic granulomatous disease
b. DiGeorge syndrome
c. X-linked agammaglobulinemia
d. Selective IgA deficiency
e. C3 deficiency