Immuno Deficiencies

7/28/2019 Immuno Deficiencies

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Micro 11/17/08 1st hour

Infections Associated to Immunodeficiencies, ClinicalCorrelation

Dr. Estrada

Slide 1

This hour, were focusing on infections that you mainly see inimmunodeficient pts. This lecture will be case-based.

Slide 2

This is a child that presents with periorbital cellulitis. Thereis significant inflammation of the periorbital tissues. Thenthe child developed meningitis. He has been immunizedappropriately (pneumonia, influenza, etc.). Because he hasmeningitis, there is a lumbar puncture performed.

Slide 3

Here is a gram stain of the CSF. This is Gram (-) rodmeningitis. In this case, it could be E. coli, but its not. Weusually see this in infants at 1-2 months of age. This isHaemophilus influenza type B. It is very common worldwide.In this country, we dont see this that often anymore due tovaccination. Remember this baby had been immunized, sowhenever you have this condition in a patient that wasimmunized, you have to think about immunodeficiency. Thispatient has a combined Ab deficiency. This is H. influenza

meningitis.

Skip to Slide 5

This is a 15-yo male with a history of cough and recurrentpneumonia. He has had multiple skin and soft tissueinfections with S. aureus. He has an abnormal chest x-ray, soyou do a BAL (broncheoalveolar lavage). This is a gram stainof the bronchial secretions. These are Gram (+) rods. Thereis a limited number of Gm (+) rods. Your differential for Gm(+) rods that can cause pneumonia would include C.

diphtheria (but this pt doesnt have the symptoms ofdiphtheria), Listeria (usually affects very young babies or

older individuals, but it doesnt look filamentous like thispicture does), Bacillus (anthrax), etc. Clostridium rarelycauses pneumonia. This patient has Nocardia. Nocardiausually causes infections in immunocompromised people. Itcan cause localized cutaneous infections inimmunocompetent people, but in general, a patient withNocardia pneumonia will have an immunodeficiency. Oneprimary immunodeficiency you would need to rule out here isChronic Granulomatous Disease (CGD) because is a male andbecause he has also had chronic S. aureus infections. Thetreatment for this condition isTrimethoprim/Sulfamethoxazole.

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This is a 4-yo presenting with fever and cough. He has hadprevious episodes of bacteremia caused by the sameorganism that is now causing the fever and cough. The chestx-ray shows consolidation in the right lung. When you see

this, you have to suspect some type of bacterial pneumonia.This patient has bacteremia. The organism shown in the toppicture is Streptococcus. These are Gm (+) diplococci. Thetype of Strep that is most likely diplococci is Streptococcuspneumoniae. This pt had a prior infection with this sameorganism. This is rather unusual. The immunodeficiencyassociated with these recurrent invasive infections with S.pneumoniae is a complement deficiency. This is easy toscreen for. Also, you should consider an Ab deficiency. IgA isthe most common Ab deficiency. You can easily test forthese as well.

Slide 6

This is just to remind you that CGD can be associated withunusual organisms, which in this case, caused abdominalabscesses. This one is caused by Candida.

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This is a child that has had recurrent infections caused by thesame organism for the last two years. On this childs hand is

a sore that has a dark area in it. This is necrotic tissue. Ifyou see this in a recurrent fashion, you need to take a


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biopsy. The lower picture is what you see on the biopsy.This is a fungal infection. This is a septated fungus. In apatient with a necrotic sore that shows a septated fungus, itis Aspergillus until proven otherwise. There are differentspecies of Aspergillus. Aspergillus infections are usually ahallmark for people who are immunocompromised. Peoplewith recurrent Aspergillus infections should always be testedfor immunodeficiencies (ex: CGD). An immunocompromisedstatus can increase the chances of Aspergillus infection. Oneof the most common symptoms in a case like this isneutropenia. The treatment for this is debridement and anti-fungal meds.

Slide 9

This is an 18-month old child that presents with a skinabscess. It is a large, red, indurated mass. The patient hashad multiple draining boils in the past. On exam, the child isafebrile, has mild eczema, blue eyes, and a 3x4 cm abscess.

His WBC and platelet count are normal. This is the 4th timethis patient presents with a skin abscess during the last 6months. You drain the abscess in your office. The gram stainof the material from the abscess is shown in the top picture.This is Staphylococcus, most likely S. aureus. These are Gm(+) cocci in clusters. This is probably the most commonbacterial infection that you will see in your practice. What isnot common is that this has been recurring, and the ptdoesnt have a fever. He also has other conditions likeeczema and blue eyes. This should raise a suspicion ofHyper-IgE syndrome, also known as JOB syndrome. Pts with

recurrent S. aureus infections and eczema should be testedfor Hyper-IgE syndrome. These pts tend to have IgE levels10x higher than normal (1000 to 2000 range). They alsohave eosinophilia.

Slide 10

This is a 20-month old presenting with fever and Gm (-)diplococci in the blood. This is his second infection with thesame organism. He has petechial lesions initially. This isshown in the top picture. Eventually, it progressed to look

like the bottom picture with necrotic tissue. He showed signsof sepsis and DIC. This is probably Neisseria meningitidis.

You will want to check for complement deficiency in thispatient. There is a vaccine against meningococcal diseaseapproved for children over age 11.

Slide 11

This child presents at one month of age with this lesion on hismouth. This is the pts only problem. He has Candida. It is

not uncommon to see Candida in young babies. This casedoes not require testing for immunodeficiency. This is a verycommon occurrence in children up to a month of age. Whatis unusual, though, is to see oral Candidiasis outside of theneonatal period (first month or so of life) or recurrent oralCandidiasis. In this case, you have to test for T-celldeficiencies. The most common one is HIV. Usually pts withHIV will also have Candida esophagitis.

Slide 12

Normal infants usually do well with topical treatment for oralCandidiasis. We also see a large number of prematurebabies, and they are severely immunocompromised. This isa baby with skin cutaneous Candida infection. This is aninvasive Candida infection that requires IV AB treatment.You want to diagnose Candida infections in premature babiesASAP because by the time it gets to this point, theres a verypoor prognosis.

Slide 13

This is a skin biopsy of a pt with severe disseminatedCandidiasis.

Slide 14

Another condition in which you can see severe Candidainfections is chronic mucocutaneous Candidiasis. These ptsdevelop a chronic Candidiasis of the skin and mucusmembranes. Most of them do not have Candidemia where itinvolves the blood stream, but this is usually a chronic,indolent infection.

Skip to Slide 16


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This is one of my patients at 10-yo. His thrush, to this day,has never gone away, and he has now graduated from highschool. We just control it with antifungals. He has also hadskin involvement. We dont know why these pts dont getCandidemia. These pts tend to also have an autoimmuneendocrinopathy. The outcome is not very favorable.

Back to Slide 15

This is another picture of oral Candidiasis.

Slide 17

Another organism that can cause problems inimmunocompromised pts is cytomegalovirus. Neonates candevelop CNS problems due to CMV infections duringgestation if the mother is CMV nave. These babies havewhat we call blueberry muffin syndrome. They are yellowbecause of jaundice and have purple lesions on the skin from

extramedullary hematopoiesis. This CT scan shows multiplecalcifications in the ventricles of the brain. This ischaracteristic for CMV. The calcifications are in theventricles. CMV can also cause problems inimmunocompromised pts.

Slide 18

One of the complications of CMV in addition to CNS problemsis retinitis and resulting blindness. An ophthalmologicalexam should be done in any CMV pt to rule this out. Thispicture shows CMV retinitis. There are drugs we can use totreat CMV.

Slide 19

This is a 7-month old boy with hypoxemia and tachypnea.His O2 saturation is only about 80%, and he is cyanotic. Hehas a congenital heart defect and low calcium levels. This x-ray shows hyperinflation with some infiltrate. BAL shows theorganism stained with a silver stain. With this pts history,you should be concerned about DiGeorge syndrome. This isa pt with potential T-cell dysfunction. The organism shown in

this BAL is Pneumocystis jiroveci, previously known as P.

carinii. This is seen in immunocompromised patients with T-cell deficiencies. Prophylaxis helps to prevent theseinfections, so immunocompromised pts should be put ontrimethoprim-sulfamethoxazole prophylaxis. The treatmentof choice is IV trimethoprim-sulfamethoxazole 3 times a weekthen prophylaxis for life. These pts rarely have bacteremiaand fever. Note that the x-ray shows a more diffusehyperinfiltrate.

Slide 21

Tuberculosis can happen in immunocompetent andimmunocompromised individuals. Pts with HIV are at highrisk. Young children are at a much higher risk of getting thedisease (if they are exposed) than adults are. The toppicture shows a positive PPD. With this test, you measureinduration (how hard it feels); you dont measure redness.This test tells you that the pt has been exposed to TB.Induration of >15mm diameter in an immunocompetent pt

tells you that the pt has been exposed, and a measurementof just 5mm in an immunocompromised pt is consideredpositive. So its important to know if your pt isimmunocompromised or immunocompetent.

Slide 21

Toxoplasma is common in immunocompromised pts withadvanced T-cell dysfunction. Toxoplasmosis is usually seenin HIV pts when their CD4 count is less than 100. It usuallypresents with CNS manifestations. This is a CT scan of a

baby with a CNS Toxoplasma infection and hydrocephalus.The infection is causing an obstruction of flow of CSF.

Slide 23

Molluscum contagiosum is a skin disease cause by a poxvirus. The classic presentation is papular lesions with thisumbilicated characteristic. If the infection only happensonce, you shouldnt be too concerned aboutimmunodeficiency. The problem is when it doesnt go awayor when it is recurrent. Something that can mimic Molluscum

contagiosum is skin streptococcal disease.


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Slide 24

Cryptococcus is a skin disease, but it can also cause a CNSinfection. The test you do is a streptococcal Ag test to theCSF or you can stain with india ink. Cryptosporidium parvumdoesnt cause CNS disease, but it causes GI problems inimmunocompromised pts. They have diarrhea that is difficultto treat.

Slide 25

Pts with HIV are at risk of many clinical manifestations. HIVper se can cause many direct problems. One of those is HIVmyocarditis. The virus itself can cause inflammation of themyocardium, which can lead to heart failure. Opportunisticinfections can also occur. This can cause brain atrophy anddementia. This (top right) is a pt with Molluscumcontagiosum. The bottom right picture shows oralleukoplakia, and the bottom left picture shows CMV retinitis.

Slide 26

HIV can also cause wasting syndrome (top left). They arehypermetabolic. This pt (top right) has numerous ringworms.Usually these lesions in immunocompetent pts are singlelesions that are easily treated. When you see multiplelesions, think about immunodeficiency. If you see multiplewarts (bottom left), you have to suspect the possibility of T-cell dysfunction. Another thing that can happen is parotitis(bottom right). The presentation is similar to mumps.

Slide 27

There is also a risk of developing chronic atypicalmycobacterium infections with chronic granulations in thecervical area. They can also develop recurrent HSVinfections (top right) or recurrent shingles (bottom picture).

Slide 28

There is also a risk of Kaposis sarcoma, which is associatedwith HHV-8 infection.

Slide 29

This is another picture of Kaposis.

Slide 30

Pseudomonas aeruginosa is important inimmunocompromised pts, especially those that areneutropenic or undergoing chemotherapy. Sometimes youcan see ecthyma gangrenosum, shown in the bottom picture.

There are dark areas in the skin. If you see this, check forthe organism and start ABs ASAP.

Slide 31

Neutropenia is a significant risk factor for Aspergillusinfection. This is a dark scar with necrotic tissue. Try to takethis tissue out. Even with anti-fungal therapy, its importantto remove the tissue.

Slide 32

Exposure to Varicella is important in immunocompromisedpts. Most of us have either been infected with Varicella orseen a case of chicken pox in our lifetimes. However, youwont see it much in your career due to the vaccine. But, youwill see this in immunocompromised patients. These pts canget really sick and possibly die due to the infection. If yoususpect Varicella in an immunocompromised pt, start IV ABsright away.

Slide 33

Once youve had Varicella, you are always at risk ofdeveloping shingles. These manifest as vesicular lesions ona particular dermatomal region. If you see this, its shinglesuntil proven otherwise. Many people will have a tinglingsensation in the area a couple days before the painful lesionsappear. You usually see this in elderly individuals, but youcan see it in immunocompromised children as well. If yousee recurrent shingles infections in a child, you shouldsuspect immunodeficiency. (He gives an example of a 15-yochild that had been hospitalized 8 times for shingles andnever tested. The child ended up having HIV, and his CD4


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count was in the single digits. He is now in college and isdoing well.)

Slide 16

This is another picture of Varicella. You can see lesions indifferent stages simultaneously. They will rupture andbecome scabbed. If the lesions are not scabbed, do not

expose immunocompromised pts to the infected pt.

Slide 17

There are different types of transplants. Depending on thetype of transplant, you will have different types of infectiousprocesses. Dont memorize which infections happen when,but just know that different infections happen at differenttimes, depending on the type of transplant.

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Immuno Deficiencies